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1.
SynthesisandCharacterizationofTri(organotin)SubstitutedHeteropolytungstatesYANGQi-hua,DAIHui-cong,LIUJing-fu(DepartmentofChem...  相似文献   

2.
Positive-ion mass spectra of organotin compounds include a large number of different ions and therefore the absolute detection level is reduced. Negative-ion mass spectra are usually less complex and detection levels may therefore be improved. The negative-ion mass spectra of selected organotin compounds of the type R4Sn, R3SnCI, R2SnCI2 and RSnCl3 were investigated using conventional electron impact ionization conditions. Simplified mass spectra, suitable for compound speciation, were obtained for R3SnCI2 and R2SnCI2 materials but the same fragmentation product SnCI was obtained from all the RSnCI3 samples. R4Sn compounds produced no negative-ion data in these studies. No significant gains in detection levels were noted but some interesting re-arrangement reactions leading to the formation of compounds consisting of substituents from the original tin atom were identified. These reactions may be of synthetic importance.  相似文献   

3.
The influence of intermolecular interactions on the M?ssbauer quadrupole splitting (Delta) of 119Sn was investigated in detail by density functional theory (DFT) calculations. Six organotin(IV) complexes [Me2Sn(acac)2 (1), Ph3SnCl (2), Me3Sn-succinimide (3), Me3Sn-phthalimide (4), Me3SnCl (5), and cHex3SnCl (6)] of known solid-state structures and quadrupole splittings were selected. Theoretical Delta values were calculated for both fully optimized geometries and experimental solid-state structures of different size, and the results were compared to the experimental Delta values. Compared to a synthetic procedure described in the literature for compound 4, a more convenient synthesis is reported here. The experimental Delta of this compound has also been redetermined at 80 K. For compounds with negligible intermolecular interactions in the solid state, calculated Delta values obtained did not vary significantly. In contrast, the calculated Delta values turned out to be very sensitive to the size of the supramolecular moiety considered in the crystal lattice. The crystal structure of compound 2 shows no significant intermolecular interactions; however, the calculated and the experimental Delta values remained very different, even when the supramolecular moiety considered was extended. Distortion of the coordination sphere of tin in the molecule of 2 toward a trigonal bipyramidal geometry was considered, and a possible weak intermolecular Sn...Cl interaction was included in the model. Steps of the distortion followed the new structure correlation function, which was found for the R3SnCl (R=alkyl, aryl) compounds. The experimental Delta value could be approached by this method. These results suggest that compound 2 is involved in some unexpected intermolecular interaction at 80 K.  相似文献   

4.
Phosphoproteinsplayimportantrolesinbiologicalsignallingcascades,bywhichchemicalsignalsarepassedacrossthecellmembraneandfurthertothecellnucleusl.Forthestudythisprocess,structurallywell-definedpeptidescontainingthecharacteristiclinkageregionofthepeptidebackbonewiththephosphoricacidestercanusedwithmanyadvantages.Ingeneral,estersofoligopeptideswerephosphorylatedwithphosphorylchlorideorwithdialkylordiarylphosphorochloridates'.Butaminogroupsinoligopeptidesshouldbeprotectedwhenhydroxylgroupswerephosp…  相似文献   

5.
The influence of the organoaluminium compound nature, Zr π-ligand environment, solvent type and reagent ratio on the chemoselectivity of reactions of trialkylalanes (AlMe3, AlEt3) with alkenes, catalyzed with L2ZrCl2 [L = Cp, Cp′ (Cp′-η5-C5H4CH3), Cp (Cp5-C5(CH3)5), Ind (indenyl), Flu (fluorenyl)] has been studied. It is shown that in the case of AlMe3, the hydro- and carboalumination products, and alkene dimers are formed. The catalytic reaction of AlEt3 with the olefins yields aluminacyclopentanes altogether with the hydro- and carboalumination products, and the dimers. A probable reaction mechanism has been proposed.  相似文献   

6.
CyclopropanationofDiazoacetatewithOlefinsCyclopropanationofDiazoacetatewithOlefins¥ZhengNingLI;HuiLinCHEN(DalianInstituteofCh...  相似文献   

7.
MalebodeanditSderivatvesarewell-bowntopolyInrizetogivethermallystablepolyTnersandthecopolymeriZationwithvariousvinylmonomershasbeenexaminedtohaProvethethermalpropeniesofthepolymers[';-'].HoweverlessworkhasbeendoneonthecopolyInerizationofN-phenylmaletride(PHMI)withcyclohexene(CH).Inthisletter,wesynthesizedanewcopolymerfromthepolymerizahonofPHMIwithCH.ThemonomerPHMIwaspreparedfrommaleicanhydrideandedlineaccordingtoT.OkadaI41.2,2'-Azobisisobutyronitrile(AIBN)wasrecrystallizedtWicefro…  相似文献   

8.
Superoxide ion O~-_2 is prepared in aprotic media by carbon gas-diffusion-electrode for the first time. The experimental results indicate that this electrode is superior to carbon plane-electrode in the reaction of O~-_2 with p-bromonitrobenzene. When the gas-diffussion-electrode is used, the yield of the product nitrophenol increases by 20%, and the selectivity of the reaction is nearly doubled as compared with the plane-electrode.  相似文献   

9.
-Halonitrosoalkanes react with resorcinol as nitrosylating agents to form 3-hydroxy-N-(2,4-dihydroxyphenyl)-1,4-quinone imine.Translated fromIzvestiya Akademioi Nauk. Seriya Khimicheskaya, No. 3, pp.773–774, March, 1996.  相似文献   

10.
The reaction of cryptotanshinone and tanshinone IIA with several biogenic amine metabolites involved in the pathogenic pathways of HE were investigated and eight 1,2,3,4-tetrahydrophenanthrene derivatives,2-6 and 8-10,were obtained.The probable mechanism on reaction was discussed.  相似文献   

11.
The copolymerization of isobutylene with α-pinene has been investigated by using EtA1Cb in ethyl chloride diluent at ca. -105°C. The copolymerizations proceeded readily and gave random copolymers of reasonably high molecular weights. Copolymer homogeneity, composition and structure was investigated by GPC, solubility behavior, PMR (60 and 300 MHz), CMR, reactivity ratio determination, and vulcanization behavior.  相似文献   

12.
Reactions of α-nitroacrylates with aromatic thiols like 4-methyl- and 4-chlorothiophenols afford a series of new 3-arylsulfanyl-2-nitropropanoates. The latter were isolated as diastereomerically pure substances or mixtures of two diastereomers. Structures of the obtained S-adducts were confirmed by IR, 1H and 13C-{1H} NMR spectroscopy using HMQC and HMBC experiments.  相似文献   

13.
14.
RemovalofalundnumfromNaYzeolitewithacidisanimportantprocessinthemodificationofzeolite.ItisdifficulttoremovealundnumfromNaYzeolitedirectlywithacidwhilekeepinghighcrystallinity.Intheworkreportedhere,alundnumisremoveddirectlyfromNaYwithoxalicacidandthemodifiedzeolitekeepshighcrystallinity.Reactionconditions:CSBlreflux,acidaddedin3ondn,allowedtoreactfor3OAnn.CSB2reflux,acidaddedrapidly,allowedtoreactfor3Owhn.CS2525-C,acidaddedraPidly,allowedtoreactfor3Omin.CSA25"C,acidaddedin3omin,a1lowe…  相似文献   

15.
Benzofuranone derivatives have been synthesized by the condensation of p-benzoquinone with anilides of -aminocrotonic acids under the conditions of the Nenitzescu reaction.  相似文献   

16.
17.
Two series of indomethacin conjugates with D-glucosamine were prepared with the objectives of reducing ulcerogenic potency, increasing the bioavailability of indomethacin and exerting the coordinative effects on osteoarthritis. The structures of the conjugates were identified by ^1H NMR and ^13C NMR. The ester conjugates inhibited edema as potent as indomethacin.  相似文献   

18.
The reaction of -arylacryloyloxiranes with phenythydrazine under the conditions of acid catalysis leads to 3 arylvinyl-I-phenylpyrazoles and 2-hydroxymethyl-5-aryl-1,4-pentadien-3-one phenythydrazones.Belorussian State Technological University. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3 pp. 324–327, March, 1996. Original article submitted June 26, 1995.  相似文献   

19.
3-(-Vinyloxyalkylimino)-2,3-dihydroindol-2-ones and 3-(vinyloxyphenylimino)-2,3-dihydroindol-2-ones were synthesized in 34-93% yield by reactions of -aminoalkyl and aminophenyl vinyl ethers with isatin.  相似文献   

20.
Our group have explored the reaction of allylsamarium bromide with a variety of substrates, such as N-(2-aminoalkyl)benzotriazoles1, imines2, nitriles3, diorgano diselenides4, disulfides5, isocyanates6 and nitroalkenes7. Here we wish to report the monoallylation of gem-diacetates with allylsamarium bromide. Gem-diacetates are stable in neutral and basic media, thus they are frequently used to protect aldehydes8. However, the presence of two leaving groups at the same carbon may make carbon …  相似文献   

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