Doubly phenoxo-bridged M-Na (M = Cu(II), Ni(II)) complexes of tetradentate Schiff base: Structure, photoluminescence, EPR, electrochemical studies and DFT computation

Abstract

Phenoxo-bridged complexes [M(mu-L)Na(ClO4)(CH3OH)] (M = Cu(II) (1) and Ni(II) (2)) (H2L = N,N'-bis(3-methoxysalicylidenimino)-1,3-diaminopropane, C6H3(OMe)(OH)-CH = N-(CH2)(3)-N = CH-C6H3(OMe)(OH)) are structurally characterised by single-crystal X-ray diffraction study. M(II) appears in the square-plane geometry with MN2O2 coordination sphere, while the sodium ion exists with NaO6 distorted octahedral environment. The molecules pack in the solid-state forming three-dimensional arrays through C-H---O, O-H---O, C-H---pi, and pi---pi interactions. The spectral and redox properties are theoretically explained by DFT computation of optimised geometry of the complexes.