STRUCTURES OF [NB2CL6(C4H8S)(PET3)2], [NB2CL6(C4H8S)(C4H8O)2] AND [TA2CL6(C4H8S)(PME3)2]

Di-mu-chloro-tetrachlorobis(tetrahydrothiophenato)(triethylphosphino)diniobium(III), [Nb2Cl6(C4H8S)(PEt3)2], di-mu-chloro-tetrachlorobis(tetrahydrofuranato)tetrahydrothiophenatodiniobium(III), [Nb2Cl6(C4H8S)(C4H8O)2] and di-mu-chloro-tetrachlorobistetrahydrothiophenato(trimethylphosphino)ditantalum(III), [Ta2Cl6(C4H8S)(PMe3)2] crystallized in two crystal phases. These molecules are confacial bioctahedra with two bridging Cl atoms and one C4H8S molecule. (I) [Nb2Cl6(C4H8S)(PEt3)2], M(r) = 723.02, orthorhombic, P2(1)2(1)2(1), a = 9.512 (2), b = 14.171 (3), c = 21.948 (5) angstrom, V = 2958 (1) angstrom 3, Z = 4, D(x) = 1.623 g cm-3, lambda(Mo K-alpha) = 0.71069 angstrom, mu = 14.7 cm-1, F(000) = 1456, T = 294 K, R = 0.0471, 2153 unique observed reflections with I > 3-sigma(I). The Nb-Nb distance is 2.718 (1) angstrom. The Nb-Cl(bridge) distances range from 2.496 (3) to 2.530 (3) angstrom and Nb-S distances are 2.456 (3) and 2.461 (3) angstrom. The range of Nb-Cl(terminal) distances is 2.392 (4) to 2.406 (3) angstrom. The Nb-P distances are 2.678 (4) and 2.675 (3) angstrom. (II) [Nb2Cl6(C4H8S)(C4H8O)2], M(r) = 630.91, monoclinic, C2/c, a = 13.367 (4), b = 10.642 (4), c = 15.317 (5) angstrom, beta = 93.71-degrees, V = 2174 (1) angstrom 3, Z = 4, D(x) = 1.927 g cm-3, lambda(Mo K-alpha) = 0.71069 angstrom, mu = 18.5 cm-1, F(000) = 1248, T = 294 K, R = 0.0557, 1026 unique observed reflections with I > 3-sigma(I). The Nb-Nb distance is 2.684 (2) angstrom. The Nb-Cl(bridge) distances are 2.495 (4) and 2.497 (4) angstrom and the Nb-S distance is 2.401 (1) angstrom. The Nb-Cl(terminal) distances are 2.372 (4) and 2.406 (3) angstrom. The Nb-O distance is 2.401 (4) angstrom. (IIIa) [Ta2Cl6(C4H8S)(PMe3)2], M(r) = 814.94, triclinic, P1BAR, a = 10.615 (4), b = 12.189 (2), c = 10.529 (2) angstrom, alpha = 102.35 (2), beta = 117.91 (3), gamma = 87.86 (2)-degrees, V = 1173 (1) angstrom 3, Z = 2, D(x) = 2.307 g cm-3, lambda(Mo K-alpha) = 0.71069 angstrom, mu = 101 cm-1, F(000) = 760, T = 294 K, R = 0.0692, 3263 unique reflections with I > 3-sigma(I), (IIIb) [Ta2Cl6(C4H8S)(PMe3)2], triclinic, P1BAR, a = 10.412 (1), b = 10.569 (2), c = 23.763 (6) angstrom, alpha = 88.04 (2), beta = 87.17 (2), gamma = 64.52 (1)-degrees, V = 2357.6 (9) angstrom 3, Z = 4, D(x) = 2.296 g cm-3, lambda(Mo K-alpha) = 0.71069 angstrom, mu = 101 cm-1, F(000) = 1520, T = 294 K, R = 0.0692, 5549 unique observed reflections with I > 3-sigma(I). For these two crystal phases the average bond distances for Ta-Ta, Ta-S, Ta-Cl(bridge), Ta-Cl(terminal) and Ta-P bonds are 2.682 (3), 2.422 (6), 2.502 (13), 2.375 (9) and 2.623 (8) angstrom, respectively.