15min:

MASAKAZU NAKAJIMA, AKIRA MIYOSHI, Department of Chemical System Engineering, The University of Tokyo, Tokyo, 113-8656, Japan; YOSHIHIRO SUMIYOSHI AND YASUKI ENDO, Department of Basic Science, The University of Tokyo, Tokyo, 153-8902, Japan.

Precise molecular constants of the CH₂CHS (vinylthio) radical in the ground vibronic level were determined by Fourier-transform microwave (FTMW) and FTMW-millimeter wave double-resonance spectroscopy\footnoteY.~Sumiyoshi et al. , J.~Chem.~Phys. \underline\textbf123, 054324 (2005).. The B -- X electronic transition of CH₂CHS was observed by LIF spectroscopy. Rotational constants in the upper electronic state were determined from a rotationally resolved LIF excitation spectrum of jet-cooled CH₂CHS. A dispersed fluorescence spectrum from the zero-vibtational level of the B state was also measured to determine vibrational frequencies in the ground electronic state. The experimental molecular constants were compared with results of ab~initio calculations.