SYNTHESIS AND MOLECULAR-STRUCTURES OF 6-COORDINATE STANNABICYCLOOCTANES, ROOCCH2CH2SN(S2CNME2)(XCH2CH2)2Y (X = O, S, Y = O, S, NME)

Abstract

New hexacoordinate stannabicyclooctanes ROOCCH2CH2Sn(L)(XCH2CH2)2Y (1 R = Me, L = Me2NCS2, X = S, Y = O; 2 R = Me, L = Cl, X = S, Y = O; 3 R = Me, L = Me2NCS2, X = S, Y = S; 4 R = Me, L = Me2NCS2, X = O, Y = NMe; 5 R = Et, L = Me2NCS2, X = O, Y = NMe) have been prepared and characterized. The molecular structures of the representative compounds 1 and 5 were determined by X-ray analysis. 1 crystallizes in the triclinic space group P1BAR (Z = 2) with a = 10.514 (2) angstrom, b = 11.617 (2) angstrom, c = 8.071 (2) angstrom, alpha = 107.23 (2)-degrees, beta = 108.12 (2)-degrees, gamma = 91.51 (2)-degrees, and V = 887.2 (5) angstrom 3. The structure was refined to R = 0.026. 5 crystallizes in the monoclinic space group Pnma (Z = 4) with a = 15.080 (2) angstrom, b = 9.765 (1) angstrom, c = 13.120 (2) angstrom, and V = 1932.0 (6) angstrom 3. The structure was refined to R = 0.045. Hexacoordination around the tin atom is achieved by a Sn-Y transannular dative bond (Sn-O, 2.615 (2) angstrom for 1; Sn-N, 2.322 (7) angstrom for 5) and a chelating dithiocarbamate in both structures. For 1, however, unusually unsymmetrical chelation of the dithiocarbamate ligand (Sn-S(1), 3.094 (1) angstrom; Sn-S(2), 2.492 (1) angstrom) resulted in a highly distorted octahedral arrangement in contrast to the isobidentate chelation of the dithiocarbamate ligand in 5. The IR and H-1 and Sn-119 NMR data have shown that 3 and 4 have the structures similar to those of 1 and 5, respectively, both in the solid state and in solution and that their coordinate structures are retained in solution.