In organic chemistry, carbon nitrides are compounds consisting only of carbon and nitrogen atoms. Beta carbon nitride - a solid with a formula β-, which is predicted to be harder than diamond. Graphitic carbon nitride - g-, with important catalytic and sensor properties. a combined triazole and triazine framework. MCN-12 () and MCN-13 (). Azafullerenes are a class of heterofullerenes in which the element substituting for carbon is nitrogen. Examples include (biazafullerenyl), (diaza[60]fullerene), (triaza[60]fullerene) and . Cyanofullerenes are a class of modified fullerenes in which cyano- groups are attached to a fullerene skeleton. These have the formula , where n takes the values 1 to 9. Cyanogen - () Isocyanogen - () Diisocyanogen - () Paracyanogen - a cyanogen polymer, Paraisocyanogen - a cyanogen polymer, dicyanoacetylene - or , also called carbon subnitride or but-2-ynedinitrile tetracyanoethylene - or tetracyanomethane - or 2,2-diisocyanopropanedinitrile - or hexacyanoethane - or hexacyanocyclopropane - or hexacyanobutadiene - or Dicyanopolyynes are composed of a chain of carbon atoms with alternating single and triple bonds, terminated by nitrogen atoms. Although not a polyyne dicyanoacetylene () otherwise fits within this series. or , dicyanobutadiyne (dicyanodiacetylene) or , dicyanohexatriyne or or or or or or or tetraazidomethane - or pentacyanopyridine - tetracyanopyrazine - tricyanotriazine - tetracyano-bitriazine - dicyanotetrazine - hexacyanotrisimidazole - hexacyanohexaazatriphenylene - hexacyanobenzene - octacyanonaphthalene - decacyanoanthracene - cyanonitrene - or (one of the nitrogens is univalent) azodicarbonitrile - or , cis and trans isomers cyanogen azide - or 1-diazidocarbamoyl-5-azidotetrazole - 2,2′-azobis(5-azidotetrazole) - triazidotriazine (cyanuric triazide) - () triazidoheptazine - () tricyanomethanimine (dicyanomethylene-cyanamide) - or diazidodicyanoethylene - or and , cis and trans dicyanodiazomethane - or dicyanocarbene - or (and isomers cyanoisocyanocarbene , diisocyanoca