Photochromic fulgides: Transformation of the non-photochromic (Z)-isomer of a fulgide into a highly photochromic (E)-isomer via structural modification involving enhanced conjugation

✍ Scribed by Zhiyuan Sun; Ramachandra S. Hosmane; Maher Tadros

• Publisher: Journal of Heterocyclic Chemistry
• Year: 2000
• Tongue: English
• Weight: 241 KB
• Volume: 37
• Category: Article
• ISSN: 0022-152X
• DOI: 10.1002/jhet.5570370606

✦ Synopsis

Abstract

The non‐photochromic fulgide (1‐Z) has been successfully converted into the highly photochromic (3‐Z) analogue. A dicyanomethylene group was introduced at the 5‐position of 1‐Z in order to enhance the latter's conjugation properties that would facilitate the photochemical Z→E isomerization process. The irradiation of the product 3‐Z with a UV light at λ~max~ 350 nm formed a bluish green solution which absorbed at λ~max~ 620 nm, corresponding to the ring‐closed product 4. The latter was also formed from the reference dicyanomethylene product 3‐E synthesized from 1‐E. The irradiation of 4 at λ~max~ 532 nm produced the reversion to the original pale yellow color of 3‐E.