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1.
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.  相似文献   

2.
29Si Chemical Shifts of Alkoxy(amino)silanes The 29Si NMR spectra of a series of alkoxy(amino)silanes (RO)nMe3?nSiNHC6H4X (n = 1–3) have been measured and are discussed by means of relative paramagnetic screening constants σ*, calculated by a simplified quantum-chemical model. The Hammett plots of the silicon chemical shift show both positive and negative slopes with changes of the number of electronegative atoms (O, N) attached to silicon. The steric and electronic shift contributions of the alkoxy groups are given.  相似文献   

3.
Spectroscopic Investigations on Substituent Effects in Silylmethylsilanes The silanes Me3?n(Me3SiCH2)nSiH (n = 1–3), (RMe2SiCH2)3SiH (R = n-Bu, n-Pr, Et, PhCH2, Ph) and Me3ElCH2SiMe2H (El = Ge, Sn) were prepared. The frequencies of the Si? H stretching vibration, the 29Si? 1H coupling constants and the 29Si n.m.r. chemical shifts were measured. The ?(SiH) and J(29Si? 1H) values in the silanes Me3?n(Me3SiCH2)nSiH depend on the number of trimethylsilymethyl groups. There is hardly an influence of the substituents R on these values in the silanes (RMe2SiCH2)3SiH. The frequencies of the Si? H stretching vibrations in the silanes Me3ElCH2SiMe2H (El = Si, Ge, Sn) show the order Si?Ge > Sn. The 29Si n.m.r. chemical shifts of the Si(H) signals are approximately equal in the silanes Me3?n(Me3SiCH2)nSiH and (RMe2SiCH2)3SiH.  相似文献   

4.
13C, 15N (at natural abundance) and 29Si NMR data (chemical shifts and coupling constants) are reported for aminosilanes R2R′SiNHR1 (1), bis(silyl)amines Me2R′SiNHSiMe3 (2), 1,2-bis(amino)-ethanes (3), bis(amino)silanes RR′Si(NHR1)2 (4), 1,2-bis(amino)tetramethyldisilanes (5) and 1,1,2,2-tetrakis(amino)dimethyldisilanes (6). The δ15N values depend more on the nature of the substituents R1(H, alkyl, aryl) at the nitrogen atom (in the same way as for other amines) than on different substituents at the silicon atom. A linear correlation between 1J(29Si15N) and 1J(29Si13C) is proposed for silanes in which the SiN unit is replaced by the SiCH unit. This correlation comprises all 1J(29Si15N) values for aminosilanes R4-nSi(N)n (n = 1–4) and—most likely—also for aminodisilanes, and it predicts 1J(29Si15N)>0 if the corresponding value |1J(29Si13C)|>25 Hz. For the first time a two-bond coupling across Si, 2J(29Si 15N) = 6.9 Hz, has been observed for 6a. In the case of 6b (R1 = sBu) all resonances for the diastereomers are resolved in the 15N and 29Si NMR spectra in contrast to the 1H and 13C NMR spectra.  相似文献   

5.
The 2,6-Diisopropyl-phenyl Group as a Bulky Substituent in Boron-Nitrogen Compounds 2,6-Diisopropylaniline (RNH2), the monosilylated derivative (RNH? SiMe3) and its lithium salt (RNLiSiMe3) have been reacted with F3B · OEt2 by variation of the reaction conditions. Products as RNH? BF? NR? BF? NHR, 1 , RNH? BF? NHR, 3 , Me3SiNR? BF2, 4 , and (Me3SiNR)2BF, 5 are thus obtained. Substitution of fluorine atoms in 4 by lithium organyls (R′Li) leads to aminoboranes of the type Me3SiNR? B(F)R′ (R′ = Me, CMe3, C6H5, NHR, N(SiMe3Si)2N), 7a–7e . Thermolysis of 7b gives the diazadiboretidine (? BCMe3? NR? )2, 8 . Attempted preparation of the corresponding amino-iminoborane by elimination of Me3SiF and HF from 5 or Me3SiNR? BF? NHR, 7d , yielded the benzoannelated heterocycle 6 and the 1,3-diaza-2-sila-4-bore-tidine 9 . The compounds are characterized by analyses and their mass and n.m.r. (1H, 11B, 13C, 15N, 19F, 29Si) spectra.  相似文献   

6.
Reactions of Lithium Hydridosilylamides RR′(H)Si–N(Li)R″ with Chlorotrimethylsilane in Tetrahydrofuran and Nonpolar Solvents: N‐Silylation and/or Formation of Cyclodisilazanes The lithiumhydridosilylamides RR′(H)Si–N(Li)R″ ( 2 a : R = R′ = CHMe2, R″ = SiMe3; 2 b : R = R′ = Ph, R″ = SiMe3; 2 c : R = R′ = CMe3, R″ = SiMe3; 2 d : R = R′ = R″ = CMe3; 2 e : R = Me, R′ = Si(SiMe3)3, R″ = CMe3; 2 f – 2 h : R = R′ = Me, f : R″ = 2,4,6‐Me3C6H2, g : R″ = SiH(CHMe2)2, h : R″ = SiH(CMe3)2; 2 i : R = R′ = CMe3, R″ = SiH(CMe3)2) were prepared by reaction of the corresponding hydridosilylamines RR′(H)Si–NHR″ 2 a – 2 i with n‐butyllithium in equimolar ratio in n‐hexane. The unknown amines 1 e – 1 i and amides 2 f – 2 i have been characterized spectroscopically. The wave numbers of the Si–H stretching vibrations and 29Si–1H coupling constants of the amides are less than of the analogous amines. This indicates a higher hydride character for the hydrogen atom of the Si–H group in the amide in comparison to the amines. The 29Si‐NMR chemical shifts lie in the amides at higher field than in the amines. The amides 2 a – 2 c and 2 e – 2 g react with chlorotrimethylsilane in THF to give the corresponding N‐silylation products RR′(H)Si–N(SiMe3)R″ ( 3 a – 3 c , 3 e – 3 g ) in good yields. In the reaction of 2 i with chlorotrimethylsilane in molar ratio 1 : 2,33 in THF hydrogen‐chlorine exchange takes place and after hydrolytic work up of the reaction mixture [(Me3C)2(Cl)Si]2NH ( 5 a ) is obtained. The reaction of the amides 2 a – 2 c , 2 f and 2 g with chlorotrimethylsilane in m(p)‐xylene and/or n‐hexane affords mixtures of N‐substitution products RR′(H)Si–N(SiMe3)R″ ( 3 a – 3 c , 3 f , 3 g ) and cyclodisilazanes [RR′Si–NR″]2 ( 6 a – 6 c , 6 f , 6 g ) as the main products. In case of the reaction of 2 h the cyclodisilazane 6 h was obtained only. 2 c – 2 e show a very low reactivity toward chlorotrimetyhlsilane in m‐xylene and toluene resp.. In contrast to Me3SiCl the reactivity of 2 d toward Me3SiOSO2CF3 and Me2(H)SiCl is significant higher. 2 d react with Me3SiOSO2CF3 and Me2(H)SiCl in n‐hexane under N‐silylation to give RR′(H)Si–N(SiMe3)R″ ( 3 d ) and RR′(H)Si–N(SiHMe2)R″ ( 3 d ′) resp. The crystal structures of [Me2Si–NSiMe3]2 ( I ) ( 6 f , 6 g and 6 h ) have been determined.  相似文献   

7.
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.  相似文献   

8.
Basicity and 29Si N.M.R. Spectroscopic Investigations of Ethoxysiloxanes Ethoxysiloxanes of the types (RMe2SiO)3SiOEt, Me3?n(R3SiO)nSiOEt, [(Me3SiO)3SiO]n(Me3SiO)3?nSiOEt (n = 1–3), and (Me3SiO)3Si[OSi(OSiMe3)2]2OEt have been prepared. The relative basicity of the (Si)OEt group and the 29Si n.m.r. chemical shifts of the Si(OEt) signal were determined. The relative basicity as well as the 29Si n.m.r. chemical shifts depend on the kind and number of the siloxy groups. Basicity and 29Si n.m.r. chemical shifts of the respective types of compounds are connected directly with each other.  相似文献   

9.
29Si, 13C and 1H NMR spectra are reported for the series of linear permethylpolysilanes Me(SiMe2)nMe where n = 1 to 6, for the cyclic permethylpolysilanes (Me2Si)n where n = 5 to 8, and for a few related compounds. For linear polysilanes the 29Si and 13C chemical shifts can be accurately calculated from simple additivity relationships based on the number of silicon atoms in α, β, γ and δ positions. Adjacent (α) silicon atoms lead to upfield shifts in the 29Si and 13C resonances, whereas more remote silicon atoms lead to downfield shifts. The 29Si chemical shifts of the polysilane chains are linearly related to the 13C shifts of the carbon atoms attached to the silicon. The 29Si and 13C resonances of the cyclic silanes deviate from this relationship. Ring current effects arising from σ delocalization are suggested as an explanation for the deviations. Proton-coupled 29Si NMR spectra are reported for Me3SiSiMe3 and for (Me2Si)n, n = 5 to 7.  相似文献   

10.
Abstract

Aminophosphine des Typs Rn P(NR′2)3-n (n= 2, 1, 0; R = Ph, c-Hex, (-)Men, t-Bu; R′= Me, Et, n-Bu) reagieren mit 2, 4-Bis(aryl)-1, 3, 2, 4-dithiadiphosphetan-2, 4-disulfiden (ArPS2)2(Ar: Ph, 4-Methoxyphenyl = An, Naphthyl, Thienyl) unter formaler Insertion monomerer {ArPS2)-Einheiten in eine oder in zwei der λ3-P—N-Bindung zu chiralen Organophosphorverbindungen Ar(R′2N)P(S)—S—PRn (NR′2)2-n(n = 2, 1, 0) und [Ar(R′2N)P(S)—]2PR2(NR′2)1-n (n = 1.0). In diesen werden bei Raumtemperatur bevorzugt die λ3—P—N—und λ3—P—S-Bindungen durch H2O oder Methanol unter Bildung von Produktgemischen solvolysiert. Mit Chlorwasserstoff bildet sich aus An(Et2N)P(S)—S—PPh(NEt2) das An(Et2 N)P(S)—S—PPh(C1). Addition von Schwefel führt zu Ar(R′2N)P(S)—S—P(S)Rn (NR′)2-n (n=2, 1). Die Stereoisomerenbildung der neuen Verbindungen wird besprochen und ihre Struktur sowie die Zusammensetzung der Reaktionsmischungen aus den 31P-Spektren hergeleitet.

Aminophosphines Rn P(NR′2)3-n (n = 2, 1, 0; R = Ph. c-Hex, (-)Men, t-Bu; R′= Me, Et, n-Bu) react with 2, 4-Bis(aryl)-1, 3, 2, 4-dithiadiphosphetane-2, 4-disulfides (ArPS2)2 (Ar: Ph, 4-Methoxyphenyl = An, Naphthyl, Thienyl) under formal insertion of monomeric {ArPS2)-units in one or in two of the λ3-P—N-bonds to yield chiral organophosphorus compounds Ar(R′2N)P(S)—S—]2PRn (NR′2)2 (n = 2, 1, 0) and [Ar(R′2N)P(S)—S—]2 PR2 (NR′2)2-n (n = 1, 0). At room temperature chiefly the A—P—N and A3—P—S-bonds in these products are solvolyzed by H, O or methanol with formation of mixtures of compounds. With hydrogen chloride An(Et2N)P(S)—S—PPh(NEt2) is converted into An(Et2N)P(S)—S—PPh(Cl). Addition of sulfur yields Ar(R′2N)P(S)—S P(S)Rn (NR′2)2-n (n = 2, 1). Stereoisomerism of the new compounds is discussed and their structures as well as the composition of reaction mixtures are deduced from “P-NMR-spectra”.  相似文献   

11.
Preparation and Spectroscopic Properties of Alkoxyaminosilanes (RO)nMe3–nSiNHC6H4X By reaction of chlorosilanes with anilines and aminolysis of silylamines 22 new alkoxyaminosilanes of general formula (RO)nMe3-nSiNHC6H4X, n = 0, 1, 2, 3 have been prepared. Their IR und 1H-NMR spectra were measured and the influence of variabel polarizability effects of the (RO)nMe3-nSi groups on the Hammett's correlations of Δv and δ of the N? H proton were discussed.  相似文献   

12.
Metalla- and Phosphaheterocycles with Diaminosupermesitylboryl Units RB(NMeLi)2 is reacted with dimethylmetaldichlorides to give four membered (n = 1) metallacycles of the type (? RB? NMe? MMe2? NMe? )n (M = Si, IIa ; M = Ge, IIb ) and the eight membered ring (n = 2) with M = Sn, III . The four membered ring (? RB? NMe? PCMe3? NMe? ), IV , is formed with Me3CPCl2. RBF2 and lithiated N,N′-dimethylethylenediamine give the five membered ring RB(? NMe? CH2—)2, Va . The reaction of RB(NHMe)2 with trimethylaluminum upon elimination of methane yields the symmetrical eight membered ring system (? RB? NMe? AlMe? NMe? )2, VI . The compounds are characterized by their m.s. and n.m.r. (1H, 11B, 13C, 29Si, 31P, 119Sn and in part 15N) spectra, and with the exception of III and VI also by elemental analyses. An X-ray structure analysis is provided for III .  相似文献   

13.
Monomeric Dialkyl Metal Complexes of the R2M(NR′)2XR Type with M = Al, Ga, In, Tl; X = S, C and R, R′ = Alkyl and Silyl N,N′-Bis(trimethylsilyl)sulfurdiimide reacts with the trimethyl derivatives of aluminium, gallium, and indium within insertion. Hereby monomeric sulfinic acid imidamidates Me2M(NSiMe3)2SMe (Me = CH3) are formed. The lithium amidinates Li(NR′)2CMe (R′ = i-C3H7 and SiMe3) are formed likewise by insertion reactions with LiMe and the corresponding carbodiimides R′N?C?NR′ and were used in reactions with R2MCl (M = Al to Tl) to synthesize dialkyl metal amidinates R2M(NR′)2CMe. The NMR (1H and 13C) and the vibrational spectra (IR and Raman) are discussed and applied to describe the structure of these chelat complexes.  相似文献   

14.
I.R. and N.M.R. Spectroscopic Investigations on Substituent Effects in Siloxy and Alkoxysilanes Siloxy and alkoxysilanes of the types (RMe2SiO)3SiH, (RMe2CO)3SiH, (Me3–nPhnSiO)m(Me3SiO)3–mSiH (m = 1—3, n = 1—3), and Me3–n(RMe2SiO)nSiH (n = 1—3) have been prepared. The influence of the substituent effects through the (Me2)Si? O- a (Me2)C? O- group on the Si? H band is approximately equal.  相似文献   

15.
Cyclic Titanium Amides with Sila-titana-diazacyclobutane Structure N,N′ dilithiated diaminosilanes Me2Si(NHR)2, R = i-Pr, t-Bu and Me3Si, react with TiCl4 in a 2:1 ratio to form spirocyclic titanium amides ( B, C 1 ; see Inhaltsübersicht). In a 1:1 ratio or upon reaction with (R′2N)2TiBr2, R′ = Me, Et, titanacyclobutanes ( C 2—C 6 ) are obtained. Compounds with R = Me3Si exhibit particularly high thermal stability.  相似文献   

16.
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.  相似文献   

17.
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.  相似文献   

18.
The reaction of bis(trimethylsilyl)aminofluorsilanes, (Me3Si)2NSiF2R (R = CH3 or F), with sodium alcoholates or sodium phenylate yields under elimination of NaF alkoxy- and aryloxy-aminofluorosilanes of the composition (Me3Si)2NSiF(R)OR′(R′ = CH3, C2H5, C3H7, C6H5). A disiloxane is formed by thermal elimination of diethyl ether from bis(trimethylsilyl)aminomethylfluoroethoxysilane. The IR, mass, 1H and 19F NMR spectra of the above-mentioned compounds are reported. ab]Die Reaktion von Bis(trimethylsilyl)-aminofluorsilanen des Typs (Me3Si)2NSiF2R (R = F, CH3) mit Natriumalkoholaten und Natriumphenolat führt unter NaF-Abspaltung zu Alkyl- und Aryloxyaminofluorsilanen der Zusammensetzung: (Me3Si)2NSiF(R)OR′ (R′ = CH3, C2H7, C6H5, C6H5). Ein Disiloxan könnte durch die thermische Eliminierung von Diäthyläther aus Bis(trimethylsilyl)aminomethyl-fluor-äthoxy-silylarnin erhalten werden.Die IR-, Massen-, 1H- und 19F-NMR-Spektren der dargestellten Verbindungen werden mitgeteilt.  相似文献   

19.
Two series of diorganotin(IV) dialkyldithiophosphates, [RR′Sn{SSP(OR″)2}2](R = Me or Et; R′= Ph; R″ = Et, Prn, Pri or Bun) and [RR′Sn(Cl){SSP(OR″)2}] (R = R′= Me, Et or Ph; R″ = Ph; R″ = Et, Pri or Bun) were prepared and characterised by i.r. and NMR (1H, 13C, 31P, 199Sn) spectroscopy. The NMR data indicate five and six coordinate geometries for [RR′Sn(Cl){SSP(OR″)2}] and [RR′Sn{SSP(OR″)2}2] complexes, respectively. The chloro complexes showed 2J (PSn) whereas such couplings were not observed in the spectra of [RR′Sn{SSP(OR″)2}2].  相似文献   

20.
The 2,6-Diisopropyl-phenyl Group as a Bulky Substituent in Boron-Nitrogen Compounds. II Fluoro-bis(amino)boranes R′ (Me3Si)N–BF–NHR (R = 2,6-)Me2CH)2C6H3, R′ = Me ( Ia ), CH2Me ( Ib ), CHMe2 ( Ic ), CMe ( Id ), SiMe3 ( Ie ), R ( If ) react with t-butyllithium (molar ratio 1:1) by elimination of HF to give the amino-imino-boranes ( IIa – f ). The thermal stabilities of the latter depend upon the steric requirement of the substituent R′, IIa – c and IIe dimerize to yield the diazaboretidines IIIa – c and IIIe. IId remains unchanged at 200°C and above, and IIf isomerizes forming the B–Me substituted diazasilaboretidine IVf . If a twofold amount of t-butyllithium is employed, B–CMe3 substituted diazasilaboretidines ( Va – f ) are the main products. All compounds are characterized by elemental (C, H) analyses and their mass- and n.m.r. (1H, 13C, 15N (in part), 19F, 29Si) spectra. Characteristic i.r.-bands are reported for the amino-imino-boranes ( II ). An X-ray structure analysis is presented for IVf .  相似文献   

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