Onium ion

=== Group 13 (boron group) onium cations === • boronium cation, (protonated borane) • further boronium cations, (protonated boranes) === Group 14 (carbon group) onium cations === • Carbonium ions (protonated hydrocarbons) have a pentacoordinated carbon atom with a +1 charge. The specific cation is called methanium.. Typically named for the parent hydrocarbon, e.g. is ethanium. • silanium (sometimes silonium), (protonated silane) (should not be called siliconium) • disilanium, (protonated disilane) • further silanium cations, (protonated silanes) • germonium, (protonated germane) Unstable derivative known of R3Ge+. • stannonium, (protonated stannylene, ) (not protonated stannane ) stable at cryogenic conditions. ===Group 15 (pnictogen) onium cations=== • ammonium (IUPAC name azanium), (protonated ammonia (IUPAC name azane)) exists in aqueous solution and as salts. • primary, secondary, and tertiary organic derivatives {{chem2|[NH_{n}R_{4-n}]+}}, derived from protonation of amines; e.g. methylammonium halides, diethylammonium chloride, trimethylammonium • quaternary ammonium cations ; e.g. tetrabutylammonium • phosphonium, (protonated phosphine) • primary, secondary, and tertiary organic derivatives {{chem2|[PH_{n}R_{4-n}]+}}, derived from protonation of phosphines • quaternary phosphonium cations ; e.g. tetraphenylphosphonium • arsonium, (protonated arsine) known as derivatives or as an unstable salt at cryogenic temperatures. • bismuthonium, (protonated bismuthine) only known as derivatives. ===Group 16 (chalcogen) onium cations=== • oxonium, (protonated water (IUPAC name oxidane). Oxonium is better known as hydronium, though hydronium implies a solvated or hydrated proton. It may also be called hydroxonium.) • Organic derivatives can be primary (, protonated alcohols), secondary (, protonated ethers), or ternary (, as trimethyloxonium). • peroxonium, (protonated hydrogen peroxide) • sulfonium, (protonated hydrogen sulfide) • Organic derivatives can be primary (, protonated thiols), secondary (, protonated thioethers), or ternary (, e.g. trimethylsulfonium) • selenonium, (protonated hydrogen selenide) • Tertiary organic derivatives are known, with trimethylselenonium iodide being the first. • telluronium, (protonated hydrogen telluride) Hydrogen onium cation • hydrogenonium, better known as trihydrogen cation, (protonated molecular or diatomic hydrogen), found in ionized hydrogen and interstellar space ===Group 17 (halogen) onium cations, halonium ions, (protonated hydrogen halides)=== • fluoronium, (protonated hydrogen fluoride) • chloronium, (protonated hydrogen chloride) • bromonium, (protonated hydrogen bromide) • iodonium, (protonated hydrogen iodide) ====Pseudohalogen onium cations==== • aminodiazonium, (protonated hydrogen azide) • methylidyneammonium and hydrocyanonium, , isomers (protonated hydrogen cyanide) ===Group 18 (noble gas) onium cations=== • hydrohelium or helonium, better known as helium hydride ion, (protonated helium) known in gas phase. • neonium, (protonated neon) known in gas phase. • argonium, (protonated argon) known in gas phase. • kryptonium, (protonated krypton) known in gas phase. • xenonium, (protonated xenon) known in gas phase. ==Onium cations with monovalent substitutions==

• tertiary selenonium cations, • triphenylselenonium, • tertiary telluronium cations, • triphenyltelluronium, • primary fluoronium cations, (protonated fluorides RF) • secondary fluoronium cations, • dichlorofluoronium, • secondary iodonium cations, • diphenyliodonium, ==Onium cations with polyvalent substitutions==

• secondary ammonium cations having one double-bonded substitution, • diazenium, (protonated diazene) • guanidinium, (protonated guanidine) (has a resonance structure and a planar molecular geometry) • tertiary ammonium cations having one triple-bonded substitution, R≡NH+ • nitrilium, (protonated nitrile) • diazonium or diazynium, (protonated nitrogen, in other words, protonated diazyne) • cyclic tertiary ammonium cations where nitrogen is a member of a ring, (the ring may be aromatic) • pyridinium, (protonated pyridine) • quaternary ammonium cations having one double-bonded substitution and two single-bonded substitutions, • iminium, (substituted protonated imine) • diazenium, (substituted protonated diazene) • thiazolium, (substituted protonated thiazole) • quaternary ammonium cations having two double-bonded substitutions, • nitronium, • bis(triphenylphosphine)iminium, • quaternary ammonium cations having one triple-bonded substitution and one single-bonded substitution, • diazonium, (substituted protonated nitrogen, in other words, substituted protonated diazyne) • nitrilium, (substituted protonated nitrile) • tertiary oxonium cations having one triple-bonded substitution, • acylium ions, • nitrosonium, • tertiary sulfonium cations having one triple-bonded substitution, • thionitrosyl, • dihydroxyoxoammonium, (protonated nitric acid) • trihydroxyoxosulfonium, (protonated sulfuric acid) • cyclic tertiary onium cations • pyrylium, • thiopyrylium, • selenopyrylium, • telluropyrylium, ==Double onium dications==

• hydrazinediium or hydrazinium(2+) dication, (doubly protonated hydrazine, in other words, doubly protonated diazane) • diazenediium cation, (doubly protonated diazene) • diazynediium cation, (doubly protonated dinitrogen, in other words, doubly protonated diazyne) ==Enium cations==

The extra bond is added to a less-common parent hydride, a carbene analog, typically named -ene or -ylene, which is neutral with 2 fewer bonds than the more-common hydride, typically named -ane or -ine. • borenium cations, (protonated borylenes a.k.a. boranylidenes) • carbenium cations, (protonated carbenes) have a tricoordinated carbon atom with a +1 charge. • alkenium cations, (n ≥ 2) (protonated alkenes) • methenium cation, (protonated methylene) • ethenium, (protonated ethene) • benzenium, (protonated benzene) • tropylium, (protonated tropylidene) • silylium cations, (protonated silylenes) • nitrenium cations, (protonated nitrenes) • phosphinidenium cations, (protonated phosphinidene) • mercurinium cations, (protonated organomercury compounds; formed as intermediates in oxymercuration reactions) Substituted eniums • diphenylcarbenium, (di-substituted methenium) • triphenylcarbenium, (tri-substituted methenium) ==Ynium cations==

• carbynium ions (protonated carbynes) have a carbon atom with a +1 charge. • alkynium cations, (n ≥ 2) (protonated alkynes) • methynium cation, (protonated methylidyne radical) • ethynium, (protonated ethyne) ==See also==