Untersuchungen zur Umsetzung von [Lithium(trimethylsilyl)amido]-methyl-trimethylsilylamino-silan Me(Me3SiNLi)(Me3SiNH)SiH mit verschiedenen Elektrophilen

Investigations of the Reaction between the [Lithium(trimethylsilyl)amido]-methyl-trimethyl-silylamino-silane Me(Me₃SiNLi)(Me₃SiNH)SiH and different Electrophiles The lithium silylamide Me(Me₃SiNLi)(Me₃SiNH)SiH 1 reacts with chlorotrimethylsilan in the nonpolar solvent n-hexane to the N-substitution product Me[(Me₃Si)₂N](Me₃SiNH)SiH 2 and to the cyclodisilazane [Me(Me₃SiNH)Si—N(SiMe₃)]₂ 3 nearly in same amounts. The reaction of 1 with chlorotrimethylstannane gives besides small amounts of the cyclodisilazane 3 the N-substitution product Me[(Me₃Si)(Me₃Sn)N](Me₃SiNH)SiH 4 . By the reaction of 1 with trimethylsilyltriflate the cyclodisilazane 3 is obtained as the main product. Furthermore 2 and the cyclodisilazane 5 are formed. Ethylbromide shows no reaction with 1 under the same conditions. These results indicate the existence of an equilibrium of the lithium silylamide 1 , the silanimine Me(Me₃SiNH)Si?N(SiMe₃) and lithium hydride.     

Kristallstruktur des Bis[lithium-tris(trimethylsilyl)-hydrazids] und Reaktionen mit Fluorboranen, -silanen und -phosphanen

Crystal Structure of Bis[lithium-tris(trimethylsilyl)hydrazide] and Reactions with Fluoroboranes, -silanes, and -phospanes Tris(trimethylsilyl)hydrazine reacts with n-butyllithium in n-hexane to give the lithium-derivative 1 . The reaction of 1 with SiF₄, PhSiF₃, BF₃ · OEt₂, F₂BN(SiMe₃)₂ and PF₃ leads to the substitution products 2–6 . The 1,2-diaza-3-bora-5-silacyclopentane 7 is formed by heating (Me₃Si)₂N? N(SiMe₃)(BFNSiMe₃)₂ ( 5 ) at 250°C. In the reaction of (Me₃Si)₂N? N(SiMe₃)PF₂ ( 6 ) with lithiated tert.-butyl(trimethylsilyl)amine the hydrazino-iminophosphene (Me₃Si)₂N? N = P? N(SiMe₃)(CMe₃) ( 8 ) is obtained. In the molar ratio 2:1 1 reacts with SiF₄ and BF₃ · OEt₂ to give bis[tris(trimethylsilyl)hydrazino]silane 9 and -borane 10 .     

Zur Reaktion des 1-Lithio-3-(trimethylsilyl)-2,2,4,4,6,6-hexamethylcyclotrisilazans mit Silicium-Fluor-Verbindungen

The Reaction of 1-Lithio-3-(trimethylsilyl)-2,2,4,4,6,6-hexamethylcyclotrisilazane with Silicon-Fluoro Compounds 1-lithio-3-(trimethylsilyl)-2,2,4,4,6,6-hexamethylcyclotrisilazane reacts with fluoroorganylsilanes RR′SiF₂ (R = F, CH₃, sec-C₄H₉; R′ = CH₃, sec-C₄H₉, C₆H₅) to give mono- and disubstituted trimethylsilylhexamethylcyclotrisilazanes and LiF. The mass-, ¹H- and ¹⁹F-n.m.r. spectra are reported.     

Bildung siliciumorganischer Verbindungen. 70 [1]. Reaktionen Si-fluorierter 1,3,5-Trisilapentane mit CH3MgCl und LiCH3

Formation of Organosilicon Compounds. 70. Reactions of Si-fluorinated 1,3,5-Trisilapentanes with CH₃MgCl and LiCH₃ F₃Si? CCl₂? SiF₂? CH₂? SiF₃ 3 reacts with meMgCl. (me = Ch₃ starting with a Si-methylation and not with a C-metallation as in the corresponding Si- and C-chlorinated compounds, e. g. (Cl₃Si? CCl₂)₂SiCl₂ [2]. A CCl-hydrogenation is observed too, which in the case of F₃Si? CCl₂? SiF₂? CHCl? SiF₃ 4 gives meS₃Si? CCl₂? Sime₂? CH₂? Sime₃. (F₃Si? CCl₂)_{2 5} reacts with meMgCl to form preferentially 1,2-Disilapropanes by cleaving a Si? Cbond. The isolation of F₃Si? CCl₂H and meF₂Si? CCl₂? SiF₂me allows to locate the bond where 5 is cleaved at the beginning of the reaction. With meLi 5 reacts to form mainly me₃Si? C?C? Sime₃, showing that in the reaction of meLi, being a stronger reagent than meMgCl, and 5 a C-metallation occurs, following the same mechanism as in the reaction with (Cl₃Si? CCl₂)₂)SiCl₂ [2]. The reaction conditions for the synthesis of Si-fluroinated and C-chlorinated 1,3,5-Trisilapentanes in a 0.1 mol scale are reported. N.m.r. data of all investigated compounds are tabulated.     

Acyclische und cyclische Silylhydrazone und Hydrazonylsilane

Acyclic and Cyclic Silylhydrazones and Hydrazonylsilanes Dimethylketone-di-tert-butylmethylsilylhydrazone ( 1 ) is obtained in the reaction of the silylhydrazine and dimethylketone by condensation. Di-tert-butyldifluorosilane reacts with lithiated hydrazones to give fluorosilylhydrazones 2–4 , (CMe₃)₂SiF? NH? N = CRR′, ( 2 : R=Me, R′=CMe₃; 3 : R,R′=CHMe₂; 4 : R,R′=Ph). The bis(hydrazonyl)silane 5 , (CMe₃)₂Si(NH? N=CPh₂)₂, is formed in a molar ratio 1:2. Tris( 6 )- and tetrakis(hydrazonyl)silanes ( 7 ) are obtained from CMe₃SiF₃ ( 6 ), SiF₄ ( 7 ), and lithiated tert-butylmethylketon-hydrazone. The lithium derivatives 8–11 are formed in the reaction of 1–4 with butyllithium. Bis(silyl)hydrazones ( 12–15 ) are the result of the reaction of halogensilanes and the lithium derivatives of 1(8), 2(9) and 3(10); 12 : (CMe₃)₂SiMe(CMe₃SiF₂)-N? N=CMe₂, 13 : (CMe₃)₂MeSi(PhSiF₂)N? N=CMe₂, 14 : (CMe₃)₂SiF(Me₃Si)N? N=C(Me)(CMe₃), 15 : (CMe₃)₂SiF (SiMe₃)N? N=C(CHMe₂)₂. Saltelimination out of 10 und 11 leads to the formation of the first bis(imino)-2,2,4,4-cyclodisilazanes, 16 :[(CMe₃)₂ SiN? N=C(CHMe₂)₂]₂, 17 : [(CMe₃)₂SiN? N=CPh₂]₂. Cyclisation occurs in the reaction of 12 und 14 with tert-butyllithium, 2-silyl-1,2-diaza-3-sila-5-cyclopentenes ( 18 and 19 ) are formed. Dilithiated 1 reacts with SiF₄ to give the spirocyclic compound 20 . HF-elimination from 18 and dimerisation of the intermediate diazasilacyclopentadiens lead to the formation of the tricyclus 21 .     

N-Silylierung und Si?O-Bindungsspaltung bei der Reaktion lithiierter Siloxy-silylamino-silane mit Chlortrimethylsilan

N-Silylation and Si? O Bond Splitting at the Reaction of Lithiated Siloxy-silylamino-silanes with Chlorotrimethylsilane Lithiated Siloxy-silylamino-silanes were allowed to react in tetrahydrofurane (THF) and in n-octane (favoured) and n-hexane, resp., with chlorotrimethylsilane. The monoamide (Me₃SiO)Me₂Si(NLiSiMe₃) gives in THF and in n-octane the N-substitution product (Me₃SiO)Me₂Si · [N(SiMe₃)₂] 1 , the diamide (Me₃SiO)MeSi(NLiSiMe₃)₂ only in THF the N-substitution products (Me₃SiO)MeSi[N(SiMe₃)₂]₂ 2 (main product) and (Me₃SiO)MeSi[N(SiMe₃)₂](NHSiMe₃) 3 . In n-octane the diamide reacts mainly under Si? O bond splitting. The cyclodisilazane [(Me₃SiNH)MeSi? NSiMe₃]₂ 6 is obtained as the main product. Byproducts are 2, 3 and the tris(trimethylsilylamino) substituted disilazane (Me₃SiO)(Me₃SiNH)MeSi? N · (SiMe₃)? SiMe(NHSiMe₃)₂ 7 . The triamide (Me₃SiO)Si · (NLiSiMe₃)₃ reacts under Si? O and Si? N bond splitting in n-octane as well as in THF. The cyclodisilazanes [(Me₃SiNH)₂ · Si? NSiMe₃]₂ 10 and ( 11 : R = Me₃SiNH, 12 : R = (Me₃Si)₂N) are formed. in THF furthermore the N-substitution products (Me₃SiO)Si[N(SiMe₃)₂] · (NHSiMe₃)₂ 4 and (Me₃SiO)Si[N(SiMe₃)₂]₂(NHSiMe₃) 5 . The Si? O bond splitting occurs in boiling n-octane also in absence of the chlorotrimethylsilane. An amide solution of (Me₃SiO)MeSi(NHSiMe₃)₂ with n-butyllithium in the molar ratio 1 : 1 leads in n-octane and n-hexane to 6 and 7 , in THF to 3 . The amide solutions of (Me₃SiO)Si · (NHSiMe₃)₃ with n-butyllithium the molar ratio 1 : 1 and 1 : 2 give in THF 4 and 5 , respectively.     

Solid state reactions of hexafluorosilicates

At beginning thermal decomposition K₂[SiF₆] loses SiF₄-planes from [SiF₆]^2?-octahedrons, which has been proved by x-ray-diffraction [1], [2]. Analogous disorder structures are supposed to be present with all solids having complex ions including carbonates, sulfates and others. The result is a high reactivity at this spots. Another reactive form in hexefluorosilicates is represented by mobile SiF-species, perhaps SiF₃⁺. The reactivity is shown by heterogenous reactions with CHCl₃ and by solid-solid reactions for instance with halides, oxides etc. As an example corundum (α-Al₂O₃) reacts at 600°C giving K₃ AlF₆ and KAlSiO₄ [3].     

Quantenchemische Modellrechnungen zur Baugruppenwanderung in Hexafluorosilicaten

Quantum Chemical Model Calculations on the Migration of Si? F Groups in Hexafluorosilicates The transport of different Si? F species was simulated using two [SiF₆]^2? octahedra as example. Activation barriers and charge distributions were calculated with the EHT method. Bearing in mind the structure of cubic hexafluorosilicates calculations were carried out on the migration both along an edge and along a (110) face of the elementary cell. At first [SiF₂]²⁺ and SiF₄ groups were removed from an [Si₂F₁₂]^4? unit to produce a surface vacancy. During a second step planar SiF₄ groups were moved to the neighbouring lattice position. A diffusion of planar SiF₄ is favoured, if the electrostatic interaction between moved and fixed fluorine atoms is as small as possible.     

Lithio-di-t-butylfluorsilylphenylphosphan; im Kristall ein (SiFLiP)2-Achtring

Di-t-butylfluorosilylphenylphosphane (I) reacts with CMe₃Li to give the lithium compound [(CMe₃)₂SiFLi(THF)₂PC₆H₅]₂ (II) and butane. The crystal structure of II has been determined. The SiP bond length (217.1 pm) in the eight-membered ring is extremely short. The SiP spin coupling constant (84.12 Hz) in II is remarkably large. LiF elimination from II leads to the formation of the four-membered (SiP) ring III. The bis(fluorosilyl)phosphane IV is formed in the reaction of II with Me₂SiF₂.     

Über die Si---N-bindung : XLIV. Die umsetzung von benzophenon mit bis- und tris(trimethylsilyl)amin

The thermal LiHal elimination of

- and

functional compounds provides a simple synthetic route to four-membered SiC and SiN rings. In attempts to inhibit dimerisation sterically, bulky silylmethyl and silylamino substituents were introduced (I–III). (Me₃Si)₃CSiF₂R reacts with LiNHR′, 1,3- migration of a silyl group from carbon to the nitrogen (I, R′= 2,4,6-Me₃C₆H₂) taking place. Substitution occurs for R′ = SiMe₂CMe₂, (II, III) only.Dichloro-bis(trimethylsilyl)methane reacts with halogenosilanes and lithium in THF to give bis(trimethylsilyl)-halogenosilaethanes (Me₃Si)₂CHSi(Hal)RR′; R= Me, R′ = N(SiMe₃)₂, IV, Hal = F; V, Hal = Cl. However a reductive THF cleavage accompanied by a silyl group migration to the oxygen occurs and 1-halogenosilyl-1- trimethylsilyl-5-trimethylsiloxi-pent-1-ene,(Me₃Si)(RR′SiHal)CCH(CH₂)₃OSiMe₃, Are The main products (VII–X) of these reactions. Disubstitution occurs with F₃Si-i-Pr (VI). (Me₃Si)₃CSiFNHSiMe₂CMe₃ (II) reacts with C₄H₉Li in a molar ratio $\text{1}\text{2}$ to give an 1-aza-2,3-disilacyclobutane (XI), involving substitution, LiF elimination, and nucleophilic migration of a methanide ion of the unsaturated precusor.(Me₃Si)₂CHSiFMeN (2,4,6-Me₃C₆H₂)SiMe₃ cyclizes under comparable conditions in the reaction with MeLi via a methylene group of the mesityl group (XII).     

tert‐Butyldiphenylsilylhydrazin – ein Baustein für Tetrakis‐silylhydrazine,Silylhydrazone und O‐Silylpyrazolone

tert ‐Butyldiphenylsilylhydrazine – Precursors for Tetra(silyl)hydrazines, Silylhydrazones, and O‐Silylpyrazolones tert‐Butylchlorodiphenylsilane reacts with hydrazine in presence of triethylamine to give the mono(silyl)hydrazine Me₃CSiPh₂NHNH₂ ( 1 ). The lithium derivative of 1 ( 1 a ) forms the N,N′‐bis(silyl)hydrazines 2 and 3 in the reaction with chlorosilanes. ( 2 : Me₃CSiPh₂NHNHSiPh₂CMe₃; 3 : Me₃CSiPh₂NHNHSiMe₂CMe₃). The monomeric dilithiumhydrazide 4 , (Me₃CSiPh₂)₂N₂Li₂(THF)₃, is obtained from 2 and the bimolar amount of C₄H₉Li in THF. 4 reacts with an excess of SiF₄ to give the tetra(silyl)hydrazine 5 , Me₃CSiPh₂(SiF₃)N–N(SiF₃)SiPh₂CMe₃. 1 and ketones undergo condensation to silylhydrazones, Me₃CSiPh₂NHN=C(Me)R ( 6 : R = Me; 7 : R = CMe₃), with elimination of H₂O. Only one of the two possible isomers of 7 is formed. Cis/trans isomers ( 8 a , b ) are obtained in the analogous reaction of 1 and ethyl acetoacetate, Me₃CSiPh₂NH–N=CMe–CH₂–COOEt ( 8 a , b ). 8 condenses thermally with elimination of EtOH and formation of the O‐silylpyrazolone 9 , Me₃CSiPh₂O–(C=N–NH–CMe=CH–). The results of the crystal structure analysis of the compounds 2 , 4 , and 7 are reported.     

Quantenchemische Untersuchungen zur Stabilität von Si—F-Spezies

Quantumchemical Investigations on the Stability of Si? F Species Semiempirical MO calculations (EHT, CNDO/2) have been used to examine the stability of Si—F-species (SiF₆^2?, SiF₄ planar and tetrahedral, SiF₃⁺ planar and pyramidal, and SiF₂ (SiF₂²⁺) linear and angled). The calculations showed, that the appearance of planar structures is possible from the energetical point in solid state reactions. In the case of SiF₂ (SiF₂²⁺) it was not possible to find an energetic difference between linear and not linear forms. The neutral form is energetic more stable than SiF₂²⁺. A comparison of investigated species shows, that with growing bonding angle and in this way with decreasing number of fluorine atoms in the molecule the bond lengths are decreased. The EHT-bond energies become more negative in the same way.     

Synthese neuer Aminofluorsilane,sowie Alkoxylierung von Bis (trimethylsilyl)-amino-fluorsilanen

The reaction of aminofluorsilanes of the type (R=H,F) (Me ₃Si)₂N?SiF₂R with two moles of ammonia, or of a mono- or dialkylamine, yields the corresponding amino-compounds, e.g. (Me ₃Si)₂N?Si(F)R?NH₂, (Me ₃Si)₂N?Si(F)R?NHR′ and (Me ₃Si)₂N?Si(F)R?NR₂′ (R′=Me, Et). Analogous products are obtained by reaction of the aminofluorosilanes with lithium salts of amines with bulky organic substituents in a 1 : 1 molar ratio. Alkoxy- and aryloxyaminofluorosilanes are prepared by the reaction of sodium alcoholates and sodium phenolate with (Me ₃Si)₂N?Si(F₂)R (R=H, C₂H₃, C₂H₅, C₆H₅). The i.r.-, mass-,¹H- and¹⁹F-NMR spectra of the above compounds are reported.     

Darstellung,Charakterisierung und Reaktionsverhalten von Natrium‐ und Kaliumhydridosilylamiden R2(H)Si—N(M)R′ (M = Na,K) — Kristallstruktur von [(Me3C)2(H)Si—N(K)SiMe3]2·THF

Preparation, Characterization and Reaction Behaviour of Sodium and Potassium Hydridosilylamides R₂(H)Si—N(M)R′ (M = Na, K) — Crystal Structure of [(Me₃C)₂(H)Si—N(K)SiMe₃]₂ · THF The alkali metal hydridosilylamides R₂(H)Si—N(M)R′ 1a‐Na — 1d—Na and 1a‐K — 1d‐K ( a : R = Me, R′ = CMe₃; b : R = Me, R′ = SiMe₃; c : R = Me, R′ = Si(H)Me₂; d : R = CMe₃, R′= SiMe₃) have been prepared by reaction of the corresponding hydridosilylamines 1a — 1d with alkali metal M (M = Na, K) in presence of styrene or with alkali metal hydrides MH (M = Na, K). With NaNH₂ in toluene Me₂(H)Si—NHCMe₃ ( 1a ) reacted not under metalation but under nucleophilic substitution of the H(Si) atom to give Me₂(NaNH)Si—NHCMe₃ ( 5 ). In the reaction of Me₂(H)Si—NHSiMe₃ ( 1b ) with NaNH₂ intoluene a mixture of Me₂(NaNH)Si—NHSiMe₃ and Me₂(H)Si—N(Na)SiMe₃ ( 1b‐Na ) was obtained. The hydridosilylamides have been characterized spectroscopically. The spectroscopic data of these amides and of the corresponding lithium derivatives are discussed. The ²⁹Si‐NMR‐chemical shifts and the ²⁹Si—¹H coupling constants of homologous alkali metal hydridosilylamides R₂(H)Si—N(M)R′ (M = Li, Na, K) are depending on the alkali metal. With increasing of the ionic character of the M—N bond M = K > Na > Li the ²⁹Si‐NMR‐signals are shifted upfield and the ²⁹Si—¹H coupling constants except for compounds (Me₃C)(H)Si—N(M)SiMe₃ are decreased. The reaction behaviour of the amides 1a‐Na — 1c‐Na and 1a‐K — 1c‐K was investigated toward chlorotrimethylsilane in tetrahydrofuran (THF) and in n‐pentane. In THF the amides produced just like the analogous lithium amides the corresponding N‐silylation products Me₂(H)Si—N(SiMe₃)R′ ( 2a — 2c ) in high yields. The reaction of the sodium amides with chlorotrimethylsilane in nonpolar solvent n‐pentane produced from 1a‐Na the cyclodisilazane [Me₂Si—NCMe₃]₂ ( 8a ), from 1b‐Na and 1‐Na mixtures of cyclodisilazane [Me₂Si—NR′]₂ ( 8b , 8c ) and N‐silylation product 2b , 2c . In contrast to 1b‐Na and 1c‐Na and to the analogous lithium amides the reaction of 1b‐K and 1c‐K with chlorotrimethylsilane afforded the N‐silylation products Me₂(H)Si—N(SiMe₃)R′ ( 2b , 2c ) in high yields. The amide [(Me₃C)₂(H)Si—N(K)SiMe₃]₂·THF ( 9 ) crystallizes in the space group C2/c with Z = 4. The central part of the molecule is a planar four‐membered K₂N₂ ring. One potassium atom is coordinated by two nitrogen atoms and the other one by two nitrogen atoms and one oxygen atom. Furthermore K···H(Si) and K···CH₃ contacts exist in 9 . The K—N distances in the K₂N₂ ring differ marginally.     

Zwei Wege zu Si-funktionellen Cyclosilazanen – Kristallstruktur des 1,3,6,8,10,12-Hexa-aza-2,4,5,7,9,11-hexasila-dispiro[4.1.4.1]dodecan

Two Ways to Si-functional Cyclosilanes — Crystal Structure of 1,3,6,8,10,12-Hexa-aza-2,4,5,7,9,11-hexasila-dispiro [4.1.4.1]dodecan Aminochlorosilanes [RSiCl₂NHCMe₃, R ? Cl ( 1 ), H ( 2 )] are obtained in the reaction of the chlorosilanes with LiNHCMe₃. HSiCl₂N(iso-Bu)SiMe₃ ( 3 ) is formed in the reaction of HSiCl₃ and LiN(iso-Bu)SiMe₃. HSiCl₃ reacts with LiN(CMe₃)SiMe₃ under LiCl and Me₃SiCl elimination to give the cyclodisilazane [(HSiCl? NCMe₃)₂ ( 4 )]. In addition to C₆H₅SiCl₂N(CMe₃)SiMe₃ ( 5 ), the main product of the reaction of trichloro-phenylsilane with LiN(CMe₃)SiMe₃ is C₆H₅SiCl₂NHCMe₃ ( 6 ). 3 loses Me₃SiCl thermally, giving the cyclotrisilazane [(HSiCl? N? iso-Bu)₃ ( 7 )]. 5 loses iso-butane thermally with formation of C₆H₅? SiCl₂? NH? SiMe₃ ( 8 ). 1 , 2 and 6 react with LiC₄H₉ under butane and LiCl elimination to give the cyclodisilazes [(RSiCl? NCMe₃)₂, R ? H ( 4 ), Cl ( 9 ), C₆H₅ ( 10 )]. 4 is fluorinated to (HSiF? NCMe₃)₂ ( 11 ) by NaF. The alcoholysis of 4 leads to the formation of [(H(RO)Si? NCMe₃)₂, R ? Me ( 12 ), C₆H₅ ( 13 )], the aminolysis to [(H(NR₂)Si? NCMe₃)₂, R ? Me ( 14 ), C₂H₅ ( 15 )], only one chloro atom of 4 is substituted in the reaction with H₂NCMe₃ ( 16 ). 4 reacts with lithium to give the 1,3,6,8,10,12-hexa-aza-2,4,5,7,9,11-hexasila-dispiro[4.1.4.1]dodecan ( 17 ), for which the crystal structure is reported.     

2,4‐Disila‐1,3,5‐oxadiazin,Cyclodisilazan‐Carbonsäure‐silylamid und ‐silylester

The lithium salts of the Me₃Si‐ as well as Me₃Si‐ and Me₂SiF‐substituted Cyclotrisilazanes I and II react with tert‐butylacylchloride under ring contraction and formation of the cyclodisilazane‐silylester, Me₃SiN(SiMe₂–N)₂SiMe₂–O–CO–CMe₃ ( 1 ). The lithium salt of the fluorodi‐methylsilyl‐substituted cyclotrisilazan III forms with benzoylchloride primarily in the analogous reaction the carboxy‐silyl‐amide, Me₂SiF(N–SiMe₂)₂SiMe₂–NH–CO–C₆H₅⁺ ( 2 ), which can be converted with III and benzoylchloride into the cyclodisilazane‐silylester, Me₂SiF(NSiMe₂)₂SiMe₂–O–CO–C₆H₅, ( 3 ). A silylester substituted six‐membered disila‐oxadiazine ( 4 ) is the result of the reaction of the lithiated cyclotrisilazane, (Me₂SiNH)₂, (Me₂SiNLi) with tert‐butyl‐acylchloride. The reaction includes anionic ring contraction and can be rationilized by a process analogous to keto‐enol‐tautomerism. Dilithiated octamethyl‐cyclotetrasilazane, (Me₂SiNHMe₂SiNLi)₂, reacts with tert‐butyl‐acylchloride or benzoylchloride in a molar ratio 1:2 to yield symmetrically acylestersubstituted cyclodisilazanes, (RCO–O–SiMe₂–NSiMe₂)₂, R = C₆H₅ ( 5 ), CMe₃ ( 6 ). The reaction mechanisms are discussed and the crystal structures of 2 and 6 are reported.     

Interaction of Fluosilicic Acid with <Emphasis Type="Italic">N-tert</Emphasis>-Butyl-Substituted Urea. Crystal Structure of <Emphasis Type="Italic">N,N</Emphasis>-Di-<Emphasis Type="Italic">tert</Emphasis>-butylurea

Fluosilicic acid reacts with solutions of N,N-di-tert-butylurea (DTBU) in methanol or acetone to form crystalline compounds 2DTBU ? H₂SiF₆ and 2DTBU ? H₂SiF₆ ? Me₂CO, which were characterized by the IR and ¹⁹F NMR spectra and mass spectroscopy supplemented by theoretical calculations. According to the data of IR and ¹⁹F NMR spectra, the complexes are hexafluorosilicates of O-protonated DTBU. They undergo hydrolysis in organic media with water traces; their solubility in water is very low (0.10 and 0.14 wt %, respectively). In the DTBU structure, two independent ligand molecules are joined by hydrogen bonds NH?O(N?O) 2.888(5)–2.944(5) Å).     

Substitutionsreaktionen mit Schwefeldiimiden

Substitution Reactions with Sulphur Diimides Substituted sulphur diimides are obtained by the reactions of (CH₃)₃Si? N?S?N? Si(CH₃)₃ with CH₃SO₂Cl and CCl₃SCl or with P₂O₃F₄ and (CH₃)₃Si? N?S?N? SN(CH₃)₂. S₄N₄ reacts with (CH₃)₂Si[N(CH₃)₂]₂ to from (CH₃)₂Si(N(CH₃)₂)? N?S?N? SN(CH₃)₂ while S₃N₂Cl₂ yields (CH₃)₂Si(Cl)? N?S?N? SN(CH₃)₂. It is possible to substitute the chlorine atom by diethylamine in the last compound. The new compounds are intermediates for the syntheses of cyclic sulphur-nitrogen compounds. They were characterized by mass-, ir-, ¹H-nmr spectra and elemental analysis.     

Unusual transformations of difluorosilanone F<Subscript>2</Subscript>Si=O

The structure and properties of fluorosilicon polymer (fluorosil) formed by the reaction of phenyltrifluorosilane with aliphatic alcohols have been studied by the methods of IR, ¹⁹F, ²⁹Si NMR spectroscopy, high temperature mass-spectrometry, derivatography and atom emission analysis. Due to its high reactivity, this polymer readily reacts with glass of the reaction vessel extracting the ions of all metals entering into its composition. Fluorosil formed in a quartz, teflon or polypropylene reactors is characterized by low stability and is slowly decomposed to SiF₄ and SiO₂. Apparently, fluorosil is the product of incorporation of SiF⁴ into the SiO₂ matrix.     

Zur Kenntnis der Chemie der Silazane. IV. Über ein Sulfurylphosphazo-silazan

Trichlorophosphazo-sulphurylchloride. Cl₃P?N? SO₂Cl, reacts with heptamethyldisilazane to yield the Si? N? P compound (I) formulated in ?Inhaltsübersicht”?. (I) reacts with PCl₅ or C₆H₅? PCl₄ forming the known 2,2,2,4,4,4-hexachloro-1,3-di-methylcyclo-diphosphazane(II), accompanied by the compound Cl₃P?N? SO₂Cl and C₆H₅? PCl₂?N? SO₂Cl, respectively, which were detected by means of ³¹P-NMR spectroscopy.