Strong ferromagnetic metal–ligand exchange in a nickel bis(3,5-dipyridylverdazyl) complex

Abstract

A new 1,5-dipyridyl verdazyl, synthesized from the corresponding dipyridyl hydrazone, coordinates nickel(II) to form a structurally characterized, pseudooctahedral complex analogous to Ni(terpy)₂²⁺. The unusually short Ni–verdazyl distance results in strong ferromagnetic exchange (J_Ni–rad = +300, J_rad–rad = +160 cm⁻¹) between all three paramagnetic species along with a metal–ligand charge transfer band in the electronic spectrum.