Discrimination of two low-energy conformers of octahydroanthracene in supersonic jet

The S0 and S1 states’ vibronic features of two low-energy conformers of octahydroanthracene have been investigated by laser induced fluorescence excitation, dispersed emission and UV–UV hole burning spectroscopy in a cold seeded jet. UV–UV hole burning spectra have been used to distinguish the two conformers and their S1 state vibrational modes. In addition, semi-empirical and ab initio calculations have been performed to correlate the calculated S0 frequencies of vibrational modes with the experimental results. It is found that the observed spectra correspond well with sym-twist (a) (C2h) and antisym-twist (b) (D2) forms.