Organometallic nickel(II) complexes with substituted benzonitrile ligands. Synthesis, electrochemical studies and non-linear optical properties. The X-ray crystal structure of [Ni(¿5-C5H5){P(C6H5)3}(NCC6H4NH2)][PF6]

Abstract

A new family of organometallic Ni II benzonitrile derivatives bearing strong donor substituents of general formula Ni - C H P C H NCC H R PF R NH , N CH , C H , OCH , H, F has been synthesized. A structural study by X-ray 5 5 6 5 3 6 4 6 2 3 2 6 5 3 diffraction of the compound with R NH showed crystallization on the centrosymmetric monoclinic space group, P2 n, with a quasi 2 1 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 Hu¨ckel method found a small amount of delocalization due to the cancelling effects on the interaction of the metal fragment orbitals with and nitrile orbitals.