Mono- and dinuclear manganese(II) complexes derived from the cis/trans isomers of 2,4,5-tris(2-pyridyl)-4,5-dihydroimidazole

摘要

Two new manganese(II) complexes, [Mn(L1)(L1H)(ClO4)(H2O)][ClO4](2)center dot 0.5CH(3)CN center dot H2O (1) [L1 = trans-(+/-)2-(2,5-di(pyridin-2-yl)-4,5-dihydro-1H-imidazol-4-yl) pyridine)] and [Mn-2(mu-L2)(2)(H2O)(3)(CH3CN)(3)][ClO4](4)center dot 2 CH3CN (2) [L2 = cis-(+/-)2-(2,5-di(pyridin-2-yl)-4,5-dihydro-1H-imidazol-4-yl) pyridine)], have been prepared and examined by single-crystal X-ray diffraction analysis, showing that complex 1 is a mononuclear compound, whereas complex 2 is a dinuclear species. The cis/trans isomers L1 and L2 have similar coordination properties, but behave as bidentate and tridentate chelating ligands, respectively, giving distorted octahedral metal coordination geometries. X-ray diffraction studies revealed that the molecular and crystal structures are stabilized by a series of intra-and intermolecular interactions. In both cases extended supramolecular networks are generated, in compound 1 through O-H center dot center dot center dot O, O-H center dot center dot center dot N, N-H center dot center dot center dot O, N-H center dot center dot center dot N, C-H center dot center dot center dot O, C-H center dot center dot center dot N, C-H center dot center dot center dot pi and pi center dot center dot center dot pi interactions, and in compound 2 through O-H center dot center dot center dot O, O-H center dot center dot center dot N, C-H center dot center dot center dot O and pi center dot center dot center dot pi interactions. The observed structural differences between the two metal complexes might be a consequence of these stabilizing effects.