Phthaleins

{
  "id": "MLC-T-CHM-008945",
  "term": "Phthaleins",
  "field": "Chemistry",
  "definition": "A class of organic compounds derived from phthalic anhydride and phenols, characterized by a central carbon atom bonded to two aryl groups and one oxygen atom, forming a lactone ring. These compounds are widely known for their use as pH indicators, exhibiting distinct color changes over specific pH ranges due to structural rearrangements involving quinoid forms. Phenolphthalein is a prominent example, changing from colorless to pink in alkaline solutions.",
  "subject": "Organic and Biomolecular Chemistry",
  "see_also": [
    "phenols",
    "xanthene dyes"
  ],
  "references": [
    "PAC, 1995, 67, 1307. 'Glossary of class names of organic compounds and reactivity intermediates based on structure (IUPAC Recommendations 1995)' on page 1359 (https://doi.org/10.1351/pac199567081307)"
  ],
  "url": "https://mlchart.com/terminology/chemistry/phthaleins/"
}