Rationalization of the structural, electronic and photophysical properties of silver(I) halide -picolylamine hybrid coordination polymers.

Hybrid coordination polimers based on AgX (with X = Cl, Br) and 2-, 3-, 4-picolylamine ligands, obtained by means of solvent-free methods, show peculiar luminescence properties that are strongly influenced by their structural motif, which in turn is defined by the adopted isomer of the ligand. A comprehensive study, combining photophysical methods and DFT calculations, allowed to rationalize the emissive behaviour of such hybrid coordination polymers in relation to their crystal structures and electronic properties. By means of luminescence measurements at variable temperatures, the nature of the emissive excited states and their deactivation dynamics was interpreted, revealing XMLCT transitions in the [(AgX)(2-pica)] compounds, a TADF behaviour in the case of 3-pica derivatives, and a dual emission at room temperature for the [(AgX)(4-pica)] family.

Liquid reagents are not enough for liquid assisted grinding in the synthesis of [(AgBr)(-pica)].

This study investigates the mechanochemical reactions between AgBr 3-picolylamine and 4-picolylamine. The use of different stoichiometry ratios of the reagents allows [(AgBr)(-pica)] and [(AgBr)(-pica)] to be obtained, and we report the new structures of [(AgBr)(3-pica)] and [(AgBr)(4-pica)] which are characterized by the presence of the following: (a) infinite inorganic chains, (b) silver atom coordinated only by bromide atoms and (c) argentophilic interactions. Furthermore, we studied the interconversion of [(AgBr)(-pica)]/[(AgBr)(-pica)] by mechanochemical and thermal properties.

AgX-based hybrid coordination polymers: mechanochemical synthesis, structure and luminescence property characterization.

Hybrid coordination polymers are interesting for their ability to converge the properties of both inorganic and organic systems in one single compound and recently attention has been focused on silver based hybrid coordination polymers due to their luminescence properties. We searched the CSD to establish the propensity of AgXL (X = Cl, Br and I) with L as an organic ligand to form hybrid coordination polymers. About 800 AgXL structures are deposited in the CSD, with huge structural variability: indeed, it is possible to recognize some structural preferences based on the halide nature.