noun
- Any of a class of synthetic organic compounds derived from phthalic anhydride, used as dyes, pigments, and indicators in chemistry.
Usage: technical; chemistry
Examples
- Phenolphthalein is a common phthalin used as a pH indicator in laboratory titrations.
- The chemist selected a phthalin dye for the textile experiment.
- Phthalin compounds are valued for their bright colors and stability in industrial applications.
- The phthalin pigment provided excellent coverage on the painted surface.