Bis(thienyl)ethenes with α-methoxymethyl groups. Syntheses, spectroscopic Hammett plots, and stabilities in PMMA films.

ABSTRACT: A series of bis(thienyl)ethenes (BTEs) possessing perfluorocyclopentene backbones and methoxymethyl groups (MOM) in the 2/2'-positions of the thiophenes was prepared and examined. The substitution pattern of the 5/5'-positions was varied, covering the range from electron-donating to electron-withdrawing. The substituent effects of the absorption wavelengths of the ring-opened and the ring-closed isomers, which are interconverted by reversible 6π-electrocyclizations and cycloreversions, are studied by means of the spectroscopic Hammett equation and the Hammett-Brown equation. Excellent correlations of these linear free energy relationships were found, when the σ_p values of the Hammett equation, which summarize inductive, mesomeric and field effects, were replaced to the Ha

SUBMITTER: Weingartz T 

PROVIDER: S-EPMC10462923 | biostudies-literature | 2023 Aug

REPOSITORIES: biostudies-literature