Electronic structure of the excited triplet state of nonphosphorescent tropolone studied by time-resolved EPR

Tadaaki Ikoma, Kimio Akiyama, Shozo Tero-Kubota, Yusaku Ikegami

Research output: Contribution to journalArticlepeer-review

5 Citations (Scopus)

Abstract

Time-resolved EPR measurements and semi-empirical MO calculations have been carried out to clarify the electronic structure of the T1 state of nonphosphorescent tropolone. The observed zero-field splitting parameters indicate that the T1 state has a pure ππ* character and the energy order among the spin sublevels was Tγ (in-plane) > Tx (in-plane) > 0 > Tz (out-of-plane), which is the same as tropone for a parent molecule. However, the principal X-axis slightly turns out of the carbonyl bond direction so that the intersystem crossing from the S1 state to the Tγ sublevel becomes more active. The spin densities obtained from hyperfine splittings of protons and MO calculation of AM1 method show an asymmetric distribution of unpaired π-electrons over two oxygens as well as the seven-membered ring. This unbalanced distribution makes the deviation of the X-axis from the carbonyl bond clear. We found two sites that can exchange each other by intramolecular proton transfer in a durene single crystal.

Original languageEnglish
Pages (from-to)1197-1201
Number of pages5
JournalJournal of the Chemical Society - Faraday Transactions
Volume94
Issue number9
DOIs
Publication statusPublished - 1998 Jan 1

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry

Fingerprint Dive into the research topics of 'Electronic structure of the excited triplet state of nonphosphorescent tropolone studied by time-resolved EPR'. Together they form a unique fingerprint.

Cite this