Arvind Barak
Excited‐State Intramolecular Charge‐Transfer Dynamics in 4‐Dimethylamino‐4′‐cyanodiphenylacetylene: An Ultrafast Raman Loss Spectroscopic Perspective
Barak, Arvind; Dhiman, Nishant; Sturm, Floriane; Rauch, Florian; Lakshmanna, Yapamanu Adithya; Findlay, Karen S.; Beeby, Andrew; Marder, Todd B.; Umapathy, Siva
Authors
Nishant Dhiman
Floriane Sturm
Florian Rauch
Yapamanu Adithya Lakshmanna
Karen S. Findlay
Professor Andrew Beeby andrew.beeby@durham.ac.uk
Professor
Todd B. Marder
Siva Umapathy
Abstract
The D-π-A compound 4-dimethylamino-4′-cyanodiphenylacetylene (DACN-DPA) exhibits intramolecular charge transfer (ICT) upon photoexcitation. Ultrafast Raman Loss Spectroscopy (URLS) measurements show distinct spectral and temporal dynamics of C≡C and C=C vibrational modes in MeCN and n-hexane, revealing that ICT is strongly coupled to the structural dynamics. Photo-initiated intramolecular charge transfer (ICT) processes play a pivotal role in the excited state reaction dynamics in donor-bridge-acceptor systems. The efficacy of such a process can be improved by modifying the extent of π-conjugation, relative orientation/twists of the donor/acceptor entities and polarity of the environment. Herein, 4-dimethylamino-4′-cyanodiphenylacetylene (DACN-DPA), a typical donor-π-bridge-acceptor system, was chosen to unravel the role of various internal coordinates that govern the extent of photo-initiated ICT dynamics. Transient absorption (TA) spectra of DACN-DPA in n-hexane exhibit a lifetime of >2 ns indicating the formation of a triplet state while, in acetonitrile, a short time-constant of ∼2 ps indicates the formation of charge transferred species. Ultrafast Raman loss spectroscopy (URLS) measurements show distinct temporal and spectral dynamics of Raman bands associated with C≡C and C=C stretching vibrations. The appearance of a new band at ∼1492 cm−1 in acetonitrile clearly indicates structural modification during the ultrafast ICT process. Furthermore, these observations are supported by TD-DFT computations.
Citation
Barak, A., Dhiman, N., Sturm, F., Rauch, F., Lakshmanna, Y. A., Findlay, K. S., Beeby, A., Marder, T. B., & Umapathy, S. (2022). Excited‐State Intramolecular Charge‐Transfer Dynamics in 4‐Dimethylamino‐4′‐cyanodiphenylacetylene: An Ultrafast Raman Loss Spectroscopic Perspective. ChemPhotoChem, 6(12), Article e202200146. https://doi.org/10.1002/cptc.202200146
Journal Article Type | Article |
---|---|
Acceptance Date | Sep 2, 2022 |
Online Publication Date | Sep 29, 2022 |
Publication Date | 2022-12 |
Deposit Date | Oct 25, 2022 |
Publicly Available Date | Mar 22, 2023 |
Journal | ChemPhotoChem |
Print ISSN | 2367-0932 |
Electronic ISSN | 2367-0932 |
Publisher | Wiley |
Peer Reviewed | Peer Reviewed |
Volume | 6 |
Issue | 12 |
Article Number | e202200146 |
DOI | https://doi.org/10.1002/cptc.202200146 |
Public URL | https://durham-repository.worktribe.com/output/1187528 |
Files
Published Journal Article
(1.5 Mb)
PDF
Publisher Licence URL
http://creativecommons.org/licenses/by/4.0/
Copyright Statement
This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
You might also like
Tuning Emission Lifetimes of Ir(C^N)2(acac) Complexes with Oligo(phenyleneethynylene) Groups
(2023)
Journal Article
Enolization rates control mono- versus di-fluorination of 1,3-dicarbonyl derivatives
(2019)
Journal Article
Highly Linearized Twisted Iridium(III) Complexes
(2018)
Journal Article
Downloadable Citations
About Durham Research Online (DRO)
Administrator e-mail: dro.admin@durham.ac.uk
This application uses the following open-source libraries:
SheetJS Community Edition
Apache License Version 2.0 (http://www.apache.org/licenses/)
PDF.js
Apache License Version 2.0 (http://www.apache.org/licenses/)
Font Awesome
SIL OFL 1.1 (http://scripts.sil.org/OFL)
MIT License (http://opensource.org/licenses/mit-license.html)
CC BY 3.0 ( http://creativecommons.org/licenses/by/3.0/)
Powered by Worktribe © 2024
Advanced Search