Inorganic Chemistry, Vol.45, No.19, 7821-7827, 2006
Synthesis, crystal structures, and magnetic properties of cyano-bridged honeycomblike layers M-V-Cu-II (M = Mo, W) chelated by a macrocyclic ligand
Two cyano-bridged Cu-II-M-V [M = Mo (2), W (3)] complexes formed by self-assembly of octacyanometalates [M(CN)(8)](3)-(M = Mo, W) with a new molecular precursor [Cu(L2)](2+) (1) (L2 = a macrocyclic ligand) in a 2: 3 ratio have been investigated in terms of structures and magnetic behaviors. The M2Cu3 repeating unit of both bimetallic compounds is extended to a two-dimensional honeycomblike layered structure. The pendant ethyl groups on L2 noticeably influence the structural parameters around the Cu center. Compared with the system composed of a macrocycle without a side group, Cu-N-ax (ax = axial) distances become shorter and the Cu-N-ax-C-ax angles are more bent for 2 and 3. The magnetic data denote that the Cu(II) and M(V) spins undergo explicit ferromagnetic interactions via CN bridges. From a structural and magnetic point of view, given that the Cu-N-ax bond length in the tetragonally distorted octahedral Cu(II) environment is long enough, the overall ferromagnetic character remains despite the variation of Cu-N-ax-C-ax angle in this system.