Syntheses, structural characterizations, and electrochemical and fluorescent properties of homo- and hetero-polynuclear transition metal(II) complexes

摘要

Rare homo- and hetero-polynuclear transition metal(II) complexes, [{Cu(L-1)}(2)] (1) and [Cu(L-2)Ni-2(CH3OH)(2)] (2), were prepared and structurally characterized. Complex 1 possesses an uncommon dinuclear structure bonded by two alkoxy bridges, and all the Cu(II) atoms are tetra-coordinated with slightly distorted square planar geometries. The Cu1Cu2 bond distance is 2.994(3) angstrom. Complex 2 exhibits an unexpected trinuclear heterobimetallic structure from two chelating (L-2)(3-) units in crossover mode, which is the first heterobimetallic 3d-3d salamo-type transition metal complex. The two Ni(II) atoms are penta-coordinated with slightly distorted square pyramidal geometries (tau = 0.269 (Ni1) and 0.498 (Ni2)), and the Cu(II) atom is tetra-coordinated with a slightly distorted square planar geometry. Moreover, fluorescence behaviors of 1 and 2 were investigated, and electrochemical study reveals that the electrolytic redox reactions of 1 are irreversible processes.