Molybdenum-copper-sulfur Mo3CuS4 cubes

Reaction of the incomplete cubane-type cluster[Mo3S4(H2O)(9)](4+) (1) with CuCl in 2 M HCl gives a novel cubane-type cluster [M3CuS4Cl(H2O)(9)](4+) (2). The nitrilotriacetato complex [Mo3CuS4Cl(Hnta)(3)](2-) (3), the derivative of 2, has been prepared. The crystallographic results obtained were as follows: K-2[Mo3CuS4Cl(Hnta)(3)]. 9H(2)O (3a), triclinic, P1, a=10.634(1), b=11.032(2), c = 10.299(4) Angstrom, alpha = 112.34(2), beta = 98.76(2), gamma = 81.91(1)degrees, V= 1100.3(4) Angstrom(3), Z = 1, R = 5.7%; (NH4)(2)[Mo3CuS4Cl(Hnta)(3)]. 9H(2)O (3b), triclinic, P1, a = 10.714(1), b = 11.121(1), c = 10.379(3) Angstrom, alpha = 112.07(1), beta = 99.375(8), gamma = 81.168(7)degrees, V= 1124.9(4) Angstrom(3), Z= 1, R = 8.3%; (NH4)(2)[Mo3CuS4Cl(Hnta)]. 9H(2)O (3c) trigonal, R3m, a = 16.332(2), c = 14.301(2) Angstrom, V= 3303.5(4) Angstrom(3), Z= 3, R = 4.2%. Binding energies of Cu 2p(3/2), Cu 2p(1/2), Mo 3d(5/2) and Mo 3d(3/2), from X-ray photoelectron spectroscopy measurements are 933.35, 953.26, 230.07 and 233.24 eV for 3a, 933.47, 953.25, 230.18 and 233.31 eV for 3b, respectively (C-18 = 285.0 eV). The binding-energy values of Cu 2p(3/2) for 3a and 3b and the absence of satellites indicate the Cu(I) oxidation state in the respective clusters. The comparison of [Mo3CuS4Cl(H2O)(9)](4+) (2) in hydrochloric acid with [Mo3CuS4(H2O)(10)](5+) (2) in Hpts reveals that the coordination of chloride ion to copper atom increases very much the stability of 2 in hydrochloric acid solution. Air oxidation of [Mo3CuS4Cl(H2O)(9)](3+) (4) and [Mo3CuS4(H2O)(10)](4+) (5) and the reaction and reaction products of [Mo3FeS4(H2O)(10)](4+) (5) with Cu(II) ion will be discussed. (C) 2000 Elsevier Science S.A. All rights reserved.