J-Aggregate Formation of Spiropyran Derivatives in LB and Vapor-Deposited Thin Films

ABSTRACT

J-aggregate formation in the films of spiropyran derivatives (SP1822 and SP18) prepared with Langumuir-Blodegett (LB) and vapor-deposition methods was investigated. In the films of SP1822, J-aggregate formation occurred with UV light illumination and thermal treatment. In the case of SP18 film, on the other hand, only photoisomerization occurred. When the PMC-form of SP18 was transferred onto a glass plate, J-like aggregate formation occurred after UV light illumination. By UV light illumination during evaporation process, SP1822 formed J-aggregate. Finally, SP1822 J-aggregate film oriented one-dimensionally was fabricated by using a PTFE layer as a substrate.

Keywords:

• J-aggregate
• J-like aggregate
• LB method
• photochromic behavior
• spiropyran
• vapor-deposition method

Acknowledgments

This work was partially supported by a Grant-in-Aid for Scientific Research (B) (No. 16360040) from the Japan Society for the Promotion of Science. This work was also supported by the Tokyo Ohka Foundation for the Promotion of Science and Technology and by the Photonics Materials Laboratory Project of the VBL of the Graduate School of Science and Technology, Kobe University.