Dynamical and environmental effects on the optical properties of an heteroleptic Ru(II)-polypyridine complex: a multilevel approach combining accurate ground and excited state QM-derived force fields, MD and TD-DFT

An integrated multilevel approach is here built by combining classical Molecular Dy- namic (MD) simulations, Time-Dependent Density Functional Theory (TD-DFT) calculations and solvation dynamics linear response (LR) analysis, and successively employed to investigate the optical properties and solvation structure of a prototypical heteroleptic Ru(II)-polypyridyl complex, widely employed in dye sensitized solar cells. The MD simulations are performed with an accurately parameterized intramolecular force field (FF), specifically derived from the quantum chemical (DFT) description of the molecule, both for its singlet and triplet ground states. Solvent effects, in ethanol (EtOH) and dimethyl sulfoxide (DMSO), are taken into account at different level of approximation, going from a totally implicit description (polarizable continuum) to an hybrid explicit/implicit scheme. Our results show that the developed FFs were able to accurately describe and preserve the octahedral coordination of the Ru(II) center along...