Copper(II) thiocyanate complexes of 2-(2-pyridinyl)-benzthiazole: synthesis, structure, redox behavior, thermal aspects, and DFT calculations.

Reaction of 2-(2-pyridinyl)-benzthiazole (Pbt), KSCN, and copper(II)perchlorate hexahydrate in 1 : 2 : 1 molar proportion in dimethyl sulfoxide gives monomeric [Cu(Pbt)(SCN)2DMSO] (1a). In another run, identical proportions of the same reactants in methanol generates a symmetric thiocyanate bridged dimeric copper(II) compound, [Cu2(Pbt)2(SCN)2] (2a), in 72% yield. Both1aand2ahave been characterized by C, H, and N microanalyses, copper estimation, FTIR, UV–vis spectra, and room temperature magnetic susceptibility measurements. The X-ray crystal structures of1aand2ahave been determined. Electrochemical studies of1aand2ashow Cu(II) to Cu(III) oxidation in solution. The thermal behaviors of1aand2ahave been studied. Bond valence sum method of analysis was performed to assign the oxidation state for each copper center in1aand2a. Geometry optimization of1a,2a,and their linkage isomers has also been performed at the level of the density functional theory to show that1aand2aare the most stable congeners. These results corroborate our experimental findings. [ABSTRACT FROM AUTHOR]