Any of a class of heteroaromatic compounds derived from indulines, many of which show a red fluorescence in solution and have been used as dyes.
Fluorindines have a pentacyclic structure of three benzene rings with both pairs of adjacent rings joined at two points by nitrogen atoms.
fluorindine/flʊəˈrɪndiːn/ /flɔːˈrindiːn/ /flʊˈrindiːn/
Late 19th century; earliest use found in Journal of the Chemical Society. From German Fluorindin from fluor-, variant (before vowels) of fluoro- + ind- (in Indulin) + -in; so called on account of their fluorescence and their preparation from indulines.