Synthesis, Photo-, and Ionochromic Properties of Indolylmaleimides with Terpyridine Receptor

Indolyl(thienyl)maleimides with terpyridine receptor in the bridge part have been synthesized. Irradiation of their toluene solutions with light at [lambda] = 436 nm has led to the formation of cyclic isomers. The reverse ring opening reaction has occurred during the photolysis with visible light ([lambda] > 500 nm). 1- (4([2,2':6',2"-Terpyridin]-4'-yl)phenyl)derivatives have exhibited the properties of chromogenic naked-eye sensors to [Fe.sup.2+] cations in acetonitrile solution, changing the solution color from bright-orange to red. Keywords: indole, thiophene, maleimides, terpyridine, photochromic properties, ionochromic properties DOI: 10.1134/S1070363219030071