Nuova ricerca

PAOLO ZANNINI

PROFESSORE FUORI RUOLO Esterno
Dipartimento di Scienze Chimiche e Geologiche - Sede Dipartimento di Scienze Chimiche e Geologiche

Home | Didattica |


Pubblicazioni

2021 - Unveiling an odd fate after death: The isolated Eneolithic cranium discovered in the Marcel Loubens Cave (Bologna, Northern Italy) [Articolo su rivista]
Belcastro, M. G.; Nicolosi, T.; Sorrentino, R.; Mariotti, V.; Pietrobelli, A.; Bettuzzi, M.; Morigi, M. P.; Benazzi, S.; Talamo, S.; Miari, M.; Preti, N.; Castagna, L.; Pisani, L.; Grandi, L.; Baraldi, P.; Zannini, P.; Scarponi, D.; Waele, J. D.
abstract

An isolated human cranium, dated to the early Eneolithic period, was discovered in 2015 at the top of a vertical shaft in the natural Marcel Loubens gypsum Cave (Bologna area, northern Italy). No other anthropological or archaeological remains were found inside the cave. In other caves of the same area anthropic and funerary use are attested from prehistory to more recent periods. We focused on investigating the circumstances surrounding the death of this individual, since the cranium shows signs of some lesions that appear to be the results of a perimortem manipulation probably carried out to remove soft tissues. Anthropological analyses revealed that the cranium belonged to a young woman. We analysed the taphonomic features and geological context to understand how and why the cranium ended up (accidentally or intentionally) in the cave. The analyses of both the sediments accumulated inside the cranium and the incrustations and pigmentation covering its outer surface suggested that it fell into the cave, drawn by a flow of water and mud, likely from the edges of a doline. The accidental nature of the event is also seemingly confirmed by some postmortem lesions on the cranium. The comparison with other Eneolithic archaeological sites in northern Italy made it possible to interpret the find as likely being from a funerary or ritual context, in which corpse dismemberment (in particular the displacement of crania) was practiced.

2020 - Notes on Vestorius’ Blue – New findings and investigations [Articolo su rivista]
Fontana, R.; Baraldi, P.; Fedi, M. E.; Galeotti, M.; Omarini, S.; Zannini, P.; Striova, J.
abstract

Egyptian blue (EB) is amongst the first man-made pigments. Archaeological EB samples from Pozzuoli, Herculaneum and Pompei and modern EB mock-ups have been investigated by multianalytical approach: fibre optics reflectance spectroscopy (FORS), optical microscopy (OM), scanning electron microscopy with probe EDS (SEM-EDS) and particles induced X-ray emission (PIXE). To examine the effect of heating temperature and time on the properties of the produced pigment, modern EB samples were synthesized by varying firing temperature (850, 900, 950 °C) and time (τ = 1, 2 and 5 h). Some correlations, in terms of morphologic and colorimetric properties of produced material, related to the manufacturing temperature of firing are drawn. Moreover, the study confirms that there is a great variety of utilized substances linked to materials available for the manufacturer at the moment.

2019 - Archeometria della pittura parietale a Reggio Emilia: gli intonaci dipinti dello scavo di Palazzo Mogardini [Poster]
Capurso, Annalisa; Baraldi, Pietro; Zannini, Paolo; Baraldi, Cecilia; Lugli, Stefano; Tirelli, Giulia; Rossi, Andrea
abstract

A Reggio Emilia, durante lo scavo di un cortile di Palazzo Mongardini nel 2009, è stato rinvenuto un gruppo di circa 500 frammenti di intonaco dipinto di epoca romana sui quali, dal 2017, è stato intrapreso uno studio da parte di una équipe multidisciplinare. lacerti pittorici, per quanto in giacitura secondaria, appaiono di grande interesse sia in relazione al luogo di ritrovamento, sia per la tecnica di esecuzione. Le indagini XRF, Raman e IR-ATR hanno mostrato che la tavolozza dei pigmenti impiegata è ampia e fa uso di pigmenti stesi con latte di calce a formare uno strato di colore ad affresco. Ma anche la tecnica a mezzo fresco risulta applicata, come nel caso di ripresa di colori dopo la carbonatazione per coprire una stesura o per avere determinati effetti coloristici.

2019 - DA PLACENTIA AD ARIMINUM: TECNICHE E MATERIALI DELLA PITTURA MURALE ROMANA NELLE DOMUS DELLA OCTAVA REGIO Pitture frammentarie di epoca romana da Roma e dal Lazio: nuove ricerche [Articolo su rivista]
Baraldi, Pietro; Baraldi, Cecilia; Ferrari, Giorgia; Tassi, Lorenzo; Zannini, Paolo
abstract

The analyses of polychrome plaster from the Octava Regio of ancient Roman Italy have enabled the identification of the palette of pigments used, the pictorial techniques and the different ways of decorating painted surfaces. Despite the short distances between the towns founded along the Via Aemilia, the paintings exhibit differences relating to these important domus: the decorative motifs, pigments, intonachinos and plaster all vary. Some of the more unusual pigments may come from geological features found in the territory or from the nearby mountains.

2019 - Identificazione preliminare dei materiali lapidei naturali e artificiali. [Capitolo/Saggio]
Lugli, Stefano; Pallante, Paolo; Papazzoni, Cesare Andrea; Zannini, Paolo
abstract

Questa breve nota illustra le analisi preliminari effettuate per identificare i materiali costitutivi di alcuni manufatti della collezione egiziana del Museo Civico Archeologico Etnologico di Modena.

2018 - Cermodel 2017: Modelling and Simulation Meet Innovation in Ceramics Technology: July 26–28, 2017, Trento, Italy [Articolo su rivista]
Bigoni, D.; Tampieri, A.; Zannini, P.
abstract

2018 - Images and colors from the tombs of Paestum: a multidisciplinary study of the pigments in the flora and fauna iconography [Articolo su rivista]
Ferrari, G.; Bosi, G.; Ansaloni, I.; Sala, L.; Pederzoli, A.; Baraldi, P.; Mussi, L.; Nannini, Matteo; Zannini, P.; Bandini Mazzanti, M.
abstract

This work presents the results of a multidisciplinary study on iconographic elements and painting technique of painted tombstones from Paestum (Italy), dated from the end of the V century to the end of the IV century BC. The focus was a botanical and zoological analysis of the flora and fauna present in 33 tombs, from both the iconographic and chemical point of view. Pigments (red, yellow, orange, pink, blue, green, black, grey and brown) have been studied by XRF and Raman techniques. The animal and vegetal elements (the formers gen- erally represented with more accuracy and details) in Paestum funerary art are not simply decorations, but they have numerous meanings, in both decorative systems and figured scenes, related to the ideal image of the dead (the social status of the dead, victory, heroic transfigurations, the voyage to the afterlife, etc.). Their high fre- quency confirms their important symbolism in funeral rituals. The artists' palette is quite limited and coherent with the contemporary funerary art in the Mediterranean basin. The use of Egyptian blue and of a red ochre enriched in manganese is interesting and deeper studies on these materials could help to better clarify the commercial background of Paestum during the 4th century BC.

2018 - Le pitture parietali delle ville di Stabia: materiali e degrado [Poster]
Baraldi, P.; Zannini, P.; Baraldi, C.; Tassi, L.; Rossi, A.; Troisi, G.
abstract

A partire dal 2009 con una serie di missioni in area stabiana, dopo il rilascio dei permessi da parte della Soprintendenza archeologica di Napoli e Pompei, sono state attuate indagini sulle pitture murali delle ville imperiali (Villa Arianna e Villa San lvlarco) per avere una descrizione dettagliata delle tecniche e dei materiali impiegati nelle pitture murali dei vari ambienti. Sono stati anche programmati controlli sul degrado dei materialj pittorici. Di concerto con archeologi e restauratori presenti sul sito, consapevoli delle operazioni di restauro attuate nel passato e tenendo conto dell'effetto degli eventi drammatici del 79 d.C., si è cercato di capire la situazione conservativa delle pitture per fornire indicazioni sulle operazioni di restauro. Nel corso delle missioni si sono osservate mediante microscopio digitale le superfici pittoriche divari ambienti e si sono effettuati dei microprelievi in posizioni marginali e rappresentative delle cromie presenti. Successivamente i campioni sono stati sottoposti ad analisi presso i laboratori universitari, ad analisi con varie tecniche analitiche e spettroscopìche di tipo atomico e molecolare, come la fluorescenza di raggi X (XRF). la spettroscopia FT-lR in trasmissione e in riflessione, la microscopia Raman con laser rosso e verde. Una considerevole massa di dati ottenuta con i vari tipi di analisi permette di tracciare una sinossi delle tavolozze pittoriche degli artisti al lavoro, dello stato di conservazione dello strato pittorico, del degrado di alcuni dei pigmenti utilizzati in antico, e della presenza di materiali impiegati per il restauro nel corso dei decenni. Sono state evidenziate opere di mani differenti, in base all'impiego di tonalità realizzate con miscele di pigmenti e con sovrapposizione di materiali diversì. ln alcune aree il cinabro risulta virato in nero con produzione di solfocloruri di mercurio. Le decorazioni a mezzo fresco risultano spesso alterate e soggette a caduta di parti dello strato pittorico.

2017 - VOCs monitoring of new materials for ceramic tiles decoration: GC-MS analysis of emissions from common vehicles and inkjet inks during firing in laboratory [Articolo su rivista]
Ferrari, G.; Zannini, P.
abstract

The decoration of ceramic tiles "ink-jet revolution" has brought significant advantages to tiles manufacturing, but the explosive diffusion, until 4-5 years ago, of this technique has not been accomplished by an adequate scientific research. Among all the features that have to be studied yet, one of the most important is the influence of the new generation inks on the total emission at ceramic chimneys. In this paper, we present a first characterization of emissions from a set of commercial inks and vehicles: they were collected by propter firing of samples in an electric kiln and analyzed by GC-MS. This study is part of a larger research project, which includes the chemical characterization and the evaluation of thermal behavior of inks and vehicles by TG-DTA and other techniques. The obtained results permit to divide common vehicles into 3 classes, depending on their thermal behavior and emissions pattern. Inks, most of which present an ester based formulation, sometimes mixed with glycols or paraffins, follow the behavior of their single components. The most common formulation leads to the presence in the emission pattern of evaporation products (2-ethylhexyl esters of lauric, myristic, decanoic and octanoic acids) and decomposition products (mainly aldehydes and 2-ethyl-1-hexanol).

2016 - Cermodel 2015: Modelling and Simulation Meet Innovation in Ceramics Technology, July 1-3, 2015, Trento, Italy [Articolo su rivista]
Tampieri, A.; Bigoni, D.; Zannini, P.
abstract

2016 - Development of a redox polymer based on poly(2-hydroxyethyl methacrylate)for disposable amperometric sensors [Articolo su rivista]
Zanardi, Chiara; Pigani, Laura; Maccaferri, Giulio; DEGLI ESPOSTI, Micaela; Fabbri, Paola; Zannini, Paolo; Seeber, Renato
abstract

Membranes based on poly(2-hydroxyethyl methacrylate), chemically modified with ferrocene functionalities, are proposed as novel coatings for the development of disposable amperometric sensors. They are mass-produced on an inert support through an UV photo-induced polymerization, forming self-standing films that can be transferred on an electrode surface. Thanks to the characteristic of the functionalized methacrylate matrix to rapidly and reversibly swell by incorporation of large amounts of water, the ferrocene moieties are in intimate contact with the electrolytic solution. They can activate effective electrocatalytic processes that can be exploited in the field of amperometric sensing. The performance of the methacrylate coating with respect to the determination of hydroquinone benchmark analyte has been tested both in a static solution and in a flux cell.

2016 - Hexavalent chromium and some trace metals in concrete from buildings of different ages in northern Italy [Articolo su rivista]
Costeri, Eric; Martinelli, Giovanni; Sighinolfi, Giampaolo; Tassi, Lorenzo; Zannini, Paolo
abstract

The content of total hexavalent chromium (CrVI), total chromium (Cr) and other metals (Fe, Mn, Ni and Co) was determined in the cement matrix of concrete present in samples collected in both old and recent buildings located in the town of Modena (northern Italy). The cement matrix of concrete was obtained by eliminating the aggregate components by means of disaggregation and was ground until it could pass through a 63-μm-sieve. In addition, samples of bagged commercial cements were considered. Metal determination was obtained by inductively coupled plasma optical emission spectroscopy after strong acid dissolution (HCl–HNO3). Total Cr(VI) determination was obtained after mild acid attack (HCl) and analysed by UV–Vis spectrophotometry. Analytical data values obtained indicate that the highest concentrations of metals were found in concrete and in bagged cement samples characterized by high Fe concentration. High Cr(VI) concentrations both in the cement matrix of concrete and in cement samples were found in total Cr-rich samples. Cr(VI) concentrations were about 20–30% of total Cr. The data obtained indicate that secondary raw materials and industrial by-product powders utilized in the modern cement industry may significantly increase Cr(VI) in concrete.

2016 - Thermal behavior of vehicles and digital inks for inkjet decoration of ceramic tiles [Articolo su rivista]
Ferrari, G.; Zannini, P.
abstract

Nowadays, after a sudden development in the last 2–3 years, inkjet decoration of ceramic tiles is the major decoration technique, but scientific studies on characteristics and behaviors of digital inks are quite rare. A set of common vehicles and digital inks for ceramic decoration have been studied by FTIR spectrometry to characterize their organic components and TG-DTA to understand their thermal behavior. This characterization is necessary to evaluate how inks react entering in the firing kilns and how they can influence emissions at chimneys. We were able to identify 6 classes of inks, depending on the nature of their vehicles. First thermal data show that the major part of inks start to evaporate, between 170 and 285 °C, then volatile compounds decompose with exothermic reactions, between 200 and 315 °C, depending on the nature of vehicles and heating rate. Differences in the intensity of phenomena are clearly visible between slow and fast heating rates, suggesting a predominance of combustion over evaporation at fast heating rates. Further studies are necessary to clarify the competition between evaporation and combustion phenomena.

2015 - Study of outdoor and indoor emissions of digital ceramic inks by GC-MS [Poster]
Ferrari, Giorgia; Zannini, Paolo
abstract

From 2001, inkjet technology has been applied to ceramic tiles decoration, and nowadays it is the most widespread method in this field. Decoration possibilities and performances are in constant evolution, but the formulation of inks remains one of the most critical point. Inks for ceramic tiles decoration are characterized by: 1) a solid pigment: a coloring grounded mineral component, 2)a dispersing phase: mix of organic compounds that keeps the solid phase in suspension and allows inks printability. This study focuses on the characterization of VOCs coming from the firing of inks, during tiles production, to evaluate their impact on outdoor and indoor pollution.

2014 - A study of some illuminated Armenian manuscripts [Abstract in Atti di Convegno]
Keheyan, Yeghis; Baraldi, Pietro; Zannini, Paolo; Eliazan, Gayane; Baraldi, Cecilia; Gamberini, Maria Cristina; Nunziante, Stella
abstract

Due to its early Christianization, Armenia has preserved a huge patrimony of religious figures in paintings, statues, icons and illuminated codices. Most of the latter are still conserved in Matenadaran Library in Yerevan and their chronology is widely represented from the Middle Ages to XIX century. Armenian manuscripts embrace also various humanities, such as history, philosophy, law, medicine and mathematics. A rich historiographic literature is also present. Therefore it was attractive to carry out an attempt to discover materials and techniques used in the past to prepare the manuscripts and to assemble the codices. Inks and gilding were also considered. Specific materials of Armenian culture will be emphasized. The samples were taken by some of us at the Matenadaran Library of Yerevan (Armenia) and some additional materials, such as Armenian bole and cochineal powder, were found in Yerevan too. The samples were taken with a lancet on deteriorated portions of some papers and parchments pertaining to Armenian codices. Only small fragments were used, since the spectroscopic techniques used need amount down to some micrograms. This is due to their high spatial resolution, enabling also the overlapping layers of pigments and preparation to be studied and their molecular identity to be ascertained in a non-destructive non –invasive way: the same samples could be subjected to other analyses with other techniques. The use of so small samples enabled the use of high performance instrumentation in the Centre of Great Instruments in Modena (CIGS) and to carry out additional experiments with silver nano-particles for Sers technique (surface enhanced Raman spectroscopy). Fourier-Transform infrared (FTIR) spectra were recorded using an Alpha FT-IR spectrometer (Bruker) equipped with the Diffuse Reflection Infrared Fourier Transform ( DRIFT) module in the spectral range 7500 – 375 cm-1 at a resolution of 2 cm-1 cumulating at least 200 scans. The use of SEM-EDX technique was important for characterization of papers and inks. Py/GS/MS was fundamental for organic binding media characterization. The methods of study were the application of atomic (XRF X-ray fluorescence spectroscopy), molecular (FT-IR and microRaman), SEM-EDX and pyrolisis GS/MS spectroscopic techniques to the samples in such a way to obtain the information useful for the understanding of the materials and art techniques applied. Particularly, the analysis of the different inks used in different times and the decoration with gilding on bole with a proper binder was taken into consideration. Experimental Results. Many materials were seen to be used through centuries in Armenian illumination. As already pointed out by Orna and co-workers [1, 2] many materials were identified and the execution techniques were clarified. According to recent investigation [3] other results on new materials and specific products coming from the territory have appeared based on Raman microscopy. A rich polychromy was often present and rare materials are shown to have been employed, such as the green antlerite, a basic copper sulfate mineral present in Caucasus and South of Iran. Lazurite, vermilion, azurite, orpiment, white lead, red lead, indigo, litharge, massicot, carbon were identified. Gilding was applied on an assisa. The Armenian bole is shown to be composed of white Kaolinite and Hematite. Forthcoming information is the application of Raman Sers technique for the identification of the materials and techniques used in Armenian illumination through times. The Armenian Cochineal (from Porphyrophora hamelii Brandt) is composed of carminic acid, that is highly fluorescent in Raman microscopy, unless Sers is used on a sample. With the application of simple atomic and molecular spectroscopy techniques available in many laboratories it was shown to be possible to obtain fundamental information on the specificity of Armenian illuminati

2014 - An integrated multi-analytical approach to the study of the dome wall paintings by Correggio in Parma cathedral [Articolo su rivista]
Zannini, Paolo; Danilo, Bersani; Michela, Berzioli; Simone, Caglio; Antonella, Casoli; Pier Paolo Lottici: Laura, Medeghini; Gianluca, Poldi
abstract

The restoration of one of the most famous masterpieces of the Renaissance, the wall paintings regarding the Assumption of the VirginMary painted inside the dome of the Cathedral of Parma by Antonio Allegri called Correggio (1489–1534) between 1526 and 1530, allowed an in-depth chemical-physical study of materials. Non-invasive infrared imaging and spectroscopic techniques (reflectance spectrometry in the visible range and in-situ X-ray fluorescence) and micro-invasive analytical techniques (optical microscopy, scanning electron microscopy with energy dispersive X-ray microanalysis, powder X-ray diffraction, micro-FTIR spectroscopy, micro-Raman spectroscopy, and gas chromatography coupled with mass spectrometry) were chosen in order to provide the higher set of significant data, limiting as much as possible sampling. The joined use of different techniques allowed to deeply explore Correggio's palette, on the use of a frescoand/or a secco technique, to study aswell degradation products and the diffused and old restoration materials like consolidants. The study allowed the characterization of a wide range of pigments, the identification of the binding media, mainly egg and animal glue, the restoration materials (acrylic resins, paraffin waxes, various pigments) and the degradation products (calcium sulfate dihydrate and calcium oxalate).

2014 - Archaeometric analysis of painted tombstones (IV century BC) from Paestum (Italy) [Poster]
Ferrari, Giorgia; Baraldi, Pietro; Cipriani, Marina; Nannini, Matteo; Zannini, Paolo
abstract

50 graves, painted by fresco technique, have been analyzed by micro-Raman Spectroscopy and X-Ray Fluorescence in order to identify the artists’ palettes and attempt to differentiate various workshops. Before sampling, points of interest were selected by a preliminary in situ XRF analysis. Then, samples were collected and analyzed in laboratory by micro-Raman Spectroscopy. We sampled from Green, Blue, Red, Yellow and Black areas, from every grave, and created a database where we put together analytical and historical data. Red and Yellow are obtained by Hematite and Goethite, respectively; Blue is always Egyptian Blue; Black contains Carbon or Magnetite, or a mix of them. Interesting data came from Green areas. We found 2 mixtures: Egyptian Blue and Yellow Ochre, or Yellow Ochre and Carbon. This peculiarity could be useful in the future for the discrimination of the different workshops.

2014 - Cermodel 2013: Modelling and Simulation Meet Innovation in Ceramics Technology, July 10-12, 2013, Trento, Italy (Editorial) [Articolo su rivista]
Bellosi, A; Bigoni, D; Zannini, Paolo
abstract

nessuno

2014 - Chemical characterization of inks for inkjet decoration of ceramic tiles [Poster]
Ferrari, Giorgia; Zannini, Paolo
abstract

The inkjet decoration of ceramic tiles has become the most widespread decoration technology in this field. It is also a technology in constant evolution, in order to obtain: better color performances, inks with improved stability and rheological properties, lower production costs, etc. Inks formulation is one of the most critical point because polluting emissions during firing, rheological parameters, jettability and stability of inks depend on inks formulation itself. This study focuses on the characterization of inks now in commerce, to understand their thermal behavior, chemical composition, polluting emissions during firing and rheological properties. We performed TG-DTA analysis, FTIR spectrometry, X-Ray fluorescence, and we are testing GC-MS and HPLC methodologies, on both inks and dispersing agents. First data from TG-DTA seem to underline different thermal behaviors between different dispersing agents. By cross-checking these data with FTIR results, we divided our samples in 5 groups, depending on dispersing agents class: paraffin oil, esters, paraffin oil added with esters, tripropylene glycol n-butyl ether (TpnB), water added with paraffin oil. From X-ray fluorescence on liquid inks and by comparison with literature [3,4], we recognized the chemical composition of coloring phases of inks. Our study is now focusing on testing GC-MS and HPLC methodologies to characterize polluting emissions, collected by firing a selected quantity of samples in a tubular kiln that simulates industrial processes. The following step will be the cross-check of data coming from TG-DTA, rheological characterization, that will be carried out by ISTEC-CNR in Faenza (Bologna), and chromatographies. The final phase of this project will focus on a possible re-formulation of inks, to reach even better properties and decrease potential polluting emissions during firing processes.

2014 - Studio dei materiali da costruzione come contributo alla storia della fabbrica [Capitolo/Saggio]
Lugli, Stefano; MARCHETTI DORI, Simona; Caroselli, Marta; Zannini, Paolo; Pallante, Paolo; Selmo, Enrico Maria
abstract

La Chiesa Parrocchiale ed il Monastero Abbaziale di San Pietro a Modena, nella sua originaria configurazione comprendente anche l’ex caserma Garibaldi, rappresentano esempi emblematici della complessa evoluzione dell’edilizia storica modenese, sia in termini di approvvigionamento delle materie prime che di evoluzione delle fasi costruttive. Tale complessità emerge dal confronto, non solo con gli illustri esempi del sito UNESCO modenese, il Duomo e la torre Ghirlandina [Lugli et al. 2009 e 2010], ma anche con il panorama edilizio dell’intera provincia modenese: il Palazzo Ducale di Sassuolo [Lugli, 1996; 2000], la Rocca di Formigine [Lugli 1997, Marchetti Dori 2005], il palazzo Comunale di Modena [Lugli, 2010] e la Rocca di Vignola [Lugli e Marchetti Dori 2006; Lugli et al. 2013]. Tra i fattori più significativi e peculiari annoveriamo il reimpiego di materiale lapideo romano mai segnalato fino ad oggi, come il marmo tasio dalla Grecia [Lugli et al. 2010] e l’utilizzo di materie prime non appartenenti alla tradizione modenese, come la pozzolana.

2014 - Study of Black Core, ceramic tile’s defect, by a multi technique approach [Relazione in Atti di Convegno]
Ferrari, Giorgia; Zannini, Paolo; Baraldi, Cecilia
abstract

The traditional ceramic industrial production, for most of its applications, i.e. Ceramic Tiles, Heavy Clay Products, Tableware and Sanitaryware, is often affected by the formation, during the firing process, of a dark color core, normally named “Black Core”, that can represent an aesthetical and technological problem. The true nature of this defect was never clearly stated, but it is known to be due to the presence of chromophores, like Iron, and organic or reducing materials, combined with a lack of permeability of the unfired body. A novel, mullti-approach study was made by XRD, XRF, SEM-EDS, FTIR and Mossbauer Spectroscopy, and by micro Raman spectroscopy and mapping, with the aim to clarify the morphology, the composition and the Iron oxidation state of this inner layer. Possible solutions were suggested, by the addition to the recipe of proper additives.

2012 - ANALYSES OF ROMAN WALL PAINTINGS , BASILICA OF SANTA MARIA MAGGIORE, TRENTO. [Relazione in Atti di Convegno]
Minghelli, Silvia; Baraldi, Pietro; Zannini, Paolo; M. T., Guaitoli
abstract

Questo studio mira alla caratterizzazione chimico-fisica dei numerosi frammenti di pittura romana rinvenuti durante lo scavo archeologico della Basilica di Santa Maria Maggiore a Trento.L’obiettivo è quello di confermare la destinazione d’uso delle strutture di epoca romana riportate in luce, identificate dagli archeologi con i resti di un impianto termale pubblico risalente al I secolo d.C., attraverso l’identificazione dei pigmenti e delle tecniche pittoriche usate per la loro decorazione. Le principali tecniche analitiche utilizzate per determinare la composizione dei campioni sono state la spettrometria infrarossa a trasformata di Fourier (FT-IR), la microscopia Raman e la fluorescenza a raggi X (XRF).

2012 - First analytical evidences of precious colourants on Mediterranean illuminated manuscripts [Articolo su rivista]
Aceto, M.; Agostino, A.; Fenoglio, G.; Baraldi, Pietro; Zannini, Paolo; Hofmann, C.; Gamillscheg, E.
abstract

Two Byzantine VI century manuscripts known as Vienna Dioskurides and Vienna Genesis, held in the Aus- trian National Library at Vienna, were analysed with in situ non-invasive techniques. Raman spectros- copy, UV-Vis diffuse reflectance spectrophotometry with optic fibres and X-ray fluorescence spectrometry were used to characterise the palette of these early Middle Ages manuscripts. The analyt- icaI study was performed to have a better knowledge on the colourants used by ancient miniature paint- ers, a subject known more on the basis of traditional sources (i.e. medieval treatises) than of analytical evidences. Indeed these illuminated manuscripts afe, to the authors' knowledge, among the oldest ever being analysed, so that the coIourants found in them can be considered among the oldest evidences of their use. The main feature of Vienna Dioskurides and Vienna Genesis palettes is their richness, exemplified by the simultaneous presence of gold and ultramarine blue: in Vienna Dioskurides cinnabar is al so presento Information regarding ultramarine blue is surprising, being the analytical evidence of the use of this pre- cious pigment at least three centuries before its use in Western manuscripts, a feature justified by the fact that the Byzantine Empire was the dominant culture in early Middle Ages in the Mediterranean World. Other colourants include azurite and indigo, red lead, orpiment, red and yellow ochres, while a mixture of blue and yellow colourants, known as vergaut, was used to render green hues. Organic colourants were also used, such as madder and Tyrian purple, the latter employed to dye the parchment of Vienna Genesis.

2012 - INDAGINI ARCHEOMETRICHE SU PITTURE MURALI DALL’INSEDIAMENTO DI MONTEGIBBIO. [Relazione in Atti di Convegno]
Baraldi, Pietro; Zannini, Paolo; F., Guandalini; Ferrari, Giorgia
abstract

Frammenti di pittura murale di epoca romana, provenienti dall'insediamento di Montegibbio (Modena), sono stati analizzati tramite Spettroscopia μ-Raman, FT-IR e XRF. I campioni provenienti dagli strati datati nel primo periodo imperiale sono stati confrontati con frammenti provenienti dagli strati tardo-antichi; è stata ricostruita una tavolozza piuttosto ampia,caratterizzata da particolari miscele di pigmenti per ottenere determinate tonalità.

2012 - Identification of colorants on XVIII century scientific hand-coloured print volumes [Articolo su rivista]
Zannini, Paolo; Baraldi, Pietro; Aceto, Maurizio; Agostino, Angelo; Fenoglio, Gaia; Bersani, Danilo; Canobbio, Eleonora; Schiavon, Elisabetta; Zanichelli, Giusi; De Pasquale, Andrea
abstract

Two series of printed volumes, respectively, created in Parma and in Vienna at the end of XVIII century, were analysed in arder to characterise the palettes used in the hand-coloured miniatures and to determine whether decoration had been carried out simultaneously to, or shortly after, the ti me of printing. The application of complementary non-invasive analytical techniques allowed to yield a thorough knowledge of the colorants present and to determine that artists used a mixing of ancient, traditional materials such as cinnabar, minium or indigo, and materials of recent introduction in late XVIII century such as gamboge, Prussian blue or blue verditer. There was no evidence of colorants created successively to the age of printing, so that it can be conduded that decoration could have been done at the ti me of printing. Interesting is the use of metal pigments in the Vienna volumes, either in powder form and in foil form as a basis to obtain iridescence effects, a due to evaluate the great skillfulness of the artist. Among the colorants identified, particularly relevant is the identification of gamboge, a colorant almost exdusively used among Far Eastern Asian painters according to the literature; this fact suggests that information on the use of pictorial materials can be strongly updated by diagnostic analyses.

2012 - Indagini Archeometriche su Lacerti di Pittura Murale da Cattolica (Rimini) [Relazione in Atti di Convegno]
M., Nannini; Baraldi, Pietro; Zannini, Paolo; L., Stoppioni
abstract

Il lavoro svolto ha avuto come oggetto lo studio di frammenti d’intonaco dipintiprovenienti da uno dei siti archeologici di epoca romana, rinvenuti a Cattolica. Mediante l’uso di tecniche spettroscopiche Raman ed FT-IR è stato possibile determinare i pigmenti utilizzati, ricostruire la tavolozza, discriminare contaminazioni accidentali e avvalorare l’ipotesi dell’esistenza del substrato romano cittadino.

2010 - Saint Petronio Basilica in Bologna (Italy): a case study on a XVI C. mural painting [Articolo su rivista]
Campani, E; Casoli, A; DARECCHIO M., E; Paccagnella, F; Zannini, Paolo
abstract

During the last restoration (2006) of mural paintings by Girolamo da Treviso in Saint Petronio Basilica in Bologna (Italy), scientific investigations were carried out to acquire detailed information about the painting technique and the degradation products. The identification of materials allowed a correct restoration. Fourteen micro samples were collected in different areas selected by the restorer who identified the original partszones of the work painting. The study was based on analysis of fragments and cross-sections, that were prepared to acquire stratigraphic informations. The following techniques were used to investigate inorganic and organic materials: stereo microscopy in visible and UV light, X-ray powder diffraction (XRD), Raman micro-spectroscopy, Fourier Transformed Infrared micro-spectroscopy (μ-FTIR) used in Attenuated Total Reflection (ATR), Scanning Electron Microscope coupled with Energy Dispersive X-ray Spectroscopy (SEM-EDS) and Gas Chromatography coupled with Mass Spectrometry (GC-MS). Few pigments were identified, all very traditional, and a clear presence of organic binding media was detected. This study emphasizes that the paint technique is not a typical “buon fresco”. Probably the pictorial technique itself, used in this cycle, together with environmental conditions, caused the darkening of some white areas. A diffuse presence of gypsum was also detected in some degraded painting portion.

2009 - Caratterizzazione analitica della pittura murale "Madonna con bambino, San Martino ed offerente" ritrovata nel chiostro della Chiesa di San Biagio al Carmine in Modena [Articolo su rivista]
Baraldi, Pietro; Muscio, Alberto; Zannini, Paolo
abstract

Indagini analitico-strumentali sono state effettuate su di un dipinto murale del XIV secolo ritrovato fortuitamente nel 2005 durante i lavori di restauro del chiostro della Chiesa di San Biagio in Modena. Indagini in diffrattometria di raggi X, microscopia elettronica SEM-EDS, spettroscopia Raman, riflettografia UV e termografia IR sono state effettuate per stabilire la tecnica di realizzazione, la natura dei pigmenti e dei leganti, le problematiche di risalita capillare di umidità e per guidare i lavori di consolidamento e restauro.

2007 - A micro-Raman archaeometric approach to Roman wall paintings [Articolo su rivista]
Baraldi, Pietro; Baraldi, Cecilia; R., Curina; Tassi, Lorenzo; Zannini, Paolo
abstract

Infrared and Raman spectra have been recorded on the surface of plasters from Regium Lepidi (Reggio Emilia, Italy). A palette has been identified, that can be compared with the ones from the nearby towns of the Roman Empire, but some peculiarities can be outlined. Some of the pigments could come from the territory, even though the techniques could be ascribed to those usually present in the 1st century a.c.

2007 - Development of Complementary Microscopic Techniques in the Analisis of Cultural Heritage [Articolo su rivista]
Baraldi, Pietro; F., Paccagnella; Zannini, Paolo
abstract

Development of Complementary Microscopic Techniques in the Analisis of Cultural Heritage

2006 - Analytical characterization of Roman plasters of the 'Domus Farini' in Modena [Articolo su rivista]
Baraldi, Pietro; Bonazzi, A; Giordani, N; Paccagnella, Francesca; Zannini, Paolo
abstract

The paper refers to the analytical characterization of Roman painted plasters dating back to the second century AD. The following techniques were used: optical microscopy (OM), scanning electron microscopy (SEM-EDS), micro-Raman and Fourier transform infrared spectroscopies (mu-Raman and FT-IR), X-ray diffraction (XRPD), colorimetry and thermal analyses (TG/DTA). The investigation analysed the chemical composition and structure of the plasters, the chemical composition of the pigment layers, the use of binders and any chemical alteration of pigments as well as deterioration of the samples. Stratigraphic analysis of plasters allowed identification of their individual components, which proved helpful in finding out more about the mural painting technique employed.

2006 - Analytical investigation of attacks on enamelled ceramic surfaces [Articolo su rivista]
Zannini, Paolo
abstract

Analytical investigation of attacks on enamelled ceramic surfaces

2006 - Aragonite in Roman wall paintings of the VIIIa Regio, Aemilia, and Xa Regio, Venetia et Histria [Articolo su rivista]
Ga, Mazzocchin; Ef, Orsega; Baraldi, Pietro; Zannini, Paolo
abstract

In the Roman wall paintings different white colours were used, named Paraetonium, Melinum, Anularia, Eretria, Argentaria, etc. FTIR, Raman spectroscopy and X-Ray diffraction were applied to study different white pigments, such as calcite, aragonite, dolomite and huntite, white carbonates present in archaeological findings from roman walls in the Mediterranean region. This study showed that it is possible to distinguish and identify these components in white colours. About 450 samples of Roman wall paintings were analysed and it was observed that often aragonite is associated to precious coloured pigments. On the basis of the obtained results some considerations about the period in which the different kinds of white pigments were used are proposed.

2006 - VIBRATIONAL SPECTRA OF SOME PIGMENTS FROM POMPEII [Articolo su rivista]
Baraldi, Pietro; C., Fagnano; A., LOSCHI GHITTONI; Tassi, Lorenzo; Zannini, Paolo
abstract

Some powder pigments found in bowls in the ruins of Pompeii were investigated. Their chemical and mineralogical compositions were obtained by using FT-IR spectroscopy, Raman microscopy, X-Ray diffraction and DSC. With FTIR spectroscopy and X-Ray diffraction the main components were ascertained and the pigments attributed to Plinius' names as far as possible. With Raman microscopy a detailed examination of minor components was carried out, thereby enabling some considerations on the pigment preparation techniques to be traced. Two unusual pigments were identified, namely jarosite and buntite, already detected in wall painting and ceramics elsewhere.

2005 - Aragonite in Roman wall paintings of the VIII Regio, Aemilia and X Regio, Venetia et Histria [Relazione in Atti di Convegno]
Mazzocchin, G. A.; Baraldi, Pietro; Zannini, P.
abstract

Aragonite was found in white stripes painted on mural paintings of the Roman period. This is so in VIII and X Regio of Italy

2005 - Materiali pittorici e pigmenti [Relazione in Atti di Convegno]
Baraldi, Pietro; Bonazzi, A.; Fagnano, C.; Tassi, Lorenzo; Zannini, Paolo
abstract

Le pitture di Pompei e le indagini scientifiche sui materiali e le tecniche, con i rinvenimenti più comuni e più insoliti

2005 - Study and synthesis of organic precursors for salt treatments developed to protect and strengthen building materials and "frescos" [Articolo su rivista]
M., Matteini; F., Paccagnella; Pinetti, Adriano; Zannini, Paolo
abstract

An attempt to find out possible ways to synthesise sulphates and oxalates, to be utilised for strengthening and consolidating limestone and frescos surfaces was made. Particularly organic sulphates were prepared and tested for their reactivity with barium salts, trying to obtain slow sulphates hydrolysis and, so, BaSO4 precipitation. Different solutions were applied on Opificio delle Pietre Dure´s standards using different methodologies and applications times. The characterisation of chemical interactions between carbonaceous bodies and solutions was done by X-ray diffraction (XRPD), Fourier transformed infrared spectroscopy (FTAR), scanning electron microscopy (SEM-EDS). The synthesis of organic sulphates resulted not difficult and the solutions are very easy to use. More difficult was oxalate synthesis. The application results are promising.

2004 - A study of the dielectric behavior and the liquid structure of a ternary solvent system [Articolo su rivista]
Cocchi, Marina; Franchini, Giancarlo; Marchetti, Andrea; Pigani, Laura; Seeber, Renato; Tassi, Lorenzo; Ulrici, Alessandro; Zanardi, Chiara; Zannini, Paolo
abstract

The static dielectric constant of the {DMF(1) + ME(2) + DME(3)} ternary mixtures was measured as a function of temperature (25 less than or equal to t/degreesC less than or equal to 80) and composition, over the whole mole fraction range 0 less than or equal to x(1),x(2),x(3) less than or equal to 1. The experimental values were processed by an empirical equation accounting for the dependence epsilon = epsilon(T, phi(i)), where phi(i) is the volume fraction of the components. A comparison between calculated and experimental data shows that this fitting relationship can be effectively employed to predict epsilon values in correspondence to experimental data gaps. Starting from the experimental measurements, some derived quantities such as molar polarisation (P), and excess counterpart (P-E) were obtained. Both the excess properties, epsilon(E) and P-E, take values partly positive and partly negative under all experimental conditions. The values of the excess quantities are indicative of the presence of specific interactions among different components in the mixtures.

2004 - Mineral treatments for the conservation of cultural heritage materials. Analytical characterisation and trial applications of barium oxalates and aluminates [Articolo su rivista]
M., Matteini; Zannini, Paolo
abstract

Mineral treatments for the conservation of cultural heritage materials. Analytical characterisation and trial applications of barium oxalates and aluminates

2004 - Modern decoration technologies for tiles: new products, new additives, new problems [Relazione in Atti di Convegno]
Zannini, Paolo
abstract

This lecture wants to emphasise the main evolution in the latest years of the decoration techniques for ceramic tiles, particularly referring to the necessity that was risen on the evolution of the liquid part of the inks : vehicles, binders, fixatives, additives etc.

2003 - Il sistema solvente ternario 1,2-etandiolo + 1,2-dimetossietano + acqua: proprietà dielettriche a diverse temperature [Relazione in Atti di Convegno]
Foca, Giorgia; Franchini, Giancarlo; Manfredini, Matteo; Manzini, Daniela; Tassi, Lorenzo; Ulrici, Alessandro; Zannini, Paolo
abstract

-

2003 - Le Pilae di Vitruvio e gli intonaci bolognesi di età imperiale [Relazione in Atti di Convegno]
Baraldi, Pietro; Pradelli, M.; Zannini, P.
abstract

Indagini sulla composizione di alcune palline di blu egiziano rinvenute nella città di Bologna

2003 - Mineral treatments for the conservation of cultural heritage materials. Analytical characterization and trial application of barium oxalates and aluminates [Articolo su rivista]
M., Matteini; Zannini, Paolo
abstract

Mineral treatments for the conservation of cultural heritage materials. Analytical characterization and trial application of barium oxalates and aluminates

2003 - Viscosimetric properties and internal structure of N,N-dimethylformamede+1,2-dimethoxyethane binary mixtures [Articolo su rivista]
Cocchi, Marina; M., Manfredini; D., Manzini; Marchetti, Andrea; S., Sighinolfi; Tassi, Lorenzo; Ulrici, Alessandro; M., Vignali; Zannini, Paolo
abstract

The kinematic viscosities (v) of liquid binary mixtures of N,N-dimethylformamide and 1,2-dimethoxyethane were measured at 19 temperatures in the range -10 less than or equal to t / degreesC less than or equal to 80, employing the pure species and 9 their solutions covering the whole miscibility range expressed by the condition 0 less than or equal to x(i) less than or equal to 1. The measured values have been used to test some empirical equations of the type v=v(T), v=v(x(i)), and v=v(T,x(i)), in order to obtain useful correlation models with predictive ability in correspondence of the experimental data gaps. Starting from the experimental data, the excess kinematic viscosities (v(E)) have been calculated. Sign and magnitude of these quantities have been discussed in terms of type and nature of specific intermolecular interactions. Some derived quantities such as thermodynamic parameters of the viscous flow (DeltaG*, DeltaH* and DeltaS*), have been calculated on the basis of Eyring's model. Furthermore, the fluidity of this binary solvent system was analysed and interpreted following Hildebrand and modified-Hildebrand correlation models. (C) 2003 Elsevier Science B.V. All rights reserved.

2002 - Applied Ceramic Technology Voll. 1 and 2 [Monografia/Trattato scientifico]
Zannini, Paolo
abstract

2 manuali di tecnologia ceramica applicata e difettologia ceramica

2002 - Beta-functionalised polythiophenes as microelectrode modifiers in low conductive media [Articolo su rivista]
Cocchi, Marina; Franchini, Giancarlo; M., Manfredini; Marchetti, Andrea; Pigani, Laura; Seeber, Renato; Tassi, Lorenzo; Ulrici, Alessandro; M., Vignali; Zanardi, Chiara; Zannini, Paolo
abstract

A study on polythiophene coated microelectrodes is reported, the goal being that of checking the capability of these electrochemical systems to work in low conductive media. The possibility of electrochemically p-doping the polymer in the presence of very low concentrations or even in the absence of supporting electrolyte in the solution is ascertained, opening the way to the use of similar systems in pure solvent media. This result is obtained in such conditions that the presence of residual charges - and corresponding counterions - trapped inside the film coating can be reasonably hypothesised.

2002 - Caratterizzazione dei contenuti cosmetici nei balsamari di Oplontis [Abstract in Atti di Convegno]
Baraldi, Pietro; Ferioli, Valeria; Benedetti, Adriano; Baraldi, Cecilia; Zannini, Paolo
abstract

Lo scavo, condotto secondo metodologie scientifiche avanzate, del sito di Oplontis rappresenta per l’archeologo e l’archeometra una possibilità nuova di indagine e comprensione di una somma di situazioni importanti. Una di queste è rappresentata certamente dal rinvenimento di 17 balsamari pressoché intatti contenenti una quantità considerevole di residuo. La collaborazione con la Soprintendenza Archeologica di Pompei ci ha consentito di accedere ai reperti e di eseguire per la prima volta prelievi di campioni da sottoporre all’analisi.I campioni si presentavano più o meno scuri, ma non contenevano pigmenti neri, bianchi o di altro colore chiaramente osservabili. Alcuni presentano un odore caratteristico, simile a quello della colofonia. Per i campioni è stata seguita una doppia strada di indagine: la spettroscopia FT-IR e la gascromatografia GC-MS su estratti ottenuti con le metodiche internazionali. Le analisi in GC-MS hanno mostrato che gli estratti metanolici presentano una serie di componenti che vanno dal patchoulolo ad acidi grassi liberi, ad esteri, ad idrocarburi e a terpeni classici. L’esame degli spettri IR ha evidenziato la presenza di acidi grassi liberi ed esteri e tracce di cere.La presenza del patchoulolo risulta di particolare interesse in quanto si tratta di un componente presente nell’estratto del Pogostemon cablin, una pianta originaria dell’India e dell’estremo Oriente, utilizzata anche in epoca recente per la produzione di profumi. La sua provenienza dall’area indiana consente di ipotizzare l’elevato pregio del cosmetico, che ne consentiva l’utilizzo alle classi sociali elevate quali quelle del contesto di Oplontis.

2002 - Confronto tra vari metodi per la misura della plasticità di impasti ceramici estrusi [Articolo su rivista]
G., Dircetti; M., Dondi; M., Raimondo; Zannini, Paolo
abstract

Confronto tra vari metodi per la misura della plasticità di impasti ceramici estrusi

2002 - Pigments from Bowls and Walls of Pompeii [Abstract in Atti di Convegno]
Baraldi, Pietro; Fagnano, C.; Scagliarini, D.; Tinti, A.; Taddei, P.; Zannini, Paolo
abstract

analyses of some bowls from Pompeii carried out by IR and Raman spectroscopy; the results were compared with those from the wall paintings

2002 - Quantitative determination of fluoride as a major pollutant in the emissions from the thermal treatment of clayey raw materials [Articolo su rivista]
Zannini, Paolo
abstract

Three clayey raw materials for production of traditional ceramics, all with medium to high fluorine content, have been investigated for determining their attitude to fluoride emission during firing, at varying parameters of the firing cycle, maximum firing temperature included, and in the presence or in the absence of calcium carbonate either added to the sample or naturally present in it. Different analytical methods for the determination of fluoride have been tested, together with different sample preparation procedures aimed to obtain minimum loss of fluoride in the pre-treatment step.

2002 - Temperature and composition dependence of the refractive indices of the 2-chloroethanol + 2-methoxyethanol binary mixtures [Articolo su rivista]
Cocchi, Marina; M., Manfredini; Marchetti, Andrea; Pigani, Laura; Seeber, Renato; Tassi, Lorenzo; Ulrici, Alessandro; M., Vignali; Zanardi, Chiara; Zannini, Paolo
abstract

AbstractMeasurements of the refractive index n for the binary mixtures 2-chloroethanol + 2-methoxyethanol in the 0 ≤ T/°C ≤ 70 temperature range have been carried out with the purpose of checking the capability of empirical models to express physical quantity as a function of temperature and volume fraction, both separately and together, i.e., in a two independent variables expression. Furthermore, the experimental data have been used to calculate excess properties such as the excess refractive index, the excess molar refraction, and the excess Kirkwood parameter Ag over the whole composition range. The quantities obtained have been discussed and interpreted in terms of the type and nature of the specific intermolecular interactions between the components.

2002 - Vibrational Spectra of some Pigments from Pompei [Relazione in Atti di Convegno]
Baraldi, Pietro; Fagnano, C.; Ghittoni, A. L.; Tassi, Lorenzo; Zannini, P.
abstract

identification of mural paintings in ancient excavations by Raman spectroscopy

2001 - Misure archeometriche su ceramiche grezze romande di area padana [Relazione in Atti di Convegno]
Baraldi, Pietro; Fagnano, C.; Giordani, N.; LOSCHI GHITTONI, A.; Moze, O.; Tinti, A.; Zannini, P.
abstract

studio dei materiali per la preparazione di impasti ceramici antichi.

2001 - Refractive properties of binary mixtures containing N,N-dimethylformamide+2-methoxyethanol or 1,2-dimethoxyethane [Articolo su rivista]
Franchini, Giancarlo; Marchetti, Andrea; Seeber, Renato; Tassi, Lorenzo; Zannini, Paolo
abstract

Refractive index (n) and related properties such as molar refraction (R) have been investigated for DMF+ME and DMF+DME binary mixtures over the entire composition range, at 15 different temperatures in the range 0 less than or equal to t/degreesC less than or equal to 70. Some relationships have been applied to study the dependence of the measured and derived quantities by temperature and composition. Furthermore, the excess functions n(E), R-E and the excess Kirkwood correlation parameters Deltag have been examined, in order to identify the presence of solvent-cosolvent adducts in these binary mixtures. The results obtained have been interpreted on the basis of specific intermolecular interactions between different species.

2001 - Una testimonianza di blu egiziano nella Bologna del '500 [Relazione in Atti di Convegno]
Baraldi, Pietro; Fagnano, C; Giordani, N.; Roversi, P.; Zannini, P.
abstract

Sulle pareti i una villa in restauro sono state rinvenute tracce evidenti di colore azzurro identificate come blu egiziano. Si tratta di una persistenza dell'uso del pigmento

2000 - Determinazione di Metalli in Sostanze di Abuso Mediante Spettrometria GFAAS con Campionamento Solido [Relazione in Atti di Convegno]
Marchetti, Andrea; Franchini, Giancarlo; Zannini, Paolo; Fazio, F. De; Licata, Manuela
abstract

Comunicazione Orale

2000 - Il Fluoro nell’ industria ceramica: inquadramento del problema e studio della cessione durante la cottura [Articolo su rivista]
Zannini, Paolo; V., Storari; G., Vaccari
abstract

Il Fluoro nell’ industria ceramica: inquadramento del problema e studio della cessione durante la cottura

2000 - Meccanismi di formazione di efflorescenze su matrici ceramiche estruse [Articolo su rivista]
G., Dircetti; P., Montorsi; Zannini, Paolo
abstract

Studio dei meccanismi di formazione di efflorescenze su matrici ceramiche estruse

1999 - Determination of Nichel(II) oxide in ceramic pigments [Articolo su rivista]
Gualtieri, A. F.; Mazzuccato, E.; Venturelli, P.; Viani, A.; Zannini, Paolo; Petras, L.
abstract

Determination of Nichel(II) oxide in ceramic pigments, by means of high temperature XRD

1999 - Organic additives in ceramic production : study of the thermal behaviour and identification of the pyrolysis products [Articolo su rivista]
Franchini, G. C.; Vaccari, G.; Zannini, Paolo
abstract

For the production of ceramic tiles many additives are used.During the subsequent firing process these additives undergo to a pyrolysis whose products were studied by means of thermal analyses, GC_MS

1999 - X-ray powder diffraction quantitative analysis performed in situ at high temperature: application to the determination of NiO in ceramic pigments [Articolo su rivista]
Gualtieri, Alessandro; E., Mazzucato; P., Venturelli; A., Viani; Zannini, Paolo; L., Petras
abstract

Although nickel(II) oxide (NiO) is a potential carcinogenic agent, it is still used in the synthesis of ceramic pigments because during their preparation at high temperature, NiO is thought to combine with other compounds, crystallizing as new phases with spinel-like structures. Unfortunately, there are no widely accepted methods for the determination of free NiO in ceramics, the main reason being experimental difficulties. In fact, quantitative phase analysis (QPA) by X-ray powder diffraction (XRPD) may fail because diffraction peaks of NiO with space group Fm (3) over bar m and a similar or equal to 4.18 Angstrom overlap with those of the spinel with space group Fd (3) over bar m and a similar or equal to 8.4 Angstrom. To overcome this problem, in this work QPA has been performed in situ at high temperature to resolve the peak overlap of NiO and spinel by taking advantage of the different thermal expansion of each phase. It is believed that this is the first report of the application of this technique.

1998 - Studio delle emissioni gassose presenti in fase di essiccazione di prodotti ceramici [Articolo su rivista]
G. C., Franchini; S., Fregni; G., Vaccari; Zannini, Paolo
abstract

studio sperimentale sull' emissione di vapori e gas durante il trattamento di essiccazione di piastrelle ceramiche

1996 - Caratterizzazione analitica dei sali efflorescenti e correlazione con i componenti delle materie prime [Articolo su rivista]
G., Dircetti; G., Gaido; Zannini, Paolo
abstract

Caratterizzazione analitica dei sali efflorescenti e correlazione con i componenti delle materie prime

1995 - Block "f" metal complexes with Benzodiazepines. Cytostatic and antiviral biological studies [Articolo su rivista]
G. C., Franchini; Marchetti, Andrea; C., Preti; Tassi, Lorenzo; G., Tosi; Zannini, Paolo
abstract

n.d.

1994 - Stainability and Cleanability of Fully Vitreous Stoneware [Articolo su rivista]
U., Gibertini; G. C., Moro; Zannini, Paolo
abstract

Studio sulla macchiabilità di una superficie ceramica, in funzione della sua struttura, morfologia, composizione e relative applicazioni per ottenerne la massima pulibilità

1993 - Plasticita' delle argille ed essiccazione nell'industria delle piastrelle ceramiche [Articolo su rivista]
Zannini, Paolo; G. C., Moro
abstract

correlazioni fra plasticità delle materie prime e capacità di evacuazione dell' acqua di formatura

1992 - Fast firing of heavy clay products in roller kilns [Articolo su rivista]
Zannini, Paolo
abstract

Analytic aspects of the consequencies of fast firing on the composition and structure of ceramic tiles

1991 - Analytical investigation of vapour condensations in single-layer fast firing Roller Kilns [Articolo su rivista]
Zannini, Paolo
abstract

Analytical investigation of vapour condensations in single-layer fast firing Roller Kilns, by means of chemical analysis, XRD and SEM-EDS

1991 - Research and development in traditional ceramics: recent history and future trends [Articolo su rivista]
Zannini, Paolo
abstract

review degli aspetti ecenti della R&D nel settore ceramico

1991 - Trasferimento delle esperienze maturate nel settore della essiccazione e cottura rapide di piastrelle ceramiche ai materiali per l'edilizia [Articolo su rivista]
Zannini, Paolo; Gerardi, E.
abstract

Trasferimento delle esperienze maturate nel settore della essiccazione e cottura rapide di piastrelle ceramiche ai materiali per l'edilizia

1990 - Mosaikfertigung mit Infrarottrocknung [Articolo su rivista]
Zannini, Paolo; E., Gerardi
abstract

Studio analitico delle conseguenze di un riscaldamento rapido ad IR su piastrelle ceramiche umide

1990 - Reologia e ceramica: la ricerca e le applicazioni in funzione del miglioramento della produzione [Articolo su rivista]
Zannini, Paolo
abstract

applicazione della reologia allo studio delle barbottine ceramiche di impasto e di smalto

1989 - Opportunità per gli Impiantisti ceramici nel settore dei Ceramici Avanzati [Articolo su rivista]
L., Cini; Zannini, Paolo
abstract

studio sulle possibili sinergie fra ricerca industriale applicata ai materiali ceramici avanzati ed ai materiali ceramici tradizionali

1988 - Il reparto ricerca e sviluppo in Aziende produttrici di piastrelle [Articolo su rivista]
B., Bacchilega; G., Baldassarri; Zannini, Paolo
abstract

ottimizzazione delle attività di un laboratorio ceramico, teso al controllo di produzione

1987 - Anisotropic exchange in dinuclear complexes with polyatomic bridges. Crystal and molecular structure and EPR spectra of (m-oxalato)-bis-(1,10 phenantroline) dicopper (II) dinitrate [Articolo su rivista]
A., Bencini; A. C., Fabretti; C., Zanchini; Zannini, Paolo
abstract

The X-ray crystal structure of (oxalato)bis(l,lO-phenanthroline)dicopper(II) dinitrate was determined at room temperature.The crystals are triclinic, space group Pi, with a = 9.977 (6) A, b = 9.658 (6) A, c = 7.036 (3) A, (Y = 108.03 (4)O, 0 = 95.40(4)'. y = 90.22 (4)O, and Z = 2. The least-squares refinement of the structure led to a conventional R factor of 0.036.Single-crystal EPR spectra were recorded at X-band (9-GHz) frequency at 77 K. The measured zero-field splitting tensor wasfound to be largely misaligned from the g tensor, showing that exchange contributions to the anisotropic spinspin interactionare operative. The relative influences of the dipolar magnetic and the anisotropic exchange interactions in determining the zero-field splitting in oxalato-bridged copper(I1) dimers are discussed.

1987 - Dithiocarbamate complexes of rhodium (III), iridium (III), palladium (II) and platinum (II) [Articolo su rivista]
A. C., Fabretti; C., Preti; Tassi, Lorenzo; G., Tosi; Zannini, Paolo
abstract

We report the preparation and characterization of the complexes of rhodium(III), iridium(III), palladium(II) and platinum(II) with the following ligands: Pzdtc, N-MePzdtc, N-PhPzdtc, Pipdtc, 4- PhPipdtc, Morphdtc, Timdtc, and with their methyl esters.The dithio ligands act as bidentate S,S′-donors in all the new derivatives. From the electronic absorption spectra the values of the ligand field parameters were determined. The nephelauxetic parameters are indicative of a strong covalency in the metal-ligand bond. All the compounds reported here are diamagnetic.

1987 - Structural and spectral study of 7-bromo-1,3-dihydro-5-(2-pyridyl)-2H-1,4-benzodiazepin-2-one (bromazepam) platinum (II) dichloride bis-dimethylsulfoxide [Articolo su rivista]
A., Benedetti; A. C., Fabretti; C., Preti; G., Tosi; Zannini, Paolo
abstract

The synthesis and crystal and molecular structure of the title compound are reported. It belongs to the monoclinic space groupC2/c, witha=17.889(2),b=13.511(1),c=19.912(2) Å, =99.841(4)°, andZ=8. The structure was refined to a finalR of 2.77% (R w =2.88%) for 3617 observed reflections. Vibrational spectra are recorded and discussed.

1986 - Magnetic and spectroscopic studies on copper(II) and chromium(III) complexes with sulfur chelating ligands [Articolo su rivista]
Ac, Fabretti; C., Preti; Tassi, Lorenzo; G., Tosi; Zannini, Paolo
abstract

A number of complexes of chromium(III) and copper(II) with heterocyclic dithiocarbamate ligands is reported. The newly prepared compounds are characterized on the basis of near- i.r . and far- i.r . spectroscopy, electronic and e.p.r . spectra, conductivity measurements and magnetic moment studies at different temperatures. The dithio ligands exhibit bidentate behaviour acting as S,S′-donors in all the complexes. The chromium(III) compounds have g values in the 1.991-1.999 range and nephelauxetic parameters indicative of an appreciable metal- ligand covalency. The e.p.r . data of the copper(II) derivatives provide parameters typical of sulfur coordination in planar CuS4 chromophores ; the α bonding parameters are indicative of strongly covalent metal- ligand interactions.

1986 - Microwave and plaster moulds [Articolo su rivista]
Zannini, Paolo
abstract

How to quickly dry plaster moulds by MW in the Sanitaryware industry

1986 - Structural and spectral study of 7-chloro-3-hydroxy-1-methyl-5-phenyl-1,3-dihydro-2H-1,4-benzodiazepin-2-one (temazepam) mercury (II) dichloride [Articolo su rivista]
L., Antolini; C., Preti; G., Tosi; Zannini, Paolo
abstract

The synthesis and crystal and molecular structure of the title compound is reported. It belongs to the monoclinic space groupP21/a witha=29.3990 (20),b=7.1150 (6),c=8.3140 (9) Å, =98.060 (9)° andZ=4. The structure was refined to a finalR of 3.52% (R w %=3.82) for 2354 observed reflections. Vibrational spectra have been recorded and discussed.

1986 - Synthesis and spectroscopic characterization of arsenic (III), antimony (III), bismuth (III), tin (II) and lead (II) dithiocarbamate adducts [Articolo su rivista]
A. C., Fabretti; A., Giusti; C., Preti; G., Tosi; Zannini, Paolo
abstract

The complexes of arsenic(III), antimony(III), bismuth(III), tin(II) and lead(II) with monomethylsubstituted piperidinodithiocarbamates of general formula M(Rdtc)3 and M(Rdtc)2 have been prepared and characterized by spectroscopic methods. The results of the spectroscopic studies indicate that the dithiocarbamate ligands are always bidentate, in both the 1:3 and the 1:2 complexes. All the complexes are nonconducting in DMF solution. The thermal behaviour of the complexes has been investigated by TG and DTG techniques. The molecular weight determinations indicate that the trisdithiocarbamates of arsenic and antimony are monomeric, while the bismuth trisderivatives tend to dimerize: polymeric structures can be suggested for the tin(II) and lead(II) compounds.

1986 - The problem of plasters in the new production techniques [Articolo su rivista]
Zannini, Paolo
abstract

Studio dell' essiccazione rapida di stampi in gesso per la formatura di sanitari tramite MW

1985 - A mass spectral investigation of 4-phenylpiperidine and N-phenylpiperidine-carbodithioato sodium salts and their cobalt (II), nickel (II) and copper (II) complexes [Articolo su rivista]
A., Benedetti; C., Preti; Tassi, Lorenzo; G., Tosi; Zannini, Paolo
abstract

Two new dithiocarbamate ligands and their cobalt(II), nickel(II)_and copper(II) complexes have been investigated by mass spectrometry. The fragmentation modes of the ligands have been discussed and compared with those of previously studied dithioligands and with those of the obtained complexes. An important feature of the spectra of the ligands is the absence of the molecular ion peaks which were present in the spectra of the previously studied dithioligands; however, the molecular ion peaks are present in the spectra of the complexes reported here. This behaviour is exactly the reverse of that observed in our previous studies. The postulated decomposition routes of the ligands and of the complexes are discussed in detail.

1985 - Coordinating ability of methylpiperidine dithiocarbamates toward platinum group metals [Articolo su rivista]
Franchini, Giancarlo; A., Giusti; C., Preti; Tassi, Lorenzo; Zannini, Paolo; G., Tosi
abstract

Coordinating ability of methylpiperidine dithiocarbamates toward platinum group metals

1985 - Electronic properties and crystal structure of aqua-(1,10-phenantroline)-(oxalato-O1O2) copper (II) monohydrate [Articolo su rivista]
Ac, Fabretti; Franchini, Giancarlo; Zannini, Paolo; M., Divaira
abstract

The compound aqua(1,1O-phenanthroline)- (oxalato-O1O2) copper(II)monohydrate was synthesized and characterized by spectroscopy, thermal analysis, EPR and structural measurements. The crystal and molecular structure, refined to the final R = 4.28% (Rw = 4.52%) value, shows a monomeric nature. Copper coordination is 4 + l in a slight distorted square pyramidal geometry, with a water oxygen atom in the apical position, at 2.237(4) A. from the metal ato. At 4.44 A. from copper lies a lattice water molecule, linked to the former by a hydrogen bond.

1985 - Osmium (III) halide complexes with para- and meta- substituted benzeneseleninato ligands [Articolo su rivista]
G., Graziosi; C., Preti; G., Tosi; Zannini, Paolo
abstract

The preparation and magnetic susceptibility, electronic, infrared, electrical conductivity and thermogravimetric studies of a series of monomethylsubstituted piperidine dithiocarbamates of silver(I), gold(I) and gold(III) are reported. The complexes are formulated as AgRdtc, AuRdtc, Au(Rdtc)3. Au(Rdtc)2X and AuRdtcX2 (X=Cl, Br). The dithioligands exhibit both bidentate behaviour acting as S,S ' -donors and monodentate behaviour acting as S-donors, depending on the type of the complex. The diamagnetic behaviour of the gold(III) derivatives is in accord with the usual low-spin d8 configuration. The metal-sulphur and metal-halide stretches have also been assigned and are in accord with the proposed structures. The molecular weight determinations indicate monomeric structures for the Au(Rdtc)3 and AuRdtcX2 complexes and dimeric structures for the Au(Rdtc)2X derivatives. The results of the spectroscopic studies indicate that in the Au(Rdtc)3 complexes one of the dithiocarbamate groups must act as a bidentate ligand, while the other two act as monodentates giving square planar structures.

1985 - Silver and gold complexes with cyclic carbodithioates as ligands [Articolo su rivista]
Ac, Fabretti; A., Giusti; C., Preti; Tassi, Lorenzo; Zannini, Paolo
abstract

The preparation and magnetic susceptibility, electronic, infrared, electrical conductivity and thermogravimetric studies of a series of monomethylsubstituted piperidine dithiocarbamates of silver(I), gold(I) and gold(III) are reported. The complexes are formulated as AgRdtc, AuRdtc, Au(Rdtc)3. Au(Rdtc)2X and AuRdtcX2 (X=Cl, Br). The dithioligands exhibit both bidentate behaviour acting as S,S ' -donors and monodentate behaviour acting as S-donors, depending on the type of the complex. The diamagnetic behaviour of the gold(III) derivatives is in accord with the usual low-spin d8 configuration. The metal-sulphur and metal-halide stretches have also been assigned and are in accord with the proposed structures. The molecular weight determinations indicate monomeric structures for the Au(Rdtc)3 and AuRdtcX2 complexes and dimeric structures for the Au(Rdtc)2X derivatives. The results of the spectroscopic studies indicate that in the Au(Rdtc)3 complexes one of the dithiocarbamate groups must act as a bidentate ligand, while the other two act as monodentates giving square planar structures.

1985 - Transition metal complexes with 2-methyl, 3-methyl and 4-methyl-piperidine dithiocarbamate as ligands [Articolo su rivista]
Zannini, Paolo; FABRETTI A., C; Franchini, Giancarlo; Preti, C; Tosi, G
abstract

A new series of manganese(III), cobalt(II), nickel(II), zinc(II), cadmium(II) and mercury(II) complexes with monomethylsubstituted dithiocarbamates as ligands has been synthesized and studied. Their structures are discussed in relation to their spectroscopic, magnetic and thermal properties. The dithio-ligands exhibit bidentate behaviour acting as S,S donors in all the complexes. In the far i.r. region particular attention is paid to a comparison of the spectra of the octahedral complexes with those of the other metal derivatives (1 2 metal to ligand molar ratio). The e.s.r. spectra are indicative of aD 2h symmetry in the cobalt(II) complexes.

1983 - Antibiotics as ligands. The coordinating ability of deprotonated cycloserine towards transition metals [Articolo su rivista]
F., Forghieri; C., Preti; G., Tosi; Zannini, Paolo
abstract

We report the complexes of the deprotonated cycloserine (ccs) ligand, 4-aminoisoxazolidin-3-one, with the metal ions chromium(III), manganese(II), iron(II), iron(III), cobalt(II), nicke1(II), zinc(II), zirconium(IV), palladium(II), silver(I), cadmium(II), osmium(III), platinum(II) and mercury(II). The tentative structures of the complexes have been assigned on the basis of analytical, spectral(u.v.- visible, i.r. and far i.r.) and magnetic data, and of thermal analyses (t.g. and d.t.g.). These complexes appear to contain ccs as an uninegative bidentate ligand forming five-membered rings in which the O- and the NH2 groups bind to the metals. The ligand field parameters have been evaluated and are in keeping with the proposed structures; they confirm the presence of oxygen-and nitrogen-containing chromophores.

1983 - Coordination chemistry of cycloserine derivatives. Complexes of iron (II), iron (III), manganese (II) and palladium (II) with N4, N4 –tereftal-bis(cycloserine) [Articolo su rivista]
C., Preti; Tassi, Lorenzo; G., Tosi; Zannini, Paolo; Af, Zanoli
abstract

Synthetic and other studies of iron(II), iron(III), manganese(II) and palladium(II) complexes with the cycloserine derivative, N4, N ' 4-tereftal-bis(cycloserine) or Terizidone, are reported. The methods used for the characterization of the compounds include elemental analyses, molar conductance, magnetic moments, electronic and infrared spectroscopy and thermal analyses (TG and DTG). From the magnetic properties it was concluded that the above ligand forms low-spin complexes with palladium(II) and high-spin complexes with iron(II), iron(III) and manganese(II). The wavelengths of the principal absorption bands have been accounted for quantitatively in terms of the crystal field theory for manganese(II) and tetrahedral iron(III) complexes. The values of B and C in the iron(III) derivatives are less than in the corresponding manganese(II) complexes. Far-infrared spectra have been extensively studied and the relationship between metal-halogen stretching vibrations and stereochemistry of the complexes is outlined and shown to have potential application in the assignment of the stereochemistry and coordination number of these new metal-halide complexes. The ligand is always monodentate N-bonded through the nitrogen of the imino group of the isoxazole ring. Under our experimental conditions no metal-induced cycloserine ring opening was observed.

1983 - Preparation and spectroscopic studies of antimony (III) and bismuth (III) halodithiocarbamate derivatives [Articolo su rivista]
A., Giusti; C., Preti; G., Tosi; Zannini, Paolo
abstract

The complexes of antimony(III) and bismuth(III) with piperidine (Pipdtc), morpholine (Morphdtc) and thiomorpholinedithiocarbamate (Timdtc) of general formula Sb2-(Rdtc)3X3 and M(Rdtc)X2 (M is antimony or bismuth, X a halogen and Rdtc the dithiocarbamates) have been prepared and characterized by spectroscopic methods. The IR spectra suggest that the dithiocarbamate group coordinates as a bidentate ligand; the metal-sulphur and metal-halide stretching modes have also been assigned. The spectral data are discussed and compared with those of the corresponding trisdithiocarbamate and monohalobisdithiocarbamate derivatives. The molecular weight determinations indicate that all these dithiocarbamate complexes are dimeric. Tentative stereochemistries are proposed and discussed on the basis of the results obtained.

1983 - Substituted benzeneseleninic acids as bidentate ligands. Synthesis and spectroscopic studies of manganese (II) and iron (II) complexes [Articolo su rivista]
G., Candrini; W., Malavasi; C., Preti; G., Tosi; Zannini, Paolo
abstract

The para- and meta-substituted seleninato anion, XC6H4SeO−2, forms complexes with manganese(II) and iron(II) of the type [M(XC6H4SeO2)2(H2O)2], which have been shown to contain the bidentate ligand in seleninato-O, O′ derivatives, the water molecules being coordinated to the metals. From the electronic absorption spectra and from the magnetic susceptibility data we have proposed for all the complexes a distorted octahedral D4h symmetry. The structure of the anhydrous para- and meta-substituted benzeneseleninato complexes of manganese(II) and iron(II) have been investigated by means of electrical conductance measurements, spectral (electronic and i.r.) studies and magnetic susceptibility measurements. The anhydrous complexes are always of the seleninato-O, O′ type with the ligands tetrahedrally coordinated to the central atom. The wavelengths of the principal absorption peaks have been accounted for quantitatively in terms of the crystal field theory for manganese(II) derivatives. The nephelauxetic parameters are all indicative of an appreciable metal-ligand covalency.

1982 - Cycloserine derivatives as ligands. The coordination ability of 4,4’-[1,4-phenylenebis(methylidynenitrilo)bis(isoxazolidin-3-one)] towards chromium (III), ruthenium (III) and rhodium (III) halides [Articolo su rivista]
C., Preti; Tassi, Lorenzo; G., Tosi; Zannini, Paolo; Af, Zanoli
abstract

The complexes of the cycloserine derivative, 4,4'-[1,4-phenylenebis(methylidynenitrilo)]bis(isoxazolidin-3-one) or terizidone, with chromium(III), ruthenium(III) and rhodium(III) have been synthetized; their structures have been suggested on the basis of analytical, conductivity, spectral (visible, infrared and far-infrared) and magnetic data, and the thermal analyses have revealed the extent of coordinated water among the chromium and ruthenium complexes. The various ligand field parameters have been evaluated; the B' values suggest a strong covalency in the metal-ligand σ bond and the Dq values show a medium-strong ligand field. The position and multiplicity of the metal-halogen stretching modes in the far-infrared region have been extensively investigated and discussed; the results are particularly useful in distinguishing between the mer- and fac-isomers in the octahedral compounds of the ML3X3 type. The ligand is monodentate O-bonded or N-bonded through the oxygen of the keto group or through the nitrogen of the imino group of the isoxazole ring. We have never observed a metal-induced cycloserine ring opening under the present experimental conditions.

1980 - Interactions between sodium dithiocarbamates and p- and d- block metals [Abstract in Atti di Convegno]
C., Preti; G., Tosi; Zannini, Paolo
abstract

n.d.

1980 - Investigations on chromium (III), manganese (II), tin (II) and lead (II) dithiocarbamate complexes [Articolo su rivista]
C., Preti; G., Tosi; Zannini, Paolo
abstract

Piperidine-, morpholine-4-, N-methylpiperazine-4- and thiornorpholine-4-carbodithioate complexes of chromium(III), manganese(III), tin(II) and lead(II) are prepared and characterized by chemical analyses, spectroscopic methods (I.R. and electronic spectra), magnetic susceptibilities, conductivity measurements and mass spectra. The complexes are of the type M(R2dtc)n, where n is the oxidation number of the metal ion. Where possible a tentative stereochemistry of the complexes is discussed on the basis of the results obtained. In all the complexes the dithiocarbamate ligands show bidentate behaviour.

1980 - Mass spectral investigations on benzeneseleninic acid [Articolo su rivista]
Benedetti, Adriano; C., Preti; G., Tosi; Zannini, Paolo
abstract

The mass spectra of benzeneseleninic acid and of diphenyl diselenide have been examined and a full analysis is reported. The fragmentation patterns and the fragment ions are discussed. A molecular-ion peak was not observed for benzeneseleninic acid; instead the ion with highest mass number appeared in a multiplet, with the most intense peak at m/e 314, having a general shape typical of the presence of two selenium atoms and corresponding to the diphenyl diselenide (C6H5–Se–Se–C6H5) ion.

1980 - Metal-ligand bonding in benzeneseleninato complexes of p- and d- block metals [Articolo su rivista]
C., Preti; G., Tosi; Zannini, Paolo
abstract

New complexes of lead(II) and zirconium(IV) withmeta-andpara-substituted benzeneseleninic acids are reported and characterized by chemical analyses, spectroscopic methods and conductivity and magnetic measurements. The complexes are of the Pb(XC6H4SeO2)2 and ZrO(XC6H4SeO2)2 type; for zirconium(IV), working with a 1:4 metal:ligand stoichiometrical ratio, invariably the oxy derivative was obtained. The i.r. spectral data suggest that the complexes contain RSeO 2 – ligands acting as bidentate in O,O -seleninato complexes, Where possible, a tentative stereochemistry for the complexes is discussed on the basis of the results obtained.

1980 - Osmium carbodithioato derivatives. Syntesis and spectroscopic studies [Articolo su rivista]
C., Preti; G., Tosi; Zannini, Paolo
abstract

Several new dithiocarbamate complexes of osmium(III) and osmium(II) have been synthetized and characterized by i. r. and electronic spectra, magnetic susceptibilities and conductivity measurements. The dithio ligands show a bidentate behaviour in all the complexes. From the electronic absorption spectra the values of the ligand field parameters were determined; the nephelauxetic parameter is indicative of a strong covalency in the metal-ligand bond as confirmed by the Dq values. All the complexes of osmium (III) and osmium(II) were octahedral, distorted owing to the presence of two molecules of coordinated water the metal(II) derivatives; the room temperature magnetic susceptibility values show that the complexes are of low-spin type: the osmium(III) derivatives have one unpaired electron, while the osmium (II) ones were diamagnetic.

1980 - The reactivity of areneseleninato complexes. New zinc (II) benzeneseleninato derivatives with 1,10-phenantroline as bidentate nitrogen donor ligand [Articolo su rivista]
C., Preti; G., Tosi; Zannini, Paolo
abstract

Treatment of the O,O'-seleninatodiaquozinc(II) derivatives of the type [Zn(H2 O)2 (X-C6 H4 SeO2)2] (X=H, p-Cl, m-Cl, p-Br, m-Br, p-Me, p-NO2) with 1,10-phenanthroline produces 1 : 2 or 1 : 3 complexes, depending on the metal: o-phen stoichiometrical ratio. The 1 : 2 complexes were non-conducting and of the O-seleninato type, whereas the triscomplexes behaved as 1 : 2 electrolytes; the nitrogen donor ligand is always bidentate. The newly prepared complexes are characterized by far-I.R. and near-I.R. spectroscopy, as well as conductivity measurements. The possible stereochemistries of the complexes are discussed.

1979 - Antibiotics as ligands. Coordination behaviour of cycloserine towards cobalt (II), nickel (II), zinc (II), cadmium (II) and mercury (II) halides [Articolo su rivista]
C., Preti; G., Tosi; Zannini, Paolo
abstract

The complexes of cycloserine, 4-amino-3-isoxazolidone, (Ccs) with cobalt(II), nickel(II), zinc(II), cadmium(II), and mercury(II) halides have been synthetized. Their structures have been assigned on the basis of analytical, conductivity, spectral (visible, i.r. and far-i.r.) and magnetic data. The ligand behaves as monodentate O-bonded. The position and multiplicity of the metal-halide stretching frequencies are discussed and used as a guide to the stereochemistry. The most convincing structural evidence for the cobalt derivatives is a predominantly planar environment for the chloro-complex with terminal ligands and terminal halides, while for the 1:3 complexes we could suggest a pentacoordinate structure with terminal both ligands and halides. The nickel(II) chloro- and bromo-derivatives seem to have a pseudo-tetrahedral symmetry, while the iodo-complex resulted pentacoordinate. Both the cobalt(II) and nickel(II) derivatives resulted high spin, with the exception of Co(Ccs)2Cl2. Tetrahedral monomeric and dimeric structures with bridging halide atoms, and pentacoordinate geometries are present in the zinc(II), cadmium(II), and mercury(II) complexes. The water resulted always uncoordinated lattice water. Assignments for the electronic spectra are proposed for all the above reported symmetries; the assignments for the metalligand and metal-halides stretching modes have also been made. We have never observed a metalinduced ring opening under the present experimental conditions.

1979 - Preparation and studies of some antimony and bismuth trisdithiocarbamate and five-coordinate monohalobisdithiocarbamate derivatives [Articolo su rivista]
C., Preti; G., Tosi; Zannini, Paolo
abstract

The complexes of antimony(III) and bismuth(III) with piperidinedithiocarbamate (Pipdtc), morpholinedithiocarbamate (Morphdtc) and thiomorpholinedithiocarbamate (Timdtc) of general formula M(Rdtc)3 have been prepared, and characterized by spectroscopic methods. The data show that the complexes have a distorted octahedral stereochemistry, this distortion being due to the stereochemically active lone-pair of electrons on the antimony and bismuth atoms.A new series of pentacoordinate complexes of general formula M(Rdtc)2X, M being antimony or bismuth, X a halogen and Rdtc the above dithiocarbamates, has been prepared by reacting the corresponding trisdithiocarbamates with chlorine, bromine and iodine. The compounds have been characterized by IR and electronic spectroscopy and molecular weight determinations. The infrared spectra suggest that each dithiocarbamate group coordinates as a bidentate ligand; the metal—halide and metal—sulphur stretching modes have also been assigned. The spectral data are discussed and compared with those of the corresponding trisdithiocarbamate derivatives. The molecular weight determinations indicate that the trisdithiocarbamate complexes are monomeric; for the monohalobisdithiocarbamates, the antimony derivatives are shown to be monomeric, while the bismuth derivatives tend to dimerize.

1979 - Study of the reactivity of some square planar nickel (II) carbodithioato derivatives towards ethylenediamine [Articolo su rivista]
C., Preti; G., Tosi; Zannini, Paolo
abstract

Five-coordinate bis(carbodithioato)tris(ethylenediamine)-nickel(II) complexes are obtained by reaction of piperidine-, morpholine-4-, piperazine-4-,N-methylpiperazine-4-, and thiomorpholine-4-carbodithioato nickel derivatives with ethylenediamine. The square planar starting complexes react with three moles of ethylenediamine to give five-coordinate products with the dithio ligands acting in a monodentate fashion only. The new complexes were characterized by their far i.r., near i.r. and electronic spectra, as well as by magnetochemical investigations and conductivity measurements. The most attainable geometry is square pyramidal, probably slightly distorted; tentative assignments for the electronic spectra are proposed. The room temperature magnetic moments show that all the complexes are of high-spin type, the values lying in the ranges usually observed for other high-spin penta-coordinated nickel(II) derivatives. The metal-sulphur and metal-nitrogen stretching vibrations are also assigned.

1979 - Synthesis and characterization of ruthenium dithiocarbamate complexes [Articolo su rivista]
C., Preti; G., Tosi; Zannini, Paolo
abstract

Piperidine carbodithioate (Pipdtc), morpholine-4-(Morphdtc), thiomorpholine-4-(Timdtc), piperazine-4-(Pzdtc) and N-methylpiperazine-4-carbodithioate (CH3-Pzdtc) complexes of ruthenium have been prepared and characterized by spectroscopic methods (IR and electronic spectra), magnetic susceptibilities and conductivity measurements. Where possible a tentative stereochemistry of the complexes is discussed based upon the obtained results. The dithiocarbamate ligands show in all the complexes a bidentate behaviour. A distorted octahedral geometry is proposed for the water containing 1:2 derivatives: in fact from a detailed analysis of the infrared spectra the water resulted always coordinated to the metal. The Pzdtc 1:2 derivative resulted polymeric octahedral with the NH group of the heterocyclic ring involved in the coordination.

1979 - The reactivity of areneseleninato complexes. New pentacoordinate nickel (II) complexes with benzeneseleninato ions and ethylenediamine as ligands [Articolo su rivista]
C., Preti; G., Tosi; Zannini, Paolo
abstract

Five-coordinate bis(Se-benzeneseleninato)tris(ethylenediamine)nickel(II) complexes are obtained by reaction of the Ni(H2O)2(XC6H4SeO2)2 complexes (X = H,p-Cl,m-Cl,m-Br orp-Me) with ethylenediamine. All the diaquo complexes react with three moles of ethylenediamine to form Se-seleninato derivatives. The compounds are characterized on the basis of far i.r. and near i.r. spectroscopy, electronic spectra and magnetochemical investigations. The most attainable geometry is the square pyramidal, probably slightly distorted; tentative assignments for the electronic spectra are proposed. Conductivity data indicate that these new complexes are nonelectrolytes; both areneseleninato and ethylenediamine behave as monodentate ligands. The magnetic moments show that all the complexes are of high-spin type, the values lying within the ranges observed for other high-spin five-coordinate nickel(II) complexes.

1977 - Five-coordinate low-spin cobalt (II) complexes with benzeneseleninato ions and ethylenediamine as ligands [Articolo su rivista]
C., Preti; G., Tosi; Zannini, Paolo
abstract

Five-coordinate bis(benzeneseleninato)tris(ethylenediamine) cobalt (II)complexes are obtained by reaction of Co(H2O)2 (XC6 H4 SeO2)2 complexes (X = H, p-Cl, m-CI, p-Br, ni-Br, p-Me,p-NO2) with ethylenediamine. The diaquo complexes (one mole)react with ethylenediamine (three moles)to form O-seleninato derivatives. Spectral and magnetic properties show that the complexes are low-spin (s = 1/2) and,on the basis of the electronic spectra a distorted trigonal geometry,D 3h , is suggested. Assignments for the electronic spectra are proposed. Conductivity data indicate that these derivatives are nonelectrolytes. Both ethylenediamine and [RSeO2 ]– behave as monodentate ligands.