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

Abstract

Rare homo-and hetero-polynuclear transition metal(II) complexes, [{Cu(L 1 )} 2 ](1) and [Cu(L 2 )Ni 2 (CH 3 OH) 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 Cu1─Cu2 bond distance is 2.994(3) Å.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 pentacoordinated with slightly distorted square pyramidal geometries (τ = 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.