Author, as appears in the article.: Kovalenko, Olha; Reguero, Mar;

Department: Química Física i Inorgànica

URV's Author/s: Reguero de la Poza, Maria del Mar

Keywords: Spiropyran Reaction mechanism Photochromic spiropyrans Molecules Molecular switch Merocyanine Exchange Dynamics Dft Conformations Chromic materials Behavior

Abstract: Spiropyran (SP) is a chromic material that undergoes isomerization to merocyanine (MC) under irradiation. To extend its applicability as a molecular switch, it would be convenient to be able to induce and control its isomerization also in the dark, what seems to be possible in acidic media. We present here a computational study of the mechanism of isomerization of protonated SP. We have found that protonation induces the stabilization of MC, protonated at O, relative to SP, protonated at N. Given the different site of protonation for both species, the ring-opening reaction must take place together with a proton transfer event. We have shown that the barrier of this process decreases if a protic solvent molecule take part in the reaction. In this way, the rate determining step of the process is the isomerization between different rotamers of protonated MC. The detailed knowledge of the reaction mechanism can help in the design of structural or electronic modifications of SP to improve its switchability.

Thematic Areas: Química Physics, multidisciplinary Physics and astronomy (miscellaneous) Mathematical physics Materiais Matemática / probabilidade e estatística Interdisciplinar Geociências General physics and astronomy Ensino Engenharias iv Engenharias iii Engenharias ii Condensed matter physics Ciências biológicas ii Biotecnología Atomic and molecular physics, and optics Astronomia / física

licence for use: https://creativecommons.org/licenses/by/3.0/es/

Author's mail: mar.reguero@urv.cat

Author identifier: 0000-0001-9668-8265

Record's date: 2023-02-19

Papper version: info:eu-repo/semantics/acceptedVersion

Link to the original source: https://iopscience.iop.org/article/10.1088/1402-4896/ab5ff2

Licence document URL: http://repositori.urv.cat/ca/proteccio-de-dades/

Papper original source: Physica Scripta. 95 (5):

APA: Kovalenko, Olha; Reguero, Mar; (2020). Why thermal isomerization of the chromic switch spiropyran-merocyanine is enhance in polar protic solvents. A computational study of the reaction mechanism. Physica Scripta, 95(5), -. DOI: 10.1088/1402-4896/ab5ff2

Article's DOI: 10.1088/1402-4896/ab5ff2

Entity: Universitat Rovira i Virgili

Journal publication year: 2020

Publication Type: Journal Publications