dc.creator Chen, Chiao-Wei en_US dc.creator Merer, Anthony J. en_US dc.creator Chao, Jun-Mei en_US dc.creator Hsu, Yen-Chu en_US dc.date.accessioned 2010-07-12T14:29:59Z dc.date.available 2010-07-12T14:29:59Z dc.date.issued 2010 en_US dc.identifier 2010-MI-09 en_US dc.identifier.uri http://hdl.handle.net/1811/46410 dc.description Author Institution: Institute of Atomic and Molecular Sciences, Academia Sinica, Box 23-166, Taipei, Taiwan 10617 en_US dc.description.abstract The vibrational structure of the $\tilde{A}{}^1\Pi_u$ electronic state of C${}_3$ in the region 26000-31000 cm${}^{-1}$ has been re-examined, using laser excitation spectra of jet-cooled molecules. Rotational constants and vibrational energies have been determined for over 60 previously unreported vibronic levels; a number of other levels have been re-assigned. The vibrational structure is complicated by interactions between levels of the upper and lower Born-Oppenheimer components of the $\tilde{A}{}^1\Pi_u$ state, and by the effects of the double minimum potential in the $Q_3$ coordinate, recognized by Izuha and Yamanouchi. The present work shows that there is also strong anharmonic resonance between the overtones of the $\nu_1$ and $\nu_3$ vibrations. For instance, the $\Sigma^+_u$ vibronic levels 2 1${}^+$1 and 0 1${}^+$3 are nearly degenerate in zero order, but as a result of the resonance they give rise to two levels 139 cm${}^{-1}$ apart, centered about the expected position of the 2 1${}^+$1 level. Similarly, the 202 level lies 60 cm${}^{-1}$ lower than expected because of interaction with the 400 and 004 levels. With these irregularities recognized, every observed vibrational level up to 29550 cm${}^{-1}$ (a vibrational energy of nearly 5000 cm${}^{-1}$) can now be assigned. en_US dc.language.iso en en_US dc.publisher Ohio State University en_US dc.title HIGHER VIBRATIONAL LEVELS OF THE $\tilde{A}{}^1\Pi_u$ STATE OF C${}_3$ OBSERVED BY LASER-INDUCED FLUORESCENCE en_US dc.type Article en_US dc.type Image en_US dc.type Presentation en_US
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