Complementing Adiabatic and Nonadiabatic Methods To Understand Internal Conversion Dynamics in Porphyrin Derivatives

We analyze the internal conversion dynamics within the <i>Q</i>_<i>y</i> and <i>Q</i>_<i>x</i> excited states of both bare and functionalized porphyrins, which are known to exhibit significantly different time constants experimentally. Through the integration of two complementary approaches, static calculation of per-mode reorganization energies and nonadiabatic molecular dynamics, we achieve a comprehensive understanding of the factors determining the different behavior of the two molecules. We identify the key normal and essential modes responsible for the population transfer between excited states and discuss the efficacy of different statistical and nonstatistical analyses in providing a full physics-based description of the phenomenon.