Valence isomer

{
  "id": "MLC-T-CHM-012500",
  "term": "Valence isomer",
  "field": "Chemistry",
  "definition": "A constitutional isomer that can be interconverted with another through a pericyclic reaction, involving the reorganization of sigma and pi bonds without the migration of any atoms or groups. This interconversion, known as valence tautomerism, results in molecules with different connectivity but the same molecular formula. The classic example is the equilibrium between cycloheptatriene and its valence isomer, norcaradiene.",
  "subject": "Organic and Biomolecular Chemistry",
  "see_also": [
    "isomer",
    "pericyclic reaction",
    "tautomerism",
    "valence"
  ],
  "references": [
    "PAC, 1994, 66, 1077. 'Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994)' on page 1175 (https://doi.org/10.1351/pac199466051077)"
  ],
  "url": "https://mlchart.com/terminology/chemistry/valence-isomer/"
}