Synthesis and Spectroscopic Characterization of Pyrrolidyl and Piperidyl Dithioformate Derivatives of Dimethyltellurium(IV) Compounds. Crystal Structures of Me(2)Te[S(2)CN(CH(2))(3)CH(2)](2), Me(2)Te[S(2)CN(CH(2))(4)CH(2)](2), Me(2)Te{[S(2)CN(CH(2))(3)CH(2)][S(2)CN(CH(2))(4)CH(2)]}, Me(2)TeCl[S(2)CN(CH(2))(3)CH(2)], Me(2)TeBr[S(2)CN(CH(2))(3)CH(2)], Me(2)TeI[S(2)CN(CH(2))(3)CH(2)], Me(2)TeCl[S(2)CN(CH(2))(4)CH(2)], and Me(2)TeI[S(2)CN(CH(2))(4)CH(2)].

Dimethylbis(pyrrolidyl and piperidyl dithioformato)tellurium(IV) compounds and the corresponding halodimethyl compounds, Me(2)TeX[S(2)CN(CH(2))(n)()CH(2)], where n = 3, 4 and X = Cl, Br, and I, have been prepared. The compounds were characterized by elemental analysis and IR, Raman, and multinuclear NMR spectroscopies, including some variable temperature studies. The following crystallize as monoclinic in space group P2(1)/c (No. 14). Me(2)Te[S(2)CN(CH(2))(3)CH(2)](2) (1): a = 6.38(1) Å, b = 18.902(7) Å, c = 14.672(6) Å, beta = 97.73(6) degrees V = 1752(2) Å(3), Z = 4, R = 0.0636, R(w) = 0.0642. Me(2)Te{[S(2)CN(CH(2))(3)CH(2)][S(2)CN(CH(2))(4)(CH(2))]} (3): a = 6.55(1) Å, b = 19.716(6) Å, c = 14.900(9) Å, beta = 95.27(8) degrees, V = 1928(3) Å(3), Z = 4, R = 0.0618, R(w) = 0.0511. Me(2)TeCl[S(2)CN(CH(2))(3)CH(2)] (4): a = 9.952(3) Å, b = 6.386(3) Å, c = 18.834(3) Å, beta = 95.32(2) degrees, V = 1191.7(6) Å(3), Z = 4, R = 0.0358, R(w) = 0.0314. Me(2)TeBr[S(2)CN(CH(2))(3)CH(2)] (5): a = 10.085(4) Å, b = 6.446(4) Å, c = 19.020(5) Å, beta = 95.08(3) degrees, V = 1231.7(8) Å(3), Z = 4, R = 0.0559, R(w) = 0.0469. Me(2)TeCl[S(2)CN(CH(2))(4)CH(2)] (7) is P2(1)/a (No. 14) with a = 9.756(2) Å, b = 11.242(2) Å, c = 12.028(3) Å, beta = 92.26(3) degrees, V = 1318.2(7) Å(3), Z = 4, R = 0.0438, R(w) = 0.0442, and Me(2)TeI[S(2)CN(CH(2))(4)CH(2)] (9) is P2(1) (No. 4) with a = 6.019(3) Å, b = 8.986(4) Å, c = 13.012(2) Å, beta = 100.61(3) degrees, V = 691.7(6) Å(3), Z = 2, R = 0.0364, R(w) = 0.0305. Me(2)TeI[S(2)CN(CH(2))(3)CH(2)] (6) is orthorhombic in Pbca (No. 61) with a = 13.951(6) Å, b = 19.849(8) Å, c = 9.261(4) Å, V = 2564(1) Å(3), Z = 8, R = 0.0392, R(w) = 0.0326, and Me(2)Te[S(2)CN(CH(2))(4)CH(2)](2) (2) is triclinic in P&onemacr; (No. 2) with a = 9.624(2) Å, b = 12.904(3) Å, c = 9.008(2) Å, alpha = 98.29(2) degrees, beta = 111.19(2) degrees, gamma = 99.64(2) degrees, V = 1002.5(4) Å(3), Z = 2, R = 0.0504, R(w) = 0.0454. The immediate environment about Te is that of a sawhorse structure in which the lone pair is apparently stereochemically active and occupying an equatorial position in a distorted trigonal bipyramid. The second sulfur atom appears also to be in the coordination sphere resulting in the following distorted arrangements about Te: pseudo pentagonal bipyramidal in 1 and 3, octahedral in 2, and square pyramidal in 5, 6, 7, and 9.