Excited‐State Intramolecular Charge‐Transfer Dynamics in 4‐Dimethylamino‐4′‐cyanodiphenylacetylene: An Ultrafast Raman Loss Spectroscopic Perspective
Please always quote using this URN: urn:nbn:de:bvb:20-opus-312280
- 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 ICTPhoto‐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.…
Author: | Arvind Barak, Nishant Dhiman, Floriane Sturm, Florian Rauch, Yapamanu Adithya Lakshmanna, Karen S. Findlay, Andrew Beeby, Todd B. Marder, Siva Umapathy |
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URN: | urn:nbn:de:bvb:20-opus-312280 |
Document Type: | Journal article |
Faculties: | Fakultät für Chemie und Pharmazie / Institut für Anorganische Chemie |
Language: | English |
Parent Title (English): | ChemPhotoChem |
Year of Completion: | 2022 |
Volume: | 6 |
Issue: | 12 |
Article Number: | e202200146 |
Source: | ChemPhotoChem 2022, 6(12):e202200146. DOI: 10.1002/cptc.202200146 |
DOI: | https://doi.org/10.1002/cptc.202200146 |
Dewey Decimal Classification: | 5 Naturwissenschaften und Mathematik / 54 Chemie / 540 Chemie und zugeordnete Wissenschaften |
Tag: | 4-dimethylamino-4′-cyanodiphenylacetylene; TD-DFT; charge transfer; transient absorption; ultrafast Raman loss spectroscopy |
Release Date: | 2023/06/21 |
Licence (German): | CC BY: Creative-Commons-Lizenz: Namensnennung 4.0 International |