Cyanide-Bridged Lanthanide(Iii)-Transition Metal Extended Arrays: Interconversion Of One-Dimensional Arrays From Single-Strand (Type A) To Double-Strand (Type B) Structures. Complexes Of A New Type Of Single-Strand Array (Type C)

A series of one-dimensional arrays of lanthanide-transition metal complexes has been prepared and characterized. These complexes, {(DMF) (10)Ln(2)[Ni(CN)(4)](3)}(infinity) crystallize as linear single-strand arrays (structural type A) (Ln = Sm, 1a; Eu, 2a) or double-strand arrays (structural type B) (Ln = Sm, 1b; Eu, 2b) depending upon the conditions chosen, and they are interconvertible. The single-strand type 4 structure can be converted to the double-strand type B structure. When the Ib and 2b type B crystals are completely dissolved in DMF, their infrared spectra are identical to the infrared spectra of la and 2a type A crystals dissolved in DMF. These solutions produce type A crystals initially. It is believed that formation of the,type A structure is kinetically favored while the type B structure is thermodynamically favored for lanthanide-nickel complexes 1 and 2. On the other hand the complex {(DMF) Y-10(2)[Pd(CN)(4)](3)}(infinity), 3, appears to crystallize only as the double-strand array (type B). The complexes ((DMF) Ce-12(2)[Ni(CN)(4)](3)}(infinity), 4, and {(DMF)(12)Ce-2[Pd(CN)(4)](3)}(infinity), 5, crystallize as a new type of single-strand array (structural type C). This structural type is a zigzag chain array. Crystal data for la: triclinic space group P1, a = 10.442(5) Angstrom, b = 10.923(2) Angstrom, c = 15.168(3) Angstrom, alpha = 74.02(2)degrees, beta = 83.81(3)degrees, gamma = 82.91(4)degrees, Z = 2. Crystal data for 1b: triclinic space group P (1) over bar, a = 9.129(2) Angstrom, b = 11.286(6) Angstrom, c = 16.276(7) Angstrom, alpha = 81.40(4)degrees, beta = 77.41(3)degrees, gamma = 83.02(3)degrees, Z = 2. Crystal data fur 2a: triclinic space group P (1) over bar, a 10.467(1) Angstrom, b = 10.923(1) Angstrom, c = 15.123(1) Angstrom, alpha = 74.24(1)degrees, beta = 83.61(1)degrees, gamma 83.13(1)degrees, Z = 2. Crystal data for 2b: triclinic space group P (1) over bar, a 9.128(1) Angstrom, b = 11.271(1)Angstrom, c = 16.227(6) Angstrom, alpha = 81.46(2)degrees, beta = 77.43(2)degrees, gamma = 82.99(1)degrees Z = 2. Crystal data for 3: triclinic space group P (1) over bar, a = 9.251(3) Angstrom, b = 11.193(4) Angstrom, c 16.388(4) Angstrom, or 81.46(2)degrees, beta = 77.18(2)degrees, gamma = 83.24(3)degrees, Z = 2. Crystal data for 4: triclinic space group P (1) over bar, a = 11.279(1) Angstrom, b = 12.504(1) Angstrom, c = 13.887(1) Angstrom, alpha = 98.68(1)degrees, beta = 108.85(1)degrees, gamma = 101.75(1)degrees Z = 2. Crystal data for 5: triclinic space group P (1) over bar, a = 11.388(3) Angstrom, b = 12.614(5) Angstrom, c = 13.965(4) Angstrom, alpha = 97.67(3)degrees, beta = 109.01(2)degrees, gamma = 101.93(2)degrees Z = 2.