Dispersed fluorescence spectra of chlorobenzene

We report vibrationally-resolved spectra of the S1  S0 transition of chlorobenzene using resonance-enhanced multiphoton ionization (REMPI) spectroscopy. We study chlorobenzene-h5 as well as its perdeuterated isotopologue, chlorobenzene-d5. Changes in the form of the vibrational modes between the isotopologues and also between the S0 and S1 electronic states are discussed for each species. Vibrational bands are assigned utilizing quantum chemical calculations, previous experimental results and isotopic shifts, including those between the 35 Cl and 37 Cl isotopologues. Previous work and assignments of the S1 spectra are discussed. Additionally, the vibrations in the ground state cation, D0 + , are considered, since these have also been used by previous workers in assigning the excited neutral state spectra.

Section: A Neutral Clbz-h5mentioning

confidence: 99%

Assignment of the vibrations of the S, S1, and D+ states of perhydrogenated and perdeuterated isotopologues of chlorobenzene

Andrejeva

Tuttle

Harris

et al. 2015

“…67 and references therein), and this has also been confirmed in dispersed fluorescence studies by Imhof and Kleinermanns. 68 It may be noted that for both toluene isotopologues and for flu-orobenzene, a small band to the blue of the main M 29 band has also been assigned to the combination M 14 M 19 , but that the presence of a Fermi resonance is not obvious, suggesting that for chlorobenzene these features have moved into almost complete resonance. This supports the appearance of the ZEKE spectra recorded from each component of the double feature, 67 and is also in line with the results of the dispersed fluorescence study.…”

Section: Rempi Spectramentioning

confidence: 98%

“…This supports the appearance of the ZEKE spectra recorded from each component of the double feature, 67 and is also in line with the results of the dispersed fluorescence study. 68 The ZEKE spectra exciting via the origin and M 29 are discussed below.…”

Section: Rempi Spectramentioning

confidence: 99%

Vibrations of the low energy states of toluene ($\tilde X$X̃ 1A1 and $\tilde A$Ã 1B2) and the toluene cation ($\tilde X$X̃ 2B1)

Gardner

Green

Tamé-Reyes

et al. 2013

We commence by presenting an overview of the assignment of the vibrational frequencies of the toluene molecule in its ground (S 0 ) state. The assignment given is in terms of a recently proposed nomenclature, which allows the ring-localized vibrations to be compared straightforwardly across different monosubstituted benzenes. The frequencies and assignments are based not only on a range of previous work, but also on calculated wavenumbers for both the fully hydrogenated (tolueneh 8 ) and the deuterated-methyl group isotopologue (α 3 -toluene-d 3 ), obtained from density functional theory (DFT), including artificial-isotope shifts. For the S 1 state, one-colour resonance-enhanced multiphoton ionization (REMPI) spectroscopy was employed, with the vibrational assignments also being based on previous work and time-dependent density functional theory (TDDFT) calculated values; but also making use of the activity observed in two-colour zero kinetic energy (ZEKE) spectroscopy. The ZEKE experiments were carried out employing a (1 + 1 ) ionization scheme, using various vibrational levels of the S 1 state with an energy <630 cm -1 as intermediates; as such we only discuss in detail the assignment of the REMPI spectra at wavenumbers <700 cm -1 , referring to the assignment of the ZEKE spectra concurrently. Comparison of the ZEKE spectra for the two toluene isotopologues, as well as with previously reported dispersed-fluorescence spectra, and with the results of DFT calculations, provide insight both into the assignment of the vibrations in the S 1 and D 0 + states, as well as the couplings between these vibrations. In particular, insight into the nature of a complicated Fermi resonance feature at ∼460 cm -1 in the S 1 state is obtained, and Fermi resonances in the cation are identified. Finally, we compare activity observed in both REMPI and ZEKE spectroscopy for both toluene isotopologues with that for fluorobenzene and chlorobenzene.

“…The frequencies of the ClBz ground state have previously been calculated by the Becke-3-Lee-Yang-Parr, MP2, and CASSCF methods, 26 and the HF method. 27 However, as the symmetries of the vibrational modes were not indicated in Ref.…”

Section: A Ground Statementioning

confidence: 99%

“…27 However, as the symmetries of the vibrational modes were not indicated in Ref. 26, we only compare the present CASSCF calculated result with the HF results in Ref. 27 and the experimental results; see Table II.…”

Section: A Ground Statementioning

confidence: 99%

Multireference calculations of the phosphorescence and photodissociation of chlorobenzene

Liu¹,

Persson²,

Lunell³

2004

Multireference complete active space self-consistent-field ͑CASSCF͒ and multireference CASSF second-order perturbation theory ͑MSCASPT2͒ calculations were performed on the ground state and a number of low-lying excited singlet and triplet states of chlorobenzene. The dual phosphorescence observed experimentally is clearly explained by the MSCASPT2 potential-energy curves. Experimental findings regarding the dissociation channels of chlorobenzene at 193, 248, and 266 nm are clarified from extensive theoretical information including all low-energy potential-energy curves.