Data for paper Gas phase electronic spectra of xylene-water aggregates

Research data for paper published in Journal of Molecular Spectroscopy (March 2023).

The data consist of multiphoton ionisation spectroscopy of xylene and xylene-water clusters and computational output files for calculations for xylene monomers and xylene-water clusters using Gaussian and PGOPHER.

Raw experimental data from the Jet spectroscopy molecular beam experiment for the following species; p-xylene, p-xylene⋅H2O, p-xylene⋅(H2O)2, m-xylene, m-xylene⋅H2O, m-xylene⋅(H2O)2, o-xylene, o-xylene⋅H2O and o-xylene⋅(H2O)2. These files are .csv and can be opened in Excel or equivalent packages.

Gaussian16 output files for Opt+Freq, NCI, NBO and QTAIM calculations at the CAM-B3LYP/aug-cc-pVDZ level of theory for the following species in the S0 and S1 states; p-xylene, p-xylene⋅H2O, p-xylene⋅(H2O)2, m-xylene, m-xylene⋅H2O, m-xylene⋅(H2O)2, o-xylene, o-xylene⋅H2O and o-xylene⋅(H2O)2. These files can be opened as text files, but will need computational software to display the structures.

PGOPHER output files for Franck-Condon factor simulations for the following species; p-xylene, p-xylene⋅H2O, p-xylene⋅(H2O)2, m-xylene, m-xylene⋅H2O, m-xylene⋅(H2O)2, o-xylene, o-xylene⋅H2O and o-xylene⋅(H2O)2. To open these files, PGOPHER will be needed.

Article abstract

Using a jet spectroscopy molecular beam setup, gas phase electronic spectra of three xylene isomers (para, meta and ortho)  have been collected for the neutral monomer species as well as for  their clusters with one and two water molecules. Scans at a resolution  of ±0.02 nm showed a clear 0-0 transition for each xylene isomer as well  as the vibronic progression. The spectra were assigned with the help of  Franck–Condon factor PGOPHER simulations from theoretical studies at  the CAM-B3LYP/aug-cc-pVDZ level of theory. The vibronic spectra of the  xyleneHO and xylene(H2O)2 clusters showed broad features between 36800–38400 cm−1 (260–272 nm) for p- and m-xylene, while the water clusters of o-xylene  gave more defined bands. The separation of the vibronic bands in the  clusters mirrors the progression of the neutral monomers implying that,  for the S1  S0  transition, it is the same vibrational modes that are involved in the  monomer as in the clusters with water. Both the separation and the  spectral width of the bands can be explained by the calculated  differences in geometries of the clusters in the ground and first  electronic excited states.