مشخصات پژوهش

Two mononuclear rhenium coordination compounds with hydrazone ligand, [ReOBr2(PPh3)(HL)]⋅(CH3CN) (1) and [ReCl2(PPh3)2(HL)]⋅(CH3CN) (2), were synthesized by the reaction of ReOBr3(PPh3)2 or ReOCl3(PPh3)2 with H2L in acetonitrile (H2L = (E)-N’-(1-(4‑hydroxy-6-methyl-2-oxo-2H-pyran-3-yl)ethylidene)picolinohydrazide). Compounds 1 and 2 were characterized by spectroscopic methods and their structures were determined by single crystal X-ray analysis. Structural studies indicated that despite the similarity of the reactions and structures, the oxidation state of rhenium ion in 1 is mainly Re(V) but, in compound 2 it is reduced to Re(III) during the synthesis procedure. The hydrazone ligand in these compounds has similar coordination mode and it is coordinated as a bidentate N- and O-donor mononegative ligand, HL-1. TGA analysis showed that these compounds are stable up to 200 ◦C and they decompose in two steps in the range of 200–700 ◦C. The intermolecular interactions in these compounds were investigated by Hirshfeld surface analysis which revealed there are several intermolecular C􀀀 H⋅⋅⋅N, C􀀀 H⋅⋅⋅X (X = Br and Cl) and C􀀀 H⋅⋅⋅π interactions which contribute in the stabilization of the crystal structures.