Brom- und Chlorthionitrenkomplexe des Rheniums. Die Kristallstruktur von (PPh4)2 [ReBr4(NS)(NSBr)]·CH2Br2 Bromo- and Chlorothionitrene Complexes of Rhenium The Crystal Structure of (PPh4)2[ReBr4(NS)(NSBr)]·CH2Br2

Abstract

Abstract The thionitrosyl-halothionitrene com pounds (PPh4)2[ReX4(NS)(NSX)]·2 CH2X2, X = Cl or Br, are obtained by nucleophilic ring cleavage of the Re(N2S2) rings of complexes [ReX4(N2S2)]⊖ with PPh4X in CH2X2. (AsPh4)2[ReCl4(NS)(NSCl)] · CH2Cl2 can also be obtained by the reaction of [ReCl4(NSCl)(POCl3)] with S(NSiMe3)2 and subsequent addition of AsPh4Cl. The pyridine complex [ReBr2(NS)(NSBr)(NC5H5)2] · CH2Br2 forms by bromination of the corresponding chloro compound with Me3SiBr. The IR spectra are reported. The crystal structure of (PPh4)2[ReBr4(NS)(NSBr)] · CH2Br2 was determ ined by X-ray diffraction (4158 independent observed reflexions, R = 0.059). Crystal data: a = 1039.7, b - 1232.5, c - 2158.4 pm, α = 81.59, β = 87.05, γ = 77.06°, Z = 2, space group P1̄. The compound consists of PPh4 ⊕ ions, CH2Br2 molecules, and anions [ReBr4(NS)(NSBr)]2⊖ in which the rhenium atoms are coordinated by four bromine atoms, one thionitrosyl and one brom othionitrene group. The latter have cis arrangement and ReN bond lengths of 186 pm. W hereas the thionitrosyl group is nearly linear, the R = N = SBr group has an ReNS angle of 165°.