1∕f spectrum and memory function analysis of solvation dynamics in a room-temperature ionic liquid

摘要: To understand the nonexponential relaxation associated with solvation dynamics in ionic liquid 1-ethyl-3-methylimidazolium hexafluorophosphate, we study power spectra of fluctuating Franck–Condon energy gap a diatomic probe solute via molecular simulations. Results show 1∕f dependence wide frequency range over 2–3 decades, indicating distributed times. We analyze memory function and time framework generalized Langevin equation using simple model description for spectrum. It is found that crossover toward white-noise plateau directly related to scale thus time. Specifically, low observed leads slowly decaying tail its long By contrast, acetonitrile characterized by high (near) absence behavior shows fast the...