Synthesis, characterization, and magnetic properties of new binuclear CuIICuII bis(oxamato) complexes

Two new neutral, binuclear CuIICuII bis(oxamato) complexes with the formula [Cu2(opba)(pmdta)(MeOH)] · 1/2MeOH · dmf (3) and [Cu2(nabo)(pmdta)(MeOH)] (4), with opba = o-phenylene-bis(oxamato), nabo = 2,3-naphthalene-bis(oxamato), pmdta = N,N,N′,N″,N″-pentamethyldiethylenetriamine and dmf = dimethylformamide have been synthesized and their crystal structures have been determined. The structure of 3 consists of dimeric [Cu2(opba)(pmdta)(MeOH)] entities, joined together by mutual intermolecular Cu⋯O contacts of the Cu2+ ion of one [Cu(opba)]2− complex fragment and one carboxylate atom of the oxamato group of a second [Cu(opba)]2− complex fragment. The structure of 4 consists of neutral binuclear complexes joined together by hydrogen bonds and π–π interactions, giving rise to an unique supramolecular 1D-chain. The magnetic properties of 3 and 4 were studied by susceptibility measurements versus temperature. For the intramolecular J parameter, identical values of (−114 ± 2) cm−1 (3) and (−112 ± 2) cm−1 (4) were obtained.