Vibrational OH-stretching overtone spectroscopy of jet-cooled resorcinol and hydroquinone rotamers.
We have measured the OH-stretching fundamental and overtone spectra of resorcinol and hydroquinone in a supersonic jet using nonresonant ionization detected infrared/near-infrared spectroscopy. Anharmonic oscillator local mode calculations of the OH-stretching frequencies and intensities and Boltzmann populations of the stable rotamers have been calculated at the B3LYP/6-311++G(3df,2pd) level to help interpret the observed spectra. Resorcinol has three stable rotamers and in the recorded second and third OH-stretching overtone spectra there is evidence of two distinguishable rotamers. Hydroquinone has two stable rotamers; however, the OH-stretching oscillators of each rotamer are so similar in nature that even up to the fourth OH-stretching overtone the transitions coincide. These results place a limit on the ability of the jet-cooled overtone spectroscopy technique to distinguish between rotamers.
Hattori
Kaori
K
Chemical Resources Laboratory, Tokyo Institute of Technology, Nagatsuta, Yokohama 226-8503, Japan.
Ishiuchi
Shun-ichi
S
Fujii
Masaaki
M
Howard
Daryl L
DL
Kjaergaard
Henrik G
HG