M. Noltemeyer

Sterically crowded aryl bismuth compounds: synthesis and characterization of bis{2,4,6-tris(trifluoromethyl)phenyl} bismuth chloride and tris{2,4,6-tris(trifluoromethyl)phenyl} bismuth

The reactions of BiCl3 with 2,4,6-tris(trifluoromethyl)phenyl lithium (LiRf) in ether solution in 1 : 2 and 1 : 3 ratios have led to the isolation of Bi(Rf)2Cl (I) and Bi(Rf)3 (II). The hexane-soluble compounds have been spectroscopically and structurally characterized I: monoclinic space group P21/c, a = 8.816(2), b = 30.459(6), c = 8.817(2)A, β = 109.58(2)°, Z = 4, V = 2230.7(8)A3;II: monoclinic space group P21/c, a = 11.769(2), b = 17.029(3), c = 16.213(3)A, β = 102.74(3)°, Z = 4, V = 3169.3(10)A3. Both compounds are monomeric in the solid state. Compound II is unstable in solution even under inert atmosphere producing RfH. In the solid state the compound is stable in inert atmosphere but decomposes slowly upon exposure to air producing RfOH and (Rf)2O. In the presence of BiCl3, II undergoes exchange to produce I and another complex which is probably Bi(Rf)Cl2.

Syntheses and crystal structures of compounds containing short TeN bonds

The reaction of tellurium(IV)chloride with N-trimethylsilyl-P-triphenyliminophosphorane in a molar ratio of 1:2 gives (Ph3PN)2TeCl2. A similar procedure with RTeCl3 (R = p-MeOC6H4) gives the monosubstituted product Ph3PNTe(R)Cl2. X-Ray diffraction studies show that both compounds contain short TeN bonds, with lengths of ca. 192 pm. Additional telluriumnitrogen compounds have been obtained from reactions of RTeCl3 with Me2S(O)NSiMe3, (Me3SiN)2S, and Me3SiN(Me)C(O)(m-CF3C6H4)SiMe3, which give Me2S(O)NTe(R)Cl2, Me3SiNSNTe(R)Cl2, and MeNC(O)N(m-CF3C6H4)Te(R)Cl, respectively.

Reactivity of a silanediyl towards nitriles — the role of azasilacyclopropenes as intermediates

Abstract Cyclotrisilane 1a reacts with different nitriles to yield products 4–6 . the formation of which is likely to proceed via initially generated azasilacylopropenes 3a–c . Disilane 6 represents the first example of a structurally characterized pentacoordinated silyl cyanide.

Von lithiierten Aminofluorsilanen zu mono- und dimeren Iminosilanen / From Lithiated Aminofluorosilanes to Mono- and Dimeric Iminosilanes

Abstract Depending on the solvent and the bulkiness of the substituents, Iithiated aminofluorosilanes are dimers, monomers, or LiF-adducts of iminosilanes. In the crystal structure of the dimeric lithium derivative of di-tert-butyl(rm-butylamino)fluorosilane, each lithium atom is coordinated by one fluorine and two nitrogen atoms. LiF-elimination leads - if sterically possible - to dimerisation. The limits of dimerisation are reached with the dimer diisopropyl(tri-tert-butylphenyI- imino)silane, for which the crystal structure analysis shows severe steric distortions. Fluorine- chlorine-cxchange occurs in reactions of lithiated (tri-tert-butylphenylimino)fluorosilanes with Me3SiCl. Iminosilanes are obtained by thermal LiCl-elimination from the resulting salts.

Reaktion von cyanformamidinen MIT 2,2,4,4-tetrakis(trifluormethyl) -1,3-dithietan

Abstract The reaction of cyanogen with secondary amines at low temperatures leads to N.N-dialkylformamidines, which react further with 2,2,4,4-tetrakis(trifluoromethyl) -1,3-dithiane to yield substituted 2,5-dihydro-5-imino-2,2-bis(trifluoromethyl)- thiazole derivatives 1 and 2 . The products are obtained in a 1:3 molar ratio. This reaction is not influenced by stoichiometry or temperature.The crystal structure of 1 is reported.

Reaktion von N-Trimethylsilyl-N′(N″ -trimethylsilylammodiphenylphosphoranylidenimino) sulfamid mit Wolframoxitetrachlorid und die Struktur von (Cl3WNPPh2N)2 Reaction of N-Trimethylsilyl-N′(N″ -trimethylsilylaminodiphenylphosphoranylidene)sulfamide with Tungstenoxitetrachloride and the Structure of (Cl3WNPPh2N)2

1 The reaction of ClSO2N = PPh2Cl () with NH3 yields H2NSO2N = PPh2NH2 (2).This compound is converted to Me3Si(H)NSO2N = PPh2N(H)SiMe3 (3) by Me3SiNMe2. 3 reacts with WOCl4 under elimination of (Me3Si)2O and ClSO2NH2 to yield the eight-membered ring system (Cl3WNPPh2N)2 (4).The molecular structure of 4 was investigated by an X-ray structure analysis.

5-Methylene-2-cyclopentenones as new formal [2 + 2 + 1] cycloaddcts from[2-(dibenzylamino)ethenyl]carbenechromium complexes and alkynes

2-Alylsubstituted pentacarbonyl {[2-(dibenzylamino]ethoxycarbene} chromium complexes 3a,b react with diphenylethyne 4, but 2-yne 5, or cyclooctne 6, to give 5-(dibenzylaminomethylene)-4-ethoxy-w-cyclopentenones 8a,b, 9a, 10a, and 10b in good yields (59–78%).

Structural and chemical properties of tribenzo-4,7-dihydroacepentalene derivatives and their central pyramidalised double bonds

Dipotassium tribenzodihydroacepentalenediide 42– reacts with electrophiles to give 4,7-disubstituted tribenzodihydroacepentalene derivatives 3 with a highly pyramidalised double bond, as evidenced by X-ray structural determinations; protonation of the dianion 42– yields an interesting polycyclic [2 + 2] dimer 5.

The crystal structure of 1,2-dibenzylidenehydrazinium hexafluoroarsenate

The structure of [C6H5CH = N H N = CHC6H5][AsF6] has been determined from single-crystal X-ray diffraction data. The crystals are orthorhombic, space group Pca2u a = 19.183(12), b = 9.704(6), c = 8.568(6)Â, Ζ = 4, U = 1595.0Â and Dx = 1.658g · cm 3 . The structure was solved by Patterson and Fourier methods, and refined to R = 0.051 for 1353 unique data with F > 4 σ (F). The cation is nearly planar and adopts the transoid conformation. The planes of the phenyl rings are inclined by 7.1 ° to one another.

Reaktionen von N-Lithio-N, N′-di(t-butyl)-S-phenylsulfinsäureimidamid mit Chloriden der Elemente der 4. Gruppe des Periodensystems Struktur des O[TiCl2N2(But)2SPh]2/Reactions of N -Lithio-N ,N′-di(t-butyl)-S -phenylsulfinic Acid Imidamide with Chlorides of the Elements of Group 4 of the Periodic System Structure of O[TiCl2N2(But)2SPh]2

Abstract N-Lithio-N,N′-di(t-butyl)-S-phenylsulfinic acid imidamide (1) reacts with TiCl4, SiCl4, GeCl4, SnCl4 and Ph2SnCl2 with monosubstitution at the metal center to yield compounds 2-6. TiCl3N2(But)2SPh (2) slowly hydrolyzes to form O[TiCl2N2(But)2SPh]2 (7). The molecular structure of 7 was investigated by an X-ray structure analysis.