Search for cyclopropylbenzene conformers by studying the S1 ← S0 electronic transition

The resonance-enhanced multiphoton ionization, (1+1) REMPI and (2+2) REMPI S1 ← S0 spectra of cyclopropylbenzene (CPBz) have been measured in supersonic jet expansion under various cooling conditions. Both spectra include the pure electronic transition and one vibrationally induced transition. The vibronic analysis of these spectra revealed the presence of only one conformer. The present experiment cannot give the form of the conformer. The bisected structure, which was found by microwave spectroscopy [Q. Shen, C. Wells, M. Traetteberg, R.K. Bohn, A. Willis, J. Knee, J. Org. Chem., 66 (2001) 5840] is acceptable.