A General Strategy to Enhance Donor‐Acceptor Molecules Using Solvent‐Excluding Substituents. Issue 12 (3rd February 2020)

• Record Type: Journal Article
• Authors: Hoelzel, Conner A.; Hu, Hang; Wolstenholme, Charles H.; Karim, Basel A.; Munson, Kyle T.; Jung, Kwan Ho; Zhang, Han; Liu, Yu; Yennawar, Hemant P.; Asbury, John B.; Li, Xiaosong; Zhang, Xin
• Is Part Of: Angewandte Chemie international edition. Volume 59:Issue 12(2020)
• Page Start: 4785
• Page End: 4792
• Publication Date: 2020-02-03
• Subjects: amines -- charge transfer -- donor-acceptor systems -- fluorescence -- solvent effects; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201915744
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: While organic donor‐acceptor (D‐A) molecules are widely employed in multiple areas, the application of more D‐A molecules could be limited because of an inherent polarity sensitivity that inhibits photochemical processes. Presented here is a facile chemical modification to attenuate solvent‐dependent mechanisms of excited‐state quenching through addition of a β‐carbonyl‐based polar substituent. The results reveal a mechanism wherein the β‐carbonyl substituent creates a structural buffer between the donor and the surrounding solvent. Through computational and experimental analyses, it is demonstrated that the β‐carbonyl simultaneously attenuates two distinct solvent‐dependent quenching mechanisms. Using the β‐carbonyl substituent, improvements in the photophysical properties of commonly used D‐A fluorophores and their enhanced performance in biological imaging are shown. Abstract : On the bright side : The photophysical behavior of donor‐acceptor (D‐A) molecules can be improved through installation of a polar, solvent‐shielding auxiliary to an amino‐donating group. This β‐carbonyl substituent generally enhances the fluorescence quantum yield of D‐A fluorophores, enabling brighter labeling probes for live‐cell imaging.