https://doi.org/10.1351/goldbook.H01881
An affix giving a topological indication of the bonding between a π-electron ligand and the
central atom
in a coordination entity
. A right superscript numerical index indicates the number of ligating atoms in the π-electron system of the ligand which bind to the central atom
. Examples: - [Fe(CO)3(C4H6SO)], tricarbonyl(η2-dihydrothiophene 1-oxide-κO)iron.
- [Cr(CO)4(C4H6)], tetracarbonyl(η4-2-methylene-1,3-propanediyl)chromium.