Solvatomorphs of dimeric transition metal complexes based on the V4O12 cyclic anion as building block: Crystalline packing and magnetic properties

Dinuclear [{M(phen)2}2V4O12] · C6H12O · H2O (MII = Co, Mn, Ni and Cu) and [{Cu(phen)2}2V4O12] · 3.5H2O has been prepared. All five structures exhibit the {V4O12}4− cluster in a chair-like configuration, covalently bonded to two [M(phen)2]2+ fragments, producing a superexchange magnetic phenomenon. The magnetic study of the complexes shows that they are very weak antiferromagnetically coupled systems, with −J cm−1 values of 0.14, Mn; 0.64, Ni; 0.23, Cu.