Indolium
{{Chembox
| ImageFile = Indolium.png
| PIN = 1H-Indol-1-ium
|Section1={{Chembox Identifiers
| CASNo = 783272-65-1
| PubChem = 4528438
| ChemSpiderID = 3723290
| ChEBI = 52840
| StdInChI=1S/C8H7N/c1-2-4-8-7(3-1)5-6-9-8/h1-6,9H/p+1
| StdInChIKey = SIKJAQJRHWYJAI-UHFFFAOYSA-O
| SMILES = C1=CC=C2C(=C1)C=C[NH2+]2
}}
|Section2={{Chembox Properties
| C=8|H=8|N=1|Formula_Charge=+1
}}
}}
Indolium is a cation with molecular formula C8H8N+, and forms chemical compounds in combination with anions. It is an onium ion derived from its parent compound, indole, by the addition of a proton.{{Cite web |title=Indolium |url=https://pubchem.ncbi.nlm.nih.gov/compound/4528438 |access-date=2020-09-08 |website=National Center for Biotechnology Information}}