首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
Conclusions When,-dichlorovinyl ketones are reacted with Na2S, NaSC(S)N(C2H5)2, KSC(S)OC2H5, and NaSCOCH3, two types of sulfur-containing heterocyclic compounds are formed: 1,3-dithietanes and 1,3-dithiols , at which time the ratio of the products depends on the nature of the sulfur-containing nucleophilic reagent.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2940–2048, September, 1976.  相似文献   

2.
Conclusions The direction of the reaction of the silicon hydrides: R2SiH2, RSiH3, and with primary aliphatic amines, in the presence of catalysts based on Group VIII compounds, as a function of the structure of the silicon hydride and the nature of the employed catalyst, was established.Deceased.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 10, pp. 2330–2333, October, 1972.  相似文献   

3.
Zusammenfassung Es wird die Frage untersucht, ob bei der thermischen Umlagerung von entsprechend allyl-substituierten o-Benzochinol-acetaten der Allyl- oder der Acetoxylrest rascher wandert. Das 2-Allyl-2-acetoxy-cyclohexadienon liefert bei der genannten Reaktion (es sind schon Temperaturen um 100° ausreichend) überwiegend ein Monoacetat des 4-Allylbrenzcatechins. Damit ist bewiesen, daß der Rest rascher als der Rest in die p-Stellung zur Carbonylgruppe des Chinolacetates wandert. Eine Wanderung des Acetoxylrestes in die o- oder in die p-Stellung zur Carbonylgruppe, welche zur Bildung von 3-Allyl-brenzcatechin bzw. 2-Allylhydrochinon führen müßte, konnte nicht beobachtet werden. Entsprechend liefert das 2,6-Diallyl-2-acetoxy-cyclohexadienon bei der thermischen Umlagerung überwiegend ein Monoacetat des 3,5-Diallyl-brenzcatechins. Nach einem anderen Mechanismus verläuft die Umlagerung des 2-Methyl-6-allyl-2-acetoxy-cyclohexadienons. Es entsteht neben wenig 2-Methyl-6-allyl-hydrochinon in der Hauptmenge ein Monoacetat des 3-Methyl-5-allyl-brenzcatechins. Es wird also die Allylgruppe durch den in die o-Stellung wandernden Acetoxylrest verdrängt. Auf diese Reaktion wird näher eingegangen, weil sie in engem Zusammenhang mit der Frage steht, ob ganz allgemein eine Umlagerung von o-Chinolacetaten vom Typ in die Isomeren möglich ist.Mit 2 AbbildungenHerrn Prof. Dr.F. Feigl zum 70. Geburtstag in alter Freundschaft!F. W. E. Zbiral, F. Wessely undE. Lahrmann, (gilt als 1. Mitt. dieser Reihe), Mh. Chem.91, 331 (1960).  相似文献   

4.
Conclusions The principal products of the telomerization of propylene with methyl propionate are telomers with the structure , where n=1–4.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2534–2537, November, 1973.  相似文献   

5.
Conclusions Employing the EPR method and 2-methyl-2-nitrosopropane as the spin trap, we recorded the formation of the radicals (n = 1 and 2; X = O, N, or a chain composed of C and O atoms; R = H or alkyl) during the photolysis of acetals and their heteroanalogs in the presence of di-tertbutyl peroxide.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2097–2099, September, 1976.The authors are indebted to A. Sh. Mukhtarov for assistance in running the experiments.  相似文献   

6.
The title silanethione reacts with phosphorus ylides under conditions of kinetic control to give betaines containing a linear fragment. Under conditions of thermodynamic control, the derivatives of phosphonium 1-silaacenaphthene-1-thiolate are formed.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2140–2141, December, 1993.  相似文献   

7.
Conclusions The activity of bis-[N-alkyl-(or aryl)-aminomethyl] phosphonic acids of the general formula (RNHCH2)2 in the interfacial polycondensation reaction with bisphenol A has been studied.In their activity the diamines studied can be placed in the following series: R=C6H5CH2, C4H9, C6H5, C3H7.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 633–636, March, 1969.  相似文献   

8.
Electrochemical reduction of the complexes Rh(CO)ClL2 [L = (EtO)2PCN (1), Ph2PCN (2)] and Rh2(CO)4L [L = P(CN)3 (3), (4)] and their catalytic properties in electrochemical reduction of 2-carbomethoxy-2-methyl-1,1-dichloro-cyclopropane were studied. The catalytic electroreduction of a substrate at the reduction potentials of the central ion was developed for complexes2–4. This process is accelerated substantially for complexes2 and3 in the presence of anthracene.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1970–1972, October, 1995.  相似文献   

9.
Conclusions The previously proposed structure for the salts of primary nitramines was corro-borated on the basis of the vibrational spectra and quantum-chemical calculations.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 948–950, April, 1972.The authors wish to thank S. Gagarin, who took part in the calculations.  相似文献   

10.
Conclusions The band in the 1270–1280 cm–3 region, corresponding to the vibrations of the -C -N=bond in the grouping , can be used to determine the presence of azoxy groups in polyazopolyarenes.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2623–2625, November, 1970.  相似文献   

11.
According to IR spectroscopy data, the interaction of bi-, tri-, and tetranuclear cyclopentadienylcarbonyl rhodium complexes with rather weak protic acids (phenols, fluoroalcohols) in low-polarity media results in the formation of hydrogen bonds of the OH...O=C type with bridged carbonyl groups. According to1H NMR data, protonation of these complexes with strong acids (CF3COOH and HBF4) occurs at the the Rh-Rh bond to give the symmetrical bridge.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 386–388, February, 1995.This work was carried out with the financial support of the Russian Foundation for Basic Research (Project No. 93-03-0461).  相似文献   

12.
The structure of 5-methyl-3-(1-methyl-3-isopropoxyallyl)-1-formyl-3,4,4-tricyano-1-cyclopentene was determined by an x-ray diffraction structural analysis. A discussion was given for the pseudoaxial orientation of the CN and C-H groups at the 3,5-positions, steric strain, the effect of this strain leading to a large ring flexure angle and extension of the C-C bonds, the bipolar nature of the enaminoformyl fragment, twisting of the NH2 group due to an unusual intramolecular hydrogen bond involving the ethereal oxygen atom, the lack of extension of the bond under conditions of np(O)–*(C=C) conjugation, and the conformation of the isopropyl group relative to the O-C(sp3) bond.Communication 12, see our previous work [1].Institute of Chemical Physics, Academy of Sciences of the USSR. Translated from Zhurnal Strukturnoi Khimii, Vol. 30, No. 5, pp. 108–113, September–October, 1989.  相似文献   

13.
Summary Hindered rotation around the bond in the N-acylamidines has been investigated by PMR spectroscopy, and the kinetic parameters of the hindered rotation have been determined.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 758–762, April, 1981.  相似文献   

14.
Conclusions The teloHierization of vinyl chloride with methyl propionate was accomplished and it was shown that telomers of type are formed.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2537–2540, November, 1973.  相似文献   

15.
Nonempirical calculations were carried out for the potential energy surfaces of OF2Li+, SF2Li+, F2Li+, and ClFLi+ using the SCF/TEHD+P approximation. The stability of the bridged structure in comparison with the classical structure is enhanced upon replacement of the oxygen atom by sulfur and replacement of fluorine by chlorine. A bridged structure with Li–F–M and . bonds is the major form for all the fluorides examined. The classical structure LiMF k +, where Li is bound directly to the M atom, corresponds to an apex of a potential barrier and is either close or greater on an energy scale to the dissociation limit to Li++MF k . A comparison was made with analogous hydride complexes, which, in contrast to the fluorides, display isomerism.Institute of New Chemical Problems, Academy of Sciences of the USSR. Translated from Zhurnal Strukturnoi Khimii, Vol. 30, No. 6, pp. 19–22, November–December, 1989.  相似文献   

16.
Zusammenfassung Nachdem plausibel gemacht werden konnte, daß bei verschiedenen Zersetzungs- bzw. Regenerationsprozessen als Zwischenprodukt freie Cellulosexanthogensäure (CXS.) auftritt und dieselbe z. B. in vorliegender Arbeit im frisch gesponnenen Faden tatsächlich nachweisbar war, wurde auch versucht, die Dissoziationskonstante derselben abzuschätzen. Die dabei auftretenden Schwierigkeiten — sowohl hinsichtlich der experimentellen Durchführung wie auch die durch das Fehlen einer Theorie polyvalenter Makroionen — werden diskutiert. Aus mehreren unabhängigen Messungen, unter Bedachtnahme auf Ergebnisse an Celluloseglycolsäureäther vonKagawa undKatsuura, wird wahrscheinlich gemacht, daß die Dissoziationskonstante der verdünnten Säure zwischen 2,1 und 5,5·10–5 liegt. Mithin ist die Cellulosexanthogensäure etwas stärker als Essigsäure, die im verdünnten Zustand bekanntlich Na-Cellulosexanthogenat ziemlich unzersetzt läßt2, 9, 12.Abschließend wurde noch das Röntgendiagramm von präzipitiertem Na-Cellulosexanthogenat wiedergegeben.Mit 4 AbbildungenHerrn Prof. Dr.A. Skrabal zum 75. Geburtstag gewidmet.  相似文献   

17.
Cyclopropyl type radicals were identified on a surface of activated silica by ESR. The possibility of their preparation by two methods,i.e., by photocyclization of substituted allyl radicals and by interaction of cyclopropane molecules with particular surface defects, was demonstrated. The effects of -substituents on radiospectroscopic characteristics and thermal stabilities of the radicals were studied. Rate constants and activation energies of decomposition of substituted cyclopropyl radicals were estimated. The experimental data obtained were compared with the results of quantum-chemical calculations of model systems. The mechanism of photocyclization of allyl radicals was discussed. The transition states of decomposition of cyclopropyl and -fluorine-substituted cyclopropyl radicals were calculated. Electronegative substitution was found to result in a considerable decrease in the activation energy of the cyclopropane ring opening.The authors are grateful to E. G. Baskir for calling their attention to this publication.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2409–2421, December, 1995.The work was carried out with financial support of the Russian Foundation for Basic Research (Project code 94-03-09137) and the International Science Foundation (Grant No. MK9000).  相似文献   

18.
Conclusions When alkanesulfenyl chlorides are added to acrylic derivatives CH2=CHR (R=COOH, COOCH3, COOCH3 CN, CONH2 a mixture of the isomers and is formed and the proportions of these depend on the nature of the substituent R.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1069–1075, June, 1966.  相似文献   

19.
The values of the energy barriers to intramolecular 1,3-H shift reactions, in whichaci-forms of N- and C-nitro-compounds: 1 and are capable of transforming into 2 and , respectively, have been calculated by the semi-empirical AM1 method. The barrier heights (39 and 59.4 kcal/mol) reflect the kinetic stability of both tautomeric forms of the N- and C-nitro-compounds.Ab initio calculations in the 3–21G basis set of the structure and energies of stationary points on the potential energy surface of the system MeN=NO2 H3O demonstrated that there exists the principal possibility of the formation of only tautomer 2 (which is more stable than1).Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No 1, pp. 100–104, January, 1993.  相似文献   

20.
Conclusions The -allylidene complex is formed in the photochemical reaction of with 1,3-butadiene and 1,3-cyclohexadiene, with subsequent replacement of the carbonyl group by the appropriate ligand.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2130–2131, September, 1977.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号