Substitutionsreaktionen an der N-Chlornitrenogruppe des [WCl4(NCl)]2. Die Kristallstrukturen von [CH3CN—WCl4(NSMe)] und [WNCl3 · NC—CH3]4 / Substitution Reactions at the N-Chloronitreno Group of [WCl4(NCl)]2. The Crystal Structures of [CH3CN—WCl4(NSMe)] and [WNCl3 · NC—CH3]4

[WCl₄(NCl)]₂ reacts in acetonitrile with the trimethylsilyl compounds Me₃SiSR (R = Me, Ph), and Me₃SiESiMe₃ (E = S, Se), with substitution of the chlorine atom of the N-chloronitreno group W=N–Cl and formation of CH₃CN–WCl₄(NSR) and CH₃CN–WCl₄(NEN)WCl₄–NCCH₃, respectively. Excess Me₃SiBr reacts with CH₃CN–WCl₄(NSMe) to afford CH₃CN–WBr₄(NSMe). [CH₃CN–WNCl₃]₄ was obtained from CH₃CN–WCl₄(NCl) and N(SiMe₃)₃. The products were characterized by their IR spectra. Two X-ray crystal structure determinations were also carried out. CH₃CN—WCl₄(NSMe) forms twinned crystals, and only non-overlapping reflexions of one of the twin individuals were used for the structure determination (846 unique values, R = 0.055). Crystal data: a = 592.4(2), b = 758.8(2), c = 1203.7(8) pm, β = 95.06(4)°, monoclinic, space group P2₁/m, Z = 2. The compound is a monomer in which the acetonitrile ligand is situated in the trans position to the W≡N–S–Me group. The bond lengths (W≡N 174(2), N–S 161(2) pm) and bond angles (WNS 176(1), NSC 102.1(9)°) are in agreement with the proposed formula. Crystal data for [CH₃CN–WNCl₃]₄: a = 1009.5(2), b = 1274.5(2), c = 1287.9(2) pm, β = 108.17(1)°, monoclinic, space group P2₁/c, Z = 2 (2113 unique reflexions, R = 0.057). The compound forms tetrameric units, in which the W atoms form a square and are linked with one another via N atoms at alternating distances (W=N 171(2), W–N 207(2), W–NCMe 238(2) pm).