Reversed photochromism reactivity of malononitrile attached bisthienylthene

ABSTRACT

An electron acceptor, malononitrile, was attached to bisthienylethene derivative. The significant influence of electron nature result a reversed phtochromism. Investigation of MT in THF demonstrates the reversible ring-open and ring-close. Upon irradiation of 405 nm laser, the solution color changed from yellowish to colorless, which is different from most of the photochromic colored phenomenon. Upon 254 nm irradiation, the original yellowish state can be recovered. Due to the attachment of malononitrile, the photo-/thermal-stability were enhanced. The ring-open/ring-closed forms were optimized by Dmol³. The distance between photocyclizing atoms in aptiparallel conformation meets the requirement for photochromic reaction. And the calculated absorption values were also in agreement with the experimental ones.

KEYWORDS:

• Bisthienylethene
• malononitrile
• photo- and thermal-stability
• photocyclizing atoms
• reversed photochromism

Additional information

Funding

This work was supported by the National Natural Science Foundation of China (21272060, 21772034), and the Program for Innovative Research Team in Science and Technology in University of Henan Province (15IRTSTHN003). This study was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT and Future Planning (Grant No. NRF-2017R1E1A1A01074266).