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

Reaction of Gd^III(NO)₃·6H₂O 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) Å, b = 16.8052(8) Å, c = 20.2499(11) Å β = 103.2893(08)°, Z = 4), and 2 crystallizes in the monoclinic system of the P2₁ space group (a = 9.761(2) Å, b = 19.573(5) Å, c = 10.502(4) Å, β = 109.247(12)°, 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(l)cm ^-1 for 2.