Azido, Cyanato, and Thiocyanato Coordination Induced Distortions in Pentacoordinated [CoIIA(bip)]2 (A = NCS–, N3–, or NCO–) Complexes
Résumé
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 ions are 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 fitted to an isotropic Heisenberg dimer model that allowed estimation of the antiferromagnetic interactions for 1–3.