In SilicoStudy of Molecular-Engineered Nanodevices: A Lockable Light-Driven Motor in Dichloromethane Solution
Author(s)
Date Issued
2013
Type
article
Volume
4
Issue
22
Start Page
3885
End Page
3890
Abstract
A light-driven molecular rotor, featuring an acid–base-triggered self-complexing lock in dichloromethane dilute solution, is investigated for the first time by an integrated computational strategy allowing a quantitative reproduction of all of the main experimental features in terms of a comprehensive and interpretable molecular picture. In particular, we have simulated the peculiar conformational preferences of the rotor in two different protonation states, characterized the free-energy landscape that drives the threading→dethreading motion, and then reproduced the available spectroscopic data under equilibrium conditions. Interestingly, we also observed that the confinement of the R2NH2+ arm within the [1]pseudorotaxane moiety actually inhibits the cis–trans isomerization within the photoactive xanthene//2,6-dioxonaphthalene unit, creating a friction (resistance) against the threading→dethreading motion. Together with the specific interest of the studied system, this contribution highlights the potentialities of modern computational techniques to fully simulate complex and flexible devices in which noncovalent forces can finely modulate energy-conversion schemes working at the nanoscale level.