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1.
The plasmachemically activated reaction between N2 and SiCl4 leads via nitrogen atoms to numerous chlorosilazanes: NSi3Cl9, N2Si4Cl10, NSi4Cl11, N2Si4Cl12, N2Si5Cl14, N3Si6Cl15 (3 isomers), N2Si6Cl16 and some related compounds (NOSi4Cl11, N2O2Si6Cl14, N2OSi5Cl12). GeCl4 shows an similar behaviour. This could be shown by GC/MS‐investigations. The structures of N2Si5Cl14, N2Si6Cl16 and N3Si6Cl15 have been determined by quantum chemical methods. The angle sums around the N atoms are close to 360°.  相似文献   

2.
The reactions of Me2MCl2 (M = Si, Ge, Sn), Si2Me4Cl2, Si2Me2Cl3, Si2Me2Cl4 and CH2(SiCl2Me)2, and suitable mixtures thereof, with H2S / NEt3 and Li2E (E = Se, Te) have been investigated and lead to a variety of new group 14 chalcogenide systems.  相似文献   

3.
Schröder  D.  Schwarz  H. 《Russian Chemical Bulletin》2001,50(11):2087-2091
Sector-field mass spectrometry was used to probe the fragmentation patterns of the cationic silicon chlorides Si2Cln + (n = 1—6). For almost all Si2Cln + ions, Si—Si fragmentation predominates the Si—Cl bond cleavage both in the metastable ion and collisional activation mass spectra. Analysis of the fragmentation patterns indicates that the long-lived radical cation Si2Cl6 ·+ corresponds to a complex [SiCl2·SiCl4]·+ rather than the intact molecular ion of hexachlorodisilane. The behavior of Si2Cl5 + is consistent with the formation of the (trichlorosilyl)dichlorosilyl cation Cl3SiSICl2 +. Structural aspects are also discussed for the other Si2Cln + species. A semi-quantitative analysis of the fragmentation patterns in conjunction with the literature thermochemistry data was used to estimate some thermochemical properties of the Si2Cln + cations.  相似文献   

4.
A series of mono-bipy and -phen complexes (bipy = bipyridine, phen = phenanthroline) of the perhalodisilanes, Si2F6, Si2Cl6 and Si2Br6, mixed methylhalodisilanes (Si2MenX6?n, X = Cl, I; n = 2,3) and Si3Cl8 · bipy have been prepared by reaction of the components, and have been characterized. 11 complexes are obtained exclusively.The structures of all complexes involve coordination of the base to the more acidic silicon and perpendicular alignment of the SiSi axis on the plane of the ligand. This may be rationalised in terms of steric requirements of the different groups, the more demanding groups occupying the sterically more favorable positions vertical to the plane of the ligand. For Si3Cl8 · bipy, spectroscopic and chemical evidence suggests bipy-coordination to the center silicon. PMR investigations of the dissociation equilibria of the complexes in solution led to determination of the heats of formation of four of the complexes and to a qualitative estimation of the relative acceptor strengths of several disilanes. Contrary to expectation, silyl groups increase the acceptor strength of silicon considerably and in the order SiMe3 < SiMe2Cl < SiMeCl2 < SiCl3. The effect of a SiMe3, substituent group may be compared to that of Cl. Methylchlorosilyl groups may exceed the effect of Cl as indicated by the increase in acceptor strength in the sequence (R =) Me < Ci < SiMe2Cl < SiMeCl2 for the acceptor RSiCl2Me. Si3Cl8 is the strongest acceptor in the series. Assuming the structural suggestion for Si3Cl8 · bipy (center coordination) to be correct an increase in acceptor strength is indicated in the sequence SiCl3(Si2Cl5) < SiCl2(SiCl3)2 (Si = coordinating center). This may be interpreted mainly in terms of charge accepting capacity of the polarisable silyl groups. Another interesting sequence of acceptor strengths measured in this work is 1,1,2-Si2Me3F3, 1,2-Si2Me2F4 < Si2Me3Cl3 < 1,2-Si2Me2Cl4, showing fluorodisilanes to be weaker acceptors than chlorodisilanes. This result is compared to the heats of formation of SiX4 · 2py complexes.  相似文献   

5.
Of the two crystalline products obtained by reacting a silicon tetrachloride/nitrogen mixture in a glow discharge tube, the more volatile (m. p. 78°C) has been confirmed to be tris(trichlorosilyl)amine NSi3Cl9 whereas the less volatile component (m. p. 66°C) has been identified as N,N′-bis(trichlorosilyl)-Si,Si′-tetrachloro-cyclodisildiazane N2Si4Cl10. These conclusions are supported by mass and vibrational spectroscopy and single crystal X-ray structures. NSi3Cl9 possesses a nearly planar NSi3 skeleton with average N? Si distances of 1.734(2) Å. The N2Si4 fragment of N2Si4Cl10 is roughly planar with endocyclic N? Si? N and Si? N? Si angles of 89.2(1) and 90.8(1)°, respectively, and mean N? Si distances of 1.731(3) (endocyclic) and 1.687(3) Å (exocyclic).  相似文献   

6.
Pr4S3[Si2O7] and Pr3Cl3[Si2O7]: Derivatives of Praseodymium Disilicate Modified by Soft Foreign Anions For synthesizing both the disilicate derivatives Pr4S3[Si2O7] and Pr3Cl3[Si2O7], Pr, Pr6O11 and SiO2 are brought to reaction with S and PrCl3, respectively, in suitable molar ratios (850 °C, 7 d) in evacuated silica tubes. By using NaCl as a flux, Pr4S3[Si2O7] crystallizes as pale green, transparent single crystals (tetragonal, I41/amd, a = 1201.6(1), c = 1412.0(2) pm, Z = 8) with the appearance of slightly compressed octahedra. On the other hand, Pr3Cl3[Si2O7] emerges as pale green, transparent platelets and crystallizes monoclinically (space group: P21, a = 530.96(6), b = 1200.2(1), c = 783.11(8) pm, β = 109.07(1)°, Z = 2). In both crystal structures ecliptically conformed [Si2O7]6– units of two corner‐linked [SiO4] tetrahedra with Si–O–Si bridging angles of 131° in the sulfide and 148° in the chloride disilicate are present. In Pr4S3[Si2O7] both crystallographically independent Pr3+ cations show coordination numbers of 8 + 1 (5 S2– and 3 + 1 O2–) and 9 (3 S2– and 6 O2–). For Pr1, Pr2 and Pr3 in Pr3Cl3[Si2O7] coordination numbers of 10 (5 Cl and 5 O2–) and 9 (2 ×; 4 Cl and 5 O2– or 3 Cl and 6 O2–, respectively) occur.  相似文献   

7.
Formation of Organosilicon Compounds. 111. The Hydrogenation of Si-chlorinated, C-spiro-linked 2,4-Disilacyclobutanes with LiAlH4 or iBu2AlH. The Access to Si8C3H20 The hydrogenation of Si-chlorinated, C-spiro-linked 2,4-disilacyclobutanes containing C(SiCl3)2 terminal groups with LiAlH4 in Et2O proceeds under complete cleavage of the fourmembered rings and under elimination of one SiH3 group. Such, Si8C3Cl20 4 forms (H3Si)2CH? SiH2? CH(SiH3)? SiH2? CH(SiH3)2 4 α, and even Si8C3H20 4a with LiAlH4 forms 4 α. The hydrogenation of related compounds containing however CH(SiCl3) terminal groups similarly proceeds under ring cleavage but no SiH3 groups are eliminated. Such, (Cl3Si)CH(SiCl2)2CH(SiCl3) 41 forms (H3Si)2CH? SiH2? CH2(SiH3) 41 α. However, in reactions with iBu2AlH in pentane neither the disilacyclobutane rings are cleaved nor are SiH3 groups eliminated. Only by this method Si8C3H20 is accessible from 4 , Si6C2H16 3a from Si6C2Cl16 3 and Si4C2H12 41a from 41 . C(SiCl3)4 cleanly produces C(SiH3)4. Based on the knowledge about the different properties of LiAlH4 and iBu2AlH in hydrogenation reactions of disilacyclo-butanes it was possible to elucidate the composition and the structures of the hydrogenated derivatives of the product mixture from the reaction of MeCl2Si? CCl2? SiCl3 with Si(Cu) [1] and to trace them back to the initially formed Si chlorinated disilacyclobutanes Si6C2Cl15Me 34 , Si6C2Cl14Me2 35 , Si8C3Cl19Me 36 and Si8C3Cl18Me2 37 . Compound 4a forms colourless crystals of space group P1 with a = 799.7(6), b = 1263.6(12), c = 1758.7(14) pm, α = 103.33(7)°, β = 95.28(6)°, γ = 105.57(7)° and Z = 4.  相似文献   

8.
Zintl Anions of Silicon in the Halides La3Cl2Si3 and La6Br3Si7 La3Cl2Si3 and La6Br3Si7 are prepared at temperatures of around 950 °C from LaX3 (X = Cl, Br), La metal and Si as starting materials. La3Cl2Si3 crystallizes in C2/m with a = 1802(3), b = 420.6(4), c = 1058(2) pm, β = 97.9(2)°, and La6Br3Si7 in Pmmn mit a = 1686.9(2), b = 412.93(11), c = 1185.2(1) pm. In both compounds the Si atoms are located in trigonal prisms of La atoms, which are connected through common triangular and rectangular faces to form layers. The bromine atoms connect the metal atom double layers. In La3Cl2Si3 the Si atoms form zig‐zag chains, in La6Br3Si7 chains build up from ‐connected Si12 rings. Both compounds are metallic conductors.  相似文献   

9.
Formation of Organosilicon Compounds. 110. Reactions of (Cl3Si)2CCl2 and its Si-methylated Derivatives as well as of (Cl3Si)2CHCl, (Cl3Si)2C(Cl)Me and Me2CCl2 with Silicon (Cu cat.) The reactions of (Cl3Si)2CCl2 1 , its Si-methylated derivatives (Me3Si)2CCl2 8 , Me3Si? CCl2? SiMe2Cl 9 , (ClMe2Si)2CCl2 10 , Me3Si? CCl2? SiMeCl2 11 , Cl2MeSi? CCl2? SiCl3 12 as well as of (Cl3Si)2CHCl 38 , (Cl3Si)2CClMe 39 and of Me2CCl2 with Si (Cu cat.) in a fluid bed reactor ( 38 and 39 also in a stirred solid bedreactor) arc presented. While (Cl3Si)2CCl2 1 yields C(SiCl3)4 2 the 1,1,3,3-tetrachloro-2,2,4,4-tetrakis(trichlorsilyl)-1,3-disilacyclobutane Si6C2Cl16 3 and the related C-spiro linked disilacyclobutanes Si8C3Cl20 4 , Si10C4Cl24 5 , Si12C5Cl28 6 , Si14C6Cl32 7 this type of compounds is not obtained starting from the Si-methylated derivatives 8, 9, 10, 11 They Produce a number of variously Si-chlorinated and -methylated tetrasila- and trisilamethanes. However, Cl2MeSi? CCl2? SiCl3 12 forms besides of Si-chlorinated trisilamethanes also the disilacyclobutanes Si6C2Cl15Me 34 and cis- and trans Si6C2Cl14Me2 35 as well as the spiro-linked disilacyclobutanes Si8C3Cl19Me 36 , Si8C3Cl18Me2 37 . (Cl3Si)2CHCl 38 mainly yields HC(SiCl3)3 31 and also the disilacyclobutanes cis- and trans-(Cl3Si)HC(SiCl2)2CH(SiCl3) 41 and (Cl3Si)2C(SiCl2)2CH(SiCl3) 45 the 1,3,5-trisilacyclohexane [Cl3Si(H)C? SiCl2]3 44 as well as [(Cl3Si)2CH]2SiCl2, and (Cl3Si)2CClMe 39 mainly yields (Cl3Si)2C?CH2and (Cl3Si)2besides of HC(SiCl3)3, MeC(SiCl3)3and (Cl3Si)3C? SiCl2Me.,. Me2CCl2 59 mainly yields Me(Cl)C?CH2, Me2CHCl and HCl2Si? CMe2? SiCl3, besides of Me2C(SiCl3)2 and Me2C(SiCl2H)2 Compound 3 crystallizes triclinically in the space group P1 (Nr. 2) mit a = 900,3, b = 914,0, c = 855,3 pm, α = 116,45°, β = 101,44°, γ = 95,86° and one molecule per unit cell. Compound 4 crystallizes monoclinically in thc space group C2/c (no. 15) with a = 3158.3,b = I 103.7, c = 2037.4 pm, β = 1 16.62° and 8 molecules pcr unit cell. The disilacyclobutane ring of compound 3 is plane, showing a mean distance of d (Si-C) =19 1.8 pm and the usual deformations of endocyclic angles: αSi = 94,2°> 85,8° = αC.The spiro-linked disilacyclobutane rings of compound 4 are slightly folded by a mean angle of (19.0°). Their mean distances were found to be d (Si? C) = 190.4 pm relating to the central carbon atom and 192.0 pm to the outer ones, respectively. The deformations of endocyclic angles: αSi = 93,9°> 84,4° = αC are comparable to those of compound 3.  相似文献   

10.
Infrared andRaman vibrational spectra ofn-Si4Cl10,n-Si5Cl12,neo-Si5Cl12 and [(SiCl3)3Si]2 have been measured and assigned. A local symmetry force field has been developed to simulate vibrational spectra of all (noncyclic) perchlorosilanes Si n Cl2n+2 known today (n=2, 3, 4, 5, 8). The observed spectra are reproduced satisfactorily
Die Vibrationsspektren linearer und verzweigter PerchlorsilaneSi n Cl 2n+2 und deren Simulierung mittels eines lokalen Symmetrie-Kraftfeldes
Zusammenfassung Infrarot- undRaman-Spektren vonn-Si4Cl10,n-Si5Cl12,neo-Si5Cl12 und [(SiCl3)3Si]2 wurden aufgenommen und zugeordnet. Ein lokales Symmetrie-Kraftfeld zur Simulation der Spektren aller bisher bekannten (nicht cyclischen) Perchlorsilane Si n Cl2n+2 (n=2, 3, 4, 5, 8) wird angegeben. Die beobachteten Spektren werden zufriedenstellend reproduziert
  相似文献   

11.
Heteroatomic Silicon-Oxygen Eightmembered Rings – Sn2O4Si2, ElO4Si3 (El ? Si, Ge, P, As, Ti) – Synthesis of a Cyclic Silylester of the Phosphorous Acid The reaction of dilithiated di-tert.-butylsilandiol with Cl2SnMe2 leads in a molar ratio 1:1 to the formation of 1,5-disila-3,7-distanna-2,4,6,8-tetraoxane ( 1 ). The dilithium salt of 1,1,5,5-tetra-tert.-butyl-3,3-dimethyltrisiloxane reacts with polyfunctional element halides – Cl2SiMe2, GeCl4, PF3, AsF3, TiCl4 – plainly to eightmembered 1-element-3,5,7-trisila-2,4,6,8-tetrasiloxanes – ElO4Si3 ( 2–6 ). The hydrolysis of the PF-containing ring 4 leads to the formation of the stable, cyclic silylester of the phosphorous acid 7 .  相似文献   

12.
The nitridosilicate chloride Ba1.63La7.39Si11N23Cl0.42:Ce3+ was synthesized by metathesis reaction starting from LaCl3, BaH2, CeF3 and the product of the ammonolysis of Si2Cl6. The title compound is stable towards air and moisture. Diffraction data of a microcrystal were recorded using microfocused synchrotron radiation. X‐ray spectroscopy confirms the chemical composition of the crystal. IR spectra corroborate absence of N–H bonds. The compound is homeotypic to Ba2Nd7Si11N23 and crystallizes in space group Cmmm with a = 11.009(3), b = 23.243(8), c = 9.706(4) Å and Z = 4, R1(all) = 0.0174. According to bond valence sum calculations, some crystallographic positions show complete occupancy by Ba or La whereas others contain significant amounts of both elements. In contrast to the structure prototype Ba2Nd7Si11N23, Ba1.63La7.39Si11N23Cl0.42:Ce3+ contains chloride ions in channels of the SiN4 tetrahedra network, hinting at various substitution possibilities of the complex zeolite‐like structure.  相似文献   

13.
Redistribution reactions between a mixture of Si2 Me 2Cl4 and Si2 Me 2Br4 show an exchange of halogen atoms at room temperature. After 10 hours at 60 °C the equilibrium state is attained and all possible compounds Si2 Me 2Cl4–n Br n are formed, but not in a statistical distribution. Possible reasons for this distribution and general rules for the exchange of substituents on disilanes are postulated.
Herrn Prof. Dr.Karl Schlögl mit besten Wünschen zum 60. Geburtstag gewidmet.  相似文献   

14.
An experimental and theoretical study of the base‐stabilized disilene 1 is reported, which forms at low temperatures in the disproportionation reaction of Si2Cl6 or neo‐Si5Cl12 with equimolar amounts of NMe2Et. Single‐crystal X‐ray diffraction and quantum‐chemical bonding analysis disclose an unprecedented structure in silicon chemistry featuring a dative Si→Si single bond between two silylene moieties, Me2EtN→SiCl2→Si(SiCl3)2. The central ambiphilic SiCl2 group is linked by dative bonds to the amine donor and the bis(trichlorosilyl)silylene acceptor, which leads to push–pull stabilization. Based on experimental and theoretical examinations a formation mechanism is presented that involves an autocatalytic reaction of the intermediately formed anion Si(SiCl3)3? with neo‐Si5Cl12 to yield 1 .  相似文献   

15.
The reaction of a metastable SiCl2 solution with the sterically less‐demanding carbene N,N‐diisopropylimidazo‐2‐ylidene (IPr) yields the salt [(IPr3Si3Cl5)+]Cl? ( 1 ‐Cl), containing a silyl cation with a Si3 backbone. Salt 1 is highly reactive, but it can be used as a reagent in deuterated dichloromethane, whereby dehalogenation with Me3SiOTf (OTf=O3SCF3) gives the dicationic silyl halide [(IPr3Si3Cl4)]2+ 2 . Quantum chemical calculations show that the HOMO is localized at the negatively charged central silicon atom of 1 and 2 , and thus although both compounds are cations they are better described as silanides, which was also corroborated by NMR investigations.  相似文献   

16.
Distribution reactions between Si2Cl6 and Si2Br6 yield all mixed chlorobromodisilanes of the form Si2ClxBr6-x. Further redistributions prevent the separation of the mixed compounds by vacuum distillation. A direct preparation of 1, 1, 1-tribromo-2, 2, 2-trichlorodisilanes via 1, 1, 1-triphenyl-2, 2, 2-trichlorodisilane by means of HBr/AlBr3 yields a pure compound.  相似文献   

17.
《Chemical physics letters》1987,136(5):447-450
In the range 110–200 nm the absorption features of Si2Cl6 closely resemble those of SiCl4 and the peaks observed are tentatively assigned to the Rydberg transitions of a Cl lone-pair electron. Two diffuse bands in the SiF3CH3 absorption are also assigned to Rydberg excitations. The spectrum of GeF4 shows a broad band considered to be a valence excitation of the outermost orbital. The emission of the SiCl21B1→X̃1A1) transition was found in the photoexcitation of Si2Cl6.  相似文献   

18.
Structures of the l,3,5-Trisilacyclohexane-Iron Dicarbonyl-cyclopentadienyl Complexes and C3H6Si3Cl5Fe(CO)2πcp and C3H6Si3Cl4(Fe(CO2)πcp)2 Trisilapentachlorocyclo-hexyl-dicarbonylcyclopentadienyliron C3H6Si3Cl5Fe(CO)2πcp 1 and Trisilatetrachlorocyclohexyl-bis(dicarboncyclopentadienyliron)C3H6Si3Cl4(Fe(CO)2πcp)2 2 are 1,3,5-Trisilacyclohexane complexes substituted by dicarbonylcyclopentadienyliron at one and two silicon atoms of the six-membered ring, respectively. The crystal and molecular structures were determined from single crystals ( 1 ; space group P21/a (No. 14); a = 1100.5 pm; b = 2033.9 pm; c = 843.3pm; β = 98.58°; Z = 4; MoKα-radiation; 3142h k l; R = 0.036. 2 ; space group P1 ; (No. 2); a = 1231.1 pm; b = 1267.3 pm; c = 1045.9 pm; α = 113.23°; β = 83.93°; γ = 115.00°; Z = 2; Mokα-radiation; 4196 h k 1; R = 0.065). In both complexes the six-membered rings of the carbosilane ligands are in skew-boat conformation. The bond lengths Fe? Si are 226.4 pm and 228.1 pm, respectively. The distances Si? C and Si? Cl are 186 pm and 206 pm in 1 and 187 pm and 209 pm in 2 . Their different lengths depend on the position in the ligand system and can be explained with the concept of bond orders.  相似文献   

19.
On Chloride Silicates of Calcium, Strontium, and Barium Alkaline earth chloride silicates are synthesized by heating of mixtures of CaCO3, SrCO3 or BaCO3, and SiO2 with different molar ratios in the melt of the relating alkaline earth chloride. They can be separated from an excess of chloride by methanol extraction. The structures of their silicate anions were investigated by the molybdate method and paper chromatographic separation. The compounds Sr5[SiO4]Cl6, Sr5[Si2O7]Cl4, and Sr8[Si4O12]Cl8, hitherto unknown, were synthesized and compared with the compounds of calcium and barium in regard of their chloride contents, silicate anion structure and crystal structure.  相似文献   

20.
The crystal structures of four substituted‐ammonium dichloride dodecachlorohexasilanes are presented. Each is crystallized with a different cation and one of the structures contains a benzene solvent molecule: bis(tetraethylammonium) dichloride dodecachlorohexasilane, 2C8H20N+·2Cl·Cl12Si6, (I), tetrabutylammonium tributylmethylammonium dichloride dodecachlorohexasilane, C16H36N+·C13H30N+·2Cl·Cl12Si6, (II), bis(tetrabutylammonium) dichloride dodecachlorohexasilane benzene disolvate, 2C16H36N+·2Cl·Cl12Si6·2C6H6, (III), and bis(benzyltriphenylphosphonium) dichloride dodecachlorohexasilane, 2C25H22P+·2Cl·Cl12Si6, (IV). In all four structures, the dodecachlorohexasilane ring is located on a crystallographic centre of inversion. The geometry of the dichloride dodecachlorohexasilanes in the different structures is almost the same, irrespective of the cocrystallized cation and solvent. However, the crystal structure of the parent dodecachlorohexasilane molecule shows that this molecule adopts a chair conformation. In (IV), the P atom and the benzyl group of the cation are disordered over two sites, with a site‐occupation factor of 0.560 (5) for the major‐occupied site.  相似文献   

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