65887-20-9Relevant articles and documents
Ion-Molecule Reactions of CF3+ with Simple Unsaturated Aliphatic Hydrocarbons at Near-Thermal Energy
Tsuji, Masaharu,Aizawa, Masato,Nishimura, Yukio
, p. 3195 - 3200 (2007/10/02)
Ion-molecule reactions of CF3+ with C2H2, C2H4, and C3H6 have been studied at near-thermal energy (0.05 eV) by using an ion beam apparatus.Initial product ion distributions and reaction rate constants were determined and compared with previous beam and selected ion flow tube (SIFT) data.The CF3+/C2H2 reaction produces exclusively the electrophilic adduct C3H2F3+ ion.For C2H4 and C3H6, hydride abstraction and electrophilic addition followed by HF elimination or fluoride transfer occur in parallel.The branching ratios of the former and latter reactions are 0.29 +/- 0.04:0.71 +/- 0.06 for the CF3+/C2H4 reaction and 0.07 +/- 0.02:0.93 +/- 0.07 for the CF3+/C3H6 reaction.On the basis of theoretical calculations of potential energies for the CF3+/C2H2 and CF3+/C2H4 systems, the lack of the HF elmination channel in the CF3+/C2H2 reaction, whereas the lack of the initial adduct ion in the CF3+/C2H4 reaction, is attributed to the different stability of the intermediate adduct ions for HF elimination.The reaction rate constants were 0.45 x 1E-9, 1.3 x 1E-9, and 1.6 x 1E-9 cm3 s-1 for C2H2, C2H4, and C3H6, respectively, which correspond to 46percent, 120percent, and 130percent of calculated rate constants from Langevin theory or a parametrized trajectory model.Although there are significant discrepancies in the product ion distributions between the present beam experiment and the previous beam data, the product ion distributions and the reaction rate constants obtained here are in reasonable agreement with the previous SIFT data.
Collision-induced Dissociations of Carboxylate Negative Ions from 2-Ethylbutanoic, 2-Methylpropanoic, and Pivalic Acids. An Isotopic Labelling Study
Stringer, Michael B.,Bowie, John H.,Eichinger, Peter C. H.,Currie, Graeme J.
, p. 385 - 390 (2007/10/02)
Deprotonation of Et2CHCO2H yields Et2CHCO21-.On collisional activation this ion forms CO2-., CH2=CH-, and MeCH=CH-.In addition, elimination of H. and Et. yield Et(R)C=CO2-. (R=Et and H, respectively).The elimination of Et. is not a simple cleavage but occurs by loss of H. from a methyl group followed by loss of ethene.The carboxylate ion also rearranges to ; this species decomposes to OH-, , and also eliminates the elements of C3H8 and CH4.All fragmentations have been studied using 2H and 13C labelling: for example it is proposed that loss of CH4 from occurs by a six-centre stepwise process in which the first step (formation of an incipient methyl anion) is rate determining.The collisional activation mass spectra of Et2CHCO2-, Me2CHCO2-, and Me3CCO2- are different, all showing characteristic decompositions.For example, all three ions eliminate methane; the mechanism is different in each case.
C3H5+ Isomers: Evidence for the Existence of Long-Lived Allyl and 2-Propenyl Cations in the Gas Phase
Bowers, Michael T.,Shuying, Liu,Kemper, Petranella,Stradling, Rod,Webb, Hung,et al.
, p. 4830 - 4832 (2007/10/02)
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