Reaktionen von Titantetrachlorid mit Bistrimethylsilylsulfid. Die Kristallstrukturen von (NEt4)2[TiSCl4], (PPh4)2[TiSCl4]·2CH2Cl2, (PPh4)2[Ti3O(S2)3Cl6]CH3CN und Ti4O(S2)4Cl6 / Reactions of Titanium Tetrachloride with Bistrimethylsilyl Sulfide. Crystal Structures of (NEt4)2[TiSCl4], (PPh4)2[TiSCl4]·2CH2Cl2, (PPh4)2[Ti3O(S2)3Cl6]CH3CN and Ti4O(S2)4Cl6

Abstract

The reaction of TiCl4 with (Me3Si)2S in dichloromethane yields black, insoluble, impure TiSCl2. In the presence of oxygen, additionally Ti3O(S2)3Cl4 and Ti4O(S2)4Cl6 are formed. By reactions of TiSCl2 with NEt4Cl and PPh4Cl in dichloromethane (NEt4)2[TiSCl2] and (PPh4)2[TiSCl4] ·2CH2Cl2 are formed, respectively. They were characterized by their IR spectra and by X-ray crystal structure determinations. They contain the square-pyramidal [TiSCl4]2- ion. which has a rather short Ti = S bond of 211.1(2) pm. Crystal data: (NEt4)2[TiSCl4]: tetragonal. P4/n, a = 923.9(3). c = 1406.7(2) pm. Z = 2. 966 unique observed reflexions. R = 0.053; positionally disordered ethyl groups. (PPh4)2[TiSCl4] · 2CH2Cl2: triclinic, P1, a = 1009.7(4), b = 1115.1(3). c = 1242.1(5) pm, α = 70.27(3), β = 79.06(3), γ = 81.37(3)°, Z = 1, 1504 reflexions, β-(AsPh4)2UCl6·2CH2Cl2 structure type, high R = 0.107 due to positional disorder of the anion. Addition of NEt4Cl or PPh4Cl in CH2Cl2 to the primary reaction product in presence of O2 yields (NEt4)2[Ti3O(S2)3Cl6] and (PPh4)2[Ti,O(S2)3Cl6] · CH2Cl2, respectively. Upon recrystallization of the latter from acetonitrile, (PPh4)2[Ti3O(S2)3Cl6] · CH3CN is obtained which forms triclinic crystals with a = 1138.8(3). b = 1268.8(4), c = 2166.4(6) pm, α = 101.26(3). β = 97.21(2). γ = 109.24(2)°, Z = 2, P1 (3053 reflexions, R = 0.070). The [Ti3O(S2)3Cl6]2- ion has a cluster-like structure with Ti atoms at the vertices of a triangle, with a μ3-O bridging atom and with tree bridging disulfide groups. Crystal data for Ti4O(S2)4Cl6: monoclinic, C2/c, a - 917.3(2), b - 1632.5(2), c = 1268.5(2) pm, β - 108.35(2)°, Z = 4. 1009 reflexions. R = 0.027. In the Ti4O(S2)4Cl6 molecule, four Ti atoms form a distorted tetrahedron around an μ4-O atom; two edges of the tetrahedron are spanned by chloro bridges, four edges by disulfide bridges.