Cyanido-bridged bimetallic two-dimensional network based on dinuclear manganese(III) Schiff base complex and hexacyanochromate(III) building block

摘要

Reaction between the dimeric [Mn2(saltmen)2(H2O)2]~(2+) cations (with saltmen=N,N'-(1,1,2,2-tetramethylethylene)bis(sali-cylideneiminato) dianion) and [Cr(CN)6]~(3-) anions results in the isolation of a 2D layered complex, [{Mn(salt-men)}4Cr(CN)6]ClO4 (1), whose crystal structure has been determined and presents pentameric cyanido-bridged CrMn4 units assembled into extended layers through saltmen phenoxo Mn—Mn bridges. Detailed magnetic measurements and their analysis show that the layers have a ferrimagnetic organization with antiferromagnetic exchange coupling (J/k_B = —7(1) K) between Mn(III) and Cr(III) ions through cyanide bridges and ferromagnetic interaction between Mn(III) ions through phenoxo bridges. Compound 1 displays a glassy ferrimagnetic ordering with T_C = 5 K. Magneto-structural discussions for 1 and three similar 2D systems are developed that explain the antiferromagnetic coupling observed in the cyanido-bridged Mn(III)-Cr(III) cases.