Ruthenium complexes with Schiff base ligands containingudbenz(othiazole/imidazole) moieties: Structural, electron spin resonanceudand electrochemistry studies

摘要

Novel ruthenium(II/III) complexes of Schiff bases containing benzimidazole (bz) or benzothiazole (bs)udmoieties were isolated: the diamagnetic ruthenium complex, cis-[RuIICl2(bzpy)(PPh3)2] (1) was formedudfrom the 1:1 M reaction between N-((pyridine-2-yl)methylene)-1H-benzimidazole (bzpy) and metal precursor,udtrans-[RuCl2(PPh3)3]. The same metal precursor, when reacted with the benzimidazole-derivedudSchiff bases [N-(2-hydroxybenzylidene)-benzothiazole (Hbsp) and N-(2-hydroxybenzylidene)-benzimidazoleud(Hbzp)], afforded the paramagnetic ruthenium(III) complexes [RuCl(bsp)2(PPh3)] (2) andudtrans-[RuCl(bzp)(PPh3)2] (3), respectively. These metal complexes were characterized via IR, mass andudUV–Vis spectroscopy, elemental analysis, single crystal XRD analysis as well as conductivity measurements.udTheir redox properties were probed by voltammetry and accompanying UV–Vis spectroelectrochemistryudexperiments. Structural features of complex 1 were further investigated by multinuclear (1Hudand 31P) NMR spectroscopy. The presence of the paramagnetic metal centres of 2 and 3 were confirmedudby X-band ESR spectroscopy.