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1.
The reactions of the trimethylsiloxychlorosilanes (Me3SiO)RR′SiCl (1a-h: R′ = Ph, 1a: R = H, 1b: R = Me, 1c: R = Et, 1d: R = iPr, 1e: R = tBu, 1f: R = Ph, 1g: R = 2,4,6-Me3C6H2 (Mes), 1h: R = 2,4,6-(Me2CH)3C6H2 (Tip); 1i: R = R′ = Mes) with lithium metal in tetrahydrofuran (THF) at −78 °C and in a mixture of THF/diethyl ether/n-pentane in a volume ratio 4:1:1 at −110 °C lead to mixtures of numerous compounds. Dependent on the substituents silyllithium derivatives (Me3SiO)RR′SiLi (2b-i), Me3SiO(RR′Si)2Li (3a-g), Me3SiRR′SiLi (4a-h), (LiO)RR′SiLi (12e, 12g-i), trisiloxanes (Me3SiO)2SiRR′ (5a-i) and trimethylsiloxydisilanes (6f, 6h, 6i) are formed. All silyllithium compounds were trapped with Me3SiCl or HMe2SiCl resulting in the following products: (Me3SiO)RR′SiSiMe2R″ (6b-i: R″ = Me, 7c-i: R″ = H), Me3SiO(RR′Si)2SiMe2R″ (8a-g: R″ = Me, 9a-g: R″ = H), Me3SiRR′SiSiMe2R″ (10a-h: R″ = Me, 11a-h: R″ = H) and (HMe2SiO)RR′SiSiMe2H (13e, 13g-i). The stability of trimethylsiloxysilyllithiums 2 depends on the substituents and on the temperature. (Me3SiO)Mes2SiLi (2i) is the most stable compound due to the high steric shielding of the silicon centre. The trimethylsiloxysilyllithiums 2a-g undergo partially self-condensation to afford the corresponding trimethylsiloxydisilanyllithiums Me3SiO(RR′Si)2Li (3a-g). (Me3)Si-O bond cleavage was observed for 2e and 2g-i. The relatively stable trimethylsiloxysilyllithiums 2f, 2g and 2i react with n-butyllithium under nucleophilic butylation to give the n-butyl-substituted silyllithiums nBuRR′SiLi (15g, 15f, 15i), which were trapped with Me3SiCl. By reaction of 2g and 2i with 2,3-dimethylbuta-1,3-diene the corresponding 1,1-diarylsilacyclopentenes 17g and 17i are obtained.X-ray studies of 17g revealed a folded silacyclopentene ring with the silicon atom located 0.5 Å above the mean plane formed by the four carbon ring atoms.  相似文献   

2.
The reaction of compound Me2Si(NSiMe3)2Si(OH)Cl with Me2SiCl2 leads to the disiloxane Me2Si(NSiMe3)2Si(Cl)OSi(Me2)Cl (1). Hydrolysis of 1 in the presence of pyridine results in Me2Si(NSiMe3)2Si(OH)OSi(Me2)OH (2), which is allowed to react with SiCl4 to give cyclotrisiloxane [Me2Si(NSiMe3)2Si](OSiMe2)(OSiCl2)O (3). The treatment of 1 with (t-BuO)2Si(OH)2 forms cyclotrisiloxane [Me2Si(NSiMe3)2Si](OSiMe2)[OSi(Ot-Bu)2]O (4). Compound 3 is obtained as a crystalline solid while 4 is an oily liquid. The ring size of these new types of cyclotrisiloxanes with three different R2Si-units is confirmed by cryoscopy in benzene, 29Si NMR chemical shifts and in case of 3, additionally by a single X-ray diffraction study. The different electronegativities of the substituents in the R2Si-units lead to different bond lengths and bond angles within the Si3O3 cycle, which are discussed in detail in the molecular structure of 3.  相似文献   

3.
The reactivity of bulky tris(trimethylsilyl)methyl group substituted aluminum trialkyl [(Me3Si)3CAlMe2·THF] (1) with a series of substituted benzoic acid derivatives has been investigated. An equimolar reaction of 4-methyl benzoic acid or 4-tert-butyl benzoic acid with 1 in toluene at 50 °C leads to the formation of cyclic dimeric aluminum carboxylates [(Me3Si)3CAl(Me)(μ-O2CC6H4R)]2 (R = Me 2; tBu 3). Reaction of 3,5-di-iso-propylsalicylic acid (H2dipsa) with 1 leads to the exclusive isolation of a trimeric organoaluminum carboxylate [(Me3Si)3CAl(μ-dipsa)]3 (4), in which each aluminum is bound to two carboxylates, a phenoxide, and an alkyl group and produce a 12-membered macrocycle. Deliberate, but controlled, introduction of water in the form of 3,5-di-tert-butyl salicylic acid monohydrate (H2dtbsa·H2O) in the reaction with 1 in toluene leads to the isolation of carboxylate [(Me3Si)3CAl(μ-O)(μ-Hdtbsa)}2] (5) with a bicyclic structure. Compound 5 represents a rare example of an organoalumoxane carboxylate that simultaneously possesses alkyl, oxo, and carboxylate moieties on aluminum.  相似文献   

4.
The synthesis and characterization of complexes containing a Cp∗Sc(R2bpy) (Cp∗ = pentamethylcyclopentadienyl, bpy = 4,4′-R,R-2,2′-bipyridine, R = H, Me) motif are described. Cp∗ScI2 (1) was prepared from Cp∗Sc(acac)2 (acac = acetylacetonate) and AlI3 (2 equiv) in pentane. Compound 1 reacted with bipyridine and 4,4′-dimethyl-2,2′-bipyridine (dmb) in benzene to yield Cp∗ScI2(bpy) (3) and Cp∗ScI2(dmb) (4), respectively. Compound 3 was reduced by alkali metal reductants such as Na/Hg, NaK2, and K in aromatic solvents to yield [Cp∗ScI(bpy)]2 (5). The chloride analog of 5, [Cp∗ScCl(bpy)]2 (7), was prepared from Cp∗ScCl2 by salt metathesis with Li2(dme)2bpy (6) (dme = dimethoxyethane) in toluene. Compounds 1, 5, and 7 have been structurally characterized. Analysis of the bond distances of the bipyridine ligands in 5 and 7, together with infrared and UV/vis spectroscopic data, suggest that the bipyridine ligands in these molecules exist as radical anions. The bipyridine ligands in 5 and 7 are arranged co-facially and are in close proximity (?3.30 Å), suggesting the presence of a π-π interaction.  相似文献   

5.
The organo-tin compounds, Me2Sn(C5H4R-1)2 (R = Me (1), Pri (2), But (3), SiMe3 (4)) and Me2Sn(C5Me4R-1)2 (R = H (5), SiMe3 (6)), were prepared by the reaction of Me2SnCl2 with the lithium or sodium derivative of the corresponding cyclopentadiene. Compounds 1-6 have been characterized by multinuclear NMR spectroscopy (1H, 13C, 119Sn). In addition the molecular structures of 5 and 6 were determined by single crystal X-ray diffraction studies. The transmetalation reaction of 1-6 with ZrCl4 or [NbCl4(THF)2] gave the corresponding metallocene complexes in high yields.  相似文献   

6.
The reaction pathway for the formation of the trimethylsiloxysilyllithium compounds (Me3SiO)RR′SiLi (2a: R = Et, 2b: R = iPr, 2c: R = 2,4,6-Me3C6H2 (Mes); 2a-c: R′ = Ph; 2d: R = R′ = Mes) starting from the conversion of the corresponding trimethylsiloxychlorosilanes (Me3SiO)RR′SiCl (1a-d) in the presence of excess lithium in a mixture of THF/diethyl ether/n-pentane at −110 °C was investigated.The trimethylsiloxychlorosilanes (Me3SiO)RPhSiCl (1a: R = Et, 1b: R = iPr, 1c: R = Mes) react with lithium to give initially the trimethylsiloxysilyllithium compounds (Me3SiO)RPhSiLi (2a-c). These siloxysilyllithiums 2 couple partially with more trimethylsiloxychlorosilanes 1 to produce the siloxydisilanes (Me3SiO)RPhSi-SiPhR(OSiMe3) (Ia-c), and they undergo bimolecular self-condensation affording the trimethylsiloxydisilanyllithium compounds (Me3SiO)RPhSi-RPhSiLi (3a-c). The siloxydisilanes I are cleaved by excess of lithium to give the trimethylsiloxysilyllithiums (Me3SiO)RPhSiLi (2). In the case of the two trimethylsiloxydisilanyllithiums (Me3SiO)RPhSi-RPhSiLi (3a: R = Et, 3b: R = iPr) a reaction with more trimethylsiloxychlorosilanes (Me3SiO)RPhSiCl (1a, 1b) takes place under formation of siloxytrisilanes (Me3SiO)RPhSi-RPhSi-SiPhR(OSiMe3) (IIa: R = Et, IIb: R = iPr) which are cleaved by lithium to yield the trimethylsiloxysilyllithiums (Me3SiO)RPhSiLi (2a, 2b) and the trimethylsiloxydisilanyllithiums (Me3SiO)RPhSi-RPhSiLi (3a, 3b). The dimesityl-trimethylsiloxy-silyllithium (Me3SiO)Mes2SiLi (2d) was obtained directly by reaction of the trimethylsiloxychlorosilane (Me3SiO)Mes2SiCl (1d) and lithium without formation of the siloxydisilane intermediate. Both silyllithium compounds 2 and 3 were trapped with HMe2SiCl giving the products (Me3SiO)RR′Si-SiMe2H and (Me3SiO)RPhSi-RPhSi-SiMe2H.  相似文献   

7.
Novel half-sandwich [C9H5(SiMe3)2]ZrCl3 (3) and sandwich [C9H5(SiMe3)2](C5Me4R)ZrCl2 (R = CH3 (1), CH2CH2NMe2 (2)) complexes were prepared and characterized. The reduction of 2 by Mg in THF lead to (η5-C9H5(SiMe3)2)[η52(C,N)-C5Me4CH2CH2N(Me)CH2]ZrH (7). The structure of 7 was proved by NMR spectroscopy data. Hydrolysis of 2 resulted in the binuclear complex ([C5Me4CH2CH2NMe2]ZrCl2)2O (6). The crystal structures of 1 and 6 were established by X-ray diffraction analysis.  相似文献   

8.
Complex Cp∗PtCl2 (Cp∗ = η-C4Me4) reacts with the carborane anions [7,8-C2B9H11]2− and [9-SMe2-7,8-C2B9H10] giving platinacarboranes Cp∗Pt(η-7,8-C2B9H11) (1) and [Cp∗Pt(η-9-SMe2-7,8-C2B9H10)]+ (2), respectively. Reactions of the [Cp∗Pt]2+ fragment (as a labile nitromethane solvate) with the sandwich compounds Cp∗Fe(η-C5H3Me2BMe) and Cp∗Rh(η5-C4H4BPh) afford the triple-decker cations [Cp∗Pt(μ-η:η-C5H3Me2BMe)FeCp∗]2+ (3) and [Cp∗Pt(μ-η55-C4H4BPh)RhCp∗]2+ (4) with bridging boratabenzene and borole ligands. The structures of 1 and 3(CF3SO3)2 were determined by X-ray diffraction.  相似文献   

9.
Syntheses of [Me3SbM(CO)5] [M = Cr (1), W (2)], [Me3BiM(CO)5] [M = Cr (3), W (4)], cis-[(Me3Sb)2Mo(CO)4] (5), [tBu3BiFe(CO)4] (6), crystal structures of 1-6 and DFT studies of 1-4 are reported.  相似文献   

10.
Reactions of Me5Al3[OC(C6H5)2C(C6H5)2O]2 (1) with alcohols ROH (R = Me, Et, tBu) in a 1:1 molar ratio afforded the compound Me2Al2[OC(C6H5)2C(C6H5)2O]2(C4H8O) (2) and a mixture of methylaluminum alkoxides. The alcohols acted as the factor formally eliminating a molecule of Me3Al (as a methylaluminum alkoxide) from compound 1. tBu3Al reacted with an equimolar amount of benzopinacol to form the monomeric complex tBuAl[OC(C6H5)2C(C6H5)2O](C4H8O) (3). Reactions of Me3Ga and Me3In with benzopinacol yielded trinuclear complexes Me5M3[OC(C6H5)2C(C6H5)2O]2 (4 (M = Ga), 5 (M = In)), isostructural to compound 1. In the presence of water and alcohols, compounds 4 and 5 underwent a decomposition reaction to benzopinacol and a mixture of metalloxanes and alkoxides. An unusual methylmethoxo indium benzopinacolate Me6In4[OC(C6H5)2C(C6H5)2O]2(OCH3)2 (6) was obtained in the reaction of benzopinacol with Me3In and Me2InOMe in a 1:1:1 molar ratio. Molecular structures of the compounds 3, 4 and 6 were determined by X-ray crystallography.  相似文献   

11.
Metallation of (HMe2Si)(Me3Si)2CH (1) by LiMe gave the organolithium compound Li(THF)2C(SiMe3)2(SiMe2H) (2a), which exists in toluene solution as a mixture of covalent species and ion pairs [Li(THF)4][Li{C(SiMe3)2(SiMe2H)}2] (2b). Treatment of a mixture of 1 and LiMe with KOBut gave KC(SiMe3)2(SiMe2H) (3). This reacted with AlMe2Cl in hexane/THF to give Al(THF)Me2{C(SiMe3)2(Si Me2H)} (4). Treatment of (HMe2Si)(PhMe2Si)2CH (5) with LiMe in Et2O/THF gave the THF adduct [Li(THF)2C(SiMe2Ph)2(SiMe2H)] (6); in the presence of KOBut the solvent-free [K][C(SiMe2Ph)2(SiMe2H)] (7) was obtained. Crystal structure determinations showed that 6 crystallizes in a molecular lattice and 7 in an ionic lattice in which the coordination sphere of the potassium comprises phenyl groups and hydrogen atoms attached to silicon, as well as the central carbon of the bulky carbanion. Compound 7 reacted with an excess of AlMe2Cl to give [AlClMe{C(SiMe2Ph)2(SiMe2H)}]2 (8) and AlMe3. A small amount of the methoxo derivative [Al(OMe)Me{C(SiMe2Ph)2(SiMe2H)}]2 (9) was obtained as a byproduct, presumably after the accidental admission of traces of air. X-ray structural determinations showed that 8 forms halogen-bridged dimers, with the bulky ligands in the anti-configuration, and 9 forms methoxo-bridged species in which the bulky ligands are syn.  相似文献   

12.
The reaction of the anion [(tBuP)3As] (1) with Me2SiCl2 results in nucleophilic substitution of the Cl anions, giving the di- and mono-substituted products [Me2Si{As(PtBu)3}2] (3a) and [Me2Si(Cl){As(PtBu)3}] (3b). Analogous reactions of the pre-isolated [(CyP)4As] anion (2) (Cy = cyclohexyl) with Me2SiCl2 produced mixtures of products, from which no pure materials could be isolated. However, reaction of 2 [generated in situ from CyPHLi and As(NMe2)3] gives the heterocycle [(CyP)3SiMe2] (4). The X-ray structures of 3a and 4 are reported.  相似文献   

13.
Consecutive synthesis methodologies for the preparation of carbosilanes (Ph)(Me)Si((CH2)3B(OH)2)2 (2), Si(C6H4-4-SiMe2((CH2)3B(OH)2))4 (5), (Ph)(Me)Si((CH2)3OH)2 (3), and Si(C6H4-4-SiMe3−n((CH2)3OH)n)4 (6a, n = 1; 6b, n = 2; 6c, n = 3) are reported. Boronic acids 2 and 5 are accessible by treatment of (Ph)(Me)Si(CH2CHCH2)2 (1) or Si(C6H4-4-SiMe2(CH2CHCH2))4 (4a) with HBBr2·SMe2 followed by addition of water, while 3 and 6 are available by the hydroboration of 1 or Si(C6H4-4-SiMe3−n(CH2CHCH2)n)4 (4a, n = 1; 4b, n = 2; 4c, n = 3) with H3B·SMe2 and subsequent oxidation with H2O2.The single molecular structure of 6a in the solid state is reported. Representative is that 6a crystallized in the chiral non-centrosymmetric space group P212121 forming 2D layers due to intermolecular hydrogen bond formation of the HO functionalities along the crystallographic a and c axes.  相似文献   

14.
The cleavage of the Se-Se bond in [2-(Me2NCH2)C6H4]2Se2 (1) was achieved by treatment with SO2Cl2 (1:1 molar ratio) or elemental halogens to yield [2-(Me2NCH2)C6H4]SeX [X = Cl (2), Br (3), I (4)]. Oxidation of 1 with SO2Cl2 (1:3 molar ratio) gave [2-(Me2NCH2)C6H4]SeCl3 (5). [2-(Me2NCH2)C6H4]SeS(S)CNR2 [R = Me (6), Et (7)] were prepared by reacting [2-(Me2NCH2)C6H4]SeBr with Na[S2CNR2] · nH2O (R = Me, n = 2; R = Et, n = 3). The reaction of 3 with K[(SPMe2)(SPPh2)N] resulted in isolation of [2-(Me2NCH2)C6H4]Se-S-PMe2N-PPh2S (8). The compounds were characterized by solution NMR spectroscopy (1H, 13C, 31P, 77Se, 2D experiments). The solid-state molecular structures of 2, 4-8 were established by single crystal X-ray diffraction. All compounds are monomeric, with the N atom of the pendant CH2NMe2 arm involved in a three-center-four-electron N?Se-X (X = halogen, S) bond. This results in a T-shaped coordination geometry for the Se(II) atom in 2, 4, 6-8. In 5, the Se(IV) atom achieves a square pyramidal coordination in the mononuclear unit. Loosely connected dimers are formed through intermolecular Se?Cl interactions (3.40 Å); the overall coordination geometry being distorted octahedral. In all compounds hydrogen bonds involving halide or sulfur atoms generate supramolecular associations in crystals.  相似文献   

15.
Compound [NbCp′Me4] (Cp′ = η5-C5H4SiMe3, 1) reacted with several ROH compounds (R = tBu, SiiPr3, 2,6-Me2C6H3) to give the derivatives [NbCp′Me3(OR)] (R = tBu 2a, SiiPr32b, 2,6-Me2C6H32c). The diaryloxo tantalum compound [TaCpMe2(OR)2] (Cp = η5-C5Me5, R = 2,6-Me2C6H33) was obtained by reaction of [TaCpCl2Me2] with 2 equiv of LiOR (R = 2,6-Me2C6H3). Abstraction of one methyl group from these neutral compounds 1-3 with the Lewis acids E(C6F5)3 (E = B, Al) gave the ionic derivatives [NbCp′Me2X][MeE(C6F5)3] (X = Me 4-E. X = OR; R = SiiPr35b-E, 2,6-Me2C6H35c-E. E = B, Al) and [TaCpMe(OR)2][MeE(C6F5)3] (R = 2,6-Me2C6H36-E; E = B, Al). Polymerization of MMA with the aryloxoniobium compound 2c and Al(C6F5)3 gave syndiotactic PMMA in a low yield, whereas the tetramethylniobium compound 1 and the diaryloxotantalum derivative 3 were inactive.  相似文献   

16.
Eleven borosiloxane [R′Si(ORBO)3SiR′] compounds where R′ = But and R = Ph (1), 4-PhC6H4 (2), 4-ButC6H4 (3), 3-NO2C6H4 (4), 4-CH(O)C6H4 (5), CpFeC5H4 (6), 4-C(O)CH3C6H4 (7), 4-ClC6H4 (8), 2,4-F2C6H3 (9), and R′ = cyclo-C6H11 and R = Ph (10), and 4-BrC6H4 (11) have been synthesized and characterized by spectroscopic (IR, NMR), mass spectrometric and, for compounds where R′ = But and R = 4-PhC6H4 (2), 4-ButC6H4 (3), 3-NO2C6H4 (4), CpFeC5H4 (6) and 2,4-F2C6H3 (9), X-ray diffraction studies. These compounds contain trigonal planar RBO2 and tetrahedral R′SiO3 units located around 11-atom “spherical” Si2O6B3 cores. The dimensions of the Si2O6B3 cores in compounds 2, 3, 4, 6 and 9 are remarkably similar. The reaction between [ButSi{O(PhB)O}3SiBut] (1), and excess pyridine yields the 1:1 adduct [ButSi{O(PhB)O}SiBut]. NC5H5 (12) while the reaction between 1 and N,N,N′,N′-tetramethylethylenediamine in equimolar amounts affords a 2:1 borosiloxane:amine adduct [ButSi{O(PhB)O}3SiBut]2 · Me2NCH2CH2NMe2 (13). Compounds 12 and 13 were characterised with IR and (1H, 13C and11B) NMR spectroscopies and the structure of the pyridine complex 12 was determined with X-ray techniques.  相似文献   

17.
Addition of ethynylferrocene to nido-1,2-(CpRuH)2B3H7 (1) at ambient temperature leads to nido-1,2-(CpRu)2(1,5-μ-C{Fc}Me)B3H7 (2, 3) and closo-4-Fc-1,2-(CpRuH)2-4,6-C2B2H3 (4). Compounds 2 and 3 represent a pair of geometric isomers, nido-species in which the regiochemistry of the alkyne reduction conforms to the Markovnikoff rule. Compound 4 is an octahedral structure in which the inserted alkyne is on an open face of the closo cluster.  相似文献   

18.
A series of novel first-generation silicon-centred tin dendrimers Si(CH2CH2SnR3)4 [R = CH3 (3), iBu (4), CCCH3 (5), C6H4CH3-4 (6), C6H4OCH3-4 (7), (CH2)4OCH2CH2OCH3 (8), CH2SiMe3 (9)] was prepared by the reaction of Si(CH2CH2SnBr3)4 (2) with the appropriate Grignard reagent or LiCH2SiMe3 in tetrahydrofuran. The new compounds were characterized by multinuclear NMR studies (1H, 13C, 119Sn), mass spectrometry (MALDI-TOF, EI) and elemental analyses. The molecular structure of Si[CH2CH2SnBr3(THF)2]2[CH2-CH2SnBr3(THF)]2 (2a) was determined by single-crystal X-ray diffraction.  相似文献   

19.
The reductive reactivity of the (BPh4)1− ligand in pentamethylcyclopentadienyl [(C5Me5)2U][(μ-η21-Ph)2BPh2] (1) was compared with that of the tetramethyl analog, [(C5Me4H)2U][(μ-η61-Ph)(μ-η11-Ph)BPh2] (2) using PhSSPh as a probe to determine if the mode of (BPh4)1− bonding affected the reduction. Both complexes act as two-electron reductants to form (C5Me4R)2U(SPh)2 [R = Me, 3; H, 4], but only in the R = H case could the product be crystallographically characterized. An improved synthesis of 1 from [(C5Me5)2UH]2 (5) and [Et3NH][BPh4] is also reported as well as its reaction with MeCN that provides another route to the unusual, parallel-ring, uranium metallocene [(C5Me5)2U(NCMe)5][BPh4]2 (6).  相似文献   

20.
Two novel metal sulfur chlorides - Zn6S5Cl2 (1) and Hg3ZnS2Cl4 (2) - were obtained by solid-state reactions and structurally characterized by single-crystal X-ray diffraction. Compound 1 is characteristic of a 1-D tunnel-like structure, which connects to each other to construct a 3-D framework with the chlorine atoms locating at the voids. Compound 2 crystallizes in the acentric space group P63mc of the hexagonal system. Compound 2 features a 2-D layered motif, which is composed by the interconnected 12-membered Hg6S3Cl3 rings with chair-like conformation. There are ZnSCl3 tetrahedra located between the layers, yielding a sandwich-like structure. TG-DTA measurement shows that compound 1 is thermally stable up to 220 °C. Optical absorption spectra reveal the presence of sharp optical gap of 2.71 and 2.65 eV for 1 and 2, respectively.  相似文献   

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