Known Interstellar Molecules

Last Update: JeffMangum - 20 Dec 2005

120 Independent Species + 7 Isomers

This wiki page lists the known interstellar molecules, with references to their discovery and laboratory frequency references (for as many as I could find). The organization of these molecules is based on one suggested by Barry Turner (although I have taken some artistic license). I have also stolen heavily from Al Wootten's molecule list web page.

Note that my intention is for this to be only a stripped-down version of astrochemistry.net. If you want much more information than that provided here, go to astrochemistry.net.

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Contents

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Frequency References

• NIST Recommended Rest Frequencies
• NIST Physical Reference Data
• JPL Molecular Spectroscopy
• The Cologne Database for Molecular Spectroscopy
• IAU Astrochemistry Working Group
• DEMIRM List of Known Interstellar Molecules
• Al Wootten's molecule list web page
• astrochemistry.net

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Stable Molecules

Inorganic Molecules

Diatomic	Triatomic	Quadratomic	Quintomic
H2	H2O	NH3	SiH4
CO	H2S
CS	SO2
SiO	OCS
SiS	HNO
PN	N2O
HCl	SiH2
HF	AlNC
NaCl
AlCl
KCl
AlF
FeO

Organic Molecules

Alcohols	Aldehydes & Ketones	Acids	Hydrocarbons
CH3OH (Methanol)	H2CO (Formaldehyde)	HCN (Hydrocyanic)	CH2 (Methylene)
CH3CH2OH (Ethanol)	CH3CHO (Acetaldehyde)	HCOOH (formic)	CH4 (Methane)
CH2CHOH (Vinyl Alcohol)	H2CCO (Ketene)	HNCO (isocyanic)	C2H2 (Acetylene)
	(CH3)2CO (Acetone)		C2H4 (Ethylene)
	HCCCHO (Propynal)
	CH2CHCHO (Propenal)
	CH3CH2CHO (Propanal)
	CH2OHCHO (Glycolaldehyde)

Amides	Esters & Ethers	Organosulfur
NH2CHO (Formamide)	CH2OCHO (Methyl Formate)	H2CS (Thioformaldehyde)
NH2CN (Cyanamide)	(CH3)2O (Dimethyl Ether)	HNCS (Isothiocyanic Acid)
NH2CH3 (Methylamine)	CH3OC2H5 (Trans-ethyl Methyl Ether)	CH3SH (Methyl Mercaptan)

Paraffin Derivatives	Acetylene Derivatives	Rings	Other
CH3CN (Methyl Cyanide)	HC3N (Cyanoacetylene)	c-C2H4O (Ethylene Oxide)	CH2NH (Methylenimine)
CH3CH2CN (Ethyl Cyanide)	CH3C2H (Methylacetylene)	c-CH2CHCN (Vinyl Cyanide)
	CH3C4H (Methyldiacetylene)	c-NaCN (Sodium Cyanide)

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Unstable Molecules

Radicals	Ions	Rings	Carbon Chains	Isomers
OH	H3+	SiC2	C3S	HNC
NO	H2D+	SiC3	HC3N	l-C3H
NS	N2H+	c-C3H2	HC4N	CH3NC
SO	H3O+	c-C3H	HC5N	HCCNC
SH	SO+		HC7N	HNCCC
SiN	CO+		HC9N	MgCN
NH2	HCO+		HC11N	SiNC
CH	HCS+		CH3C3N
CN	HOCO+	C4Si	CH3C5N
CSi	HCNH+	H2C3
CP	CH2D+		H2C4
SiCN	HC3NH+		H2C6
HCO	H2COH+
C2
C2H
C2O
C2S
HCCN
C3
C3H
C3N
C3O
C4
C4H
C5
C5H
C6H
C7H
C8H
CH2CN
MgNC

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Note:

• Molecules denoted in green are detected only in circumstellar envelopes (surrounding evolved, mass-losing, red-giant stars). No detection in the general interstellar medium has been reported.

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