Computational Design and Analysis of Organic Molecules as Stimuli-Responsive Smart Materials

In this work, we carry out a thorough computational analysis of some prototypical organic molecules as smart materials that respond to external stimuli. CP1, CP2, CP3, CP4, CP5, and a carbazole-based donor–acceptor system are analyzed for their structural and electronic-and-optic properties in different switching states using DFT, TD-DFT and MD simulations. The analyses reveal significant stimulus-response effects especially in the case of CP2–merocyanine pair where dipole moment boosts from 3.7 D to 11.2 D while absorption maximum shifts from 310 nm to 560 nm with photoinduced ring opening. Also noteworthy are the Ameros/euro dihydroxy/derivative (CP3) and CP1 systems which demonstrate marked optic change along with significant narrowing of HOMO-LUMO gap (03:12 eV -> 02:07 eV and 03:55 -> 03:41 eV). Molecular dynamics simulations on poly(N-isopropylacrylamide) CP7 confirm sharp coil-to-globule transition associated with heating in addition to reduction of gyration radius from 2.10 to 1.21 nm. Thus far these results establish the computed molecular characteristics alongside macroscale responsiveness definitively illustrate rational paradigms towards the design and construction regarding future research towards complex responsive organic smart materials geared towards light weight electronics, sensors and optical devices.