Abstract
AbstractA series of 2,2‐diphenyl‐2H‐chromene derivatives bearing electron‐donating groups at the benzopyran ring have been synthesized. A significant effect of the bromoalkoxy chain length and the concentration of chromenes on the conversion of closed (CF) into open forms under UV irradiation and the equilibrium between TC (transoid‐cis) and TT (transoid‐trans) isomers in the photostationary state was found. For chromene derivatives, a sequential (CF→TC→TT) or parallel (CF→TC; CF→TT) mechanism of transformation of the closed form into an open one is possible. A high solution concentration contributes to a significant shift of the photochromic equilibrium towards the TT isomer. The proposed scheme of the ring‐opening reaction was confirmed by the analysis of the NMR spectra of acetonitrile solutions of chromene derivatives obtained by gradual irradiation. The results obtained are important for a deeper understanding of the nature of photochromic reactions.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
