Monomeric alkyne-stabilized copper(I) halide and copper(I) pseudohalide compounds - Crystal structure of [(eta(5)-C(5)H(4)SiMe(3))(2)Ti(C CPh)(2)]CuCl

The reaction of Me(3)SiC=CSiMe(3) (1), L(n)MC=CSiMe(3) (4a, L(n)M = Cp(CO)(2)Fe; 4b, L(n)M = Cp(CO)(3)Mo] and E(C=CR)(2) (6, E = Me(2)Si; 8, E = (eta(5)-C(5)H(4)SiMe(3))(2)Ti; R is a singly bonded organic ligand) with CuX (2) (X is a halide or pseudohalide) is described. 1 and 4 react with CuX (2a, X = Cl; 2b, X = Br; 2c, X = I; 2d, X = OSO2CF3) to yield the dimeric compounds [(eta(2)-Me(3)SiC=CSiMe(3))CuX](2) (3a, X = Cl; 3b, X = Br; 3c, X = I; 3d, X = OSO2CF3) or [(eta(2)-L(n)MC=CSiMe(3))CuX](2) (5a, L(n)M = Cp(CO)(2)Fe, X = Cl; 5b, L(n)M = Cp(CO)(3)Mo, X = Cl) respectively. In these compounds the C-2 building block is eta(2)-coordinated to a CuX moiety and by the formation of copper-X-bridges (Cu(2)X2) a dimer is formed. However, the reaction of Me(2)Si(C=CSiMe(3))(C=CR) (6a, R = SiMe(3); 6b, R = H) with CuX (2) (X = Cl, Br, OSO2CF3, O(2)CMe) affords polymeric {Me(2)Si[(eta(2)-C=CSiMe(3))(eta(2)-C=CR)Cu(2)X(2)]}(n) (7a, R = SiMe(3), X = Cl; 7b, R = SiMe(3), X = Br; 7c, R = H, X = Cl; 7d, R = H, X = Br; 7e, R = SiMe(3), X = OSO2CF3; 7f, R = SiMe(3), X = O(2)CMe) in high yields. In 7a-7f each alkynyl fragment is eta(2)-coordinated to a CuX unit. While the reaction of 6a or 6b with CuX yields polymeric 7a-7f, the organometallic 1,4-diyne RC=C-[Ti]-C=CR ([Ti] = (eta(5)-C(5)H(4)SiMe(3))(2)Ti; 8a, R = Ph; 8b, R = SiMe(3)) affords with CuX (2a, X = Cl; 2b, X = Br; 2c, X = I; 2e, X = CN; 2f, X = SCN) the dinuclear compounds [(eta(5)-C(5)H(4)SiMe(3))(2)Ti(C=CR)(2)]CuX (9a, R = Ph, X = Cl; 9b, R = SiMe(3), X = Cl; 9c, R = SiMe(3), X = Br; 9d, R = SiMe(3), X = I; 9e, R = SiMe(3), X = CN; 9f, R = SiMe(3), X = SCN). Compounds 9a-9f feature a monomeric copper(I) halide or copper(I) pseudohalide moiety, which is stabilized by the chelating effect of the alkynyl ligands in [Ti](C=CR)(2). [(eta(5)-C(5)H(4)SiMe(3))(2)Ti(C=CSiMe(3))(2)]CuCl (9b) reacts with AgX (X = CN, SCN, O(2)CMe, O(2)CPh) to yield [(eta(5)-C(5)H(4)SiMe(3))(2)Ti(C=CSiMe(3))(2)]CuX (9e, X = CN; 9f, X = SCN; 9g, X = OC(O)Me; 9h, X = OC(O)Ph) by precipitation of AgCl. In addition, the bis(alkynyl)-ansa-titanocene [(eta(5)-C5H4)Me(2)Si(eta(5)-C(5)H(3)SiMe(3))]Ti(C=CSiMe(3))(2) (10) yields with CuCl (2a) the dinuclear species {[eta(5)-C5H4)Me(2)Si(eta(5)-C(5)H(3)SiMe(3))]Ti(C=CSiMe(3))(2)}CuCl (11). The identity of compounds 3, 5, 7, 9 and 11 is confirmed by analytical and spectroscopic (IR, MS, H-1, C-13 NMR) data, and that of [(eta(5)-C(5)H(4)SiMe(3))(2)Ti(C=CPh)(2)]CuCl (9a) is confirmed by X-ray analysis. Crystals of 9a are monoclinic, space group Pc with cell constant a = 992.6(7), b = 1210(1), c = 1335.5(7) pm, beta = 105. 75(5)degrees, V = 1543(2) x 10(6) pm(3) and Z = 2.