Chloroselenate(IV): Darstellung,Struktur und Eigenschaften von [As(C6H5)4]2Se2Cl10 und [As(C6H5)4]Se2Cl9

Chloroselenates(IV): Synthesis, Structure, and Properties of [As(C₆H₅)₄]₂Se₂Cl₁₀ and [As(C₆H₅)₄]Se₂Cl₉ The Se₂Cl₁₀^2? and Se₂Cl₉^? anions were prepared, as the first dinuclear haloselenates(IV), from the reaction of (SeCl₄)₄ with stoichiometric quantities of chloride ions in POCl₃ solutions; they were isolated as yellow crystalline As(C₆H₅)₄⁺ salts. Complete X-ray structural analyses at ?130°C of [As(C₆H₅)₄]₂Se₂Cl₁₀ ( 1 ) (space group P1 , a = 10.296(7), b = 11.271(6), c = 12.375(8) Å, = 74.17(5)°, α = 81.38(5)°, β = 67.69(4)°, V = 1276 ų) and of [As(C₆H₅)₄]Se₂Cl₉ ( 2 ) (space group P2₁/n, a = 12.397(5), b = 17.492(6), c = 14.235(4) Å, α 93.25(3)°, V = 3082 ų) show in both cases two distorted octahedral SeCl₆ groups connected through a common edge in 1 and a common face in 2 . The terminal Se? Cl bonds (average 2.317 Å in 1 , 2.223 Å in 2 ) are much shorter than the Se? Cl bridges (av. 2.661 Å in 1 , 2.652 Å in 2 ). The stereochemical activity of the Se^IV lone electron pair causes severe distortion of the central Se₂Cl₂ ring in the centrosymmetric Se₂Cl₁₀^2? ion. The vibrational spectra of the anions are reported.     

Untersuchungen zu Struktur und Schmelzverhalten von (C6H5)2As2Se3 und (CH3)3As3Se3

Investigations of the Structure and the Melting Behaviour of (C₆H₅)₂As₂Se₃ and (CH₃)₃As₃Se₃ The compounds (C₆H₅)₂As₂Se₃ and (CH₃)₃As₃Se₃ exist in a crystalline and a glass-like form. Both phases were investigated by the methods of mass, i.r., and u.v. spectroscopy and by DTA. The mass-spectroscopic fragmentation patterns are shown. The proposed structures of the crystalline forms are confirmed by these results. In the melts equilibria exist between the cyclic molecules of the crystalline forms and chains and other rings. On attempts to prepare the compound (C₆H₅)₃As₃Se₃, only (C₆H₅)₂As₂Se₃ was found. The possible reasons of the preferred stability of the five ring molecule are discussed.     

Synthese und Struktur von [Fe6(CO)12(TePh)12]

Synthesis and Structure of [Fe₆(CO)₁₂(TePh)₁₂] The reaction of [Fe(CO)₄(HgCl)₂] with PhTeSiMe₃ leads to the formation of red needles. [Fe₆(CO)₁₂(TePh)₁₂] was characterised by single crystal x‐ray structure analysis. In this compound each iron atom is coordinated octahedrally by four μ₂‐TePh groups and two terminal CO groups. The iron atoms form a six membered planar ring.     

Thiochloroarsenate(III): Darstellung,Schwingungsspektren und Kristallstrukturen von PPh4[As2SCl5] und (PPh4)2[As2SCl6] · C2H4Cl2

Thiochloroarsenates (III): Preparation, Vibrational Spectra, and Crystal Structures of PPh₄[As₂SCl₅] and (PPh₄)₂[As₂SCl₆] · C₂H₄Cl₂ PPh₄[As₂SCl₅] can be obtained from As₂S₃ + PPh₄Cl with HCl in CH₂Cl₂ or 1,2-C₂H₄Cl₂. It reacts with a second mole of PPh₄Cl to yield (PPh₄)₂[As₂SCl₆]. The latter also is formed by the reaction of As₂S₅ + 2 PPh₄Cl with HCl, a second product being (PPh₄)₂[As₂Cl₈]. The i.r. and Raman spectra of the title compounds are reported. Their crystal structures were determined by X-ray diffraction. Crystal data: PPh₄[As₂SCl₅], monoclinic, space group P2₁/n, a = 1175.8, b = 1508.0, c = 1593.4 pm, β = 96.22°, Z = 4; (PPh₄)₂[As₂SCl₆] · C₂H₄Cl₂, triclinic, P1, a = 1166.3, b = 1188.2, c = 2044.6 pm, α = 95.47, β = 97.53, γ = 111.05°, Z = 2. Including the lone electron pairs, the coordination of the As atoms in the [As₂SCl₅]⁻ ion is distorted trigonal-bipyramidal with the S, one Cl atom, and an electron pair in equatorial positions; the two bipyramids around the two As atoms share a common edge. The As atoms in the [As₂SCl₆]²⁻ ion have a distorted octahedral coordination, the two octahedra share a common face; the lone electron pairs are in the trans positions to the S atom.     

Synthese und Kristallstruktur von (C5H5)Mo(CO)3(AuPPh3) und [(C5H5)Mo(CO)2(AuPPh3)4]PF6

Synthesis and Crystal Structure of (C₅H₅)Mo(CO)₃(AuPPh₃) and [(C₅H₅)Mo(CO)₂(AuPPh₃)₄]PF₆ CpMo(CO)₃(AuPPh₃) is obtained by the reaction of Li[CpMo(CO)₃] with Ph₃PAuCl at ?95°C in CH₂Cl₂. It crystallizes in the monoclinic space group C2/c with a = 2625.1(7), b = 883.2(1), c = 2328.4(7) pm, β = 116.39(1)° und Z = 8. In the complex the AuPPh₃ group is coordinated to the CpMo(CO)₃ fragment with a Au? Mo bond of 271,0 pm. The Mo atom thus achieves a square pyramidal coordination with the center of the Cp ring in apical position. CpMo(CO)₃(AuPPh₃) reacts under uv irradiation with an excess of Ph₃PAuN₃ to afford the cluster cation [CpMo(CO)₂(AuPPh₃)₄]⁺. It crystallizes as [CpMo(CO)₂(AuPPh₃)₄]PF₆ · 2 CH₂Cl₂ in the orthorhombic space group P2₁2₁2₁ with a = 1553.9(1), b = 1793.8(2), c = 2809.8(7) pm und Z = 4. The five metal atoms form a trigonal bipyramidal cluster skeleton with the Mo atom in equatorial position. The Mo? Au distances range from 275.5 to 280.8 pm, and the Au? Au distances are between 281.2 and 285.6 pm.