Molecular solar thermal (MOST) systems, such as norbornadiene–quadricyclane, azobenzenes, and dihydroazulenes, offer promising pathwaysfor solar energy storage via photoinduced isomerization, energy storage and subsequent thermal energy release. A key challenge in optimizingthese systems lies in accurately modeling the coupled electronic and conformational transitions within condensed phases. We present a rigoroustheoretical framework based on the Generalized Langevin Equation (GLE) that captures essential features of solute–solvent interactions, includingmemory effects and non-Markovian friction arising from slow environmental relaxation. The GLE formalism incorporates a time-dependent memorykernel Γ(t) to describe temporally correlated noise and friction over a broad range of timescales. This approach is especially well-suited for modelingMOST systems in polar and structured solvents where dielectric relaxation, hydrogen bonding, and hydrodynamic interactions critically influencethe dynamics of transition states and thermal back-reaction rates.
Kurt V. Mikkelsen (Wed,) studied this question.