Ab Initio Investigation Of Intramolecular Charge Transfer In Dmabn By Calculation Of Transient X-ray Absorption Features

Datar, Avdhoot

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https://hdl.handle.net/2142/116831 Copy

Description

Title

Ab Initio Investigation Of Intramolecular Charge Transfer In Dmabn By Calculation Of Transient X-ray Absorption Features

Author(s)

Datar, Avdhoot

Contributor(s)

• Matthews, Devin A.
• Gudivada, Saisrinivas

Issue Date

2022-06-21

Keyword(s)

Theory and Computation

Abstract

Dual fluorescence in dimethylaminobenzonitrile (DMABN) and its derivatives in polar solvents, has been studied extensively for the past several years. Intramolecular charge transfer (ICT), in addition to the localized low-energy (LE) valence minimum, has been proposed as a mechanism for this dual fluorescence, with large geometric relaxation and molecular orbital reorganization a key feature of the ICT pathway. Herein, we have used both equation-of-motion coupled-cluster singles and doubles (EOM-CCSD) and time-dependent density functional (TD-DFT) methods to investigate the landscape of excited state potential energy surfaces across the several geometric conformations proposed as ICT structures, including Franck-Condon (FC), twisted (TICT), partially twisted (PTICT), wagged (WICT), and rehybridized (RICT) structures. Initial geometries for each type of structure were selected for excited state PES optimizations, as well as a systematic exploration of the low-lying PESs starting from the FC geometry. We find a number of minimum-energy (near)-crossing points among the lowest three excited states leading to the eventual ICT minima. Finally, we have calculated the carbon and nitrogen K-edge transient absorption spectra for all important “signpost” structures in order to investigate the differential pump-probe features along the LE and ICT pathways.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

text

Language

eng

Handle URL

https://hdl.handle.net/2142/116831

DOI

https://doi.org/10.15278/isms.2022.TL03

Copyright and License Information

Copyright 2022 held by the authors

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