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Novel push-pull systems comprised of triphenylamine-tetracyanobutadiene, a high-energy CT species is linked to a near-IR sensitizer, azaBODIPY, for promoting excited state CS. These new systems revealed panchromatic absorption due to combined effect of intramolecular CT, and near-IR absorbing azaBODIPY. Using electrochemical and computational studies, energy levels were established to visualize excited state events. Fs-TA studies were performed to monitor excited state CT events. From target analysis, the effect of solvent polarity, number of linked CT entities, and excitation wavelength dependence in governing the lifetime of CS states was established. Electron exchange between two TPA-TCBD entities in 3 seem to prolong lifetime of the CS state. Importantly, we have been successful in demonstrating efficient CS upon both high-energy CT and low-energy near-IR excitations, signifying importance of these push-pull systems for optoelectronic applications operating in the wide optical window.
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An Introduction to Processing, Fitting, and Interpreting Transient Absorption Data
Transient absorption (TA) spectroscopy is a powerful time-resolved spectroscopic method used to track the evolution of excited-state processes through changes in the system's absorption spectrum. Early implementations of TA were confined to specialized laboratories, but the evolution of commercial turn-key systems has made the technique increasingly available to research groups across the world. Modern TA systems are capable of producing large datasets with high energetic and temporal resolution that are rich in photophysical information. However, processing, fitting, and interpreting TA spectra can be challenging due to the large number of excited-state features and instrumental artifacts. Many factors must be carefully considered when collecting, processing, and fitting TA data in order to reduce uncertainty over which model or set of fitting parameters best describes the data. The goal of data preparation and fitting is to reduce as many of these extraneous factors while preserving the data for analysis. In this method, beginners are provided with a protocol for processing and preparing TA data as well as a brief introduction to selected fitting procedures and models, specifically single wavelength fitting and global lifetime analysis. Commentary on a number of commonly encountered data preparation challenges and methods of addressing them is provided, followed by a discussion of the challenges and limitations of these simple fitting methods.
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- Award ID(s):
- 2313290
- PAR ID:
- 10500130
- Publisher / Repository:
- Journal of Visualized Experiments
- Date Published:
- Journal Name:
- Journal of Visualized Experiments
- Issue:
- 204
- ISSN:
- 1940-087X
- Page Range / eLocation ID:
- 1-27
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.3791/65519
