Protonated ozone
{{Chembox
| Name = Protonated ozone
| ImageFile = Protonated ozone.svg
| ImageSize = 150px
| OtherNames =
| IUPACName = Hydroxy(oxo)oxidanium
| SystematicName = Hydrotrioxygen(1+)
| Section1 = {{Chembox Identifiers
| CASNo = 74241-49-9
| ChemSpiderID =
| PubChem = 6030661
| StdInChI=1S/HO3/c1-3-2/h1H/q+1
| StdInChIKey = FQWSHTCXTQFHJZ-UHFFFAOYSA-N
| SMILES = O[O+]=O
}}
| Section2 = {{Chembox Properties
| H=1 | O=3 | Formula_Charge=+
| ConjugateBase = Ozone
}}
| Section6 = {{Chembox Related
| OtherFunction = {{ubl|
}}
| OtherFunction_label = hydrogen polyoxides
}}
}}
Protonated ozone is a hydrogen polyoxide having the molecular formula {{chem2|HO3+}} (also written {{chem2|O3H+}}). It is a cationic structure consisting of an ozone unit with a hydrogen atom attached to one end. This substance is proposed to exist as an intermediate in several interstellar, atmospheric,and synthetic chemical processes.{{cite journal |title= Protonated Ozone: Structure, Energetics, and Nonadiabatic Effects |first1 = Michele |last1= Ceotto |first2= Franco A. |last2= Gianturco |first3= David M. |last3= Hirst |journal= J. Phys. Chem. A |year= 1999 |volume= 103 |issue= 48 |pages= 9984–9994 |doi= 10.1021/jp9923769 |bibcode = 1999JPCA..103.9984C }} It has been synthesized in mass spectrometer experiments by protonation of ozone using various strong acids.{{cite journal |title= Protonated Ozone: Experimental Detection of O3H+ and Evaluation of the Proton Affinity of Ozone |first1= Fulvio |last1= Cacace |author1-link= Fulvio Cacace |first2= Maurizio |last2= Speranza |journal= Science |date= 8 July 1994 |volume= 265 |issue= 5169 |pages= 208–209 |doi= 10.1126/science.265.5169.208 |pmid= 17750658 |bibcode= 1994Sci...265..208C |s2cid= 29517377 }} Related experiments have used it as the precursor for generating hydrogen ozonide.{{cite journal |title= Experimental Detection of Hydrogen Trioxide |first1= Fulvio |last1= Cacace |first2= Giulia |last2= de Petris |first3= F. |last3= Pepi |first4= Anna |last4= Troiani |journal= Science |date= 2 July 1999 |volume= 285 |issue= 5424 |pages= 81–82 |doi= 10.1126/science.285.5424.81 |pmid= 10390365 }}