Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
Observed Interstellar Molecular Microwave Transitions, Table 1
Table 1. Listing by empirical formula of the isotopic forms of the 135 interstellar species detected by their microwave spectrum and appearing in Table 4
| Empirical Formula |
Name | Isotopic Species |
CA Number | Reference |
|---|---|---|---|---|
| AlCN | Aluminum isocyanide | AlCN a | [61192-70-9] | Ziu02 |
| AlCl | Aluminum monochloride | Al35Cl a | [13595-81-8] | Cer87c |
| Al37Cl a | ||||
| AlF | Aluminum monofluoride | AlF a | [13595-82-9] | Cer87c |
| CF+ | Flouromethyliumylidene | CF+ | [33412-11-2] | Neu06 |
| CH | Methylidyne | CH | [3315-37-5] | Ryd74, McK40 b |
| CHN | Hydrocyanic acid (hydrogen cyanide) | HCN | [74-90-8] | Sny71a |
| H13CN | ||||
| HC15N | ||||
| DCN | ||||
| CHN | Hydroisocyanic acid (hydrogen isocyanide) | HNC | [6914-07-4] | Sny71 |
| H15NC | ||||
| HN13C | ||||
| DNC | ||||
| D15NC | ||||
| CHNO | Isocyanic acid | HNCO | [75-13-8] | Sny71 |
| DNCO | ||||
| CHNS | Isothiocyanic acid | HNCS | [3129-90-6] | Fre79 |
| CHO | Oxomethyl (formyl) | HCO | [2597-44-6] | Sny76 |
| CHO+ | Oxomethylium (formylium) | HCO+ | [17030-74-9] | Buh70 |
| H13CO+ | ||||
| HC17O+ | ||||
| HC18O+ | ||||
| DCO+ | ||||
| D13CO+ | ||||
| CHO+ | Hydroxymethylidyne | HOC+ | [60528-75-8] | Woo83, Ziu95a |
| CHO2+ | Hydroxyoxomethylium | HOCO+ | [638-71-1] | Tha81 |
| CHP | Phosphaethyne | HCP | [6829-52-3] | Agú07 |
| CHS+ | Thiooxomethylium | HCS+ | [59348-25-3] | Tha81 |
| CH2 | Methylene | CH2 | [2465-56-7] | Hol89, Hol95 |
| CH2N+ | Iminomethylium | HCNH+ | [38263-97-7] | Ziu86a |
| CH2N | Methylene amidogen | CH2N | [15845-29-1] | Ohi94 |
| CH2N2 | Cyanamide | NH2CN | [420-04-2] | Tur75a |
| CH2O | Formaldehyde (methanal) | H2CO | [50-00-0] | Sny69 |
| H213CO | ||||
| H2C18O | ||||
| HDCO | ||||
| D2CO | ||||
| CH2O2 | Formic acid | HCOOH | [64-18-6] | Zuc71, Win75 |
| H13COOH | ||||
| HCOOD | ||||
| DCOOH | ||||
| CH2S | Methanethial (thioformaldehyde) | H2CS | [865-36-1] | Sin73 |
| H213CS | ||||
| H2C34S | ||||
| HDCS | ||||
| D2CS | ||||
| CH3 | Methyl | CH3a | [2229-07-4] | Feu00 |
| CH3N | Methanimine | CH2NH | [2053-29-4] | God73 |
| 13CH2NH | ||||
| CH3NO | Formamide | NH2CHO | [75-12-7] | Rub71 |
| NH213CHO | ||||
| CH3O+ | Hydroxy methylium ion | H2COH+ | [17691-31-5] | Ohi96 |
| (protonated formaldehyde) | ||||
| CH4O | Methanol (methyl alcohol) | CH3OH | [67-56-1] | Bal70 |
| 13CH3OH | ||||
| CH318OH | ||||
| CH2DOH | ||||
| CH3OD | ||||
| CHD2OH | ||||
| CH4S | Methanethiol (methyl mercaptan) | CH3SH | [74-93-1] | Lin79 |
| CH5N | Methanamine (methylamine) | CH3NH2 | [74-89-5] | Fou74a, Kai74 |
| CMgN | Magnesium cyanide | MgCN a | [74758-76-2] | Ziu95 |
| CMgN | Magnesium isocyanide | 24MgNC a | [96491-22-4] | Gue86, Gue93 |
| 25MgNC a | ||||
| 26MgNC a | ||||
| CN | Cyanogen | CN | [2074-87-5] | Jef70, McK40 b |
| 13CN | ||||
| C15N | ||||
| CNNa | Sodium cyanide | NaCN a | [143-33-9] | Tur94 |
| CNSi | Silicon cyanide | SiCN a | [29210-66-0] | Gué00 |
| CNSi | Silicon isocyanide | SiNC a | [116430-49-0] | Gué04 |
| CO | Carbon monoxide | CO | [630-08-0] | Wil70 |
| 13CO | ||||
| C17O | ||||
| C18O | ||||
| 13C18O | ||||
| 13C17O | ||||
| CO+ | Carbon monoxide ion | CO+ | [12144-04-6] | Eri81, Lat93 |
| COS | Carbon oxide sulfide (carbonyl sulfide) | OCS | [463-58-1] | Jef71 |
| OC34S | ||||
| O13CS | ||||
| 18OCS | ||||
| CO2 | Carbon dioxide | CO2 | [124-38-9] | Jus96 |
| CP | Carbon monophosphide | CP a | [12326-85-1] | Sai89, Gue90 |
| CS | Carbon monosulfide | CS | [2944-05-0] | Lis75 |
| C33S | ||||
| C34S | ||||
| C36S | ||||
| 13CS | ||||
| 13CS34S | ||||
| CSi | Silicon monocarbide | SiC a | [409-21-2] | Cer89 |
| C2H | Ethynyl | C2H | [2122-48-7] | Tuc78 |
| 13CCH | ||||
| C13CH | ||||
| C2D | ||||
| C2HN | Cyanomethylene | HCCN | [2612-62-6] | Gue91 |
| C2HNO | Cyanoformaldehyde | CNCHO | Rem08 | |
| C2H2N | Cyanomethyl | CH2CN | [2932-82-3] | Irv88a |
| C2H2O | Ethanone (ketene) | CH2CO | [463-51-4] | Tur77 |
| C2H3N | Acetonitrile (methyl cyanide) | CH3CN | [75-05-8] | Sol71 |
| 13CH3CN | ||||
| CH313CN | ||||
| CH3C15N | ||||
| CH2DCN | ||||
| C2H3N | Isocyanomethane (methyl isocyanide) | CH3NC | [593-75-9] | Cer88 |
| C2H3N | Keteneimine (ethenimine) | CH2CNH | [17619-22-6] | Lov06a |
| C2H4O | Acetaldehyde (ethanal) | CH3CHO | [75-07-0] | Got73 |
| C2H4O | Oxirane (ethylene oxide) | c-C2H4O c | [75-21-8] | Dic97 |
| C2H4O | Ethenol (vinyl alcohol) | a-CH2CHOH | [557-75-5] | Tur01 |
| s-CH2CHOH | ||||
| C2H4O2 | Methyl ester formic acid (methyl formate) | CH3OCHO | [107-31-3] | Bro75 |
| C2H4O2 | Acetic acid | CH3COOH | [64-19-7] | Meh97 |
| C2H4O2 | Hydroxy acetaldehyde (glycolaldehyde) | CH2OHCHO | [141-46-8] | Hol00 |
| C2H5NO | Acetamide | CH3CONH2 | [60-35-5] | Hol06a |
| C2H6O | trans-Ethanol (ethyl alcohol) | t-CH3CH2OH | [64-17-5] | Zuc75 |
| gauche-Ethanol | g-CH3CH2OH | Pea96 | ||
| C2H6O | Dimethyl ether (oxybismethane) | CH3OCH3 | [115-10-6] | Sny74 |
| C2H6O2 | Ethylene glycol | HOCH2CH2OH | [107-21-1] | Hol02 |
| C2O | Oxoethenylidene | CCO | [119754-08-4] | Ohi91 |
| C2P | Phosphaethenylidene | CCP | [154474-31-4] | Hal08 |
| C2S | Thioxoethenylidene | CCS | [109545-32-6] | Yam90 |
| CC34S | ||||
| C2Si | Silicon carbide (silacyclopropyne) | SiC2 | [12071-27-1] | Tha84 |
| 29SiC2 | ||||
| 30SiC2 | ||||
| Si13CC | ||||
| C3 | Tricarbon | C3 | [175780-10-6] | Gie01 |
| C3H | Cyclopropenylidyne | c-C3H b | [16165-40-5] | Yam87a |
| c-CC13CH | ||||
| C3H | Propenylidyne | l-C3H d | [53590-28-6] | Tha85 |
| C3HN | 2-Propynenitrile (cyanoacetylene) | HCCCN | [1070-71-9] | Tur71 |
| H13CCCN | ||||
| HC13CCN | ||||
| HCC13CN | ||||
| HCCC15N | ||||
| DCCCN | ||||
| C3HN | Ethyne, isocyanide | HCCNC | [66723-45-3] | Kaw92 |
| C3HN | 3-Imino-1,2-propadienylidene | HNCCC | [76092-41-6] | Kaw92a |
| C3H2 | Cyclopropenylidene | c-C3H2c | [16165-40-5] | Mat85a |
| c-H13CCCH | ||||
| c-HC13CCH | ||||
| c-C3HD | ||||
| C3H2 | 1,2-Propadienylidene | H2CCC c | [60731-10-4] | Cer91 |
| C3H2N+ | Protonated 2-propynenitrile | CCCNH+ | [76092-42-7] | Kaw94 |
| C3H2O | 2-Propynal | HCCCHO | [624-67-9] | Irv88 |
| C3H2O | Cyclopropenone | c-C2H2O | [2966080-0] | Hol06 |
| C3H3N | 2-Propenenitrile (vinyl cyanide) | CH2CHCN | [107-13-1] | Gar75 |
| 13CH2CHCN | ||||
| CH213CHCN | ||||
| C3H4 | 1-Propyne (methyl acetylene) | CH3CCH | [74-99-7] | Sny71 |
| CH3C13CH | ||||
| 13CH3CCH | ||||
| CH2DCCH | ||||
| CH3CCD | ||||
| C3H4O | 2-Propenal (acrolein) | CH2CHCHO | [107-02-8] | Hol04 |
| C3H5N | Propanenitrile (ethyl cyanide) | CH3CH2CN | [107-12-0] | Joh77 |
| CH3CH213CN | ||||
| CH313CH2CN | ||||
| 13CH3CH2CN | ||||
| C3H6 | 1-Propene (propylene) | CH2CHCH3 | [115-07-1] | Mar07 |
| C3H6O | 2-Propanone (acetone) | (CH3)2CO | [67-64-1] | Com87, Sny02 |
| C3H6O | 2-Propanal | CH3CH2CHO | [123-38-6] | Hol04 |
| C3N | Cyanoethynyl | CCCN | [62435-43-2] | Gue77 |
| C3N- | Cyanoethynyl anion | CCCN- | [12373-53-4] | Tha08 |
| C3O | 3-Oxo-1,2-propadienylidene | CCCO | [11127-17-6] | Mat84 |
| C3S | 3-Thioxo-1,2-propadienylidene | CCCS | [109545-35-9] | Yam87 |
| C3Si | 3-Silanetetrayl-1,2-propadienylidene (rhomboidal SiC3) | SiC3 | [184291-25-1] | App99 |
| C4H | 1,3-Butadiynyl radical | C4H | [53561-65-2] | Gue77 |
| 13CCCCH | ||||
| C13CCCH | ||||
| CC13CCH | ||||
| CCC13CH | ||||
| C4D | ||||
| C4H- | 1,3-Butadiynyl anion | C4H- | [59012-21-4] | Cer07 |
| C4HN | 3-Cyano-1,2-propadienylidene | HCCCCN | [847643-26-9] | Bro84 |
| C4H2 | Butatrienylidene | H2CCCC | [70571-89-0] | Bro84 |
| C4H3N | 2-Butynenitrile | CH3CCCN | [13752-78-8] | Bro84 |
| C4H3N | Cyanoallene (2,3-butadienenitrile) | CH2CCHCN | [1001-56-5] | Lov06 |
| C4Si | Silicon tetracarbide | SiC4a | [144920-67-2] | Ohi89 |
| SiCCC13C | ||||
| C5H | 2,4-Pentadiynylidyne | HCCCCC | [104602-63-3] | Cer86 |
| C5HN | 2,4-Pentadiynenitrile (cyanobutadiyne) | HCCCCCN | [59866-32-9] | Ave76 |
| H13CCCCCN | ||||
| HC13CCCCN | ||||
| HCC13CCCN | ||||
| HCCC13CCN | ||||
| HCCCC13CN | ||||
| DCCCCCN | ||||
| C5H4 | 1,3-Pentadiyne (methyl diacetylene) | CH3C4H | [4911-55-1] | Wal84 |
| C5N | 4-cyano-1,3-Butadiynylium | C5N | [129066-48-4] | Gue98 |
| C6H | 1,3,5-hexatriynyl | HCCCCCC | [88053-50-3] | Suz86 |
| C6H- | 1,3,5-hexatriynyl anion | H-CCCCCC | [169141-81-1] | McC06 |
| C6H2 | 1,3,5-Hexatriyne | HCCCCCCH a | [3161-99-7] | Cer01a |
| C6H2 | 1,2,3,4,5-hexapentaenylidene | H2CCCCCC | [129066-05-3] | Lan97 |
| C6H3N | 2,4-Hexadiynenitrile | CH3C4CN | [66486-69-9] | Sny06 |
| C7H | 2,4,6-Heptatriynylidyne | HCCCCCCC a | [129066-03-1] | Gue97 |
| C7HN | 2,4,6-heptatriynenitrile | HC7N | [65937-22-6] | Kro78 |
| C7H4 | Methyltriacetylene | CH3C6H | [66486-68-8] | Rem06 |
| C8H | 1,3,5,7-Octatetraynyl | HC8a | [88053-51-4] | Cer96 |
| C8H- | 1,3,5,7-Octatetraynyl anion | HC8- | [149673-52-9] | Brü07 |
| C9HN | 2,4,6,8-nonatetraynenitrile | HC9N | [67483-72-1] | Bro78 |
| C11HN | 2,4,6,8,10-undecapentaynenitrile | HC11N | [78950-25-1] | Bel97 |
| ClH | Hydrochloric acid | H35Cl | [7647-01-0] | Sch95 |
| H37Cl | ||||
| ClK | Potassium chloride | K35Cl a | [7447-40-7] | Cer87c |
| K37Cl | ||||
| ClNa | Sodium chloride | Na35Cl a | [7647-14-5] | Cer87c |
| Na37Cl a | ||||
| FH | Hydrogen fluoride | HF | [7664-39-3] | Neu97 |
| FeO | Iron monoxide | FeO | [1345-25-1] | Wal02 |
| HLi | Lithium Hydride | 7LiH | [7580-67-8] | Com98 |
| HNO | Nitrosyl hydride | HNO | [14332-28-6] | Uil77, Sny93 |
| HN2+ | Hydrodinitrogen(1+) (diazenylium) | N2H+ | [12357-66-3] | Tur74, Gre74 |
| 15NNH+ | ||||
| N15NH+ | ||||
| N2D+ | ||||
| HO | Hydroxyl | OH | [3352-57-6] | Wei63 |
| 17OH | ||||
| 18OH | ||||
| HS | Mercapto (thiohydroxyl) | SH | [13940-21-1] | Yam00 |
| H2N | Amidogen | NH2 | [13770-40-6] | vDi93 |
| H2O | Water | H2O | [7732-18-5] | Che69 |
| H218O | ||||
| HDO | ||||
| D2O | ||||
| H2S | Hydrogen sulfide | H2S | [7783-06-4] | Tha72 |
| H234S | ||||
| HDS | ||||
| H3+ | Hydrogen ion | H2D+ | [28132-48-1] | Sta99 |
| HD2+ | ||||
| H3N | Ammonia | NH3 | [7664-41-7] | Che68 |
| 15NH3 | ||||
| NH2D | ||||
| NHD2 | ||||
| ND3 | ||||
| H3O+ | Oxonium hydride | H3O+ | [28637-38-9] | Hol86 |
| H4Si | Silane | SiH4a | [7803-62-5] | Kea93 |
| NO | Nitrogen oxide (nitric oxide) | NO | [10102-43-9] | Lis78a |
| NP | Phosphorous nitride | PN | [17739-47-8] | Tur87b |
| NS | Nitrogen sulfide (nitric sulfide) | NS | [12033-56-6] | Got75 |
| N34S | ||||
| NSi | Silicon mononitride | SiN a | [12033-60-2] | Tur92 |
| N2O | Nitrogen oxide (nitrous oxide) | N2O | [10024-97-2] | Ziu94 |
| OP | Phosphorous oxide | PO | [14452-66-5] | Ten07 |
| OS | Sulfur monoxide | SO | [13827-32-2] | Got73b |
| 33SO | ||||
| 34SO | ||||
| S18O | ||||
| OS+ | Sulfur(1+), oxo | SO+ | [54724-05-9] | Tur92a |
| OSi | Silicon monoxide | SiO | [113443-18-8] | Wil71 |
| 29SiO | ||||
| 30SiO | ||||
| O2 | Oxygen | O2 | [7782-44-7] | Lar07 |
| O2S | Sulfur dioxide | SO2 | [7446-09-5] | Sny75a |
| 33SO2 | ||||
| 34SO2 | ||||
| OS18O | ||||
| OS17O | ||||
| SSi | Silicon monosulfide | SiS | [25423-24-9] | Mor75 |
| Si33S | ||||
| Si34S | ||||
| 29SiS | ||||
| 30SiS |
a Reported only in circumstellar clouds.
b Identification of the optical lines in McK40 were confirmed by W.S. Adams [Ada41].
c The c refers to cyclic form.
d The l refers to linear form.
Contacts
-
PML webmaster
Created June 13, 2018, Updated August 13, 2025