@phdthesis{discovery10107037,
            year = {1991},
           title = {The high resolution electronic spectrum of propynal},
            note = {Thesis digitised by ProQuest.},
          school = {UCL (University College London)},
        keywords = {Pure sciences; Ultraviolet absorption spectra},
        abstract = {The one photon ultraviolet absorption spectra of propynal (HCCCHO) and the three deuterated compounds have been recorded under a higher resolution than has previously been reported. The spectrum arising from the {\~A}1A" {$\leftarrow$} {\~A}1A' (S{$_1$} {$\leftarrow$} S{$_0$} ) transition has been studied in detail and the existing vibrational analysis has been extended. Rotational analyses of many of the vibrational bands in this spectrum have been carried out. Several vibrational and rotational perturbations have been observed and for many of these coupling matrix elements have been calculated. Where possible perturbing levels have been suggested. Existing studies on the ground electronic states of these compounds have been correlated and improved values of the molecular constants have been obtained. These values have been further enhanced from rotational analyses of the origin and lower vibrational bands of the S{$_1$} {$\leftarrow$} S{$_0$} spectrum by weighted least squares fits to both lower and excited states. On excitation of higher vibrational levels in the S{$_1$} state of propynal an overall broadening and diffuseness of rotational structure is observed. This has been charted throughout the spectrum and lifetimes of the levels concerned have been estimated from the linewidths. These observations are compared to previous fluorescence studies and interpreted in terms of vibrationally and rotationally dependent predissociation. The origin band of the T{$_1$} {$\leftarrow$} S{$_0$} transition is reported for the molecules HCCCDO and DCCCDO for the first time and partial rotational analyses are attempted. The kinetics and mechanisms of energy decay from the S{$_1$} and T{$_1$} states of propynal are discussed on the basis of the results of this and previous studies.},
             url = {https://discovery.ucl.ac.uk/id/eprint/10107037/},
          author = {Edwards, Simon Anthony}
}