Influence of Electron-Attractor Substituents on the Magnetic Properties of Ni(II) String Complexes

Abstract

Density functional theory calculations carried out on the anionic Ni(II) chain complexes {trinickeltetrakis[2,6-bis(amido)pyridine]}2- and {trinickeltetrakis[N,N'-bis(sulfonyl)pyridyldiamido]}2- show that the electron-attractor character of the sulfonyl substituent modifies the basicity of the amido ligand ends so as to raise the electronic state of the underlying metal atom from low spin (S = 0) to high spin (S = 1). The computed elongation of the outermost Ni-N bonds with the grafting of SO2H substituents is in agreement with this interpretation.