The S1 ← S0 electronic transitions of 4- and 5-phenyl imidazole in the gas phase

M. R. Hockridge, E. G. Robertson, J. P. Simons, D. R. Borst, T. M. Korter, D. W. Pratt

Research output: Contribution to journalArticlepeer-review

8 Scopus citations


The S1←S0 electronic spectrum of 4-phenyl imidazole (4PI), previously studied in the gas phase by Hockridge et al. [Chem. Phys. Lett. 302 (1999) 538], has been re-examined at both low and high resolution using fluorescence excitation and isotopic substitution techniques. The data establish a planar structure in both states; a pure a-type origin band indicates that the S1 state is 1La in character. Analysis of the torsional progressions in the S1←S0 electronic spectrum of the 4PI tautomer, 5-phenyl imidazole (5PI), indicates a planar excited state but a non-planar ground state, with a twist angle between the two ring systems of ~27°and a barrier to planarity of ~90 cm-1.

Original languageEnglish (US)
Pages (from-to)31-38
Number of pages8
JournalChemical Physics Letters
Issue number1-3
StatePublished - Feb 2 2001
Externally publishedYes

ASJC Scopus subject areas

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


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