S4N3⊕[ReCl4(NSCl)2]⊖ Synthese und Kristallstruktur

S₄N₃^⊕[ReCl₄(NSCl)₂]^?. Synthesis and Crystal Structure S₄N₃^⊕[ReCl₄(NSCl)₂]^? is formed as a byproduct in the reaction of Re₂(CO)₁₀ with excess trithiazyl chloride. The compound is characterized by a crystal structure analysis by X-ray methods. S₄N₃[ReCl₄(NSCl)₂] crystallizes in the noncentrosymmetric space group P2₁2₁2₁ with four formula units per unit cell and the lattice dimensions a = 980, b = 1205, c = 1362 pm (2376 observed, independent reflexions; R = 0.076). The compound consists of the well known cyclic planar S₄N₃^⊕-cations and anions [ReCl₄(NSCl)₂]^?, in which the rhenium atom is coordinated octahedral by four Cl atoms and two cis-positioned NSCl ligands. The mean Re? N and N? S bond lengths (177 pm and 158 pm) correspond to double bonds. The bond lengths and angles are much like in the structure of AsPh₄[ReCl₄(NSCl)₂]; however the chlorine atoms of the NSCl ligands are turned to each other.     

Darstellung,Mössbauer- und Schwingungsspektren der Komplexe [SnCl4F]⊖, [SnCl4(NCS)]⊖ und [SnCl4(NCS)2]2⊖

Preparation, Mössbauer and Vibrational Spectra of the Complexes [SnCl₄F]^?, [SnCl₄(NCS)]^?, and [SnCl₄(NCS)₂]^2? N(CH₂)₄F and N(CH₂)₄SCN react in liquid SO₂ with SnCl₄ yielding the adducts [N(CH₃)₄][SnCl₄F] (I), [N(CH₃)₄][SnCl₄(NCS)] (II) and [N(CH₃)₄]₂[SnCl₄(NCS)₂] (III).respectively. Mössbauer and vibrational spectra indicate for the anion of I a fluoro-bridged species, which is probably tetrameric like the isoelectronic SbCl₄F. For II dimeric moieties are proposed with bridging S-atoms, while [SnCl₄(NCS)₂]^2? has an octahedral structure with N-bonded isothiocyanate groups in the trans-positions.     

Röntgenographische und schwingungsspektroskopische Untersuchung der Sulvanitmischkristalle Cu3Nb(SxSe1−x)4, Cu3Nb(SexTe1−x)4, und Cu3Ta(SxSe1−x)4 und Cu3Ta(SexTe1−x)4

X-Ray and Vibrational Studies of Sulvanite Mixed Cystals Cu₃Nb(S_xSe_1?x)₄, Cu₃Nb(Se_xTe_1?x)₄, Cu₃Ta(S_xSe_1?x)₄ and Cu₃Ta(Se_xTe_1?x)₄ Solid solutions Cu₃Nb(S_xSe_1?x)₄, Cu₃Nb(Se_xTe_1?x)₄, Cu₃Ta(S_xSe_1?x)₄ and Cu₃Ta(Se_xTe_1?x)₄ with sulvanite structure have been prepared in the range 0 ≤ x ≤ 1. The lattice constants in all systems obey the Vegard rule. Infrared and Raman spectra have been measured. The spectra of the compounds with mixed anion sublattices show additional peaks, compared to those of the end members, because besides the polyhedra MX₄ and MY₄ also groups MX₃Y, MX₂Y₂, and MXY₃ are present, and all groups are able to oscillate independently. By comparison of the peak intensities and the statistical frequency of the groups according to the composition, the additional valence vibrations could be attributed to the groups.