1-Phenyl-1-halo-1-silacyclohexanes

The approaches to synthesis of 1-phenyl-1-halo-1-silacyclohexanes C₅H₁₀Si(Ph)X (X = F, Cl, Br) have been examined. 1-Phenyl-1-chloro-1-silacyclohexane has been prepared via the known reaction of phenyltrichlorosilane with dimagnesium derivative of 1,5-dibromopentane; up to 20% of 1-bromo-1-phenyl-1-silacyclohexane admixture is formed along with the target product. The minor product formation has been prevented using an alternative method of chlorination of 1-phenyl-1-silacyclohexane with N-chlorosuccinimide. 1-Phenyl-1-fluoro-1-silacyclohexane has been obtained in close to quantitative yield via the reaction of 1-phenyl-1-chloro-1-silacyclohexane with SbF₃ and in 70% yield via its reaction with HF. The synthesis of 1-phenyl-1-bromo-1-silacyclohexane via bromination of 1-phenyl-1-chloro-1-silacyclohexane with N-bromosuccinimide has given the target product as a minor one, the major product being disiloxane formed due to hydrolysis of the Si–Br bond.     

1-Chlor-1-phosphirane

The title compounds are prepared by reaction of disubstituted diazomethanes with 1-chloro-2-phenyl-2-trimethylsilyl-1-phosphaalkene. The chemistry of the 1-chloro-1-phosphiranes is described.     

Nuclear-substituted 1-phenyl-1-methyl-1-silacyclobutane derivatives

Conclusions The synthesis of some nuclear-substituted derivatives of 1-phenyl-1-methyl-1-silacyclobutane by the reaction of 1-methyl-1-chloro-1-silacyclobutane with the appropriate arylmagnesium bromides was described.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1686–1688, July, 1978.     

1-Methyl-1-ethynylsilacyclopentane

Conclusions We synthesized 1-methyl-1-ethynylsilacyclopentane, which is the first reported 1-ethynylsilacycloalkane. The reactivities of this silahydrocarbon and its magnesium bromide derivative were studied.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1403–1406, June, 1987.     

1:1 alternating copolymers of 1-bicyclobutanecarbonitrile with styrene

High molecular weight, 1:1 alternating copolymers of 1-bicyclobutanecarbonitrile with styrene were prepared in tetramethylenesulfone solution by complexing the electron-poor bicyclobutane monomer with zinc chloride. Methyl 1-bicyclobutanecarboxylate under these conditions gave copolymers containing a slight excess of styrene units (ratio 1:1.3 to 1:1.8). High molecular weight homopolymers of 1-bicyclobutanecarbonitrile and of methyl 1-bicyclobutanecarboxylate were prepared similarly. The tendency of the bicyclobutane nitrile to form 1:1 alternating copolymers is as great as that of its vinyl analog, acrylonitrile, and the synthesis of other alternating copolymers from this monomer should be possible.     

1-乙酰胺基丙叉-1,1-二膦酸和1-丙酰胺基乙叉-1,1-二膦酸与碱土金属离子的螯合作用

用pH电位法研究了1-乙酰胺基丙叉-1,1-二膦酸(S-186)和1-丙酰胺基乙叉-1,1-二膦酸(S-106)与碱土金属的螯合作用(30±O.1℃).当金属离子与配体的摩尔浓度比为10∶1、1∶1和1∶2时,在水溶液中形成了MHL、ML、ML_2和M_2L等几种类型的配合物.分别测定了它们的稳定常数,其中S-186配合物稍高于S-106,说明配合物稳定性与螯合剂的碱度有平行关系.值得注意的是,这两种螯合剂与Sr~(2 )形成的双核配合物的稳定性均较其它碱土金属离子的为高.     

The vibrational structure of the X 1A1 - A 1B1 and A 1B1 - B 1A1 band systems of GeH2/GeD2 based on global potential energy surfaces

Transition probabilities were evaluated for the X (1)A(1)-A (1)B(1) and A (1)B(1)-B (1)A(1) systems of GeH(2) and GeD(2) to analyze the X-->A-->B photoexcitation. Franck-Condon factors (FCFs) and Einstein's B coefficients were computed by quantum vibrational calculations using the three-dimensional potential energy surfaces (PESs) of the X (1)A(1), A (1)B(1), and B (1)A(1) electronic states and the transition dipole moments for the X-A and A-B systems. The global PESs were determined by the multireference configuration interaction calculations with the Davidson correction and the interpolant moving least squares method combined with the Shepard [Proceedings of the 1968 23rd ACM National Conference (ACM, New York, 1968)] interpolation. The barriers to linearity correcting the spin-orbit interaction are evaluated to be 22,000 cm(-1) for the X state, 6300 cm(-1) for the A state, and 560 cm(-1) for the B state. The obtained FCFs for the X-A and A-B systems indicate that the bending mode is strongly enhanced in the excitation since the equilibrium bond angle greatly varies within the three states. The photoexcitation and fluorescence spectra calculated for the X-A system agree well with the observed spectra. The theoretical lifetimes for lower vibrational levels of the A and B states were calculated from the fluorescence decay rates for the A-X, B-A, and B-X emissions, and the lifetimes for the A state are in good agreement with the observed values except those affected by predissociation.     

1-Trimethylsilyl-, 1-Trimethylgermyl- und 1-Trimethylstannyl-3,4-dimethylphospholen

1-Trimethylsilyl-, 1-Trimethylgermyl-, and 1-Trimethylstannyl-3,4-dimethylphospholene 1-Lithium-3,4-dimethylphospholen reacts with Me₃SiCl and Me₃GeCl yielding 1-trimethylsilyl-3,4-dimethylphospholene ( 1 ) and 1-trimethylgermyl-3,4-dimethylphospholene ( 2 ) respectively. 2 and 1-trimethylstannyl-3,4-dimethylphospholene ( 3 ) are formed using the reaction of 1 with Me₃GeCl and Me₃SnCl respectively. The ¹H, ¹³C and ³¹PNMR-spectra as well as the mass spectra of the new compounds are discussed.     

The mechanism of thermal dehydrochlorination. Pyrolysis of 1-Chloro-1-fluoroethane and 1-chloro-1, 1-difluoroethane

The thermal decompositions of 1-chloro-1-fluoroethane and 1-chloro-1,1-difluorethane at atmospheric pressure have been studied in the temperature range 500–600°C in a flow system. The dehydrochlorinations are homogenous in a carbonaceous reactor and unimolecular. The rate constants are given by and The criteria for molecular or chain processes in thermal dehydrochlorinations are discussed.     

The synthesis of 1-methyl-1-germaadamantane

The syntheses of 1-methyl-1-germaadamantane and 1-chloro-1-germaadamantane are described. Attempts to prepare the 1-methyl-1-stannaadamantane and the novel cage systems, 1-silatris-nor- and 1-silatris-homo-adamantanes are also described as well as the syntheses of a variety of Group IV 1,3,5-trisubstituted cyclohexanes.     

1-甲基-1-乙氧基-1-烷硫基甲烷类化合物的合成研究

本文以乙缩醛和烷基硫醇为原料,在30－35℃于四氯化碳中反应20min左右,分别合成1－甲基－1－乙氧基－1－烷硫基甲烷,经红外光谱,质谱以及核磁共振谱检测,确证了产物结构。     

Epimeric 1-hydroxy-1-substituted indolizidines

Epimeric mixtures of 1-hydroxy-1-phenylindolizidines and 1-hydroxy-1-methylindolizidines were obtained from the reaction of 1-ketoindolizidine with the appropriate Grignard reagent. The resulting alcohols were separated by chromatographic and distillation techniques. Infrared data and physical constants were utilized for the elucidation of the structures. Structural assignments of the indolizidinium iodides were made on the basis of nmr data.     

Synthesis of Ethyl 1-Phenyl- and 1-Alkyl-1-Indene-2-Carboxylates

The ethyl 1-phenyl and 1-alkyl-1-indene-2-carboxylates 2g and 2a-2f respectively were prepared in 68 - 83% yield by the reaction of phenyl- and alkylmagnesium halides with ethyl 1-methoxy-1-indene-2-carboxylate (1c).     

Dispersed fluorescence spectroscopy of the CBr2A1B1-X1A1 transition

Dispersed fluorescence spectra following the excitation of the CBr2A1B1-X1A1 2 and 2 bands at visible wavelengths were acquired in a discharge supersonic free jet expansion using an intensified charge-coupled device (ICCD) detector. The dispersed fluorescence spectra show signal-to-noise ratios of up to 60 and extend out to a maximum red shift frequency of 6000 cm(-1). Complete and detailed vibrational structure of the ground singlet state (X1A1) was observed. Vibrational parameters including fundamental frequencies, anharmonicities, and coupling constants were determined for the CBr2 X1A1 state. Additional vibrational structure starting at approximately 3650 cm(-1) was observed and this indicates the singlet-triplet energy gap to be >10 kcal mol(-1).     

Transsilylation of disilazanes with 1-chloro-1-methyl-1-silacyclobutane and other triorganylchlorosilanes

The first stage of the reaction of hexamethyldisilazane with 1-chloro-1-methyl-1-silacyclotmtane gives 1,3,3,3-tetramethyl-1,1-trimethylenedisilazane, and after that 1,3-dimethyl-1,3-bis(trimethylene)disilazane is formed. The latter reacts with 1-chloro-1-methyl-1-silacyclobutane to give tris[methyl(trimethylene)silyl] amine. From a large number of examples it is shown that transsilylation of disilazanes with chlorosilanes is a general reaction.     

Synthesis of 3-aryl-5-dichloromethyl-1H-pyrazole-1-carboxamides from 1-aryl-3,4,4-trichlorobut-3-en-1-ones

The reaction of 1-aryl-3,4,4-trichlorobut-3-en-1-ones with semicarbazide hydrochloride in the presence of sodium acetate is accompanied by prototropic allylic rearrangement, leading to the formation of two isomeric products, semicarbazones of the initial ketones and 1-aryl-3,4,4-trichlorobut-2-en-1-one semicarbazones. The latter undergo heterocyclization in the presence of triethylamine to give the corresponding 3-aryl-5-dichloromethyl-1H-pyrazole-1-carboxamides.     

GAS PERMEABILITY OF COPOLY(1-TRIMETHYL-SILYL-1-PROPYNE-PENTAMETHYL-DISILYL-1-PROPYNE) MEMBRANE

The permeability of copoly (1-trimethylsilyl-1-propyne-pentamethyldisilyl-1-propyne) membrane for twelve gases (0_2, N_2, CO_2, H_2, D_2, He, At, CH_4, C_2H_4, C_2H_6, C_3H_6 and C_3H_8) was examined. The basic laws of solution and diffusion of the gases in the membrane were expounded preliminarily. It was found that a linear relationship between logarithm of diffusion coefficient (D) and critical molar volume (V_c) of the gases. The permeation characteristics of the gases in the copoly (1-trimethylsilyl-1-propyne-pentamethyldisilyl-1-propyne) membrane was also discussed.     

Copolymerization of 4-methyl-2-pentyne with 1-trimethylsilyl-1-propyne and 1-trimethylgermyl-1-propyne with Nb-containing catalysts

It has been shown that the copolymerization of 4-methyl-2-pentyne with 1-trimethylsilyl-1-propyne or 1-trimethylgermyl-1-propyne with the use of niobium pentachloride-based catalytic systems in the presence of Ph₃Bi, Et₃SiH, and Bu₄Sn as cocatalysts yields corresponding copolymers of various compositions. The technique of determining the composition of copolymers from their IR spectra has been developed. The reactivity ratios of the monomers have been estimated. It has been demonstrated that these values increase in a sequence 4-methyl-2-pentyne > 1-trimethylsilyl-1-propyne > 1-trimethylgermyl-1-propyne.     

Electrophilic reactions of 1-phenylthio-1-trimethylsilylethene

The reaction of 1-phenylthio-1-trimethylsilylethene (1) with various electrophiles, in particular acid chlorides, has been investigated.     

Electronic, vibrational, and rotational structures in the S0 1A1 and S1 1A1 states of phenanthrene

Electronic and vibrational structures in the S(0) (1)A(1) and S(1) (1)A(1) states of jet-cooled phenanthrene-h(10) and phenanthrene-d(10) were analyzed by high-resolution spectroscopy using a tunable nanosecond pulsed laser. The normal vibrational energies and molecular structures were estimated by ab initio calculations with geometry optimization in order to carry out a normal-mode analysis of observed vibronic bands. The rotational structure was analyzed by ultrahigh-resolution spectroscopy using a continuous-wave single-mode laser. It has been demonstrated that the stable geometrical structure is markedly changed upon the S(1) ← S(0) electronic excitation. Nonradiative internal conversion in the S(1) state is expected to be enhanced by this structural change. The observed fluorescence lifetime has been found to be much shorter than the calculated radiative lifetime, indicating that the fluorescence quantum yield is low. The lifetime of phenanthrene-d(10) is longer than that of phenanthrene-h(10) (normal deuterium effect). This fact is in contrast with anthracene, which is a structural isomer of phenanthrene. The lifetime at the S(1) zero-vibrational level of anthracene-d(10) is much shorter than that of anthracene-h(10) (inverse deuterium effect). In phenanthrene, the lifetime becomes monotonically shorter as the vibrational energy increases for both isotopical molecules without marked vibrational dependence. The vibrational structure of the S(0) state is considered to be homogeneous and quasi-continuous (statistical limit) in the S(1) energy region.