CONSISTENT ASSIGNMENT OF THE VIBRATIONS OF CHLORO- AND BROMOBENZENE MOLECULES AND THEIR DEUTERATED ANALOGUES

The consistency of the labelling and assignments of the vibrational frequencies of the chloroand bromomonosubstituted benzene molecules is investigated in their first electronically excited states (S1). The assignments given utilise a recent nomenclaturea discussed in a previous talk, allowing the ring-localised vibrations to be compared straightforwardly across different monohalosubstituted benzenes. For the S1 state, one-colour resonance-enhanced multiphoton ionization (REMPI) spectroscopy was employed. The assignments of the frequencies include previous work but also the calculated wavenumbers for both fully hydrogenated monohalosubstituted benzenes (-h5) and the deuterated isotopologues (-d5) employing time-dependent density functional theory (TDDFT).