Thermally irreversible photochromic dithienylethenes was written by Krayushkin, M. M.;Uzhinov, B. M.;Martynkin, A. Yu.;Dzhavadov, D. L.;Kalik, M. A.;Ivanov, V. L.;Stoyanovich, F. M.;Uzhinova, L. D.;Zolotarskaya, O. Yu.. And the article was included in International Journal of Photoenergy in 1999.Name: 4-Bromo-5-methylthiophene-2-carboxylic acid This article mentions the following:
A lot of previously unknown derivatives of dithienylperfluorocyclopentene (DTPFCP) were synthesized. It was shown that 2,2′-dialkyl substituted DTPFCP’S are photochromes. The quantum yields of forward and backward photochem. reactions and spectral parameters of open and cyclic forms of the photochromes synthesized were measured. An attempt to obtain fluorescing photochromes by means of introduction of benzoxazolyl, benzthiazolyl and 1,2,4-oxadiazolyl moieties in 5 and 5′ positions of DTPFCP failed; these compounds were synthesized but they do not fluoresce. In the experiment, the researchers used many compounds, for example, 4-Bromo-5-methylthiophene-2-carboxylic acid (cas: 29421-99-6Name: 4-Bromo-5-methylthiophene-2-carboxylic acid).
4-Bromo-5-methylthiophene-2-carboxylic acid (cas: 29421-99-6) belongs to organobromine compounds. A variety of minor organobromine compounds are found in nature, but none are biosynthesized or required by mammals. Organobromine compounds have fallen under increased scrutiny for their environmental impact. Commercially available organobromine pharmaceuticals include the vasodilator nicergoline, the sedative brotizolam, the anticancer agent pipobroman, and the antiseptic merbromin. Name: 4-Bromo-5-methylthiophene-2-carboxylic acid
Referemce:
Bromide – Wikipedia,
bromide – Wiktionary