Advanced search
Start date
Betweenand
Related content
(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

A QM/MM study of the conformation stability and electronic structure of the photochromic switches derivatives of DHA/VHF in acetonitrile solution

Full text
Author(s):
Cardenuto, Marcelo Hidalgo [1] ; Cezar, Henrique M. [1] ; Mikkelsen, V, Kurt ; Sauer, Stephan P. A. [2] ; Coutinho, Kaline [1] ; Canuto, Sylvio [1]
Total Authors: 6
Affiliation:
[1] Univ Sao Paulo, Inst Fis, Rua Matao 1371, Cidade Univ, BR-05508090 Sao Paulo - Brazil
[2] Mikkelsen, Kurt, V, Univ Copenhagen, Dept Chem, Univ Pk 5, DK-2100 Copenhagen - Denmark
Total Affiliations: 2
Document type: Journal article
Source: SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY; v. 251, APR 15 2021.
Web of Science Citations: 0
Abstract

We present a detailed theoretical study of the electronic absorption spectra and thermochemistry of molecular photoswitches composed of one and two photochromic units of dihydroazulene (DHA)/vinyl-heptafulvene (VHF) molecules. Six different isomers are considered depending on the ring opening/closure forms of the DHA units. The solvent effect of acetonitrile is investigated using a sequential Molecular Mechanics/Quantum Mechanics approach. The thermochemical investigations of these photochromic molecules were performed using the Free Energy Perturbation method, and the simulations were performed using Configurational Bias Monte Carlo. We show that to open the 5-member ring of the DHA, there is no significant gain in thermal release of energy for the back reaction when a unit or two DHA units are considered. Overall, we found agreement between the solvation free energy based on Monte Carlo simulations and the continuum solvent model. However, the cavitation term in the continuum model is shown to be a source of disagreement when the non-electrostatic terms are compared. The electronic absorption spectra are calculated using TDDFT CAM-B3LYP/cc-pVDZ. Agreement with experiment is obtained within 0.1 eV, considering statistically uncorrelated configurations from the simulations. Inhomogeneous broadening is also considered and found to be well described in all cases. (C) 2021 Elsevier B.V. All rights reserved. (AU)

FAPESP's process: 14/50983-3 - INCT 2014: complex fluids
Grantee:Antonio Martins Figueiredo Neto
Support Opportunities: Research Projects - Thematic Grants
FAPESP's process: 15/25249-7 - Solvent effects and response theory in second order nonlinear optics
Grantee:Marcelo Hidalgo Cardenuto
Support Opportunities: Scholarships in Brazil - Post-Doctoral