Università degli studi di Modena e Reggio Emilia

The new polynucleating tripodal proligand H6tren(dpa)3, containing thirteen nitrogen donors of four different types, was designed, synthesized, and isolated in good yield (~60%) via a transition-metal-free triple N-arylation of H6tren with HXdpa (X = Br or F), using K2CO3 or Cs2CO3 as a base (H6tren = tris(2-aminoethyl)amine, HXdpa = 6-halogeno-N-(pyridin-2-yl)pyridin-2-amine). HFdpa was prepared with excellent yield (90−92%) by reaction of 2,6-difluoropyridine with 2-aminopyridine in LiH/toluene/py and was found more reactive than HBrdpa, affording higher conversion and higher yield. Use of Cs2CO3 turned out to be essential for achieving high regioselectivity and eliminating overarylation almost completely.

This study investigates the potential application of peach shells as lightweight aggregates in the production of non-structural lightweight concrete (LWC). The recycling and reutilization of agri-food waste presents an opportunity to address the challenges associated with waste disposal and limit the exploitation of natural resources, contributing to sustainable development goals and combatting climate change. The peach shells were subjected to heat treatment at various temperatures (160, 200, and 240 °C) to reduce the hydrophilicity of the cellulose fraction, and their chemical and physical properties were examined in relation to the performance of lightweight concrete, in terms of density, compressive strength and thermal conductivity. Two binding mixtures, one with lime only (mixture “a”) and the other with both lime and cement (mixture “b”), were studied. The experimental results indicated that the prepared lightweight concrete specimens exhibited better performance as the roasting temperature increased, starting from 200 °C. Conversely, specimens prepared with peach shells roasted at 160 °C exhibited a decreased performance compared to those prepared with only air-dried peach shells. Samples prepared with the mixture “a” have better insulating properties and lower density, but lower mechanical resistance. The enhanced properties observed in the lightweight concrete specimens prepared with higher roasting temperatures highlight the potential of utilizing peach shells as an effective and sustainable alternative to traditional lightweight aggregates.

With regards to oil-based diesel fuel, the adoption of bio-derived diesel fuel was estimated to reduce CO2 emissions by approximately 75%, considering the whole life cycle. In this paper, we present a novel continuous-flow process able to transfer an equimolar amount of CO2 (through urea) to glycerol, producing glycerol carbonate. This represents a convenient tool, able to both improve the efficiency of the biodiesel production through the conversion of waste streams into added-value chemicals and to beneficially contribute to the whole carbon cycle. By means of a Design of Experiments approach, the influence of key operating variables on the product yield was studied and statistically modeled.