Equivalence of the Energy Gaps.ΔI(1,2) and ΔE(1,2) Between Corresponding Bands in the Photoelectron (I) and Electronic Absorption (E) Spectra of Spiro[4.4]nonatetraene. An Amusing Consequence of Spiroconjugation

C. Batich, E. Heilbronner, Erika Rommel, M. F. Semmelhack, J. S. Foos

Research output: Contribution to journalArticle

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Abstract

Correlation of the photoelectron (PE) spectra of spiro[4.4]nonatetraene (1), spiro[4.4]nona-1,3,7-triene (2), spiro[4.4]nona-1,3,6-triene (3), and spiro[4.4]nona-1,3-diene (4) yields the assignment of the first three bands at 7.99, 9.22, and 10.55 eV in the PE spectrum of 1 (symmetry D2d) to ionization processes in which the photoelectron vacates the molecular orbitals 1a2(π), lb1(π), and 7e(π), respectively. The difference ΔI(1,2) = 1.23 eV between the positions of the first two PE bands of 1 is equal, within the limits of error, to the difference ΔE (1,2) ≈ 1.2 to 1.3 eV between the first two bands 8e(π*)← 1a2(π) and 8e(π*)←1b1(π) in the electronic absorption spectrum of 1. It is shown that this correspondence is the consequence of spiroconjugation between two identical alternant subsystems in a molecule of D2d symmetry, e.g., in 1.

Original languageEnglish (US)
Pages (from-to)7662-7668
Number of pages7
JournalJournal of the American Chemical Society
Volume96
Issue number25
DOIs
StatePublished - Dec 1 1974
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Catalysis
  • Chemistry(all)
  • Biochemistry
  • Colloid and Surface Chemistry

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