Ruthenium complexes with Schiff base ligands containing benz(othiazole/imidazole) moieties: Structural, electron spin resonance and electrochemistry studies
摘要:
Novel ruthenium(II/III) complexes of Schiff bases containing benzimidazole (bz) or benzothiazole (bs) moieties were isolated: the diamagnetic ruthenium complex, cis-[(RuCl2)-Cl-11(bzpy)(PPh3)(2)] (1) was formed from the 1:1 M reaction between N-((pyridine-2-yl)methylene)-1H-benzimidazole (bzpy) and metal precursor, trans-[RuCl2(PPh3)(3)]. The same metal precursor, when reacted with the benzimidazole-derived Schiff bases N-(2-hydroxybenzylidene)-benzothiazole (Hbsp) and N-(2-hydroxybenzylidene)-benzimidazole (Hbzp)], afforded the paramagnetic ruthenium(III) complexes [RuCl(bsp)(2)(PPh3)] (2) and trans-[RuCl(bzp)(PPh3)(2)] (3), respectively. These metal complexes were characterized via IR, mass and UV-Vis spectroscopy, elemental analysis, single crystal XRD analysis as well as conductivity measurements. Their redox properties were probed by voltammetry and accompanying UV-Vis spectroelectro-chemistry experiments. Structural features of complex I were further investigated by multinuclear and P-31) NMR spectroscopy. The presence of the paramagnetic metal centres of 2 and 3 were confirmed by X-band ESR spectroscopy. (C) 2014 Elsevier Ltd. All rights reserved.