Indolins styryl-like compounds

Abstract

This invention relates to color-changing stryl-like compounds and the preparing of the same. A compound according to the present invention has, as its principal ring, an indoline ring of 2nd position, and has, at stimulation reversible or irreversible change(s) between a closed ring structre of a non-plane molecular structure indicated by the following chemical formula(1) showing white or pale color, and an open ring structure of a plane molecular structure indicated by the following chemical formula(2) showing vivid visible color: ##STR1## Wherein Q represents benzene ring with or without substituted radicals and/or condensed ring(s); R.sub.1 and R.sub.2 represent lower alkyl radicals hydroxyalkyl radicals or alkoxyalkyl radicals of the same or different kinds,; R.sub.3 represents hydrogen, alkyl radical, alkoxy radical, halogen, nitrile radical, aromatic radical or phenoxy radical; Y represents oxygen (O) or sulfer (S); Z represents alkylene radical of carbon number of 2 to 4 with or without alkyl substitution radical(s) necessary to form a ring structure together with ##STR2## A represents a condensation reaction residue of an aromatic aldehyde, heterocyclic aldehyde, aromatic nitroso compound, or heterocyclic nitroso compound. And X represents an anion.

Dependencies are inferred from the claim text.