Novel p-tolylimido rhenium(V) complexes of imidazole-derived ligand – Synthesis, X-ray studies, spectroscopic characterization and DFT calculations

Three novel imido rhenium complexes of biologically relevant ligand 2-hydroxymethylbenzimidazole: [Re(p-NC6H4CH3)Cl2(hmbzim)(PPh3)]·CHCl3 (1), [Re(p-NC6H4CH3)Br2(hmbzim)(PPh3)] (2) and [Re(p-NC6H4CH3)(hmbzim)2(PPh3)]ReO4·MeOH (3) have been synthesized and characterized spectroscopically and structurally (by single-crystal X-ray diffraction). The electronic spectra of 1 and 3 were investigated at the TDDFT level employing B3LYP functional in combination with LANL2DZ. Additional information about binding in the complexes 1 and 3 was obtained by NBO analysis, which confirms a linear coordination mode of the p-NC6H4CH3 ligand and triple bond between the rhenium and imido ligand.

Graphical abstractThe paper presents a combined experimental and computational studies of three novel imido rhenium complexes of biologically relevant ligand 2-hydroxymethylbenzimidazole. The compounds [Re(p-NC6H4CH3)Cl2(hmbzim)(PPh3)]·CHCl3 (1), [Re(p-NC6H4CH3)Br2(hmbzim)(PPh3)] (2) and [Re(p-NC6H4CH3)(hmbzim)2(PPh3)]ReO4·MeOH (3) were identified by IR, UV–Vis spectroscopy and X-ray crystallography. The electronic spectra of 1 and 3 were investigated at the TDDFT level employing PBE1PBE functional in combination with LANL2DZ. Additional information about binding in the complexes 1 and 3 was obtained by NBO analysis.Figure optionsDownload full-size imageDownload as PowerPoint slide