An experimental and theoretical study of the S{sub 1}(leftarrow)S{sub 0} transition of p-ethynyltoluene

Journal Article · Wed Nov 28 04:00:00 EST 2007 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.2804865· OSTI ID:21024523

Philis, John G; Melissas, Vasilios S ^[1]

---

1. Department of Physics, University of Ioannina, GR-45110 Ioannina (Greece)

The one photon and the two photon S{sub 1}(leftarrow)S{sub 0} spectra of jet-cooled p-ethynyltoluene have been measured for the first time, and a detailed vibronic analysis for both spectra has been attained. Mass analyzed resonance enhanced multiphoton ionization spectroscopy is the employed technique. In the one photon spectrum, the allowed component (origin and Franck-Condon bands) is much weaker than the forbidden component, and the same mechanisms as in the one photon spectrum of phenylacetylene are observed. The methyl torsional transitions are active. The 0{sub 0}{sup 0} band is at 35 483 cm{sup -1}. The two photon spectrum is very strong and bears a resemblance to the two photon spectrum of phenylacetylene. The potential barrier of the methyl rotor in the S{sub 1} state has been determined as V{sub 6}=-12 cm{sup -1} with B{sub CH{sub 3}}=5.55 cm{sup -1}. Ab initio calculations, MP2(full)/cc-pVTZ and CAS/cc-pVTZ, have been implemented for the geometry optimization and the normal mode vibration computation in the S{sub 0} and S{sub 1} states.

• OSTI ID: 21024523
• Journal Information: Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 20 Vol. 127; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
CALCULATION METHODS
PERTURBATION THEORY
PHOTOIONIZATION
PHOTONS
SPECTRA
SPECTROSCOPY
TOLAN
VIBRATIONAL STATES