Editing Nitronium ion (section)

== Salts ==
A few stable nitronium salts with anions of weak [[nucleophile|nucleophilicity]] can be isolated. These include [[nitronium perchlorate]] {{chem2|[NO2]+[ClO4]-}}, [[nitronium tetrafluoroborate]] {{chem2|[NO2]+[BF4]-}}, nitronium [[hexafluorophosphate]] {{chem2|[NO2]+[PF6]-}}, nitronium [[hexafluoroarsenate]] {{chem2|[NO2]+[AsF6]-}}, and nitronium [[fluoroantimonic acid|hexafluoroantimonate]] {{chem2|[NO2]+[SbF6]-}}. These are all very [[hygroscopic]] compounds.<ref>{{cite book |title= Aromatic nitration |author= Kenneth Schofield |publisher= CUP Archive |year= 1980 |isbn= 0-521-23362-3 |page= 88 }}</ref>

The solid form of [[dinitrogen pentoxide]], {{chem2|N2O5}}, actually consists of nitronium and [[nitrate]] ions, so it is an [[ionic compound]], nitronium nitrate {{chem2|[NO2]+[NO3]−}}, not a [[molecular solid]]. However, dinitrogen pentoxide in [[liquid]] or [[gas]]eous state is [[molecule|molecular]] and does not contain nitronium ions.<ref name=G&E/><ref>{{Cite journal|url=https://aip.scitation.org/doi/10.1063/1.454679|doi = 10.1063/1.454679|title = The equilibrium constant for N2O5⇄NO2+NO3: Absolute determination by direct measurement from 243 to 397 K|year = 1988|last1 = Cantrell|first1 = C. A.|last2 = Davidson|first2 = J. A.|last3 = McDaniel|first3 = A. H.|last4 = Shetter|first4 = R. E.|last5 = Calvert|first5 = J. G.|journal = The Journal of Chemical Physics|volume = 88|issue = 8|pages = 4997–5006}}</ref>