Portal de Periódicos da CAPES

Ab initio and RRKM evidence that the McLafferty rearrangement of ionizedn-butanal is stepwise

1989; Wiley; Volume: 24; Issue: 10 Linguagem: Inglês

10.1002/oms.1210241003

2376-3884

Charles E. Hudson, Lawrence L. Griffin, David J. McAdoo,

Spectroscopy and Quantum Chemical Studies

Abstract Hartree‐Fock calculations with geometry optimization at a series of C(2)C(3) distances predict a negligible reverse critical energy for the second step of the McLafferty rearrangement of ionized n ‐butanal, in contrast to a previous conclusion. The most favorable geometry for departure of the C 2 H 4 has a dihedral angle of about 90° between the parting fragments. RRKM calculations were used to estimate rates of reactions associated with the McLafferty rearrangement These calculations indicate that the McLafferty rearrangement of the n ‐butanal ion is stepwise. The RRKM calculations predict competition of H exchange with decomposition up to much higher energies than actually occurs.