7439-87-4Relevant articles and documents
Leffek,Matheson
, p. 986,987 (1972)
Unimolecular Reactions of Isolated Organic Ions: Reactions of the Immonium Ions CH2=N+(CH3)CH(CH3)2, CH2=N+(CH3)CH2CH2CH3 and CH2=N+(CH2CH2CH3)2
Bowen, Richard D.,Colburn, Alex W.,Derrick, Peter J.
, p. 2363 - 2372 (2007/10/02)
The reactions of metastable CH2=N+(CH3)C3H7 immonium ions have been investigated by means of 2H-labelling experiments and kinetic energy release measurements.Loss of C3H6, with specific β-H transfer, is the sole channel for dissociation of CH2=N+(CH3)CH(CH3)2.This process gives rise to a Gaussian metastable peak.The isomeric ion, CH2=N+(CH3)CH2CH2CH3, also expels C3H6; however, both α-H and γ-H as well as β-H transfer occurs in this case, and the reaction proceeds with an increased kinetic energy release.The role of ion-neutral complexes in C3H6 loss from CH2=N+(CH3)C3H7 ions is discussed.In addition, CH2=N+(CH3)CH2CH2CH3 eliminates C2H4.This fragmentation yields a broad dish-topped metastable peak, corresponding to a very large kinetic energy release (T1/2 ca. 73 kJ mol-1), and it involves specific and unidirectional γ-H transfer.A potential energy profile summarising the reactions of CH2=N+(CH3)CH2CH2CH3 and CH2=N+(CH3)CH(CH3)2 is constructed.The mechanisms by which immonium ions of this general class eliminate C3H6 and C2H4 have been further probed by studying the behaviour of the higher homologue, CH2=N+(CH2CH2CH3)2.The mechanistic conclusions derived from this work are found to be in excellent qualitative agreement with those of previous studies.
The Mechanism of Ethylene Elimination from the Oxonium Ions CH3CH2CH=O+CH2CH3 and (CH3)2C=O+CH2CH3
Bowen, Richard D.,Derrick, Peter J.
, p. 1033 - 1039 (2007/10/02)
The reactions of the metastable oxonium ions CH3CH2CH=O+CH2CH3 and (CH3)2C=O+CH2CH3 are reported and discussed.Various mechanisms for ethylene elimination, which is the principal dissociation route for these ions, are considered.It is shown by means of 2H-labelling experiments and analysis of collision-induced dissociation spectra that routes involving ion-neutral complexes pre-empt 'conventional' mechanisms for these processes.In contrast, the behaviour of the lower homologues CH3CH2CH=OR+ and (CH3)2C=OR+ (R = H, CH3) is consistent with the operation of 'conventional' mechanisms for ethylene expulsion.This contrast is interpreted in energetic terms.The significance of these results for the chemistry of homologous and analogous 'onium' ions containing a Z+-R function (Z = O, S, NH, NCH3; R= CnH2n+1, n 2) is explained.