Π*–σ* Hyperconjugation mechanism on the rotational barrier of the methyl group (II): 1- and 2-methylnaphthalenes in the S0, S1, C0, and A1 states

H. Nakai, Y. Kawamura

Research output: Contribution to journalArticlepeer-review

26 Citations (Scopus)

Abstract

Internal rotation of the methyl group in 1- and 2-methylnaphthalenes has been investigated by the ab initio theory. The rotational barriers in the S0 and S1 states calculated by the Hartree-Fock and configuration-interaction with single-excitation operator methods are in reasonable agreement with experimental values. The variations of the rotational barriers by excitation (S0→S1), ionization (S0→C0), and electron attachment (S0→A1) are shown to be directly connected with the stability of the HOMO and/or LUMO by the first-order treatment. In the HOMO and LUMO, a new type of orbital interaction named π*-σ* hyperconjugation appears and determines their stability. The interpretation based on the π*-σ* hyperconjugation can consistently and comprehensively explain the barrier variations.

Original languageEnglish
Pages (from-to)298-304
Number of pages7
JournalChemical Physics Letters
Volume318
Issue number4-5
DOIs
Publication statusPublished - 2000 Feb 25

ASJC Scopus subject areas

  • Physics and Astronomy(all)
  • Physical and Theoretical Chemistry

Fingerprint Dive into the research topics of 'Π*–σ* Hyperconjugation mechanism on the rotational barrier of the methyl group (II): 1- and 2-methylnaphthalenes in the S<sub>0</sub>, S<sub>1</sub>, C<sub>0</sub>, and A<sub>1</sub> states'. Together they form a unique fingerprint.

Cite this