Vibronic spectra of organic electronic chromophores†
In this work, we illustrate how Time-Dependent Density Functional Theory (TD-DFT), that has become an everyday black-box tool for assessing the nature of electronic excited states, can be used to reach an accurate and thorough analysis of experimental optical spectra for a series of organic molecules recently proposed as building blocks for organic electronic devices. The results that yield insights regarding band shapes and extinction coefficients are shown to provide more relevant information than that obtained by the popular vertical approximation. Cases with several overlapping vibronic bands are also discussed. For the vast majority of treated molecules (10 out of 11) the agreement between the theoretical and experimental 0–0 energies and band topologies are really excellent, paving the way towards more refined theoretical designs of new organic electronic chromophores.