Binuclear Nickel(II) and Cobalt(III) Complexes with Dissimilar Bridges: Synthesis, Spectroscopy, Crystal Structure, and Magnetism

Abstract

AbstractTwo novel binuclear nickel(II) and cobalt(III) complexes with two or three dissimilar bridges, [Ni2(tacn)2(μ‐N3)2(μ‐O2CPh)](ClO4)⋅H2O (1) and [Co2(tacn)2(μ‐N3)(μ‐OH)(μ‐O2CPh)](ClO4)3 (2) (tacn=1,4,7‐triazacyclononane), were synthesized and structurally as well as magnetically characterized. Both compounds have a discrete binuclear structure, bridged by two N3− ions and one carboxylato group of the benzoate ion for 1 and one N3− ion, one carboxylato group of the benzoate ion, and one hydroxy group for 2; the macrocyclic ligand tacn acts as terminal ligand. The magnetic data of compound 1 were analyzed by means of Ĥ = −2JŜ1Ŝ2−D(Ŝ12+Ŝ22), leading to J = 19.6 cm−1, g=2.07, D = 4.01 cm−1, and zJ′ = $\rm{-}$0.32 cm−1. The ferromagnetic interaction is discussed on the basis of the structural features.