The excited state electronic structure of π conjugated phenylene–acetylene oligomers is calculated using time-dependent density functional theory approaches. The theoretical fluorescence spectra are analyzed in terms of Frank–Condon active nuclear normal modes and shown to compare well with experiment. Theoretical and experimental results for the optical absorption and emission spectra of these molecules indicate that the conjugation ...
![4-[2-(4-methylphenyl)ethynyl]aniline Structure](https://image.chemsrc.com/caspic/374/15795-03-6.png)