19252-52-9Relevant academic research and scientific papers
Ion-Molecule Reactions of Vibrationally State-Selected NO+ with Small Alkyl Halides
Wyttenbach, Thomas,Bowers, Michael T.
, p. 8920 - 8929 (2007/10/02)
The effects of vibrational excitation in NO+ (v=0-5) on its reactivity with small alkyl halides (CnH2n+1X; n=1-3; X=Cl, Br, I) have been investigated under thermal translational conditions.The method combines resonance enhanced multiphoton ionization to form state-selected NO+(v), and Fourier transform in cyclotron resonance techniques to trap, react, and detect ions.Besides vibrational quenching of NO+(v > 0), which is found to be very efficient with alkyl halides, three reaction channels are observed: charge transfer, halide transfer, and CnH2nNO+ formation.Branching ratios and rate constants have been determined for the different channels as a function of the NO+(v=0) vibrationally energy.Endoergic charge transfer is efficiently driven by vibrational excitation.Halide transfer is the major channel if it is significantly exothermic for NO+(v=0).If this is not the case, adding vibrational energy in NO+(v=0) is only marginally effective in driving this channel.The data suggest that rearrangements in NO+-alkyl halide reaction intermediates and in carbonium ions are very rapid.The CnH2nNO+ formation channel is only observed with n-propyl and isopropyl chloride where it is dominant for NO+(v=0).Increasing vibrational excitation inhibits C3H6NO+ formation.The results are discussed in terms of possible reaction mechanisms.
Ion-Molecule Reactions and Thermal Decomposition of Ions in N2-O2-Alkane (C2-C8) Mixtures Studied by Time-Resolved Atmospheric Pressure Ionization Mass
Matsuoka, Shingo,Ikezoe, Yasumasa
, p. 1126 - 1133 (2007/10/02)
The experiments were carried out at temperatures ranging from 236 to 569 K.The O2+ ion reacted with n-alkanes (CnH2n+2) via fast nondissociative and dissociative charge-transfer channels, its proportion depending on temperature.The nondissociative product CnH(2n+2)+ subsequently reacted with O2 via a slow H atom transfer path, producing alkyl ions.With increasing temperature the alkane ions CnH(2n+2)+ (n >/= 4) began to decompose thermally, producing olefinic ions and alkanes.The product olefinic ions CmH2m+ (m=4,5,6) reacted with O2 via a slow H atom transfer path, producing alkenyl ions CmH(2m-1)+.The C8H17+ decomposed thermally forming fragment alkyl ions and olefins.The fragment alkyl ions reacted with n-C8H18 reproducing C8H17+, thus leading to a chain mechanism in n-C8H18 decomposition.The equilibrium reaction, C2H5+ + C2H6 ->/+, and the subsequent dissociative rearrangement reaction, C4H11+ -> C4H9+ + H2, were studied.The reactions of NO+ and NOO+, both minor products of the irradiation of N2-O2 mixtures, with alkanes were also studied.The rate constants of the ion-molecule reactions and the unimolecular thermal decomposition reactions and the equilibrium constant were measured.
