TY - JOUR
T1 - Proton-catalyzed hydride transfer from alkanes to methylated benzyl cations : II. spectroscopy and kinetics. Isotope effects for proton exchange and hydride transfer
AU - Pelt, van, P.
AU - Buck, H.M.
PY - 1974
Y1 - 1974
N2 - The PMR and UV spectra of para-X substituted 2,3,5,6-tetramethylbenzyl cations II (a-f) (X = OCH3, CH3, F, Br, H, NO2) are discussed and from the solvolytic behaviour of the parent benzyl chlorides the stability of these ions is found to be IIa > IIb > IIc > IId ~ IIe > IIf. Proton exchange between [2-3H]isobutane and HSO3F is found to have a small isotope effect of 6.5 at - 74°. The hydride-transfer reaction between labelled isobutane and ions IIb has a larger isotope-effect, estimated to be about 20. A termolecular transition state where transferred hydrogen is symmetrically bonded is proposed for the hydride-transfer reaction.
AB - The PMR and UV spectra of para-X substituted 2,3,5,6-tetramethylbenzyl cations II (a-f) (X = OCH3, CH3, F, Br, H, NO2) are discussed and from the solvolytic behaviour of the parent benzyl chlorides the stability of these ions is found to be IIa > IIb > IIc > IId ~ IIe > IIf. Proton exchange between [2-3H]isobutane and HSO3F is found to have a small isotope effect of 6.5 at - 74°. The hydride-transfer reaction between labelled isobutane and ions IIb has a larger isotope-effect, estimated to be about 20. A termolecular transition state where transferred hydrogen is symmetrically bonded is proposed for the hydride-transfer reaction.
U2 - 10.1002/recl.19740930710
DO - 10.1002/recl.19740930710
M3 - Article
VL - 93
SP - 206
EP - 209
JO - Recueil des Travaux Chimiques des Pays-Bas
JF - Recueil des Travaux Chimiques des Pays-Bas
SN - 0165-0513
IS - 7
ER -