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http://hdl.handle.net/2289/7491
Title: | Transient Raman Snapshots of the Twisted Intramolecular Charge Transfer State in a Stilbazolium Dye |
Authors: | Karmakar, Shreetama Ambastha, Abhinandan Dharmadhikari, J.A. +4 Co-Authors |
Issue Date: | Jun-2020 |
Publisher: | American Chemical Society |
Citation: | The Journal of Physical Chemistry Letters, 2020, Vol.11, p4842−4848 |
Abstract: | Optically triggered twisted intramolecular charge transfer (TICT) states in donor–acceptor chromophores form the molecular basis for designing bioimaging probes that sense polarity, microviscosity, and pH in vivo. However, a lack of predictive understanding of the “twist” localization precludes a rational design of TICT-based dyes. Here, using femtosecond stimulated Raman spectroscopy, we reveal a distinct Raman signature of the TICT state for a stilbazolium-class mitochondrial staining dye. Resonance-selective probing of 4-N,N-diethylamino-4″-N′-methyl-stilbazolium tosylate (DEST) tracks the excited-state structure of the dye as it relaxes to a TICT state on a picosecond time scale. The appearance of a remarkably blue-shifted C=C stretching mode at 1650 cm–1 in the TICT state is attributed to the “twist” of a single bond adjacent to the ethylenic π-bridge in the DEST backbone based on detailed electronic structure calculations and vibrational mode analysis. Our work demonstrates that the π-bridge, connecting the donor and acceptor moieties, influences the spatial location of the “twist” and offers a new perspective for designing organelle-specific probes through cogent tuning of backbone dynamics. |
Description: | Restricted Access |
URI: | http://hdl.handle.net/2289/7491 |
ISSN: | 1948-7185 |
Alternative Location: | https://doi.org/10.1021/acs.jpclett.0c01124 |
Copyright: | 2020 American Chemical Society |
Additional information: | Supporting Information Available |
Appears in Collections: | Research Papers (LAMP) |
Files in This Item:
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2020_J Phys Chem Lett_Vol.11_p4842−4848.pdf Restricted Access | Restricted Access | 2.33 MB | Adobe PDF | View/Open Request a copy |
2020_J Phys Chem Lett_Vol.11_Supl Info.pdf Restricted Access | Restricted Access | 4.59 MB | Adobe PDF | View/Open Request a copy |
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