09-07-2021-1403 - Pseudohalogens analoge analogue psuedo

Pseudohalogens are polyatomic analogues of halogens, whose chemistry, resembling that of the true halogens, allows them to substitute for halogens in several classes of chemical compounds.^[1] Pseudohalogens occur in pseudohalogen molecules, inorganic molecules of the general forms Ps–Ps or Ps–X (where Ps is a pseudohalogen group), such as cyanogen; pseudohalide anions, such as cyanide ion; inorganic acids, such as hydrogen cyanide; as ligands in coordination complexes, such as ferricyanide; and as functional groups in organic molecules, such as the nitrile group. Well-known pseudohalogen functional groups include cyanide, cyanate, thiocyanate, and azide. 

Common pseudohalogens and their nomenclature[edit]

Many pseudohalogens are known by specialized common names according to where they occur in a compound. Well-known ones include (the true halogen chlorine is listed for comparison):

Group	Dimer	Hydrogen compound	Pseudohalide	Ligand name	In organic compounds	Formula	Structural formula
chloro	chlorine	hydrochloride	chloride	chlorido- chloro-	-yl chloride	~ Cl	−Cl
cyano	cyanogen	hydrogen cyanide, prussic acid, formonitrile	cyanide	cyanido- cyano-	-nitrile -yl cyanide	~ CN	−C≡N
cyapho	cyaphogen	phosphaethyne	cyaphide	cyaphido- cyapho-	-yl cyaphide	~ CP	−C≡P
isocyano		hydrogen isocyanide, isohydrocyanic acid	isocyanide	isocyanido- isocyano-	-isonitrile -yl isocyanide	~ NC	−N+ ≡C−
hydroxyl	hydrogen peroxide	water	hydroxide	hydroxido- hydroxy-	-ol	~ OH	−O−H
sulfanyl	hydrogen disulfide	hydrogen sulfide	hydrosulfide	sulfanido- thiolato-	-thiol -yl mercaptane	~ SH	−S−H
cyanate		cyanic acid	cyanate	cyanato-	-yl cyanate	~ OCN	−O−C≡N
isocyanate	diisocyanogen	isocyanic acid	isocyanate	isocyanato-	-yl isocyanate	~ NCO	−N=C=O
fulminate		fulminic acid	fulminate	fulminato-	-nitrile oxide -yl fulminate	~ CNO	−C≡N+ –O−
thiocyanate, rhodanide	thiocyanogen	thiocyanic acid	thiocyanate	thiocyanato-	-yl thiocyanate	~ SCN	−S−C≡N
isothiocyanate		isothiocyanic acid	isothiocyanate	isothiocyanato-	-yl isothiocyanate	~ NCS	−N=C=S
selenocyanate, selenorhodanide	selenocyanogen	selenocyanic acid	selenocyanate			~ SeCN	−Se−C≡N
tellurocyanate,[2] tellurorhodanide	tellurocyanogen	tellurocyanic acid	tellurocyanate			~ TeCN	−Te−C≡N
azide	hexazine	hydrazoic acid	azide	azido-	-yl azide	~ N3	−N− −N+ ≡N ↕ −N=N+ =N−
nitrogen monoxide	dinitrogen dioxide	nitroxyl		nitrosyl	nitroso-	~ NO	•N=O
nitrogen dioxide	nitrogen tetroxide			nitryl	nitro-	~ NO2	−NO2
cobalt carbonyl	dicobalt octacarbonyl	cobalt tetracarbonyl hydride	tetracarbonylcobaltate			~ Co(CO)4	−Co(C≡O)4
trinitromethanide	hexanitroethane	nitroform, trinitromethane	trinitromethanide	trinitromethanido-	-yl trinitromethanide	~ C(NO2)3	−C(NO2)3
tricyanomethanide	hexacyanoethane	cyanoform, tricyanomethane	tricyanomethanide	tricyanomethanido-	-yl tricyanomethanide	~ C(CN)3	−C(CN)3

https://en.wikipedia.org/wiki/Pseudohalogen