Sustainable synthesis of organic and hybrid smart materials

The Laboratory is dedicated to the synthesis of new functional materials for electronic and optoelectronic applications. The main focus of our research is the preparation of molecular materials through environmentally sustainable synthetic methods according to the principles of green chemistry, using eco-compatible solvents / processes and minimizing the E-factor, i.e. the ratio of the mass of waste per mass of obtained product. Structure, degree of purity and other properties of all the synthesized products are confirmed by Nuclear Magnetic Resonance (NMR) spectra, optical spectroscopies (IR, UV), steady-state and time-resolved fluorescence, elemental analysis and mass spectra; their redox properties are investigated by solution and / or film cyclovoltammetry. Organic and metallorganic synthesis
Our synthetic targets, mainly dyes or pigments, include several families of organic/metallorganic molecules and organic-inorganic hybrids:

Chemical structure of a metallophthalocyanine and cobalt(II) phthalocyanine powder) Phthalocyanines, porphyrins and other metallomacrocyclic analogues, whose unique physical properties (conductive, optical and magnetic) are accompanied by great synthetic versatility, nanoscopic dimensions, processability, biocompatibility, etc. Phthalocyanines are thermally and chemically stable compounds that exhibit a very intense absorption in the red / near infrared region of the solar spectrum and a variety of redox activity. The result is an extreme adaptability at the application level as pigments, in pharmacology as photodynamic therapy drugs, in catalysis, in sensors and in the last twenty years in molecular electronics and in the latest generation of photovoltaics. The appropriate functionalization of the periphery of the macrocycle allows to change its optical or magnetic properties based on those possessed by the chosen chemical species, optimizing them with respect to the device in which they will be implemented. The derivatives synthesized in our laboratory are mainly designed to be used as charge carriers and surface sealants in perovskite solar cells, and as p-semiconductors in organic thin film transistors (OTFTs).
Particularly interesting is the investigation of the behavior of mono- and multi-layers of phthalocyanines deposited on metals or semiconductors for the understanding of interface phenomena, which are of fundamental importance for their application in devices.

Struttura chimica di una metalloftalocianina e polvere di cobalto(II) ftalocianina

Fluorochromism of a substituted benzothienobenzothiophene derivative in (from left to right) hexane, dichloromethane, ethanol) Aromatic and heteroaromatic derivatives with specific optical, luminescence and charge transport properties for applications in OLEDs, organic transistors (OFETS, OTFTs) and luminescent solar concentrators (LSCs). In particular, variously functionalized polyciclic aromatic compounds and benzothienobenzothiophene derivatives, whose molecular structures are from time to time designed for a specific application. (e.g. induction of charge separation in the excited state to produce optical responses in luminescence, maximization of intermolecular stacking to enhance charge transport properties...).

Fluorocromismo di un derivato benzotienobenzotiofenico sostituito in (da sinistra a destra) esano, diclorometano ed etanolo)

Organic-inorganic hybrid perovskites of the MAPI and FAPI type, rising stars of the new research on the latest generation photovoltaics. The interest in understanding their fundamental properties has led us to develop a synthesis line dedicated to the production of bulk and crystalline perovskite materials.

Pasticche di CH₃NH₃PbI₃ (MAPI)