Solvation dynamics in polar solvents and imidazolium ionic liquids: failure of linear response approximations.

ABSTRACT: This study presents the large scale computer simulations of two common fluorophores, N-methyl-6-oxyquinolinium betaine and coumarin 153, in five polar or ionic solvents. The validity of linear response approximations to calculate the time-dependent Stokes shift is evaluated in each system. In most studied systems linear response theory fails. In ionic liquids the magnitude of the overall response is largely overestimated, and linear response theory is not able to capture the individual contributions of cations and anions. In polar liquids, the timescales of solvation dynamics are often not correctly reproduced. These observations are complemented by a detailed analysis of Gaussian statistics including higher order correlation functions, variance of the energy gap distribution and its time

SUBMITTER: Heid E 

PROVIDER: S-EPMC5815284 | biostudies-literature | 2018 Feb

REPOSITORIES: biostudies-literature