Synthesis, Structure, and Magnetic Properties of a Dinuclear Antiferromagnetically Coupled Cobalt Complex

A new dinuclear cobalt(II) compound,[(TPA*)CoII(DHBQ2)CoII(TPA*)]2+ (12+) {TPA* =tris[(3, 5-dimethyl-pyrazol-l-yl)methyl] amine, DHBQ = deprotonated 2, 5-dihydroxy-1, 4-benzoquinone}, was prepared and structurally and magnetically characterized. X-ray crystallography revealed the centrosymmetric dinuclear divalent cobalt ions bridged by DHBQ2 unit. The cobalt ions in the title compound have a distorted octahedral arrangement by coordination with four nitrogens of a TPA* and two oxygens of a bridging DHBQ unit. Due to the interdimer offset face-to-face pp stacking in the crystallographic ac plane, the complex shows extended 2D supramolecular structure. Magnetic experiments showed the cobalt-based dinuclear compound exhibits antiferromagnetic interactions with g = 2.35 and J/kB = 2.76 K, respectively.