Cyano-bridged gadolinium-tungstate bimetallic one-dimensional chains with a dimethylacetamide ligand

Reaction of Gd-III(NO)(3 center dot)6H(2)O and (Bu3NH)(3)[W-V(CN)(8)] (Bu3N=tributylamine) in N,N-dimethylacetamide (DMA) yielded two types of Gd - W bimetal assemblies with noncentrosymmetric crystal structures: Gd-III(DMA)(n)-[W-V(CN)(8)] (n=6, 1; n=5, 2). X-ray single crystal analyses showed that 1 crystallizes in the monoclinic system of the Cc space group (a=12.6254(6) angstrom, b=16.8052(8) angstrom, c=20.2499(11) angstrom, beta=103.2893(18)degrees, Z=4), and 2 crystallizes in the monoclinic system of the P2(1) space group (a=9.761(2) angstrom, b=19.573(5) angstrom, c=10.502(4) angstrom, beta=109.247(12)degrees, Z=2). These two crystals consist of one-dimensional linear chains, in which [Gd-III(DMA)(n)](3+) and [W-V(CN)(8)](3-) ions are linked in an alternating fashion. The difference between these two compounds, that is, 1 contains eight-coordinate Gd-III whereas 2 contains seven-coordinate Gd-III, is due to the temperature during preparation. Magnetic data showed that the magnetic interaction between Gd-III (S=7/2) and W-V (S=1/2) is antiferromagnetic coupling of -0.28(1)cm(-1) for 1 and -0.42(1) cm(-1) for 2.