Synthesis, crystal structure, and magnetic properties of two cyano-bridged bimetallic 4f-3d arrays with one-dimensional chain and two-dimensional brick wall molecular structures

The design, synthesis, and structural and magnetic properties of the two new bimetallic complexes [Sm(DMF)(4)-(H2O)(2)Cr(CN)(6)].H2O and [Sm(DMF)(2)(H2O)(3)Cr(CN)(6)].H2O (DMF = N,N-dimethylformamide) are presented. [Sm(DMF)(4)(H2O)(2)Cr(CN)(6)].H2O was prepared by the reaction between Sm3+ and [Cr(CN)(6)](3-) in a methanol-DMF solution, while [Sm(DMF)(2)(H2O)(3)Cr(CN)(6)].H2O was prepared by the reaction between Sm3+, DMF, and [Cr(CN)(6)](3-) in the molar ratio of 1:2:1 in H2O. [Sm(DMF)(4)(H2O)(2)Cr(CN)(6)].H2O crystallizes in the monoclinic space group of P2(1)/c with a = 13.161(3) Angstrom, b = 12.928(3) Angstrom, c = 19.174(4) Angstrom, beta = 109.82(3)degrees, and Z = 4, while [Sm(DMF)(2)(H2O)(3)Cr(CN)(6)].H2O is in the triclinic space group P (1) over bar with a = 7.7535(1) Angstrom, b = 9.4307(3) Angstrom, c = 16.2905(5) Angstrom, alpha = 94.1590(14)degrees, beta = 100.0597(18)degrees, gamma = 100.9154(18)degrees, and Z = 2. The. structure of [Sm(DMF)(4)(H2O)(2)Cr(CN)(6)].H2O possesses a cyano-bridged one-dimensional (1D) zigzag chain structure with alternating Sm(DMF)(4)(H2O)(2) and Cr(CN)(6) moieties. [Sm(DMF)(2)(H2O)(3)Cr(CN)(6)].H2O consists of cyano-bridged neutral brick wall-like layers in which each [Cr(CN)(6)](3-) unit uses three cyanide groups in the meridional. arrangement to connect with three [Sm(DMF)(2)(H2O)(3)](3+) units. Each [Sm(DMF)(2)(H2O)(3)](3+) unit, in turn, links three [Cr(CN)(6)](3-), generating a flat brick wall-like structure. Magnetic studies on [Sm(DMF)(2)(H2O)(3)Cr(CN)(6)].H2O showed a magnetic-phase transition temperature below 4.2 K and a coercive field of 100 Oe at 1.85 K, while no long-range magnetic ordering was observed in the 1D complex [Sm(DMF)(4)(H2O)(2)Cr(CN)(6)].H2O.