The heterobimetallic one-dimensional arrays {(DMF)(4)EuNi(CN)(4)}(infinity) and {(DMF)(4)EuPt(CN)(4)}(infinity) were prepared from the metathesis of (NH3)(x)EuCl2 with K2Ni(CN)(4) and K2Pt(CN)(4), respectively, in DMF. The analogous reaction between (NH3)(x)YbCl2 and K2Ni(CN)(4) in DMF or DMA resulted in oxidation of Yb2+ and reduction of Ni(CN)(4)(2-) to give the previously reported dinuclear Ni(I) anion Ni-2(CN)(6)(4-). Single-crystal X-ray diffraction analysis revealed that {(DMF)(4)EuNi(CN)(4)}(infinity) and {(DMF)(4)EuPt(CN)(4)}(infinity) form isostructural one-dimensional "ladder" arrays through isocyanide linkages (Eu-NC-M). Crystal data for ((DMF)4EuNi(CN)4), : triclinic space group P (1) over bar, a = 8.902(2) Angstrom, b = 10.947(2) Angstrom, c = 12.464(4) Angstrom, alpha = 82.99(2)degrees, beta = 86.86(2)degrees, gamma = 84.92(2)degrees, Z = 2. Crystal data for {(DMF)(4)EuPt(CN)(4)}(infinity) : triclinic space group P (1) over bar, a = 8.918(1) Angstrom, b = 11.160(2) Angstrom, c = 12.480(2) Angstrom, alpha = 83.27(2)degrees, beta = 86.84(1)degrees, gamma = 83.71(2)degrees, Z = 2. Electrical conductance measurements and infrared spectra of DMF solutions of these one-dimensional arrays revealed that solvent-separated ion pairs are predominant in solution.