η

{
  "id": "MLC-T-CHM-003537",
  "term": "η",
  "field": "Chemistry",
  "definition": "A hapticity symbol used in organometallic chemistry to denote the number of atoms in a ligand that are directly bonded to a central metal atom. The symbol η (eta) is followed by a superscript number indicating the hapticity, such as η⁵ for a cyclopentadienyl ligand bonded through all five carbon atoms. This notation precisely describes the bonding mode of pi-electron ligands to metal centers.",
  "synonyms": [
    "hapto",
    "eta"
  ],
  "subject": "Organic and Biomolecular Chemistry",
  "see_also": [
    "central atom",
    "coordination entity"
  ],
  "references": [
    "Red Book, 3rd ed., p. 202"
  ],
  "url": "https://mlchart.com/terminology/chemistry/e-term/"
}