ChemRxiv
These are preliminary reports that have not been peer-reviewed. They should not be regarded as conclusive, guide clinical practice/health-related behavior, or be reported in news media as established information. For more information, please see our FAQs.
Photobases Paper Revised.pdf (8.94 MB)

Structure-Photochemical Function Relationships in Nitrogen-Containing Heterocyclic Aromatic Photobases Derived from Quinoline

preprint
revised on 12.02.2020, 18:17 and posted on 13.02.2020, 06:41 by Sophya Alamudun, Kyle Tanovitz, April Fajardo, Kaitlind Johnson, Andy Pham, Tina Jamshidi Araghi, Andrew Petit

Photobases are compounds which become strong bases after electronic excitaton into a charge-transfer excited state. Recent experimental studies have highlighted the photobasicity of the 5-R quinoline compounds, demonstrating a strong substituent dependence to the pKa*. Here we describe our systematic study of how the photobasicity of four families of nitrogen-containing heterocyclic aromatics are tuned through substituents. We show that substituent position and identity both significantly impact the pKa*. We demonstrate that the substituent effects are additive and identify many disubstituted compounds with substantially greater photobasicity than the most photobasic 5-R quinoline compound identified previously. We show that the addition of a second fused benzene ring to quinoline, along with two electron-donating substituents, lowers the vertical excitation energy into the visible while still maintaining a pKa* > 14. Overall, the structure-function relationships developed in this study provide new insights to guide the development of new photocatalysts that employ photobasicity.

Funding

NSF XSEDE allocation TG-CHE180057

History

Email Address of Submitting Author

apetit@fullerton.edu

Institution

California State University, Fullerton

Country

United States of America

ORCID For Submitting Author

0000-0002-9428-3499

Declaration of Conflict of Interest

No conflict of interest

Version Notes

Revised version of the manuscript.

Exports

Logo branding

Exports