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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Probing the solvation structure and dynamics in ionic liquids by time-resolved infrared spectroscopy of 4-(dimethylamino) benzonitrile

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Ando, Romulo A. [1] ; Brown-Xu, Samantha E. [2] ; Nguyen, Lisa N. Q. [3] ; Gustafson, Terry L. [3]
Total Authors: 4
[1] Univ Sao Paulo, Dept Quim Fundamental, Inst Quim, Lab Espect Mol, CP 26077, BR-05513970 Sao Paulo - Brazil
[2] NE Illinois Univ, Dept Chem, Chicago, IL 60625 - USA
[3] Ohio State Univ, Dept Chem & Biochem, Newman & Wolfrom Lab 2104, BR-05513970 Sao Paulo - Brazil
Total Affiliations: 3
Document type: Journal article
Source: Physical Chemistry Chemical Physics; v. 19, n. 36, p. 25151-25157, SEP 28 2017.
Web of Science Citations: 2

In this work we demonstrate the use of the push-pull model system 4-(dimethylamino) benzonitrile (DMABN) as a convenient molecular probe to investigate the local solvation structure and dynamics by means of time-resolved infrared spectroscopy (TRIR). The photochemical features associated with this system provide several advantages due to the high charge separation between the ground and charge transfer states involving the characteristic nitrile bond, and an excited state lifetime that is long enough to observe the slow solvation dynamics in organic solvents and ionic liquids. The conversion from a locally excited state to an intramolecular charge transfer state (LE-ICT) in ionic liquids shows similar kinetic lifetimes in comparison to organic solvents. This similarity confirms that such conversion depends solely on the intramolecular reorganization of DMABN in the excited state, and not by the dynamics of solvation. In contrast, the relative shift of the nu(CN) vibration during the relaxation of the ICT state reveals two distinct lifetimes that are sensitive to the solvent environment. This study reveals a fast time component which is attributed to the dipolar relaxation of the solvent and a slower time component related to the rotation of the dimethylamino group of DMABN. (AU)

FAPESP's process: 15/24818-8 - Excited state dynamics of donor ­acceptor systems investigated by time resolved spectroscopic techniques
Grantee:Rômulo Augusto Ando
Support type: Scholarships abroad - Research