Novel examples of high-dimensional mixed-valence copper cyanide complexes

Abstract

The first examples of high-dimensional mixed-valence homometallic cyano-bridged copper complexes were synthesized and characterized: net-structured [Cu(CN)(4){Cu(cyclam)}(1,5)](2n)(H2O)(5n) (1), ladder-type double-chainstructured [Cu(CN)(2){Cu(CN)(2)Cu(cyclam)}],(H2O), (2), layer-structured [{Cu(CN)(2)}(2)Cu(cycalm)](n) (3), and hydrogen-bond-based 2-D [Cu(CN)(3)Cu(cyclam)](n)(CH3OH)(n) (4) (cyclam = 1,4,8,11-tetraazacyclotetradecane). 1 crystallizes in triclinic space group P1 with a = 8.3589(11) angstrom, b = 13.478(2) angstrom, c = 14.828(2) angstrom, alpha = 66.895(2)degrees, beta = 77.916(3)degrees, gamma = 85.939(3)degrees, and Z = 1; 2 crystallizes in triclinic space group P1 with a = 8.2305(12) angstrom, b = 9.8861(15) angstrom, c = 13.219(2) angstrom, alpha = 84.863(3)degrees, beta = 75.744(3)degrees, gamma = 89.818(3)degrees, and Z = 2; 3 crystallizes in monoclinic space group P2(1)/c with a = 6.830(2) angstrom, b = 8.482(2) angstrom, c = 17.306(4) angstrom, beta = 98.144(4)degrees, and Z = 2; 4 crystallizes in triclinic space group P1 with a = 9.470(1) angstrom, b = 10.034(1) angstrom, c = 12.064(1) angstrom, alpha = 67.325(2), beta = 75.593(2), gamma = 70.672(2), and Z = 2. The coordination sphere of Cu-I sites in the complexes shows diverse structures: tetrahedral [CuC4] for 1, tetrahedral [CuC3N] and triangular [CuC2N] for 2, triangular [CuC2N] for 3, and triangular [CuC3] for 4. In particular, 1 constitutes the first example of a structurally characterized system containing a bridging tetrahedral [Cu(CN)4](3-) unit. The diverse structural nature of these complexes is governed by the capping amines and the content of water in the reaction media. The magnetic interactions are negligible in these mixed-valence complexes.