Organometallic nickel(II) complexes with substituted benzonitrile ligands. Synthesis, electrochemical studies and non-linear optical properties. The X-ray crystal structure of [Ni( η5-C 5H 5){P(C 6H 5) 3}(NCC 6H 4NH 2)][PF 6

Abstract

A new family of organometallic Ni(II) benzonitrile derivatives bearing strong donor substituents of general formula [Ni( η 5-C 5H 5){P(C 6H 5) 3}NCC 6H 4R][PF 6] (R=NH 2, N(CH 3) 2, C 6H 5, OCH 3, H, F) has been synthesized. A structural study by X-ray diffraction of the compound with R=NH 2 showed crystallization on the centrosymmetric monoclinic space group, P2 1/ n, with a quasi planar structure of the coordinated nitrile. First and second hyperpolarizabilities evaluated by hyper-Rayleigh scattering and Maker fringe techniques showed essentially the same values for the complexes and the uncoordinated chromophores. Theoretical studies by the extended Hückel method found a small amount of π delocalization due to the cancelling effects on the interaction of the metal fragment orbitals with π and π * nitrile orbitals.