Free, unsolvated phenylium ions formed by the spontaneous β decay of a constituent atom of multitritiated benzene have been allowed to react with gaseous propene and cyclopropane in the pressure range from 10 to 700 torr. Phenylium ions attack efficiently both the C-H and the C-C bonds of cyclopropane, yielding respectively tritiated cyclopropylbenzene and indane as the major products. Selective attack of phenylium ions on the π bond of propene is suggested by the composition of tritiated products, isomeric phenylpropenes and isopropylbenzene. The different behavior of propene and cyclopropane toward gaseous phenylium ions is consistent with the results of related radiolytic investigations concerning gaseous systems at nearly atmospheric pressure. The reactivity pattern of the isomeric C3H6 hydrocarbons toward gaseous phenylium ions is discussed and compared with pertinent mass spectrometric data. 相似文献
Free, unsolvated phenylium ions formed by the spontaneous β decay of [1,4-3H2]benzene have been allowed to react with gaseous alcohols (ROH: R = Et, CF3CH2, Pr, or i-Pr; partial pressure: 3–56 Torr) and alkyl chlorides (R′Cl: R′ = Pr, i-Pr, or Bu; partial pressure: 20–450 Torr), in the presence of a thermal radical scavenger (O2: 4 Torr). Phenylium ion confirms its considerable site selectivity, demonstrated by the distinct preference toward the n-centre of the substrate (46–100%), although significant insertion into the alkyl group of alcohols is observed as well. Phenylium ion displays significant positional selectivity even between different n-type sites in a bidentate molecule such as CF3CH2OH. An affinity F < O < Cl trend is observed, which indicates a direct relationship between the polarizability of the n-centre of the molecule and its orienting properties toward phenylium ion. The stability features of the ionic intermediates from addition of phenylium ion with ROH or R′Cl have been evaluated, as well as their fragmentation and isomerization mechanisms. The behaviour of phenylium ion toward the selected substrates in the gas phase is discussed and compared with previous mechanistic hypotheses from related nuclear-decay studies. 相似文献
It has been established that in the interaction of NdCl3 and YCl3 with RLi, where R CH2C6H5, CH2C(CH3)2C6H5, CH2Si(CH3)3, unusual organometallic compounds are formed. They are stable in hydrocarbon solutions. The benzyl and neophyl derivatives are carbene type complexes containing one R group at a trivalent metal atom. In all cases the reaction is accompanied by the evolution of RH as the main product and some stilbene and tolan when R CH2C6H5. The mechanism of this reaction is discussed. 相似文献
The structures of [C6H5]+ species, formed from a variety of precursors, have been investigated by ion/molecule reactivity studies with pulsed ion cyclotron resonance mass spectrometry and by collision spectroscopy with mass-analyzed ion kinetic energy spectrometry. Formed by sequential ion/molecule reactions in gaseous acetylene, the [C6H5]+ species are present as a mixture of isomers, those that react with acetylene and those that do not. Ion-assisted dehalogenation reactions were used to establish that the unreactive [C6H5]+ isomer was the phenylium ion. These data were used to study and confirm collisional decomposition reactions postulated to be diagnostic of the acyclic and phenylium isomers. These diagnostic reactions were then used to study the composition of the [C6H5]+ isomers produced by electron ionization of a number of precursors. These results are contrasted with previous studies and the collision spectroscopy experiments are described in detail. The possible role of [C6H5]+ species in flame processes is discussed. 相似文献
Mass spectra of substituted benchrotrenyls RC6H5Cr(CO)3 where R?H, F, CI, I, CH3, OCH3, COOCH3, C2H5, N(CH3)2, NH2, C6H5, C(CH3)3, p-C6H4NH2, CH2C6H5, CH2CH2C6H5), 1,3,5-(CH3)3C6H3Cr(CO)3 and 1,2,3,5-(CH3)4C6H2Cr(CO)3 have been studied. It has been found that for monosubstituted benchrotrenyls there is a linear dependence of the parameter log [Cr]+/[RC6H5Cr]+) on the number of degrees of freedom of the [RC6H5Cr]+ ion. Decarbonylation of the molecular ions is not affected by the nature of the substituent R. The results are interpreted in terms of the quasi-equilibrium theory of mass spectra. 相似文献
The novel complexes CpFe(CO)(COR)P(C6H5)2NR'R* with Cp = C5H5,C9H7 (indenyl); R = CH3, C2H5, CH(CH3)2, CH2C6H5;R` = H, CH3, C2H5, CH2C6H5 and R* = (S)-CH(CH3)(C6H5), have been synthesized by reaction of CpFe(CO)2R wiht P(C6H5)2NR`R* and characterized analytically as well as spectroscopically. The pairs of diastereoisomers RS/SS have been separated by preparative liquid chromatography and fractional crystallization, respectively. The optically pure complexes (+)436- und ()436-CpFe(CO)(COR)P(C6H5)2NR`R* are configurationally stable at room temperature. At higher temperatures they equilibrate with CpFe(CO)2R and epimerize with respect to the Fe configuration. 相似文献
Compounds of the composition RR′SiFNR″Si(CH3)3 (R = H, F, CH3, C2H5, C3H7, C2H3, C6H5, C(CH3)3; R = F, CH3, C6H5; R″ = CH3, C(CH3)3, Si(CH3)3) are obtained by the reaction of silicontetrafluoride or organo-substituted silicon-fluorides with the lithium salts of alkylsilylamines in a molar ratio of . The disubstituted compounds RSiF(NR′Si(CH3)3)2 (R = H, F, CH3, C2H3, C6H5; R′ = CH3, C(CH3)3) result when the reactants are in a molar-ratio. Likewise the unsymmetrical siliconfluorsilylamines of the formulae F2Si(NRSi(CH3)3) (NR′Si(CH3)3) (R = CH3, R′ = C(CH3)3), as well as the trisubstituted compounds FSi(NCH3Si(CH3)3)3 and FSi(NCH3Si(CH3)3)2(N(Si(CH3)3)2) were made. By reacting phenyltrifluorsilane with dialkylamines () C6H5SiF2NR2(R = CH3, C2H5) was obtained. The IR-, mass-, 1H and 19F NMR spectra of the above-mentioned compounds are reported. 相似文献
Time-resolved measurements of the thermal lens effect have been made for CH3F, CH3CI and C2H4. This technique is compared to others used in the study of vibrational relaxation phenomena and is found to be applicable to the study of a wide variety of gaseous systems at relatively low pressures. Translational cooling has been observed in CH3F and an approximate lower limit of 200 msec-1 has been established for the rate of this cooling process, which corresponds to equilibration of the ν3 and ν6 states, in a mixture of 0.2 torr CH3F and 10 torr Ar. 相似文献
Organometallic Compounds of the Lanthanides. 133 Synthesis and Characterization of donor-functionalised ansa -Metallocenes of Yttrium, Neodymium, Samarium, Erbium, and Lutetium The reaction of Me2SiCl2 with K[C5H4tBu], Li[C5H4SiMe3] or K[C5H3tBuMe-3] followed by treatment with K[C5H4CH2CH2NMe2] yields mixed substituted dicyclopentadienyldimethylsilanes which after double deprotonation with KH afford the dipotassium salts K2[Me2Si(C5H3tBu-3)(C5H3CH2CH2NMe2-3)] ( 1 ), K2[Me2Si · (C5H3SiMe3-3)(C5H3CH2CH2NMe2-3)] ( 2 ), and K2[Me2Si · (C5H2tBu-3-Me-5)(C5H3CH2CH2NMe2-3)] ( 3 ), respectively. The reaction of 1 , 2 , or 3 with LnCl3(THF)x (Ln = Y, La, Nd, Sm, Er, Lu) leads to the complexes [Me2Si(C5H3tBu-3) · (C5H3CH2CH2NMe2-3)]LnCl [Ln = Y ( 4 a ), Sm ( 4 c ), Lu ( 4 e )], [Me2Si(C5H3SiMe3-3)(C5H3CH2CH2NMe2-3)]LnCl [Ln = Y ( 5 a ), Sm ( 5 c ), Lu ( 5 e )], and [Me2Si(C5H2tBu-3-Me-5)(C5H3CH2CH2NMe2-3)]LnCl [Ln = Y ( 6 a ), Nd ( 6 b ), Sm ( 6 c ), Er ( 6 d ), Lu ( 6 e )], respectively. Alkylation of 4 a , 4 c , 5 a , and 6 b , 6 e with LiCH3, LiCH2SiMe3, and LiCH(SiMe3)2 produces the alkylmetallocenes [Me2Si(C5H3tBu-3) · (C5H3CH2CH2NMe2-3)]LnR [R = CH3, Ln = Y ( 7 a ), Sm ( 7 c ); R = CH2SiMe3, Ln = Y ( 8 a )], [Me2Si(C5H3SiMe3-3) · (C5H3CH2CH2NMe2-3)]YCH3 ( 9 a ), and [Me2Si(C5H2tBu3-Me-5)(C5H3CH2CH2NMe2-3)]LnR (R = CH3, Ln = Lu ( 10 e ); R = CH2SiMe3, Ln = Lu ( 11 e ); R = CH(SiMe3)2, Ln = Nd ( 12 b ), Lu ( 12 e )], respectively. All new compounds were characterized by elemental analyses, NMR spectroscopy and mass spectrometry. The molecular structure of 6 c and 6 e was determined by single crystal X-ray structure analysis. 相似文献
2,4-Bismethylthio-1,3,2,4-dithiadiphosphetane 2,4- disulfide, IIa, is prepared from 0,0-dimethyldithiophosphoric acid, Ia, and P4S10 at 160°C. 2,4-Bis(4-phenoxyphenyl)-1,3,2,4- dithiadiphsophetane 2,4-disulfide, IIc, and 2,4-bis(4-phenylthiolophenyl)-1,3,2,4-dithiadiphosphetane 2,4-disulfide, IId, are prepared at l60°C from P4 S10 and diphenylether and diphenylsulfides, respectively. Carboxylic acids RCOOH(R = CH3 C2H5, n-C3H7, n-C4H9, C6H5CH2, C6H8) react with compound Ia at 130°C to give the corresponding methyl dithioesters. Carboxylic acids RCOOH (R = C6H8-CH2, C6H8) react with compound Ib at 200°C for 15 min to give the corresponding ethyl dithioesters, while low boiling acids (R = CH3, C2H8, n-C3H7) yielded mixtures of the corresponding ethyl dithioester and ethyl carboxylate. Carboxylic acid chlorides RCOCl (R = ClCH2, C2H5, t-C4H5 C6H5CH2, C6H5, P-NO2C6H4) react with compound IIa at 80°C to give the corresponding methyl dithioesters in good yields. S-Substituted thioesters react with IIC at 85°C to give the corresponding dithioesters in good yields. Dihydro2(3H)-furanone, VI, and 5-methyl-2(3H)-furanone, VII, react with IIa at 80°C; to dihydro-2(3H)-thiophenethione, VIII and 2,2'-dithiobis(5-methyl thiophene),IX, respectively. Also XI reacts with IIa,IIc, and IId to give VIII in nearly quantitative yields. 相似文献
Rate constants for H + Cl2, H + CH3CHO, H + C3H4, O + C3H6, O + CH3CHO, and Cl + CH4 have been measured at room temperature by the discharge flow—resonance fluorescence technique. The results are (1.6 ± 0.1) × 10?11, (9.8 ± 0.8) × 10 ?14, (6.3 ± 0.4) × 10?13) (2.00 torr He), (3.95 ± 0.41) × 10?12, (4.9 ± 0.5) × 10|su?13 and (1.08 ± 0.07) × 10?13, respectively, all in units of cm3 molecule?1 s?1. Also N atom reactions with C2H2, C2H4, C3H4, and C3H6 were studied but in no case was there an appreciable rate constant. These results are compared to previous studies. 相似文献
The syntheses and properties of the titanium(III) complexes Cp2Tir · R′CN (R = C6H5, o-, m-, p-CH3C6H4, CH2C6H5, C6F5, Cl; R′ = CH3, t-C4H9, C6H5, o-CH3C6H4, 2,6-(CH3)2C6H3) are described. In the complexes the nitrogen atom of the cyanide ligands is coordinated to the metal. The thermal stabilities of the complexes depend markedly on R and R′; on heating they undergo a novel reaction in which two cyanide ligands are coupled by formation of a CC bond, while the metal is oxidized to titanium(IV). 相似文献
Five-membered cyclic esters of phosphoric acid of the general formula: ? CH2CH(R)OP(O)-(OR′)O? polymerize readily to solid, soluble polymers of high molecular weight without any rearrangement known for various tri- and pentavalent organophosphorus monomers. 1H-, 13C-, and 31P-NMR spectra of polymers confirmed their linear structure: where R is H, with R′ = CH3, C2H5, n-C3H7, i-C3H7; n-C4H9, CCl3CH2, or C6H5, or R is CH2Cl and R′ is C2H5. The use of n-C4H9Li, (C5H5)2Mg, or (i-C4H9)3Al as initiators leads to polymers with Mn = 104–105. 相似文献
Electron Impact Fragmentation of Substituted Dimethylalkoxysilanes The mass spectra of substitued dimethylalkoxysilanes (H3C)2SiOCH3R (R ? ? F, ? Cl, ? H, ? OCH3, ? C6H5, ? CH3, ? C2H5, ? n-C3H7), and (H3C)2SiOC2H5R (R ? ? Cl, ? C6H5, ? CH3, ? C2H5) have been recorded and the fragmentation patterns are presented. The yield of the electron impact induced reaction (M-15)+→(M-45)++ H2CO occuring upon fragmentation of substituted dimethylmethoxysilanes depends on the substituent R. A quantum chemical calculation was carried out by CNDO/2 method to determine the electron density distribution in the ion at mass number (M-15). It is shown that a correlation exists between the Si? O? π bond order in this ion and the yield as well as the activation energy of this reaction. 相似文献
2,4-Bis(phenyl)-1,3-diselenadiphosphetane-2,4-diselenide (Woollins’ reagent, WR) reacts with cyanamides (1a-h) in refluxing toluene to afford a series of novel selenazadiphospholaminediselenides (RR′NCN(PhP(Se)SeP(Se)Ph, R=C6H5(CH2)1-3, 4-n-C10H21C6H4 and 4-BrC6H4CH2; R′=H, CH3, C2H5 and C(O)OC2H52a-g). Post-treatment of the reaction mixture with water led to the formation of carbamidoyl(phenyl)phosphinodiselenoic acids (RR′NC(NH2)P(SeH)2Ph, R=C6H5(CH2)2-3, 4-n-C10H21C6H4 and 4-BrC6H4CH2; R′=H and CH3, 3b, 3c, 3e and 3f) and selenoureas (RR′NC(Se)NH2, R=C6H5(CH)1-2; R′=CH3 and OC(O)C2H5, 4f and 4h) in moderate to excellent yields. All new compounds are characterised spectroscopically and five X-ray crystal structures are reported. 相似文献
The preparation of ylides of the general structure is described. Thermolysis of 14a (R = CH3, R' = H, Ar = C6H5) gave dimethylamine and 2,4-dimethyl-6-phenyl-s-triazine. Thermolysis of ylides 14b (R = C6H5; R' = CH3, Ar = C6H5) and 14c (R = C6H5, R' = CH3, Ar = p-tolyl) gave dimethylamine, ArCH = NCH3 and 1-methyl-2-Ar-4,6-diphenyl-1,2-dihydro-s-triazines ( 19a,b ). Triazines 19a and 19b were also prepared by condensation of N-methylbenzamidine with benzaldehyde and p-tolualdehyde, respectively. Thermolysis of 14d (R = C6H5, R1 = CH2C6H5,Ar = C6H5) gave 1-benzyl-2,4,6-triphenyl-1,2-dihydro-s-triazine ( 19c ) and N-benzylidenebenzylamine. Mechanistic aspects of these reactions are discussed. 相似文献
The photolysis of azomethane in the near UV has been studied at room temperature and pressures from 10 mtorr to 10 torr. The main products, C2H6 and N2, accounted for more than 99% of the reaction. Minor hydrocarbon products observed were (with quantum yields) C3H8 (3.5 × 10?3), C2H4 (3.2 × 10?4), CH4 (3 × 10?3), and n-C4H10 (trace). Quantum yields of H2 of 4 × 10?5 and 2 × 10?5 were measured at azomethane pressures of 0.1 and 1.0 torr, respectively. The minor hydrocarbon products can be accounted for by reactions of CH3 and C2H5 radicals following hydrogen abstraction from azomethane by CH3. The H2 product observed represents an upper limit for the H2 elimination from vibrationally excited C2H6 formed by CH3 combination in the system, corresponding to a rate of elimination ca. 5 × 10?5 times the competing rate of dissociation to 2CH3. Assuming a frequency factor of 1013 s?1 for the H2 elimination, a lower limit of about 90 kcal mol?1 was estimated for the energy barrier. 相似文献
Thirty triorganotin(IV) derivatives of the type R3Sn(R′COCHCOCH2COR″) and [R3Sn]2 (R′COCHCOCHCOR″) (where R = CH3, C2H5, nC3H7, nC4H9 and C6H5 and R′ = R″ = CH3, C6H5 or R′ = C6H5, R″ = CH3) have been synthesised by the interaction of R3SnCl with mono- or disodium salt of 2, 4, 6-heptanetrione, 1-phenyl-1, 3, 5-hexanetrione and 1, 5-diphenyl-1, 3, 5-pentanetrione in 1:1 and 2:1 molar ratios, respectively. The complexes have been examined by their molecular weight, IR, PMR and elemental analyses and their tentative structures assigned. Both “Z” and “E” forms have been identified in the 1:1 complexes in equilibrium with the enol form containing five coordinate tin. The 2:1 derivatives contain one five- and other four coordinated tin(IV) except the phenyl analogue where both the tins are five coordinated. 相似文献
Esters of the trimeric dithioformic acid [HCS(SR)]3 were prepared by interaction of K[HCS2] with alkyl iodides (R = CH3, C2H5). Orthoesters HC(SR)3 and di-orthoesters of the monomeric dithioformic acid were formed by reaction of formic acid with thioles (RSH mit R = CH3, C2H5, CH2C6H5) or dithioles (HS? (CH2)n? SH with n = 2, 3,4). The prepared compound were characterised by different methods. 相似文献