Chromophore Excited States - Towards Predictive Theoretical Studies
Abstract: Excited state dynamics of various popular chromophores will be discussed. In all cases the theoretical results will be presented with simple and conceptual molecular orbital analysis, i.e. free from demanding quantum mechanical details. General design principles for tuning the excited state properties of fluorescent probes and inter-system crossing (ISC) will be introduced.
Details of excited state electronic structure of BODIPY and the contrasting luminescent properties of BODIPY and dipyrrin will be corroborated. An unprecedented function for a fluorophore with high quantum yield (hence negligible triplet quantum yield), achieved by orthogonal dimerization of BODIPYs will be introduced.
Principles of transforming a good fluorophore to an efficient ISC species will be uncovered (as a promising direction for 1O2 photosensitization in photodynamic therapy (PDT)). Electronic structure motifs that enable the S1→T1 transitions will be elaborated. Our results are promising for understanding and controlling fluorescence action as well as designing new intersystem crossers.