Heterometallic One-Dimensional Arrays Containing Cyanide-Bridged Lanthanide(III) and Transition Metals

One-dimensional arrays having the general formula {(DMF)(10)Ln(2)[M(CN)(4)](3)}(infinity) [Ln = Sm, Eu, Er, Yb and M = Ni, Pd, Pt] were prepared from the reactions of 2:3 molar ratios of LnCl(3) with K(2)[M(CN)(4)] in DMF (DMF = N,N-dimethylformamide). Under similar conditions using 1:1 molar ratios of SmCl(3) and K(2)[Ni(CN)(4)] in DMF or YbCl(3) and K(2)[Ni(CN)(4)] in DMA (DMA = N,N-dimethylacetamide), the one-dimensional arrays {(DMF)(5)Sm[Ni(CN)(4)]Cl}(infinity), 8, and {(DMA)(4)Yb[Ni(CN)(4)]Cl}(infinity), 9, were prepared. An earlier study of {(DMF)(10)Yb[Ni(CN)(4)](3)}(infinity), 3, and {(DMF)(10)Yb(2)[Pt(CN)(4)](3)}(infinity), 7, showed that two different yet related one-dimensional arrays can be adopted. In the present study, X-ray crystal structures of {(DMF)(10)Sm(2)[Ni(CN)(4)](3)}(infinity), 1, and {(DMF)(10)Er(2)[Ni(CN)(4)](3)}(infinity), 2, are shown to be isomorphous with {(DMF)(10)Yb(2)[Ni(CN)(4)](3)}(infinity), 3, while {(DMF)(10)Sm(2)[Pd(CN)(4)](3)}(infinity), 4, {(DMF)(10)Eu(2)[Pd(CN)(4)](3)}(infinity), 5, and {(DMF)(10)Yb(2)[Pd(CN)(4)](3)}(infinity), 6, are isomorphous with {(DMF)(10)Yb(2)[Pt(CN)(4)](3)}(infinity), 7. Single-crystal X-ray crystal structure determinations reveal that arrays 1, 2, and 3 consist of cyanide-bridged "diamond"-shaped Ln(2)Ni(2) metal cores. These metal cores are linked together in an infinite array through cyanide bridges by [Ni(CN)(4)](2)(-) anions generating a single-strand chain. Crystal data for 1: triclinic space group P&onemacr;, a = 10.442(5) Å, b = 10.923(2) Å, c = 15.168(3) Å, alpha = 74.02(2) degrees, beta = 83.81(3) degrees, gamma = 82.91(2) degrees, Z = 2. Crystal data for 2: triclinic space group P&onemacr;, a = 10.172(1) Å, b = 11.111(3) Å, c = 15.369(2) Å, alpha = 73.17(2) degrees, beta = 85.15(1) degrees, gamma = 83.48(2) degrees, Z = 2. Arrays 4, 5, 6, and 7 consist of two parallel zigzag chains that are linked together through bridging [M(CN)(4)](2)(-) anions. Crystal data for 4: triclinic space group P&onemacr;, a = 9.304(2) Å, b = 11.351(3) Å, c = 16.257(5) Å, alpha = 81.62(2) degrees, beta = 77.51(2) degrees, gamma = 82.47(2) degrees, Z = 2. Crystal data for 5: triclinic space group P&onemacr;, a = 9.300(3) Å, b = 11.353(4) Å, c = 16.279(3) Å, alpha = 81.58(2) degrees, beta = 77.37(2) degrees, gamma = 81.58(2) degrees, Z = 2. Crystal data for 6: triclinic space group P&onemacr;, a = 9.164(2) Å, b = 11.718(3) Å, c = 16.122(3) Å, alpha = 79.88(2) degrees, beta = 74.43(2) degrees, gamma = 80.50(2) degrees, Z = 2. Electrical conductance, NMR, and infrared studies of DMF solutions of 1-7 reveal that these arrays are partially ionized in solution. Single-crystal X-ray analyses of the one-dimensional arrays 8 and 9 show that these complexes adopt the commonly observed zigzag chain structure. Crystal data for 8: monoclinic space group P2(1)/n, a =7.783(2) Å, b = 17.748(8) Å, c = 21.236(5) Å, beta = 92.87(2) degrees, Z = 4. Crystal data for 9: monoclinic space group P2(1)/n, a = 10.022(2) Å, b = 19.505(4) Å, c = 15.742(3) Å, beta = 105.94(2) degrees, Z = 4. Studies of 8 and 9 in DMF and DMA, respectively, indicate that 8 is partially ionized and 9 is almost completely ionized.