Beiträge zur Chemie der Silicium-Schwefel-Verbindungen. XXXVI [1]. Das Quecksilber(II)-bis-tri-tert-butoxysilanthiolat

Contributions to the Chemistry of Silicon-Sulfur Compounds. XXXVI. Mercury(II)-bis-tri-tert-butoxysilanethiolate Mercury(II)bis-tri-tert-butoxysilanethiolate was obtained in reaction of HgO with (t-C₄H₉O)₃SiSH. This compound forms colourless triclinic plates. The central S? Hg? S bond element is linear, with Hg? S bond distance of 231.6 pm. The Hg atom is coordinated by two oxygens of the two butoxy groups, with Hg? O distance of 287.8 pm. The mean bond angle at the two-bonded sulfur is 95.6°. (Space group P1 ; a = 930.8, b = 944.0, c = 1204.8 pm, α = 100.34, β = 97,64, γ = 116.50°; Z = 1; R = 0.035; 3390 reflections hkl).     

Beiträge zur Chemie der Silicium-Schwefel-Verbindungen. XXVIII. Trimethylsilylderivate der Trialkoxysilanthiole

Contributions to the Chemistry of Silicon-Sulphur Compounds. XXVIII. Trimethylsilylderivatives of Trialkoxysilanethiols The reactions of trialkoxysilanethiols and their salts with trimethylchlorosilane and hexamethyldisilazane were investigated. The preparation of trimethyltrialkoxydisilthianes has been described. Some properties of the obtained compounds were given and about their silylation ability has been considered.     

Beiträge zur Chemie der Silicium-Schwefel-Verbindungen. XXIX. 29Si-NMR-Untersuchungen

Contributions to the Chemistry of Silicon-Sulphur Compounds. XXIX. ²⁹Si-N.M.R. Investigations Three series of silicon-sulphur compounds (RO)₃SiSR′ (I), (i-PrO)_4?nSi(SEt)_n (II) and cyclic Si? S compounds (III) were prepared, some of them at the first time and their ²⁹Si-N.M.R. spectra were measured. In the series of trialkoxysilylthio derivatives (I) were the steric and inductive effects of the RO and R'S groups evaluated. In the series II were the ²⁹Si-N.M.R. chemical shifts related to the relative paramagnetic screening constants σ^* and netto charge at the silicon atom q(Si) using the EN-quantum-chemical model discussed. In the series III were the shift contribution of the (SiS)₂ and 1-sila-2,5-dithiacyclopentan rings determined.     

Beiträge zur Chemie der Silicium-Schwefel-Verbindungen. 44. Trialkoxysilylthioderivate der Permethylpolysilane

Contributions to the Chemistry of Silicon-Sulphur Compounds. 44. Trialkoxysilylthio Derivatives of Permethylpolysilanes By reaction of (RO)₃SiSH · NEt₃ (R = i-Pr, t-Bu) with α,ω-Cl₂(SiMe₂)_n (n = 1, 2, 3, 4, 6) or with 1-Cl(SiMe₂)_nMe (n = 2, 4) trialkoxysilylthio derivatives of polysilanes of the two series α,ω-(RO)₃SiS(SiMe₂)_nSSi(OR)₃ and 1-(RO)₃SiS(SiMe₂)_nMe have been prepared. Some properties of obtained new compounds were given. The resistance of the Si? S bond on protolytic splitting has been characterized by half-life times of the alcoholysis reaction.     

Beiträge zur Chemie der Silicium-Schwefel-Verbindungen. XXIII. Die Hydrolysereaktion der Silanthiole

Contributions to the Chemistry of Silicon-Sulphur Compounds. XXIII. The Hydrolysis Reaction of Silanethiols The kinetics of the hydrolysis reaction of silanethiols (RO)₃SiSH and R₃SiSH in dioxane-water solutions were investigated and the rate constants and the activation parameters evaluated. The mechanism of the reaction is discussed. The relationship between the structure of silanethiols and their reactivity are evaluated.     

Beiträge zur Chemie der Silicium-Schwefel-Verbindungen. XLIX. Reaktion von Silicium-Schwefel-Verbindungen mit Glykolen

Contribtions to the Chemistry of Silicon-Sulphur Compounds. XLIX. Reaction of Silicon-Sulphur Compounds with Glycols The reactions of Ph₃SiSH, (RO)₃SiSH, (RO)₂Si(SH)₂, cyclo-[(t-BuO)₂SiS]₂, and SiS₂ with aliphatic glycols were investigated. Among other compounds representatives of a new group of silanethiols (t-BuO)₂Si(SH)OrOSi(SH)(OBu-t)₂ (r = pr; neopent)

1 r = kohlenwasserstoffgerüst des Glykols: pr = ? CH₂CH₂CH₂? , bu = ? CH₂(CH₂)₂CH₂? , hex = ? CH₂(CH₂)₄CH₂? , neopent = ? CH₂C(CH₃)₂CH₂? , pin = ? C(CH₃)₂C(CH₃)₂?

were obtained. Informations about the hydrolytic splitting of the Si? S bond of the prepared silanethiols were obtained by thiomercurimetric titration. A pathway of the reaction of SiS ₂ with glycols is discussed.     

Beiträge zur Chemie der Silicium-Schwefel-Verbindungen. XXXV. Das dimere Thallium(I)-tri-tert-butoxysilanthiolat

Contributions to the Chemistry of Silicon-Sulfur Compounds. XXXV. The Dimeric Thallium(I)-tri-tert-butoxysilanethiolate Thallium(I)-tri-tert-butoxysilanethiolate is formed as a dimer by reaction of tri-tert-butoxysilanethiol with TlNO₃. The compound crystallizes as colourless triclinic plates. F.I. mass spectra show only the mass of the dimeric species (m/e = 968), in the E.I. mass spectra, however, also the peak for the monomeric unit (m/e = 484) is observed. The molecule is of 1 /C_i symmetry. The central four-membered ring is plane, the bond distances and angles therein are d (Tl? S) = 289 pm and S/Tl/S = 91.5°. The Tl atoms are additionally coordinated by an oxygen atom of the tri-tert-butoxysilyl group (d(Tl? O) = 280 pm). The mean bond angle at the threebonded sulfur atom was found to be 90° (d(S? Si) = 207.8 pm). Related details of the structure are discussed (space group P1 ; a = 927.5 pm, b = 1395.1 pm, c = 882.1 pm; α = 108.43°, β = 116.77°, γ = 90.98°; Z = 2; R = 0.032; 2887 reflections hkl).     

Beiträge zur Chemie der Silicium-Schwefel-Verbindungen. XXXIV. Das tetramere Silber(I)-Tri-tert-Butoxysilanthiolat

Contributions to the Chemistry of Silicon Sulfur Compounds. XXXIV. Tetrameric Silver(I)-tri-tert-butoxysilanethiolate Silver(I)-tri-tert-butoxysilanethiolate is formed as a tetramere by reaction of tritert-butoxysilanethiol with AgNO₃. The compound crystallizes as colourless triclinic plates and sublimes in vacuum at 170°C without decomposition. F.I. mass spectra shows only the mass of the tetrameric unit (m/e = 1 548), whereas this unit is observed in E.I. mass spectra with lower intensity. The ²⁹Si n.m.r. spectrum shows a remarkable splitting of the signal around ?68.54 ppm, which is explained by Si? Ag couplings. The central unit of the molecule is a nearly plane alternating Ag₄S₄ eight-membered ring with threefold bonded sulfur and twofold bonded silver atoms. Most important are the significant deviations from colinear S? Ag? S bonds (172.3°) resulting from shifts of the silver atoms toward the center of the eight-membered Ag₄S₄ ring (Ag? Ag = 313.5 pm). This effect is taken as a strong indication for high order direct Ag(I)-to-Ag(I) interactions. Related details of the structure are discussed. (Molecule symmetry is 2-C₂; space group P1 ; a = 1 769.7, b = 2012.8, c = 1 266.8 pm, α = 119.63°, β = 82.22°, γ = 95.08°; Z = 2; R = 0.067; 7 656 reflections h kl.)     

Beiträge zur Chemie der Silicium-Schwefel-Verbindungen. XLIII. Alkoholyse von Silicium-Schwefel-Verbindungen mit Alkoxyethanolen und 2-Mercaptoethanol

Contributions to the Chemistry of Silicon-Sulphur Compounds. XLIII. Alcoholysis Reaction of Silicon-Sulphur Compounds with Alkoxyethanols and 2-Mercaptoethanol The reactions of 2-alkoxyethanols und 2-mercaptoethanol with (RO)₃SiSH, (RO)₂Si(SH)₂, cyclo-[(t-BuO₂)SiS]₂, and SiS₂ were investigated. Besides of mixed esters of orthosilicic acid a new group of mixed trialkoxysilanethiols – (RO)₂(R′O)SiSH – was obtained. Informations about the hydrolytic splitting of the Si? S bond of these Si? S compounds were obtained by thiomercurimetric titration with HMB.     

Beiträge zur Chemie der Silicium-Schwefel-Verbindungen. XXXIII. Die Struktur des Bis(triphenylsilyl)sulfids

Contributions to the Chemistry of Silicon Sulphur Compounds. XXXIII. Structure of Bis (triphenylsilyl)sulphide The condensation of triphenylsilanethiol yielded bis(triphenylsilyl)sulphide ( 1 ). The compound is remarkable resistent to hydrolysis. 1 crystallizes monoclinically [P2₁/n (No. 14): a = 1707.8 pm; b = 1454.6 pm; c = 1225.0 pm; β = 97.27°; Z = 4; 4470 h k l; R = 0.053]. The molecule is bent with a bond angle Si? S? Si = 112.0°. The mean bond distances Si? S and Si? C are 215.2 pm and 187.4 pm, respectively. Some structural details are discussed.     

Beiträge zur Chemie der Silicium-Schwefel-Verbindungen. XVII. Darstellung von Trialkoxysilanolen aus Trialkoxysilanthiolen

Contributions to the Chemistry of Silicon-Sulphur Compounds. XVII. Preparation of Trialkoxysilanols from Trialkoxysilanethiols The hydrolysis of trialkoxysilanethiols in neutral, basic and acidic solutions was investigated and an efficient way for preparation of trialkoxysilanols was elaborated. Some trialkoxysilanols were obtained with a very good yield.     

Beiträge zur Chemie der Silicium-Schwefel-Verbindungen. XXX. Die Struktur des Tetra-t-butoxy-1,3,2,4-dithiadisiletans

Contributions to the Chemistry of Silicon-Sulfur Compounds. XXX. Structure of Tetra-t-butoxy-1,3,2,4-dithiadisiletane Alcoholysis of silicon disulfide by t-butanol yielded the title compound. [(t-BuO)₂SiS]₂ crystallizes orthorhombically in the space group Pbca (no. 61) with a = 1708.4(5), b = 1560.8(3), c = 907.1(3) pm and Z = 4 molecules per unit cell. The molecule has the crystallographic 1 –C_i point symmetry and consequently the Si₂S₂ four-membered ring is rigid plane. The bond distances of this ring are Si? S = 214.2 and 213.1 pm and the bond angles S? Si? S = 97.8° and Si? S? Si = 82.2°. Related details of the structure are discussed.     

Beiträge zur Chemie der Silicium-Schwefel-Verbindungen. 53. Die Struktur des 1,3-Dimethyl-1,1,3,3-Tetraphenyldisilthians

Contributions to the Chemistry of Silicon-Sulphur Compounds. 53. Structure of 1,3-Dimethyl-1,1,3,3-tetraphenyldisilthiane 1,3-Dimethyl-1,1,3,3-tetraphenyldisilthiane was obtained by an insertion reaction of sulphur with Ph₂ MeSiH. The compound crystallizes triclinically (P1 ; a = 1166.7; b = 1231.1; c = 988.6 pm; α = 113.23; β = 90.34; γ = 112.43°; Z = 2). The X-ray structure analysis shows a bent configuration of the molecule with Si? S? Si = 108.7°. The results are discussed together with the structures of hexaphenyldisilthiane and dimethyltetraphenyldisiloxane.     

Beiträge zur Chemie der Trifluormethylquecksilber-Verbindungen

Contribution to the Chemistry of Trifluoromethylmercury (II) Compounds CF₃HgI (I) has been obtained in appreciable amount by a newly modified method, The reaction of I with silver salts AgX or AgY₂ (X = CN, NCO, SCN, SeCN, N₃, SCF₃, IO₃; Y = O, C₂O₄, NCN) gives corresponding CF₃HgX derivatives (II–VIII, XI, XII, XVII) mostly in good yield. The synthesis of (CF₃Hg)₂S (IX) has been attained by the reaction of I with Tl₂CS₃, while it gives with Ag₂O (CF₃Hg)₂O (VIII) instead of the hydroxide. VIII reacts in ethereal solution with H₂Se giving (CF₃Hg)₂Se (X). Stable CF₃HgN and (CF₃Hg)₂N derivatives (XIII–XVII) could only be obtained when at least one more substituent on N atom, which reduces its basicity, is present. I.r., ¹⁹F-n.m.r. and mass spectroscopic data for the prepared compounds have been reported.     

Beiträge zur Chemie der Silicium-Schwefel-Verbindungen. 46 [1]. 29Si-NMR-chemische Verschiebungen von Trialkoxysilylthioderivaten der Permethylpolysilane

Contributions to the Chemistry of Silicon-Sulphur Compounds. 46. ²⁹Si-N.M.R. Chemical Shifts of Trialkoxysilylthio Derivatives of Permethylpolysilanes ²⁹Si-N.M.R. chemical shifts of trialkoxysilythio derivatives of permethylpolysilanes of the two series: α, ω-(RO)₃SiS(SiMe₂)_nSSi(OR)₃, n = 2, 3, 4, 6 and 1-(RO)₃SiS(SiMe₂)_nMe, n = 2, 4; R = i-Pr, t-Bu and also ³¹C-NMR shifts are given. The relationship of ²⁹Si-NMR chemical shift from the netto charge at the silicon atom q(Si) which value has been corrected according to the Sandorfy C quantum-chemical model is discussed. The greater reduction of the electron density at silicon in compounds with Si? X bond (X = S, P, Cl) has been explained by a conjugation of the lone of sulphur with the Si? X bonding pair.     

Beiträge zur Chemie des Phosphors. XXXIX. Zur Hydrolyse des Diphosphor-tetrajodids

In the preparation of Ba₂H₂(H₂P₂O₄)₃ by P₂I₄ hydrolysis in barium acetate/acetic acid buffer solution P(II)—P(IV), P(IV)—P(IV), P(III), and P(V) acid are formed in addition to about 17% of the starting phosphorus as P(II)—P(II) acid after separating the Ba₂H₂(H₂P₂O₄)₃. Thus in this reaction a total of 64% of P₂I₄ Phosphorus can be detected as hypodiphosphorous acid H₄P₂O₄. The precipitated yellow reaction product, obtained by water hydrolysis of P₂I₄, contains no solid phosphorus hydride — as believed previously — but as a result of elementary analysis, iodometry, and chromatography, a high molecular-weight phosphorus, hydrogen and oxygen containing substance of statistical stoichiometry with oxydation number ～0 for phosphorus. P? H, P?O, and P? O? P groups could be detected by IR-spectroscopy, but not P? OH groups. The P₂I₄ hydrolysis probably proceeds via a yellow coloured initial product with trivalent phosphorus, and yields a very complex reaction mixture in which also the intermediates partially still react further.     

Beiträge zur Chemie der Silicium-Schwefel-Verbindungen. XXV. Reaktion der Trialkoxysilanthiole mit aromatischen Aminen und Darstellung von N-(Trialkoxysilyl)arylaminen

Contributions to the Chemistry of Silicon-Sulphur Compounds. XXV. Reaction of Trialkoxysilanethiols with Aromatic Amines and Preparation of N-(Trialkoxysilyl)arylamines Pyridine and imidazole catalyze the reaction of trialkoxysilanethiols with substituted anilines. This procedure affords a convenient method for the synthesis of N-(trialkoxysilyl)-aryl-amines. Kinetics of the reaction were investigated and rate constants and activation parameters evaluated. Relationships between the structure of amines and their reactivity were discussed. The mechanism of the reaction is discussed.     

Beiträge zur Chemie der Schwefelhalogenide. 16. Dimethyliodsulfonium(IV)-Salze

Contributions to the Chemistry of Sulfur Halides. 16. Dimethyliodosulfonium(IV) Salts Some preparative methods of iodosulfonium(IV) salts, (CH₃)₂SI⁺AsF₆^? and (CH₃)₂SI⁺SbCl₆^?, are reported. These salts are stable up to ?20°C and they are characterized by Raman and n.m.r. spectroscopy.     

Beiträge zur Chemie der Schwefelhalogenide. 7. Trifluormethyliodsulfan

Contributions to the Chemistry of Sulfur Halides. 7. Trifluoromethyliodosulfane The preparation of CF₃SI is reported. The molecule is characterized by vibrational, nuclear magnetic resonance, UV/VIS, and mass spectra. CF₃SI chemically behaves like the interhalogen compound ICl. At higher temperatures the compound completely decomposes in CF₃SSCF₃ and I₂.