ACID-BASE PROPERTIES AND STABILITY OF PYRYLIUM POLYMETHINE DYES IN CHLOROHYDROCARBON SOLUTIONS

Article abstract of DOI:10.1007/BF00514988

The reactions of pyrylocyanine dyes with aqueous alcoholic alkali and with acetic acid have been studied.It has been shown that decoloration of such dyes in chlorohydrocarbon solutions only occurred under the action of alkali and was linked with the formation of an intermediate acyclic form of the dye which was the addition product of hydroxyl ion at the α position of the pyrylium ring.