Structure and magnetism of heptanuclear complex encapsulated the octacyanomolybdate(IV) core

A new heptanuclear complex [{Cu(TPA)CN}6Mo(CN)2][ClO4]8 (1) (TPA = tris(2-pyridylmethyl)amine) was formed by the reaction of [Cu(TPA)]2 + cations and K4Mo(CN)8. The octacyanomolybdate core is encapsulated by six mononuclear copper cations via cyano bridges. 1 Crystallizes in monoclinic space group P21/n with a = 22.30(2) Å, b = 27.13(3) Å, c = 24.35(2) Å, β = 94.10(2)°, and Z = 4. Variable temperature magnetic measurements have demonstrated that very weak antimagnetic interaction between the nearest paramagnetic CuII centers at low temperature is exhibited, transferred by ―NC―Mo―CN― bridging units.