Light penetration-coupled photoisomerization modeling for photodeformation of diarylethene single crystal: upscaling isomerization to macroscopic deformation

Abstract

Diarylethene is one of the photo-responsive materials that show rapid and reversible changes in their color/electrochemical properties and macroscopic deformations in the crystalline phase by light irradiation. Photoisomerization is the main cause of the photo reactivity of diarylethene, and we established a statistical model based on the density matrix formalism, which predicts quantitative isomerization progress as a population term. The model reflects photo-switching properties of the target molecule, which were characterized by first principle calculations, and external stimulus factors (light irradiation conditions and temperature). By merging light penetration physics with the model, we derived light penetration depth dependent isomerization progress to theoretically investigate photodeformation of single crystal. The model well reproduced in-plane shear deformation under ultraviolet light irradiation which would provide guideline for photoactuator design. In addition, the statistical model addressed crucial findings (primary stimuli and molecular design parameter for increasing the isomerization rate, external stimuli enhancing fluorescence performance) itself.

Mechanical Properties and Photomechanical Fatigue of Macro- and Nanodimensional Diarylethene Molecular Crystals

“…35 The degree of DAE 1a to 1b conversion efficiency is dependent on the photostationary state and solid sample thickness as a result of a positive photochrome formation. 36,37 For amorphous film and macrocrystal solids, the expected conversion efficiencies from 1a to 1b are 5−10%, similar to 6% conversion observed for a 50 μm thick DAE sample. 25 For individual nanowires with thicknesses less than 200 nm, the expected conversion efficiency will likely be closer to 79% observed for the DAE molecules in a hexane solution.…”

Connecting Wires: Photoinduced Electronic Structure Modulation in Metal–Organic Frameworks

“…The photoisomerization mechanism of the diarylethene molecule has been studied theoretically by several research groups, using cluster electronic structure codes and ab initio nonadiabatic molecular dynamics. − The collective findings can be summarized as follows: in the ground electronic state, S 0 , the "open" and "closed" ring isomers are separated by a high barrier of approximately 1.8 eV and are, therefore, thermally stable. The isomerization proceeds through the first excited electronic state, S 1 , exhibiting a conical intersection (CI) with the ground potential energy surface (PES).…”

“…The molecule relaxes to either "open" or "closed" form on the ground PES via the CI. In the reverse reaction, the vertical excitation to S1 corresponds to the visible light, and there is a barrier to the CI of about 0.6 eV …”

Multiscale Simulation Approach on Sub-10 nm Extreme Ultraviolet Photoresist Patterning: Insights from Nanoscale Heterogeneity of Polymer

“…For the second part, the rate-determining step (see Figure S2) of the deprotection of the tBOCSt group was mainly investigated to determine the reaction rate constant ( k TST in eq ) based on the transition state theory. , We located the PES of the rate-determining step, and both local minima and transition state (TS) structures were fully relaxed with B3LYP/6-311+G­(d,p) ,, using Berny and STQN algorithms, respectively. From the optimized geometry, a single-point energy calculation was performed to obtain the energy barrier (Δ E in eq ) and normal-mode frequency (reactant: ν I ; TS structure: ν TS in eq ) by employing B3LYP/6-311++G­(d,p), ,, which was determined by comparing the activation energies of various energy functional/orbital basis with those of CCSD­(T)/6-311+G­(d,p) , (see Table S2).…”