A light harvesting molecular triad is a synthetic supra-molecule that comprises of pyrrole-fullerene (C60), diaryl-porphyrin (P), and carotenoid polyene (C). This donor-acceptor molecule is capable of absorbing incident light in the visible region.1 The charge separation upon electron excitation results in a dipole moment of ~150 D with a lifetime of ~300 ns, which is highly desirable for organic photo-voltaic applications.2 We performed molecular dynamics simulations with polarizable force field to study the polarization effects on structural stability of the triad in its ground state in the presence of explicit tetrahydrofuran (THF) solvent. We derived the partial atomic charges at the level of B3LYP/cc-pvTZ with i-RESP methodology.3 We calibrated the parameters until a good agreement has been established on a number of thermodynamic properties for each triad component. We investigated the influence of induced polarization effects on the structural dynamics of triad by performing a series of molecular dynamics simulations with the aid of the replica exchange molecular dynamics simulations (REMD). The analysis of the free energy landscape indicated that the simulations with the polarizable model exhibited a narrower distribution of structural variations than a non-polarizable model.

Molecular dynamics simulations of a light-harvesting molecular triad in explicit tetrahydrofuran solvent using polarizable force field

251st National Meeting (2016)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.