Azido, Cyanato, and Thiocyanato Coordination Induced Distortions in Pentacoordinated [Co II A(bip)] 2 (A = NCS – , N 3 – , or NCO – ) Complexes

A new family of distorted pentacoordinate [Co 2 ] complexes was prepared and structurally characterized. In [Co II A(bip)] 2 · S ( 1 – 3 ) [A = NCS – , N 3 – , 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 Co II 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 . Co II 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 . (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)