List of interstellar and circumstellar molecules#Molecules
{{Short description|none}}
{{Featured list}}
{{Use British English|date=March 2021}}
File:Ssc2003-06g.jpg (image in inset), with vibrational bands of several molecules labelled in colour]]
This is a list of molecules that have been detected in the interstellar medium and circumstellar envelopes, grouped by the number of component atoms. The chemical formula is listed for each detected compound, along with any ionized form that has also been observed.
Background
File:Rotational spectrum example.png. is the rotational constant of the molecule, is the rotational quantum number, is the upper level and is the lower level.]]
The molecules listed below were detected through astronomical spectroscopy. Their spectral features arise because molecules either absorb or emit a photon of light when they transition between two molecular energy levels. The energy (and thus the wavelength) of the photon matches the energy difference between the levels involved. Molecular electronic transitions occur when one of the molecule's electrons moves between molecular orbitals, producing a spectral line in the ultraviolet, optical or near-infrared parts of the electromagnetic spectrum. Alternatively, a vibrational transition transfers quanta of energy to (or from) vibrations of molecular bonds, producing signatures in the mid- or far-infrared. Gas-phase molecules also have quantised rotational levels, leading to transitions at microwave or radio wavelengths.
Sometimes a transition can involve more than one of these types of energy level e.g. ro-vibrational spectroscopy changes both the rotational and vibrational energy level. Occasionally all three occur together, as in the Phillips band of C2 (diatomic carbon), in which an electronic transition produces a line in the near-infrared, which is then split into several vibronic bands by a simultaneous change in vibrational level, which in turn are split again into rotational branches.{{cite journal |title=Rotational fine-structure lines of interstellar C2 toward Zeta Persei |last1=Chaffee |first1=Frederick H. |last2=Lutz |first2=Barry L. |last3=Black |first3=John H. |last4=Vanden Bout |first4=Paul A. |last5=Snell |first5=Ronald L. |journal=The Astrophysical Journal |volume=236 |page=474 |year=1980 |bibcode=1980ApJ...236..474C |doi=10.1086/157764}}
The spectrum of a particular molecule is governed by the selection rules of quantum chemistry and by its molecular symmetry. Some molecules have simple spectra which are easy to identify, whilst others (even some small molecules) have extremely complex spectra with flux spread among many different lines, making them far harder to detect.{{cite journal |bibcode=2018ApJS..239...17M |doi=10.3847/1538-4365/aae5d2 |arxiv=1809.09132 |title=2018 Census of Interstellar, Circumstellar, Extragalactic, Protoplanetary Disk, and Exoplanetary Molecules |year=2018 |last1=McGuire |first1=Brett A. |journal=The Astrophysical Journal Supplement Series |volume=239 |issue=2 |page=17 |s2cid=119522774 |doi-access=free }} Interactions between the atomic nuclei and the electrons sometimes cause further hyperfine structure of the spectral lines. If the molecule exists in multiple isotopologues (versions containing different atomic isotopes), the spectrum is further complicated by isotope shifts.
Detection of a new interstellar or circumstellar molecule requires identifying a suitable astronomical object where it is likely to be present, then observing it with a telescope equipped with a spectrograph working at the required wavelength, spectral resolution and sensitivity. The first molecule detected in the interstellar medium was the methylidyne radical (CH•) in 1937, through its strong electronic transition at 4300 angstroms (in the optical). Advances in astronomical instrumentation have led to increasing numbers of new detections. From the 1950s onwards, radio astronomy began to dominate new detections, with sub-mm astronomy also becoming important from the 1990s.
The inventory of detected molecules is highly biased towards certain types which are easier to detect. For example, radio astronomy is most sensitive to small linear molecules with a high molecular dipole. The most common molecule in the Universe, H2 (molecular hydrogen), is completely invisible to radio telescopes because it has no dipole; its electronic transitions are too energetic for optical telescopes, so detection of H2 required ultraviolet observations with a sounding rocket. Vibrational lines are often not specific to an individual molecule, allowing only the general class to be identified. For example, the vibrational lines of polycyclic aromatic hydrocarbons (PAHs) were identified in 1984,{{cite journal |bibcode=1984A&A...137L...5L |title=Identification of the "unidentified" IR emission features of interstellar dust ? |last1=Leger |first1=A. |last2=Puget |first2=J. L. |author-link2=Jean-Loup Puget |journal=Astronomy and Astrophysics |year=1984 |volume=137 |page=L5}} showing the class of molecules is very common in space,{{cite journal |bibcode=2008ARA&A..46..289T |doi=10.1146/annurev.astro.46.060407.145211 |title=Interstellar Polycyclic Aromatic Hydrocarbon Molecules |year=2008 |last1=Tielens |first1=A.G.G.M. |journal=Annual Review of Astronomy and Astrophysics |volume=46 |pages=289–337 |url=https://zenodo.org/record/1234931}} but it took until 2021 to identify any specific PAHs through their rotational lines.
File:CW Leonis - HST - Heic2112a.jpg. The visible shells of circumstellar material were ejected by the central star over thousands of years.]]
One of the richest sources for detecting interstellar molecules is Sagittarius B2 (Sgr B2), a giant molecular cloud near the centre of the Milky Way. About half of the molecules listed below were first found in Sgr B2, and many of the others have been subsequently detected there. Many of the largest molecules were first detected in another molecular cloud, TMC-1. A rich source of circumstellar molecules is CW Leonis (also known as IRC +10216), a nearby carbon star, where about 50 molecules have been identified. There is no clear boundary between interstellar and circumstellar media, so both are included in the tables below.
The discipline of astrochemistry includes understanding how these molecules form and explaining their abundances. The extremely low density of the interstellar medium is not conducive to the formation of molecules, making conventional gas-phase reactions between neutral species (atoms or molecules) inefficient. Many regions also have very low temperatures (typically 10 kelvin inside a molecular cloud), further reducing the reaction rates, or high ultraviolet radiation fields, which destroy molecules through photochemistry. Explaining the observed abundances of interstellar molecules requires calculating the balance between formation and destruction rates using gas-phase ion chemistry (often driven by cosmic rays), surface chemistry on cosmic dust, radiative transfer including interstellar extinction, and sophisticated reaction networks. The use of molecular lines to determine the physical properties of astronomical objects is known as molecular astrophysics.
Molecules
The following tables list molecules that have been detected in the interstellar medium or circumstellar matter, grouped by the number of component atoms. Neutral molecules and their molecular ions are listed in separate columns; if there is no entry in the molecule column, only the ionized form has been detected. Designations (names of molecules) are those used in the scientific literature describing the detection; if none was given that field is left empty. Mass is listed in atomic mass units. Deuterated molecules, which contain at least one deuterium (2H) atom, have slightly different masses and are listed in a separate table. The total number of unique species, including distinct ionization states, is indicated in each section header.
Most of the molecules detected so far are organic. The only detected inorganic molecule with five or more atoms is SiH4. Molecules larger than that all have at least one carbon atom, with no N−N or O−O bonds.
=Diatomic (45)=
File:Carbon-monoxide-3D-vdW.png is frequently used to trace the distribution of mass in molecular clouds.]]
{{Sticky header}}
=Triatomic (45)=
{{redirect|FeCN|network congestion|FECN}}
File:Trihydrogen-cation-3D-vdW.png cation is one of the most abundant ions in the universe. It was first detected in 1993.]]
{{Sticky header}}
class="wikitable sortable sticky-header"
!style="width: 6em;"|Molecule!!style="width: 16em;"|Designation!!style="width: 4em;"|Mass!!style="width: 8em;"|Ions | ||
align="center"|AlNC | Aluminium isocyanide
|align="center"|53 | align="center"|— |
align="center"|AlOH | Aluminium hydroxide
|align="center"|44 | align="center"|— |
align="center"|C3 | Tricarbon
|align="center"|36 | align="center"|— |
align="center"|C2H | Ethynyl radical
|align="center"|25 | align="center"|— |
align="center"|CCN | Cyanomethylidyne
|align="center"|38 | align="center"|— |
align="center"|C2O | Dicarbon monoxide
|align="center"|40 | align="center"|— |
align="center"|C2S | Thioxoethenylidene
|align="center"|56 | align="center"|— |
align="center"|C2P | —
|align="center"|55 | align="center"|— |
align="center"|CO2 | Carbon dioxide
|align="center"|44 | align="center"|— |
align="center"|CaNC | Calcium isocyanide{{cite journal |doi=10.1051/0004-6361/201936040 |pmid=31327871 |pmc=6640036 |bibcode=2019A&A...627L...4C |arxiv=1906.09352 |title=Discovery of the first Ca-bearing molecule in space: CaNC |journal=Astronomy & Astrophysics |volume=627 |pages=L4 |year=2019 |last1=Cernicharo |first1=J. |last2=Velilla-Prieto |first2=L. |last3=Agúndez |first3=M. |last4=Pardo |first4=J. R. |last5=Fonfría |first5=J. P. |last6=Quintana-Lacaci |first6=G. |last7=Cabezas |first7=C. |last8=Bermúdez |first8=C. |last9=Guélin |first9=M.}}
|align="center"|92 | align="center"|— |
align="center"|FeCN | Iron(I) cyanide
|align="center"|82 | align="center"|— |
align="center"|— | Protonated molecular hydrogen
|align="center"|3 | align="center"|{{chem|H|3|+}} |
align="center"|H2C | Methylene radical
|align="center"|14 | align="center"|— |
align="center"|— | Chloronium
|align="center"|37.5 | align="center"|H2Cl+ |
align="center"|H2O | Water
|align="center"|18 | align="center"|H2O+ |
align="center"|HO2 | Hydroperoxyl
|align="center"|33 | align="center"|— |
align="center"|H2S | Hydrogen sulfide
|align="center"|34 | align="center"|— |
align="center"|HCN | Hydrogen cyanide
|align="center"|27 | align="center"|— |
align="center"|HNC | Hydrogen isocyanide
|align="center"|27 | align="center"|— |
align="center"|HCO | Formyl radical
|align="center"|29 | align="center"|HCO+ |
align="center"|HCP | Phosphaethyne
|align="center"|44 | align="center"|— |
align="center"|HCS | Thioformyl
|align="center"|45 | align="center"|HCS+ |
align="center"|— | Diazenylium
|align="center"|29 | align="center"|{{chem|HN|2|+}} |
align="center"|HNO | Nitroxyl
|align="center"|31 | align="center"|— |
align="center"|— | Isoformyl
|align="center"|29 | align="center"|HOC+ |
align="center"|HSC | Isothioformyl
|align="center"|45 | align="center"|— |
align="center"|KCN | Potassium cyanide
|align="center"|65 | align="center"|— |
align="center"|MgCN | Magnesium cyanide
|align="center"|50 | align="center"|— |
align="center"|MgNC | Magnesium isocyanide
|align="center"|50 | align="center"|— |
align="center"|NH2 | Amino radical
|align="center"|16 | align="center"|— |
align="center"|N2O | Nitrous oxide
|align="center"|44 | align="center"|— |
align="center"|NaCN | Sodium cyanide
|align="center"|49 | align="center"|— |
align="center"|NaOH | Sodium hydroxide
|align="center"|40 | align="center"|— |
align="center"|OCS | Carbonyl sulfide
|align="center"|60 | align="center"|— |
align="center"|O3 | Ozone
|align="center"|48 | align="center"|— |
align="center"|SO2 | Sulfur dioxide
|align="center"|64 | align="center"|— |
align="center"|c-SiC2 | c-Silicon dicarbide
name="aass226" /> |align="center"|52 | align="center"|— |
align="center"|SiCSi | Disilicon carbide
|align="center"|68 | align="center"|— |
align="center"|SiCN | Silicon carbonitride
|align="center"|54 | align="center"|— |
align="center"|SiNC |
|align="center"|54 | align="center"|— |
align="center"|CaC2 | Calcium dicarbide
|align="center"|64 | align="center"|— |
align="center"|TiO2 | Titanium dioxide
|align="center"|79.9 | align="center"|— |
=Four atoms (31)=
File:Formaldehyde-3D-vdW.png is an organic molecule that is widely distributed in the interstellar medium.]]
{{Sticky header}}
=Five atoms (21)=
File:Methane-3D-space-filling.svg, the primary component of natural gas, has also been detected on comets and in the atmosphere of several planets in the Solar System.]]
{{Sticky header}}
class="wikitable sortable sticky-header"
!style="width: 6em;"|Molecule!!style="width: 16em;"|Designation!!style="width: 4em;"|Mass!!style="width: 8em;"|Ions | ||
align="center"|— | Ammonium ion
|align="center"|18 | align="center"|{{chem|NH|4|+}}{{Cite web |url=https://cdms.astro.uni-koeln.de/classic/molecules:ism:ammonium |title=On Ammonium, NH4+, in the ISM |author=H. S. P. Müller |date=2013 |access-date=2022-05-25}}{{cite journal |last1=Cernicharo |first1=J. |last2=Tercero |first2=B. |last3=Fuente |first3=A. |last4=Domenech |first4=J. L. |last5=Cueto |first5=M. |last6=Carrasco |first6=E. |last7=Herrero |first7=V. J. |last8=Tanarro |first8=I. |last9=Marcelino |first9=N. |last10=Roueff |first10=E. |last11=Gerin |first11=M. |last12=Pearson |first12=J. |title=Detection of the Ammonium Ion in Space |journal=The Astrophysical Journal |date=18 June 2013 |volume=771 |issue=1 |pages=L10 |doi=10.1088/2041-8205/771/1/L10 |arxiv=1306.3364 |bibcode=2013ApJ...771L..10C |s2cid=118461954}} |
align="center"|CH4 | Methane
|align="center"|16 | align="center"|— |
align="center"|CH3O | Methoxy radical
|align="center"|31 | align="center"|— |
align="center"|c-C3H2 | Cyclopropenylidene
|align="center"|38 | align="center"|— |
align="center"|l-H2C3 | Propadienylidene
|align="center"|38 | align="center"|— |
align="center"|H2CCN | Cyanomethyl
|align="center"|40 | align="center"|— |
align="center"|H2C2O | Ketene
|align="center"|42 | align="center"|— |
align="center"|H2CNH | Methylenimine
|align="center"|29 | align="center"|— |
align="center"|HNCNH | Carbodiimide
|align="center"|42 | align="center"|— |
align="center"|— | Protonated formaldehyde
|align="center"|31 | align="center"|H2COH+ |
align="center"|C4H | Butadiynyl
|align="center"|49 | align="center"|C4H− |
align="center"|HC3N | Cyanoacetylene
|align="center"|51 | align="center"|— |
align="center"|HCC-NC | Isocyanoacetylene
|align="center"|51 | align="center"|— |
align="center"|HCOOH | Formic acid
|align="center"|46 | align="center"|— |
align="center"|NH2CN | Cyanamide
|align="center"|42 | align="center"|— |
align="center"|NH2OH | Hydroxylamine
|align="center"|37 | align="center"|— |
align="center"|— | Protonated cyanogen
|align="center"|53 | align="center"|NCCNH+ |
align="center"|HC(O)CN | Cyanoformaldehyde
|align="center"|55 | align="center"|— |
align="center"|C5 | Linear C5
|align="center"|60 | align="center"|— |
align="center"|HCS2H | dithioformic acid
|align="center"|78 | align="center"|— |
align="center"|SiC4 | Graphene#Silicon carbide|Silicon-carbide cluster
|align="center"|92 | align="center"|— |
align="center"|SiH4 | Silane
|align="center"|32 | align="center"|— |
=Six atoms (16)=
File:Formamide-3D-vdW.png (above) can combine with methylene to form acetamide.]]
{{Sticky header}}
=Seven atoms (16)=
File:Acetaldehyde-3D-vdW.png (above) and its isomers vinyl alcohol and ethylene oxide have all been detected in interstellar space.]]
{{Sticky header}}
=Eight atoms (14)=
File:Acetic-acid-3D-vdW.png, a compound found in vinegar, was confirmed in 1997.]]
{{Sticky header}}
class="wikitable sortable sticky-header"
!style="width: 6em;"|Molecule!!style="width: 16em;"|Designation!!style="width: 4em;"|Mass | |
align="center"|H3CC2CN | Methylcyanoacetylene
|align="center"|65 |
align="center"|HC3H2CN | Propargyl cyanide
|align="center"|65 |
align="center"|H2COHCHO | Glycolaldehyde
|align="center"|60 |
align="center"|(CHOH)2 | 1,2-ethenediol
|align="center"|60 |
align="center"|HCOOCH3 | Methyl formate
|align="center"|60 |
align="center"|CH3COOH | Acetic acid
|align="center"|60 |
align="center"|H2C6 | Hexapentaenylidene
|align="center"|74 |
align="center"|CH2CHCHO | Propenal
|align="center"|56 |
align="center"|CH2CCHCN | Cyanoallene
|align="center"|65 |
align="center"|CH3CHNH | Ethanimine
|align="center"|43 |
align="center"|C2H3NH2 | Vinylamine
|align="center"|43 |
align="center"|C7H | Heptatrienyl radical
|align="center"|85 |
align="center"|NH2CH2CN | Aminoacetonitrile
|align="center"|56 |
align="center"|(NH2)2CO | Urea
|align="center"|60 |
=Nine atoms (11)=
{{Sticky header}}
class="wikitable sortable sticky-header"
!style="width: 6em;"|Molecule!!style="width: 16em;"|Designation!!style="width: 4em;"|Mass!!style="width: 8em;"|Ions | ||
align="center"|CH3C4H | Methyldiacetylene
|align="center"|64 | align="center"|— |
align="center"|CH3OCH3 | Dimethyl ether
|align="center"|46 | align="center"|— |
align="center"|CH3CH2CN | Propionitrile
|align="center"|55 | align="center"|— |
align="center"|CH3CONH2 | Acetamide
|align="center"|59 | align="center"|— |
align="center"|CH3CH2OH | Ethanol
|align="center"|46 | align="center"|— |
align="center"|C8H | Octatetraynyl radical
|align="center"|97 | align="center"|C8H− |
align="center"|HC7N | Cyanohexatriyne or Cyanotriacetylene
|align="center"|99 | align="center"|— |
align="center"|CH3CHCH2 | Propylene (propene)
|align="center"|42 | align="center"|— |
align="center"|CH3CH2SH | Ethyl mercaptan
|align="center"|62 | align="center"|— |
align="center"|CH3SCH3 | Dimethyl sulfide
|align="center"|62 | align="center"|— |
align="center"|CH3NHCHO | N-methylformamide
|align="center"|59 | align="center"|— |
=Ten or more atoms (24)=
{{multiple image | direction = vertical | width = 220
|image1=Diacetylene-3D-vdW-B.png
|alt1=Diacetylene, HCCCCH
|image2=Methyldiacetylene-3D-vdW.png
|alt2=Methyldiacetylene, HCCCCCH3
|image3=Cyanooctatetrayne-3D-vdW.png
|alt3=Cyanotetraacetylene, HCCCCCCCCCN
|footer=A number of polyyne-derived chemicals are among the heaviest molecules found in the interstellar medium.
}}
{{Sticky header}}
class="wikitable sortable sticky-header"
!style="width: 2em;"|Atoms!!style="width: 6em;"|Molecule!!style="width: 16em;"|Designation!!style="width: 4em;"|Mass!!style="width: 8em;"|Ions | ||||
align="center"|10 | align="center"|(CH3)2CO | Acetone
|align="center"|58 | align="center"|— | |
align="center"|10 | align="center"|(CH2OH)2 | Ethylene glycol
|align="center"|62 | align="center"|— | |
align="center"|10 | align="center"|CH3CH2CHO | Propanal
|align="center"|58 | align="center"|— | |
align="center"|10 | align="center"|CH3OCH2OH | Methoxymethanol
|align="center"|62 | align="center"|— | |
align="center"|10 | align="center"|CH3C5N | Methylcyanodiacetylene
|align="center"|89 | align="center"|— | |
align="center"|10 | align="center"|CH3CHCH2O | Propylene oxide
|align="center"|58 | align="center"|— | |
align="center"|11 | align="center" |NH2CH2CH2OH | Ethanolamine{{Cite journal |last1=Rivilla |first1=Víctor M. |last2=Jiménez-Serra |first2=Izaskun |last3=Martín-Pintado |first3=Jesús |last4=Briones |first4=Carlos |last5=Rodríguez-Almeida |first5=Lucas F. |last6=Rico-Villas |first6=Fernando |last7=Tercero |first7=Belén |last8=Zeng |first8=Shaoshan |last9=Colzi |first9=Laura |last10=Vicente |first10=Pablo de |last11=Martín |first11=Sergio |date=2021-06-01 |title=Discovery in space of ethanolamine, the simplest phospholipid head group |journal=Proceedings of the National Academy of Sciences |language=en |volume=118 |issue=22 |arxiv=2105.11141 |doi=10.1073/pnas.2101314118 |pmc=8179234 |issn=0027-8424 |pmid=34031247|bibcode=2021PNAS..11801314R |doi-access=free }}
|align="center"|61 | align="center"|— | |
align="center"|11 | align="center"|HC8CN | Cyanotetraacetylene
|align="center"|123 | align="center"|— | |
align="center"|11 | align="center"|C2H5OCHO | Ethyl formate
|align="center"|74 | align="center"|— | |
align="center"|11 | align="center"|CH3COOCH3 | Methyl acetate
|align="center"|74 | align="center"|— | |
align="center"|11 | align="center"|CH3C6H | Methyltriacetylene
|align="center"|88 | align="center"|— | |
align="center"|12 | align="center"|C6H6 | Benzene
|align="center"|78 | align="center"|— | |
align="center"|12 | align="center"|C3H7CN | n-Propyl cyanide
|align="center"|69 | align="center"|— | |
align="center"|12 | align="center"| (CH3)2CHCN | iso-Propyl cyanide{{cite news |last=Eyre |first=Michael |url=https://www.bbc.com/news/science-environment-29368984 |title=Complex organic molecule found in interstellar space |work=BBC News |date=26 September 2014 |access-date=2014-09-26}}{{cite journal |title=Detection of a branched alkyl molecule in the interstellar medium: iso-propyl cyanide |journal=Science |date=26 September 2014 |last1=Belloche |first1=Arnaud |last2=Garrod |first2=Robin T. |last3= Müller |first3=Holger S. P. |last4=Menten |first4=Karl M. |volume=345 |issue=6204 |pages=1584–1587 |doi=10.1126/science.1256678 |pmid=25258074 |arxiv=1410.2607 |bibcode=2014Sci...345.1584B |s2cid=14573206}}
|align="center"|69 | align="center"|— | |
align="center"|13 | align="center"|CH3OCH2CH2OH | 2-methoxyethanol
|align="center"|76 | align="center"|— | |
align="center"|13 | align="center"|{{chem|C|6|H|5|CN}} | Benzonitrile
|align="center"|104 | align="center"|— | |
align="center"|13 | align="center"|HC10CN | Cyanopentaacetylene
|align="center"|147 | align="center"|— | |
align="center"|17 | align="center"|C9H8 | Indene
|align="center"|116 | align="center"|— | |
align="center"|19 | align="center"|C10H7CN | 1-cyanonaphthalene
|align="center"|153 | align="center"|— | |
align="center"|19 | align="center"|C10H7CN | 2-cyanonaphthalene
|align="center"|153 | align="center"|— | |
align="center"|21 | align="center"|C12H7CN | 1-cyanoacenaphtylene
|align="center"|177 | align="center"|— | |
align="center"|21 | align="center"|C12H7CN | 5-cyanoacenaphtylene
|align="center"|177 | align="center"|— | |
align="center"|27 | align="center"|C16H9CN | 1-cyanopyrene
|align="center"|227 | align="center"|— | |
align="center"|27 | align="center"|C16H9CN | 2-cyanopyrene
|align="center"|227 | align="center"|— | |
align="center"|27 | align="center"|C16H9CN | 4-cyanopyrene
|align="center"|227 | align="center"|— | |
align="center"|37 | align="center"|C24H11CN | cyanocoronene
|align="center"|325 | align="center"|— | |
align="center"|60 | align="center"|C60 | Buckminsterfullerene (C60 fullerene) | align="center"|720 | align="center"|{{chem|C|60|+}} |
align="center"|70 | align="center"|C70 | C70 fullerene | align="center"|840 | align="center"|— |
Deuterated molecules (22)
These molecules all contain one or more deuterium atoms, a heavier isotope of hydrogen.
{{Sticky header}}
class="wikitable sortable sticky-header"
!Atoms!!style="width: 6em;"|Molecule!!style="width: 16em;"|Designation | ||
align="center"|2 | HD | Hydrogen deuteride |
align="center"|3 | H2D+, {{chem|HD|2|+}} | Trihydrogen cation |
align="center"|3 | HDO, D2O | Heavy water |
align="center"|3 | DCN | Hydrogen cyanide |
align="center"|3 | DCO | Formyl radical |
align="center"|3 | DNC | Hydrogen isocyanide |
align="center"|3 | N2D+ | — |
align="center"|3 | NHD, ND2 | Amidogen |
align="center"|4 | NH2D, NHD2, ND3 | Ammonia |
align="center"|4 | HDCO, D2CO | Formaldehyde |
align="center"|4 | DNCO | Isocyanic acid{{cite journal |title=The ALMA-PILS survey: First detections of deuterated formamide and deuterated isocyanic acid in the interstellar medium |journal=Astronomy & Astrophysics |volume=590 |pages=L6 |date=9 May 2016 |last=Coutens |first=A. |arxiv=1605.02562 |display-authors=etal |bibcode=2016A&A...590L...6C |doi=10.1051/0004-6361/201628612 |s2cid=32878172}} |
align="center"|5 | NH3D+ | Ammonium ion |
align="center"|6 | {{chem|NH|2|CDO}}; NHDCHO | Formamide |
align="center"|7 | CH2DCCH, CH3CCD | Methylacetylene |
Unconfirmed (16)
Evidence for the existence of the following molecules has been reported in the scientific literature, but the detections either are described as tentative by the authors, or have been challenged by other researchers. They await independent confirmation.
{{Sticky header}}
class="wikitable sortable sticky-header"
!Atoms!!style="width: 6em;"|Molecule!!style="width: 16em;"|Designation | ||
align="center"|2 | align="center"|SiH | Silylidine |
align="center"|2 | align="center"|CaO | Calcium oxide |
align="center"|4 | align="center"|PH3 | Phosphine |
align="center"|4 | align="center"|MgCCH | Magnesium monoacetylide |
align="center"|4 | align="center"|NCCP | Cyanophosphaethyne |
align="center"|5 | align="center"|H2NCO+ | — |
align="center"|6 | align="center"|SiH3CN | Silyl cyanide |
align="center"|10 | align="center"|H2NCH2COOH | Glycine |
align="center"|10 | align="center"|C2H5NH2 | Ethylamine |
align="center"|12 | align="center"|CO(CH2OH)2 | Dihydroxyacetone |
align="center"|12 | align="center"|C2H5OCH3 | Ethyl methyl ether |
align="center"|18 | align="center"|{{chem|C|10|H|8|+}} | Naphthalene cation |
align="center"|24 | align="center"|C24 | Graphene |
align="center"|24 | align="center"|C14H10 | Anthracene{{cite news |last=Battersby |first=S. |url=https://www.newscientist.com/article/dn4552-space-molecules-point-to-organic-origins.html |title=Space molecules point to organic origins |publisher=New Scientist |date=2004 |access-date=11 December 2009}} |
align="center"|26 | align="center"|C16H10 | Pyrene |
align="center"|27 | align=center|C11H12N2O2 | Tryptophan |
See also
{{div col|colwidth=20em}}
- Astrochemistry
- Cosmic dust
- Diffuse interstellar band
- Lists of molecules
- Molecular astrophysics
- Molecular spectroscopy
- Molecules in stars
- Polycyclic aromatic hydrocarbon (PAH)
- Tholin
{{div col end}}
Notes
{{reflist|group=note}}
References
{{citation |last1=Berné |first1=Olivier |last2=Mulas |first2=Giacomo |last3=Joblin |first3=Christine|author3-link=Christine Joblin|title=Interstellar C60+ |journal=Astronomy & Astrophysics |date=2013 |volume=550 |page=L4 |bibcode=2013A&A...550L...4B |arxiv=1211.7252 |doi=10.1051/0004-6361/201220730 |s2cid=118684608}}
{{cite conference |last1=Hollis | first1=J. M. | contribution=Complex Molecules and the GBT: Is Isomerism the Key? | title=Complex Molecules and the GBT: Is Isomerism the Key? | contribution-url=http://www.astro.uni-koeln.de/site/vorhersagen/molecules/ism/Hollis_Asilomar.pdf | series=Proceedings of the IAU Symposium 231, Astrochemistry throughout the Universe | date=2005 | pages=119–127 | place=Asilomar, CA }}{{bsn|date=December 2024}}
{{citation |display-authors=1 |last1=Barlow |first1=M. J. |last2=Swinyard |first2=B. M. |last3=Owen |first3=P. J. |last4=Cernicharo |first4=J. |last5=Gomez |first5=H. L. |last6=Ivison |first6=R. J. |last7=Lim |first7=T. L. |last8=Matsuura |first8=M. |last9=Miller |first9=S. |last10=Olofsson |first10=G. |last11=Polehampton |first11=E. T. |date=2013 |title=Detection of a Noble Gas Molecular Ion, 36ArH+, in the Crab Nebula |journal=Science |volume=342 |issue=6164 |pages=1343–1345 |doi=10.1126/science.1243582 |pmid=24337290 |bibcode=2013Sci...342.1343B |arxiv=1312.4843 |s2cid=37578581}}
{{cite news |last=Khan |first=Amina |title=Did two planets around nearby star collide? Toxic gas holds hints |url=http://www.latimes.com/science/sciencenow/la-sci-sn-beta-pictoris-star-planet-gas-collision-comets-carbon-monoxide-20140307,0,1884709.story |newspaper=LA Times |access-date=March 9, 2014 }}
{{cite journal |display-authors=1 |last1=Dent |first1=W.R.F. |last2=Wyatt |first2=M.C. |last3=Roberge |first3=A. |last4=Augereau |first4=J.-C. |last5=Casassus |first5=S. |last6=Corder |first6=S. |last7=Greaves |first7=J.S. |last8=de Gregorio-Monsalvo |first8=I. |last9=Hales |first9=A. |last10=Jackson |first10=A.P. |last11=Hughes |first11=A. Meredith |last12=Lagrange |first12=A.-M |last13=Matthews |first13=B. |last14=Wilner |first14=D. |title=Molecular Gas Clumps from the Destruction of Icy Bodies in the β Pictoris Debris Disk |date=March 6, 2014 |journal=Science |doi=10.1126/science.1248726 |pmid=24603151 |arxiv=1404.1380 |bibcode=2014Sci...343.1490D |volume=343 |issue=6178 |pages=1490–1492|s2cid=206553853 }}
{{cite journal|first1=B.|last1=Zuckerman|first2=John A.|last2=Ball|first3=Carl A.|last3=Gottlieb|title=Microwave Detection of Interstellar Formic Acid|journal=Astrophysical Journal|volume=163|page=L41|year=1971|doi=10.1086/180663|bibcode=1971ApJ...163L..41Z}}
{{cite journal|title=Detection of the aromatic molecule benzonitrile (c-C6H5CN) in the interstellar medium |journal=Science |volume=359 |issue=6372 |pages=202–205 |date=12 January 2018 |last1=McGuire |first1=Brett A. |last2=Burkhardt |first2=Andrew M. |last3=Kalenskii |first3=Sergei |last4=Shingledecker |first4=Christopher N. |last5=Remijan |first5=Anthony J. |last6=Herbst |first6=Eric |last7=McCarthy |first7=Michael C. |doi=10.1126/science.aao4890 |pmid=29326270 |arxiv=1801.04228 |bibcode=2018Sci...359..202M |s2cid=206663501}}
{{cite journal |display-authors=1 |doi=10.3847/2041-8213/aaa0c3 |bibcode=2017ApJ...851L..46M |arxiv=1712.03256 |title=ALMA Detection of Interstellar Methoxymethanol (CH3OCH2OH) |journal=The Astrophysical Journal |volume=851 |issue=2 |pages=L46 |year=2017 |last1=McGuire |first1=Brett A |last2=Shingledecker |first2=Christopher N |last3=Willis |first3=Eric R |last4=Burkhardt |first4=Andrew M |last5=El-Abd |first5=Samer |last6=Motiyenko |first6=Roman A |last7=Brogan |first7=Crystal L |last8=Hunter |first8=Todd R |last9=Margulès |first9=Laurent |last10=Guillemin |first10=Jean-Claude |last11=Garrod |first11=Robin T |last12=Herbst |first12=Eric |last13=Remijan |first13=Anthony J |s2cid=119211919 |doi-access=free }}
{{cite journal|doi=10.3847/2041-8213/aa7ca3|bibcode=2017ApJ...843L..28M|arxiv=1706.09766|title=Detection of Interstellar HC5O in TMC-1 with the Green Bank Telescope|journal=The Astrophysical Journal|volume=843|issue=2|pages=L28|year=2017|last1=McGuire|first1=Brett A |last2=Burkhardt |first2=Andrew M|last3=Shingledecker|first3=Christopher N|last4=Kalenskii|first4=Sergei V|last5=Herbst|first5=Eric|last6=Remijan|first6=Anthony J |last7=McCarthy|first7=Michael C|s2cid=119189492 |doi-access=free }}
{{cite journal |display-authors=1
| title=The Family of Amide Molecules toward NGC 6334I
| last1=Ligterink | first1=Niels F. W.
| last2=El-Abd | first2=Samer J. | last3=Brogan | first3=Crystal L.
| last4=Hunter | first4=Todd R. | last5=Remijan | first5=Anthony J.
| last6=Garrod | first6=Robin T. | last7=McGuire | first7=Brett M.
| journal=The Astrophysical Journal
| volume=901 | issue=1 | id=37 | page=23 | date=September 2020
| arxiv=2008.09157 | bibcode=2020ApJ...901...37L
| doi=10.3847/1538-4357/abad38 | s2cid=221246432 | doi-access=free }}
{{cite journal |display-authors=1 |last1=Zeng |first1=Shaoshan |last2=Jiménez-Serra |first2=Izaskun |last3=Rivilla |first3=Víctor M. |last4=Martín-Pintado |first4=Jesús |last5=Rodríguez-Almeida |first5=Lucas F. |last6=Tercero |first6=Belén |last7=de Vicente |first7=Pablo |last8=Rico-Villas |first8=Fernando |last9=Colzi |first9=Laura |last10=Martín |first10=Sergio |last11=Requena-Torres |first11=Miguel A. |title=Probing the Chemical Complexity of Amines in the ISM: Detection of Vinylamine (C2H3NH2) and Tentative Detection of Ethylamine (C2H5NH2) |journal=The Astrophysical Journal Letters |date=1 October 2021 |volume=920 |issue=2 |pages=L27 |doi=10.3847/2041-8213/ac2c7e |arxiv=2110.01791 |bibcode=2021ApJ...920L..27Z |s2cid=238354093 |doi-access=free }}
{{cite journal |display-authors=1 |last1=Rivilla |first1=Víctor M. |last2=Colzi |first2=Laura |last3=Jiménez-Serra |first3=Izaskun |last4=Martín-Pintado |first4=Jesús |last5=Megías |first5=Andrés |last6=Melosso |first6=Mattia |last7=Bizzocchi |first7=Luca |last8=López-Gallifa |first8=Álvaro |last9=Martínez-Henares |first9=Antonio |last10=Massalkhi |first10=Sarah |last11=Tercero |first11=Belén |last12=de Vicente |first12=Pablo |last13=Guillemin |first13=Jean-Claude |last14=García de la Concepción |first14=Juan |last15=Rico-Villas |first15=Fernando |last16=Zeng |first16=Shaoshan |last17=Martín |first17=Sergio |last18=Requena-Torres |first18=Miguel A. |last19=Tonolo |first19=Francesca |last20=Alessandrini |first20=Silvia |last21=Dore |first21=Luca |last22=Barone |first22=Vincenzo |last23=Puzzarini |first23=Cristina |title=Precursors of the RNA World in Space: Detection of (Z)-1,2-ethenediol in the Interstellar Medium, a Key Intermediate in Sugar Formation |journal=Astrophysical Journal Letters |date=1 April 2022 |volume=929 |issue=1 |pages=L11 |doi=10.3847/2041-8213/ac6186|doi-access=free|bibcode=2022ApJ...929L..11R|arxiv=2203.14728}}
{{cite journal |display-authors=1 |last1=Fried |first1=Zachary T. P. |last2=El-Abd |first2=Samer J. |last3=Hays |first3=Brian M. |last4=Wenzel |first4=Gabi |last5=Byrne |first5=Alex N. |last6=Margulès |first6=Laurent |last7=Motiyenko |first7=Roman A. |last8=Shipman |first8=Steven T. |last9=Horne |first9=Maria P. |last10=Jørgensen |first10=Jes K. |last11=Brogan |first11=Crystal L. |last12=Hunter |first12=Todd R. |last13=Remijan |first13=Anthony J. |last14=Lipnicky |first14=Andrew |last15=Loomis |first15=Ryan A. |last16=McGuire |first16=Brett A. |title=Rotational Spectrum and First Interstellar Detection of 2-methoxyethanol Using ALMA Observations of NGC 6334I |journal=Astrophysical Journal Letters |date=1 April 2024 |volume=965 |issue=2 |page=L23 |doi=10.3847/2041-8213/ad37ff |doi-access=free |arxiv=2403.17341 |bibcode=2024ApJ...965L..23F }}
{{Cite journal |display-authors=1 |last1=Dhariwal |first1=Aditya |last2=Speak |first2=Thomas H. |last3=Zeng |first3=Linshan |last4=Rashidi |first4=Amirhossein |last5=Moore |first5=Brendan |last6=Berné |first6=Olivier |last7=Remijan |first7=Anthony J. |last8=Schroetter |first8=Ilane |last9=McGuire |first9=Brett A. |last10=Rivilla |first10=Víctor M. |last11=Belloche |first11=Arnaud |last12=Jørgensen |first12=Jes K. |last13=Djuricanin |first13=Pavle |last14=Momose |first14=Takamasa |last15=Cooke |first15=Ilsa R. |date=June 2024 |title=On the Origin of Infrared Bands Attributed to Tryptophan in Spitzer Observations of IC 348 |journal=The Astrophysical Journal Letters |volume=968 |issue=1 |pages=L9 |doi=10.3847/2041-8213/ad4d9a |doi-access=free |arxiv=2405.16773 |bibcode=2024ApJ...968L...9D |issn=2041-8205 |quote=there is no compelling evidence for the tryptophan assignment}}
{{cite journal |last=Iglesias-Groth |first=S. |date=August 2023 |title=A search for tryptophan in the gas of the IC 348 star cluster of the Perseus molecular cloud |journal=Monthly Notices of the Royal Astronomical Society |volume=523 |issue=2 |pages=2876–2886 |bibcode=2023MNRAS.523.2876I |doi=10.1093/mnras/stad1535 |doi-access=free}}
{{Cite journal |url=https://academic.oup.com/mnras/article/526/3/4051/7310867 |journal=Monthly Notices of the Royal Astronomical Society |doi=10.1093/mnras/stad3058|doi-access=free |title=Interstellar tryptophan revisited |date=2023 |last1=Hudson |first1=Reggie L. |volume=526 |issue=3 |pages=4051–4053 |bibcode=2023MNRAS.526.4051H |quote=there is no firm support for the tryptophan assignment}}
External links
- {{cite web | last=Woon | first=David E. | date=October 1, 2010 | url=http://www.astrochymist.org/astrochymist_ism.html | title=Interstellar and Circumstellar Molecules | access-date=2010-10-04 }}
- {{cite web | publisher=Universität zu Köln | date=April 2022 | url=https://cdms.astro.uni-koeln.de/classic/molecules | title=Molecules in Space | access-date=2022-05-25}}
- {{cite web | last=Dworkin | first=Jason P. | date=February 1, 2007 | url=http://science.gsfc.nasa.gov/691/cosmicice/interstellar.html | title=Interstellar Molecules | publisher=NASA's Cosmic Ice Lab | access-date = 2010-12-23 }}
- {{cite web | last=Wootten | first=Al | date=November 2005 | url=http://www.cv.nrao.edu/~awootten/allmols.html | title=The 129 reported interstellar and circumstellar molecules | publisher=National Radio Astronomy Observatory | access-date=2007-02-13 }}
- {{cite journal |author1=Lovas, F. J. |author2=Dragoset, R. A. |date=February 2004 |url=http://www.physics.nist.gov/PhysRefData/Micro/Html/contents.html |title=NIST Recommended Rest Frequencies for Observed Interstellar Molecular Microwave Transitions, 2002 Revision |journal=Journal of Physical and Chemical Reference Data |volume=33 |issue=1 |page=177 |access-date=2007-02-13 |archive-url=https://web.archive.org/web/20130201185607/http://www.nist.gov/pml/data/micro/index.cfm |archive-date=2013-02-01 |bibcode=2004JPCRD..33..177L |doi=10.1063/1.1633275}}
- {{cite book |last1=Williams |first1=David A. |last2=Cecchi-Pestellini |first2=Cesare |title=Astrochemistry: Chemistry in Interstellar and Circumstellar Space |date=8 February 2023 |publisher=Royal Society of Chemistry |isbn=978-1-83916-939-7 |url=https://books.google.com/books?id=agqtEAAAQBAJ |language=en}}
{{Molecules detected in outer space}}
{{DEFAULTSORT:List of interstellar and circumstellar molecules}}