Azido, Cyanato, and Thiocyanato Coordination Induced Distortions in Pentacoordinated [CoII A(bip)]2 (A = NCS–,N3–, or NCO–) Complexes

Abstract

A new family of distorted pentacoordinate [Co2] complexes was prepared and structurally characterized. In [CoIIA-(bip)]2·S(1–3)[A=NCS–,N3–, NCO–; S = dmf, MeOH, dcm; Hbip = 2,6-bis(phenylmethyliminomethyl)-4-methylphenol], the nonbonded Co···Co separations are in the 3.243 to 3.254 Å range, and the pseudohalide-coordinated CoII ionsare asymmetrically doubly bridged by the phenolate oxygen atoms of the ligand. The complementary basal–apical (b–a) and apical–basal (a–b) coordination modes of the phenolate bridges of bip–offer one O and two N donors for metal-ion coordination. In the three dinuclear complexes, the h.s.CoII ions are coupled antiferromagnetically to yield a singlet ground state. The solid-state variable-temperature magnetic susceptibility measurement data on the complexes were fit- ted to an isotropic Heisenberg dimer model that allowed esti- mation of the antiferromagnetic interactions for 1–3