Effect of the Intramolecular Hydrogen Bonding on the Photochromic Properties of the Hemiindigo Dye having a Pyrrole Ring

ABSTRACT

Photochromism and fluorescence properties of 2-(2-pyrrolylidene)indolin-3-one (1) have been studied. The quantum yields of fluorescence emissions of both Z- and E-isomer were very small in protic solvents such as ethanol and water. However, the fluorescence intensity of E-1 increased by addition of bovine serum albumin (BSA) in water, indicating that E-1 should bind to the hydrophobic site of BSA.

Keywords:

• fluorescence
• hemiindigo
• hydrogen bonding
• photoisomerization

Acknowledgments

This work was supported by a Grant-in-Aid for Scientific Research on Priority Areas (No. 417) and the 21st Century COE Program from the Ministry of Education, Culture, Sports, Science and Technology (MEXT) of the Japanese Government, by Research Foundation for Opto-Science and Technology, by University of Tsukuba Research Projects, and by the Asahi Glass Foundation.