This is a partial list of molecules that contain 2 carbon atoms.
| Chemical formula | Synonyms | CAS number |
|---|---|---|
| C2Al | monoaluminum dicarbide | 37297-57-7 |
| C2Al2 | dialuminum dicarbide | 12122-01-9 |
| C2B | boron dicarbide | 12539-98-9 |
| C2Be | beryllium dicarbide | 12070-28-9 |
| C2BrCl | bromochloroacetylene | 25604-70-0 |
| C2BrClF2O | bromodifluoroacetylchloride | 3832-48-2 |
| C2BrCl5 | bromopentachloroethane | 79504-02-2 |
| C2BrF5 | bromopentafluoroethane | 354-55-2 |
| C2Br2FN | dibromo fluoroacetonitrile | 6698-74-4 |
| C2Br2N2O2 | dibromofuroxan | 70134-71-3 |
| C2Br2O2 | oxalyl bromide | 15219-34-8 |
| C2Br6 | hexabromoethane | 594-73-0 |
| C2Ca | calcium carbide | 75-20-7 |
| C2Ce | cerium dicarbide | 12012-32-7 |
| C2CeRh | cerium rhodium dicarbide | 53262-56-9 |
| C2Cl2F2 | dichlorodifluoroethylene | 27156-03-2 |
| C2Cl2O2 | oxalyl chloride | 79-37-8 |
| C2Cl3N | trichloroacetonitrile | 108-77-0 |
| C2Cl4 | tetrachloroethylene | 127-18-4 |
| C2Cl4O | trichloroacetyl chloride | 76-02-8 |
| C2Cl4O2 | trichloromethyl chloroformate | 503-38-8 |
| C2Cl5F | pentachlorofluoroethane | 354-56-3 |
| C2CoNO3 | cobalt dicarbonyl nitrosyl | 61332-94-3 |
| C2Dy | dysprosium dicarbide | 12175-80-3 |
| C2Er | erbium dicarbide | 12192-37-9 |
| C2Eu | europium dicarbide | 12127-44-5 |
| C2FN5O10 | fluoropentanitroethane | 23072-51-7 |
| C2F2O2 | oxalyl fluoride | 359-40-0 |
| C2F3 | trifluorovinyl radical | 4605-17-8 |
| C2F3I | iodotrifluoroethylene | 359-37-5 |
| C2F3N | trifluoromethylisocyanide | 105879-13-8 |
| C2F5 | pentafluoro ethyl radical | 3369-48-0 |
| C2F5I | pentafluoroethyliodide | 354-64-3 |
| C2F6O5S2 | trifluoromethanesulfonic anhydride | 358-23-6 |
| C2F7N | perfluoroethanamine | 354-80-3 |
| C2H | ethynyl radical | 2122-48-7 |
| C2HBrClF3 | halothane | 151-67-7 |
| C2HBrO | bromoketene | 78957-22-9 |
| C2HBr2FO2 | dibromofluoroacetic acid | 353-99-1 |
| C2HBr3 | tribromoethene | 598-16-3 |
| C2HBr3O2 | tribromoacetic acid | 75-96-7 |
| C2HClO | chloroketene | 29804-89-5 |
| C2HCl3 | trichloroethylene | 79-01-6 |
| C2HCl3O | chloral | 75-87-6 |
| C2HF3OS | trifluorothiolacetic acid | 2925-25-9 |
| C2HF5O | pentafluorodimethyl ether | 3822-68-2 |
| C2HNO | formyl cyanide | 4471-47-0 |
| C2HO | ethynyloxy radical | 51095-15-9 |
| C2H2 | acetylene | 74-86-2 |
| C2H2AsCl3 | lewisite | 541-25-3 |
| C2H2BrClO | bromoacetyl chloride | 22118-09-8 |
| C2H2Br2O | bromoacetyl bromide | 598-21-0 |
| C2H2Br2O2 | dibromoethanoic acid | 631-64-1 |
| C2H2Cl2 | dichloromethane | |
| C2H2ClF2NO | chlorodifluoroacetamide | 354-28-9 |
| C2H2ClNS | chloromethyl thiocyanate | 3268-79-9 |
| C2H2Cl2O | dichloroacetaldehyde | 79-02-7 |
| C2H2FN | fluoroacetonitrile | 503-20-8 |
| C2H2F2O2 | difluoroacetic acid | 381-73-7 |
| C2H2IN | iodoacetonitrile | 624-75-9 |
| C2H2N | cyanomethyl radical | 2932-82-3 |
| C2H2O | ethynol | 32038-79-2 |
| C2H2O | ketene | 463-51-4 |
| C2H2O | oxirene | 157-18-6 |
| C2H2OS | ethynesulfenic acid | 121564-25-8 |
| C2H2O2 | glyoxal | 107-22-2 |
| C2H2O3 | formic acid anhydride | 1558-67-4 |
| C2H2O4 | oxalic acid | 144-62-7 |
| C2H2O8Pb3 | basic lead carbonate | 1319-46-6 |
| C2H2S | thioketene | 18282-77-4 |
| C2H2Se | selenoketene | 61134-37-0 |
| C2H3 | vinyl radical | 2669-89-8 |
| C2H3BF2 | vinyldifluoroborane | 358-95-2 |
| C2H3BrO | acetyl bromide | 506-96-7 |
| C2H3Br3O2 | bromal hydrate | 507-42-6 |
| C2H3Cl | methylchlorocarbene | 31304-51-5 |
| C2H3ClO | acetyl chloride | 75-36-5 |
| C2H3ClO2S | methoxycarbonylsulfenyl chloride | 26555-40-8 |
| C2H3Cl3O2 | chloral hydrate | 302-17-0 |
| C2H3FO | acetyl fluoride | 557-99-3 |
| C2H3F2NO | difluoroacetamide | 359-38-6 |
| C2H3F3O2Si | silyl trifluoroacetate | 6876-44-4 |
| C2H3F3S2 | methyl trifluoromethyl disulfide | 14410-21-0 |
| C2H3IO | acetyl iodide | 507-02-8 |
| C2H3KO2 | potassium acetate | 127-08-2 |
| C2H3N | acetonitrile | 75-05-8 |
| C2H3NO | methylcyanate | 1768-34-9 |
| C2H3NO | nitrosoethylene | 54680-52-3 |
| C2H3NO2 | nitroethene | 500016-67-1 |
| C2H3NO2 | nitroethylene | 3638-64-0 |
| C2H3NO3 | oxamic acid | 471-47-6 |
| C2H3NO4 | acetyl nitrate | 591-09-3 |
| C2H3NSe | methyl isoselenocyanate | 4426-70-4 |
| C2H3NSe | methyl selenocyanate | 2179-80-8 |
| C2H3NaO2 | sodium ethanoate | 127-09-3 |
| C2H3O | acetyl radical | 3170-69-2 |
| C2H3O | oxiranyl radical | 31586-84-2 |
| C2H3O | vinyloxy radical | 6912-06-7 |
| C2H3O2Tl | thallium acetate | 563-68-8 |
| C2H4 | ethylene | 74-85-1 |
| C2H4ClO2P | ethylene chlorophosphite | 822-39-9 |
| C2H4Cl2 | dichloroethane | 1300-21-6 |
| C2H4F2O | difluoroethanol | 359-13-7 |
| C2H4N2O2 | oxalamide | 471-46-5 |
| C2H4N2O4 | dihydroxyglyoxime | 1687-60-1 |
| C2H4N2S2 | ethanedithioamide | 79-40-3 |
| C2H4N4 | dicyanodiamide | 461-58-5 |
| C2H4N4O2 | diazenedicarboxamide | 123-77-3 |
| C2H4O | acetaldehyde | 75-07-0 |
| C2H4O | ethenol | 557-75-5 |
| C2H4O | ethylene oxide | 75-21-8 |
| C2H4OS | ethanethioic acid | 507-09-5 |
| C2H4OS | ethenesulfenic acid | 2492-74-2 |
| C2H4O2 | acetic acid | 64-19-7 |
| C2H4O2 | 1,2-dioxetane | 6788-84-7 |
| C2H4O2 | formaldehyde dimer | 61233-19-0 |
| C2H4O2 | methyl formate | 107-31-3 |
| C2H4O2 | glycolaldehyde | 141-46-8 |
| C2H4O3 | ethaneperoxoic acid | 79-21-0 |
| C2H4O3 | monomethyl carbonate | 7456-87-3 |
| C2H4O4 | formic acid dimer | 14523-98-9 |
| C2H4S | thiirane | 420-12-2 |
| C2H4S | thioacetaldehyde | 6851-93-0 |
| C2H4Se | selenoacetaldehyde | 67281-48-5 |
| C2H4Se3 | triselenothane | 121400-83-7 |
| C2H5 | ethyl radical | 2025-56-1 |
| C2H5BCl2 | ethyldichloroborane | 1739-53-3 |
| C2H5BF2 | ethylidifluoroborane | 430-41-1 |
| C2H5BrHg | ethylmercuric bromide | 107-26-6 |
| C2H6Hg | dimethylmercury | 593-74-8 |
| C2H5BrO | bromomethyl methyl ether | 13057-17-5 |
| C2H5Cl | ethyl chloride | 75-00-3 |
| C2H5ClN2O | chloroacetyl hydrazine | 30956-28-6 |
| C2H5ClO | ethyl hypochlorite | 624-85-1 |
| C2H5ClO2S | ethanesulfonyl chloride | 594-44-5 |
| C2H5ClS | chloromethylmethyl sulfide | 2373-51-5 |
| C2H5Cl2O2P | ethyl dichlorophosphate | 1498-51-7 |
| C2H5Cl2P | ethyldichlorophosphine | 1498-40-4 |
| C2H5Cl2PSe | ethylphosphonoselenoic dichloride | 14705-46-5 |
| C2H5Cl3Si | ethyltrichlorosilane | 115-21-9 |
| C2H5FO | methoxymethyl fluoride | 460-22-0 |
| C2H5FO2S | ethane sulfonyl fluoride | 754-03-0 |
| C2H5HgI | ethylmercuric iodide | 2440-42-8 |
| C2H5I | iodoethane | 75-03-6 |
| C2H5IO | iodomethyl methyl ether | 13057-19-7 |
| C2H5IS | iodomethyl methyl sulfide | 43034-68-0 |
| C2H5Li | ethyl lithium | 811-49-4 |
| C2H5N | acetaldimine | 20729-41-3 |
| C2H5N | ethenamine | 593-67-9 |
| C2H5N | ethylenimine | 151-56-4 |
| C2H5NO | acetaldoxime | 107-29-9 |
| C2H5NO | acetamide | 60-35-5 |
| C2H5NO | nitrosoethane | 925-91-7 |
| C2H5NOS | aminothioacetic acid | 758-10-1 |
| C2H5NO2 | glycine | 56-40-6 |
| C2H5NO2 | glycolamide | 598-42-5 |
| C2H5NO2S | vinylsulfonamide | 2386-58-5 |
| C2H5NO4 | ammonium acid oxalate | 5972-72-5 |
| C2H5NS | ethanethioamide | 62-55-5 |
| C2H5N3O2 | imidodicarbonic diamide | 108-19-0 |
| C2H5O | ethoxy radical | 2154-50-9 |
| C2H5P | phosphirane | 6569-82-0 |
| C2H5P | vinyl phosphine | 58436-39-8 |
| C2H5PS2 | phosphenodithioic ethane | 41391-49-5 |
| C2H5S | methylthiomethyl radical | 31533-72-9 |
| C2H6 | ethane | 74-84-0 |
| C2H6AlCl | dimethylaluminum chloride | 1184-58-3 |
| C2H6AsBr | dimethylarsine bromide | 676-71-1 |
| C2H6AsCl | chlorodimethylarsine | 557-89-1 |
| C2H6BBr | dimethylboron bromide | 5158-50-9 |
| C2H6BCl | chlorodimethylborane | 1803-36-7 |
| C2H6BClFN | dimethylaminofluorochloroborane | 38481-07-1 |
| C2H6BClO2 | chlorodimethoxyborane | 868-81-5 |
| C2H6BFO2 | fluorodimethoxyborane | 367-46-4 |
| C2H6Be | dimethylberyllium | 506-63-8 |
| C2H6ClOP | dimethylphosphinic chloride | 1111-92-8 |
| C2H6ClO2P | dimethylchlorophosphite | 3743-07-5 |
| C2H6ClPS | dimethylphosphinothioic chloride | 993-12-4 |
| C2H6Cl2Ge | dimethylgermanium dichloride | 1529-48-2 |
| C2H6Cl2Si | ethyldichlorosilane | 1789-58-8 |
| C2H6FO2P | methyl methylphosphonofluoridate | 353-88-8 |
| C2H6FP | dimethyl fluorophosphine | 507-15-3 |
| C2H6F3NS | dimethylaminosulfur trifluoride | 3880-03-3 |
| C2H6GeO | dimethylgermanone | 5061-27-8 |
| C2H6GeS | dimethylgermathione | 16090-49-6 |
| C2H6N | dimethyl amidogen | 15337-44-7 |
| C2H6N2O2 | ethylnitramine | 19091-98-6 |
| C2H6N2O4 | hydrazinium hydrogen oxalate | 20321-02-2 |
| C2H6O | dimethyl ether | 115-10-6 |
| C2H6O | ethanol | 64-17-5 |
| C2H6OS | dimethyl sulfoxide | 67-68-5 |
| C2H6OS2 | methyl methanethiosulfinate | 13882-12-7 |
| C2H6O2 | ethyl hydroperoxide | 3031-74-1 |
| C2H6O2 | ethylene glycol | 107-21-1 |
| C2H6O2S | dimethyl sulfone | 67-71-0 |
| C2H6O2S2 | methyl methanethiosulfonate | 2949-92-0 |
| C2H6O4 | dioxybismethanol | 17088-73-2 |
| C2H6O5S2 | methanesulfonic anhydride | 7143-01-3 |
| C2H6S | dimethyl sulfide | 75-18-3 |
| C2H6S | ethanethiol | 75-08-1 |
| C2H6S5 | dimethyl pentasulfide | 7330-31-6 |
| C2H6Se | dimethyl selenide | 593-79-3 |
| C2H6Se2 | dimethyl diselenide | 7101-31-7 |
| C2H6Si2 | disilyl acetylene | 1070-76-4 |
| C2H6Sn | dimethylstannylene radical | 23120-99-2 |
| C2H6Te | dimethyltelluride | 593-80-6 |
| C2H6Zn | dimethylzinc | 544-97-8 |
| C2H7As | dimethylarsine | 593-57-7 |
| C2H7AsO3 | ethylarsonic acid | 507-32-4 |
| C2H7BF3N | dimethylaminetrifluoroborane | 811-59-6 |
| C2H7BO2 | ethyldihydroxyborane | 4433-63-0 |
| C2H7ClO | dimethyl ether hydrogen chloride complex | 24521-77-5 |
| C2H7N | ethylamine | 75-04-7 |
| C2H7NO | acetaldehyde ammonia trimer | 75-39-8 |
| C2H7NO | ethanolamine | 141-43-5 |
| C2H7NO2S | ethanesulfonamide | 1520-70-3 |
| C2H7NO3S | taurine | 91105-79-2 |
| C2H7NO4S2 | dimethane sulfonamide | 5347-82-0 |
| C2H7NS | mercaptamine | 60-23-1 |
| C2H7O3P | ethylphosphonic acid | 15845-66-6 |
| C2H8BF4N | dimethylammonium tetrafluoroborate | 16970-97-1 |
| C2H8BrN | ethylammoniumbromide | 593-55-5 |
| C2H8N2 | ethylenediamine | 107-15-3 |
| C2H8N2O4 | ammonium oxalate | 1113-38-8 |
| C2H8O2Si | dimethoxysilane | 5314-52-3 |
| C2H9N2O3 | ethylammonium nitrate | 22113-86-6 |
| C2H10N2O8S2Fe | ferrous ethylenediammonium sulfate | 63589-59-3 |
| C2H12CdTe | dimethylcadmium·dimethyltellurium | 143481-66-7 |
| C2H12N6O4S | guanidine sulfate | 594-14-9 |
| C2HgN2S2 | mercuric thiocyanate | 592-85-8 |
| C2Ho | holmium dicarbide | 12071-14-6 |
| C2K2N2 | potassium cyanide dimer | 55186-08-8 |
| C2La | lanthanum dicarbide | 12071-15-7 |
| C2Li2 | lithium carbide | 1070-75-3 |
| C2Lu | lutetium dicarbide | 12175-89-2 |
| C2Mg | magnesium carbide | 12122-46-2 |
| C2N2 | bisisocyanide | 78800-21-2 |
| C2N2 | cyanogen | 460-19-5 |
| C2N2Na2 | sodium cyanide | 55186-09-9 |
| C2N2O | cyanogen isocyanate | 22430-66-6 |
| C2N2S | cyanogen isothiocyanate | 56023-03-1 |
| C2N2S | sulfur dicyanide | 627-52-1 |
| C2N2S2 | thiocyanogen | 505-14-6 |
| C2N2Se | selenium cyanide | 2180-01-0 |
| C2N4O6 | trinitroacetonitrile | 630-72-8 |
| C2N6O12 | hexanitroethane | 918-37-6 |
| C2Na2 | Sodium carbide | 2881-62-1 |
| C2Na2O4 | sodium oxalate | 62-76-0 |
| C2Nd | neodymium dicarbide | 12071-21-5 |
| C2O | dicarbon monoxide | 12071-23-7 |
| C2P | dicarbon phosphide | 12602-39-0 |
| C2Rh | rhodium dicarbide | 37306-47-1 |
| C2Sc | scandium dicarbide | 12175-91-6 |
| C2Si | silicon dicarbide | 12071-27-1 |
| C2Si2 | disiladicarbide | 12144-09-1 |
| C2Th | thorium dicarbide | 12071-31-7 |
| C2Ti | titanium dicarbide | 12071-32-8 |
| C2U | uranium dicarbide | 12071-33-9 |
| C2V | vanadium dicarbide | 12542-39-1 |
| C2Y | yttrium dicarbide | 12071-35-1 |
| C2Zr | zirconium dicarbide | 12340-54-4 |