Deuteration effects on the vibronic structure of the fluorescence spectra and the internal conversion rates of triangular [4]phenylene

Dosche C, Kumke M, Löhmannsröben HG, Ariese F, Bader A, Gooijer C, Miljanic O, Iwamoto M, Vollhardt P, Puchta R, van Eikema Hommes N (2004)

Publication Status: Published

Publication Type: Journal article

Publication year: 2004

Journal

Physical Chemistry Chemical Physics Royal Society of Chemistry

Publisher: Royal Society of Chemistry

Book Volume: 6

Pages Range: 5476-5483

Journal Issue: 24

DOI: 10.1039/b414545c

Abstract

Deuteration effects on the vibronic structure of the emission and excitation spectra of triangular [ 4] phenylene (D-3h [4]phenylene) were studied using laser-excited Shpol'skii spectroscopy (LESS) in an octane matrix at 4.2 K. For correct assignment of the vibrational modes, the experimental results were compared with calculated frequencies (B3LYP/6-31G*). CH vibrations were identified by their characteristic isotopic shifts in the spectra of deuterated triangular [4]phenylenes. Two CC stretching modes, at 100 cm(-1) and 1176 cm(-1), suitable as probes for bond strength changes in the excited state, were identified. The isotope effect on the internal conversion rates of triangular [4] phenylene was evaluated from measurements of temperature dependent lifetime. Isotope dependency and the magnitude of the internal conversion rates indicate that internal conversion in triangular [4] phenylene is most likely induced by CH vibrations. The results obtained by LESS and lifetime measurements were compared with PM3 PECI calculations of the excited state structure. The theoretical results and the relation between ground and excited state vibration energies of the 1176 cm(-1) probe vibration indicate a reduction of bond alternation of the central cyclohexatriene ring in the excited state.

Authors with CRIS profile

Ralph Puchta Naturwissenschaftliche Fakultät Nicolaas van Eikema Hommes Computer-Chemie-Centrum

Involved external institutions

Vrije Universiteit Amsterdam (VU) / University Amsterdam NL Netherlands (NL) Universität Potsdam DE Germany (DE) University of California, Berkeley US United States (USA) (US)

How to cite

APA:

Dosche, C., Kumke, M., Löhmannsröben, H.-G., Ariese, F., Bader, A., Gooijer, C.,... van Eikema Hommes, N. (2004). Deuteration effects on the vibronic structure of the fluorescence spectra and the internal conversion rates of triangular [4]phenylene. Physical Chemistry Chemical Physics, 6(24), 5476-5483. https://dx.doi.org/10.1039/b414545c

MLA:

Dosche, Carsten, et al. "Deuteration effects on the vibronic structure of the fluorescence spectra and the internal conversion rates of triangular [4]phenylene." Physical Chemistry Chemical Physics 6.24 (2004): 5476-5483.

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