Quinoline

Athanor · official

C₉H₇N · 129.16 g/mol

Also called 1-benzazine, benzo[b]pyridine, leucoline, chinoline

Rings

Open in Athanor

Drawn from its SMILES with RDKit

DangerHarmful if swallowed · Harmful in contact with skin · Causes skin irritation · Causes serious eye irritation · Suspected of causing genetic defects · May cause cancer · Toxic to aquatic life with long lasting effects

Names and identifiers

IUPAC name: quinoline
Synonyms: 1-benzazine, benzo[b]pyridine, leucoline
+ 36 more
chinoline, 1-Benzazine, Chinoline, Chinoleine, Chinolin, Quinolin, 1-Azanaphthalene, Leucol, Leukol, Benzopyridine, 2,3-Benzopyridine, Benzo[b]pyridine, Benzo(b)pyridine, USAF EK-218, 1-Benzine, FEMA No. 3470, B 500, DTXSID1021798, AI3-01241, B-500, CHEBI:17362, E66400VT9R, NSC-3396, DTXCID401798, RefChem:6194, 202-051-6, Quinoline-3-D, Quinoline-4-D, Quinoline-5-D, Quinoline-6-D, Quinoline-7-D, NSC 3396, CCRIS 547, HSDB 121, Quinoline (8CI,9CI), CHEMBL14474
Molecular formula: C₉H₇N
Empirical formula: C₉H₇N
Molecular weight: 129.16 g/mol
Exact mass: 129.05785
CAS number: 91-22-5
PubChem CID: 7047
Canonical SMILES: C1=CC=C2C(=C1)C=CC=N2
Isomeric SMILES: C1=CC=C2C(=C1)C=CC=N2
InChI: InChI=1S/C9H7N/c1-2-6-9-8(4-1)5-3-7-10-9/h1-7H
InChIKey: SMWDFEZZVXVKRB-UHFFFAOYSA-N
Molfile

Names, InChI and the identifiers from PubChem, retrieved 2026-10-14.

Physical properties

TemperaturePressureDensity

Appearance: Colorless liquid[4]
6 values
From Hazardous Substances Data Bank (HSDB), the most authoritative source here.
Value As written Source
– Quinoline appears as a colorless liquid with a peculiar odor. Slightly denser than water. Contact may irritate to skin, eyes, and mucous membranes. May be toxic by ingestion. Used to make other chemicals. [1] CAMEO Chemicals
– Liquid [2] EPA Chemical Data Reporting (CDR)
– COLOURLESS HYGROSCOPIC LIQUID WITH CHARACTERISTIC ODOUR. TURNS BROWN ON EXPOSURE TO LIGHT. [3] ILO-WHO International Chemical Safety Cards (ICSCs)
– COLORLESS TO BROWN /SRP: TECHNICAL GRADE/ [4] Hazardous Substances Data Bank (HSDB)cites U.S. Coast Guard, Department of Transportation. CHRIS - Hazardous Chemical Data. Volume II. Washington, D.C.: U.S. Government Printing Office, 1984-5.
– Highly refractive/darkens with age [4] Hazardous Substances Data Bank (HSDB)cites Lewis, R.J., Sr (Ed.). Hawley's Condensed Chemical Dictionary. 13th ed. New York, NY: John Wiley & Sons, Inc. 1997., p. 950
–shown Colorless liquid [4] Hazardous Substances Data Bank (HSDB)cites Sax, N.I. Dangerous Properties of Industrial Materials. Vol 1-3 7th ed. New York, NY: Van Nostrand Reinhold, 1989., p. 2950
Odor: Unpleasant odor[4]
Melting point: -14.78 °C[5]
3 values
3 of 3 sources agree on it (most common value).
Value As written Source
−15 °C 5 °F (NTP, 1992) [1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
−15 °C -15 °C [3] ILO-WHO International Chemical Safety Cards (ICSCs)
−14.8 °Cshown -14.78 °C [5] PAC Chemical Database, U.S. Department of Energy
Boiling point: 237.16 °C @760 [mmHg][5]
3 values
3 of 3 sources agree on it (most common value).
Value As written Source
238 °C 460 °F at 760 mmHg (NTP, 1992) [1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
238 °C 238 °C [3] ILO-WHO International Chemical Safety Cards (ICSCs)
237.2 °Cshown 237.16 °C @760 [mm Hg] [5] PAC Chemical Database, U.S. Department of Energy
Density: 1.0900 @ 25 °C/4 °C[4]
4 values
Only one source reports it.
Value As written Source
– 1.095 at 68 °F (USCG, 1999) - Denser than water [1] CAMEO Chemicalscites U.S. Coast Guard. 1999. Chemical Hazard Response Information System (CHRIS) - Hazardous Chemical Data. Commandant Instruction 16465.12C. Washington, D.C.: U.S. Government Printing Office.
1.09 g/mLshown 1.0900 @ 25 °C/4 °C [4] Hazardous Substances Data Bank (HSDB)cites Ashford, R.D. Ashford's Dictionary of Industrial Chemicals. London, England: Wavelength Publications Ltd., 1994., p. 780
– Relative density (water = 1): 1.09 [3] ILO-WHO International Chemical Safety Cards (ICSCs)
– 1.0977 @ 15°C [5] PAC Chemical Database, U.S. Department of Energy
Solubility in water: Solubility in water, g/100ml at 20 °C: 0.61 (very poor)[3]
6 values
From ILO-WHO International Chemical Safety Cards (ICSCs), the most authoritative source here.
Value As written Source
– less than 0.1 mg/mL at 72.5 °F (NTP, 1992) [1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
– Soluble in alcohol, ether, and carbon disulfide [4] Hazardous Substances Data Bank (HSDB)cites Lewis, R.J., Sr (Ed.). Hawley's Condensed Chemical Dictionary. 13th ed. New York, NY: John Wiley & Sons, Inc. 1997., p. 950
– Miscible with oxygenated solvents [4] Hazardous Substances Data Bank (HSDB)cites Ashford, R.D. Ashford's Dictionary of Industrial Chemicals. London, England: Wavelength Publications Ltd., 1994., p. 950
– More sol in hot than cold water; sol in ethanol, ethyl ether, acetone, carbon disulfide and other common organic solvents. [4] Hazardous Substances Data Bank (HSDB)cites Kirk-Othmer Encyclopedia of Chemical Technology. 4th ed. Volumes 1: New York, NY. John Wiley and Sons, 1991-Present., p. V20 (1996) 769
– In water, 6,110 mg/l @ 25 °C [4] Hazardous Substances Data Bank (HSDB)cites Smith JH et al; Environmental pathways of selected chemicals in freshwater systems. Part II. Athens, GA: USEPA-600/7-78-074 (1978)
–shown Solubility in water, g/100ml at 20 °C: 0.61 (very poor) [3] ILO-WHO International Chemical Safety Cards (ICSCs)
log P: 2.06[3]
2 values
2 of 2 sources agree on it (most common value).
Value As written Source
– log Kow= 2.03 [4] Hazardous Substances Data Bank (HSDB)cites Hansch, C., Leo, A., D. Hoekman. Exploring QSAR - Hydrophobic, Electronic, and Steric Constants. Washington, DC: American Chemical Society., 1995., p. 51
–shown 2.06 [3] ILO-WHO International Chemical Safety Cards (ICSCs)
Vapor pressure: Vapor pressure, Pa at 20 °C: 8[3]
4 values
2 of 3 sources agree on it (most common value).
Value As written Source
1 mmHg 1 mmHg at 139.5 °F [1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
5 mmHg 5 mmHg at 193.3 °F (NTP, 1992) [1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
0.06 mmHg 0.06 mm Hg @ 25 °C [4] Hazardous Substances Data Bank (HSDB)cites Daubert, T.E., R.P. Danner. Physical and Thermodynamic Properties of Pure Chemicals Data Compilation. Washington, D.C.: Taylor and Francis, 1989.
0.06 mmHgshown Vapor pressure, Pa at 20 °C: 8 [3] ILO-WHO International Chemical Safety Cards (ICSCs)
Flash point: 101 °C c.c.[3]
3 values
Sources disagree; from ILO-WHO International Chemical Safety Cards (ICSCs), the most authoritative.
Value As written Source
59 °C 138 °F (NFPA, 2010) [1] CAMEO Chemicalscites National Fire Protection Association. 2010. Fire Protection Guide to Hazardous Materials, 14th edition, edited by Guy R. Colonna. Quincy, MA: National Fire Protection Association. Note that this information is subject to the copyright restrictions of the organization that provided the data.
99 °C 99 °C, (Closed Cup) [4] Hazardous Substances Data Bank (HSDB)cites International Labour Office. Encyclopedia of Occupational Health and Safety. Vols. I&II. Geneva, Switzerland: International Labour Office, 1983., p. 1812
101 °Cshown 101 °C c.c. [3] ILO-WHO International Chemical Safety Cards (ICSCs)
Autoignition temperature: 480 °C[3]
3 values
3 of 3 sources agree on it (most common value).
Value As written Source
480 °C 896 °F (USCG, 1999) [1] CAMEO Chemicalscites U.S. Coast Guard. 1999. Chemical Hazard Response Information System (CHRIS) - Hazardous Chemical Data. Commandant Instruction 16465.12C. Washington, D.C.: U.S. Government Printing Office.
480 °C 896 °F [4] Hazardous Substances Data Bank (HSDB)cites Lewis, R.J. Sax's Dangerous Properties of Industrial Materials. 9th ed. Volumes 1-3. New York, NY: Van Nostrand Reinhold, 1996., p. 2853
480 °Cshown 480 °C [3] ILO-WHO International Chemical Safety Cards (ICSCs)
Viscosity: Reported, but no value passed the checks.
The value and why
2.997 millipascal second (=cP) at 30 °C (could not be read; source [4])

Value	As written	Source
–	Quinoline appears as a colorless liquid with a peculiar odor. Slightly denser than water. Contact may irritate to skin, eyes, and mucous membranes. May be toxic by ingestion. Used to make other chemicals.	[1] CAMEO Chemicals
–	Liquid	[2] EPA Chemical Data Reporting (CDR)
–	COLOURLESS HYGROSCOPIC LIQUID WITH CHARACTERISTIC ODOUR. TURNS BROWN ON EXPOSURE TO LIGHT.	[3] ILO-WHO International Chemical Safety Cards (ICSCs)
–	COLORLESS TO BROWN /SRP: TECHNICAL GRADE/	[4] Hazardous Substances Data Bank (HSDB)cites U.S. Coast Guard, Department of Transportation. CHRIS - Hazardous Chemical Data. Volume II. Washington, D.C.: U.S. Government Printing Office, 1984-5.
–	Highly refractive/darkens with age	[4] Hazardous Substances Data Bank (HSDB)cites Lewis, R.J., Sr (Ed.). Hawley's Condensed Chemical Dictionary. 13th ed. New York, NY: John Wiley & Sons, Inc. 1997., p. 950
–shown	Colorless liquid	[4] Hazardous Substances Data Bank (HSDB)cites Sax, N.I. Dangerous Properties of Industrial Materials. Vol 1-3 7th ed. New York, NY: Van Nostrand Reinhold, 1989., p. 2950

Value	As written	Source
−15 °C	5 °F (NTP, 1992)	[1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
−15 °C	-15 °C	[3] ILO-WHO International Chemical Safety Cards (ICSCs)
−14.8 °Cshown	-14.78 °C	[5] PAC Chemical Database, U.S. Department of Energy

Value	As written	Source
238 °C	460 °F at 760 mmHg (NTP, 1992)	[1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
238 °C	238 °C	[3] ILO-WHO International Chemical Safety Cards (ICSCs)
237.2 °Cshown	237.16 °C @760 [mm Hg]	[5] PAC Chemical Database, U.S. Department of Energy

Value	As written	Source
–	1.095 at 68 °F (USCG, 1999) - Denser than water	[1] CAMEO Chemicalscites U.S. Coast Guard. 1999. Chemical Hazard Response Information System (CHRIS) - Hazardous Chemical Data. Commandant Instruction 16465.12C. Washington, D.C.: U.S. Government Printing Office.
1.09 g/mLshown	1.0900 @ 25 °C/4 °C	[4] Hazardous Substances Data Bank (HSDB)cites Ashford, R.D. Ashford's Dictionary of Industrial Chemicals. London, England: Wavelength Publications Ltd., 1994., p. 780
–	Relative density (water = 1): 1.09	[3] ILO-WHO International Chemical Safety Cards (ICSCs)
–	1.0977 @ 15°C	[5] PAC Chemical Database, U.S. Department of Energy

Value	As written	Source
–	less than 0.1 mg/mL at 72.5 °F (NTP, 1992)	[1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
–	Soluble in alcohol, ether, and carbon disulfide	[4] Hazardous Substances Data Bank (HSDB)cites Lewis, R.J., Sr (Ed.). Hawley's Condensed Chemical Dictionary. 13th ed. New York, NY: John Wiley & Sons, Inc. 1997., p. 950
–	Miscible with oxygenated solvents	[4] Hazardous Substances Data Bank (HSDB)cites Ashford, R.D. Ashford's Dictionary of Industrial Chemicals. London, England: Wavelength Publications Ltd., 1994., p. 950
–	More sol in hot than cold water; sol in ethanol, ethyl ether, acetone, carbon disulfide and other common organic solvents.	[4] Hazardous Substances Data Bank (HSDB)cites Kirk-Othmer Encyclopedia of Chemical Technology. 4th ed. Volumes 1: New York, NY. John Wiley and Sons, 1991-Present., p. V20 (1996) 769
–	In water, 6,110 mg/l @ 25 °C	[4] Hazardous Substances Data Bank (HSDB)cites Smith JH et al; Environmental pathways of selected chemicals in freshwater systems. Part II. Athens, GA: USEPA-600/7-78-074 (1978)
–shown	Solubility in water, g/100ml at 20 °C: 0.61 (very poor)	[3] ILO-WHO International Chemical Safety Cards (ICSCs)

Value	As written	Source
–	log Kow= 2.03	[4] Hazardous Substances Data Bank (HSDB)cites Hansch, C., Leo, A., D. Hoekman. Exploring QSAR - Hydrophobic, Electronic, and Steric Constants. Washington, DC: American Chemical Society., 1995., p. 51
–shown	2.06	[3] ILO-WHO International Chemical Safety Cards (ICSCs)

Value	As written	Source
1 mmHg	1 mmHg at 139.5 °F	[1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
5 mmHg	5 mmHg at 193.3 °F (NTP, 1992)	[1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
0.06 mmHg	0.06 mm Hg @ 25 °C	[4] Hazardous Substances Data Bank (HSDB)cites Daubert, T.E., R.P. Danner. Physical and Thermodynamic Properties of Pure Chemicals Data Compilation. Washington, D.C.: Taylor and Francis, 1989.
0.06 mmHgshown	Vapor pressure, Pa at 20 °C: 8	[3] ILO-WHO International Chemical Safety Cards (ICSCs)

Value	As written	Source
59 °C	138 °F (NFPA, 2010)	[1] CAMEO Chemicalscites National Fire Protection Association. 2010. Fire Protection Guide to Hazardous Materials, 14th edition, edited by Guy R. Colonna. Quincy, MA: National Fire Protection Association. Note that this information is subject to the copyright restrictions of the organization that provided the data.
99 °C	99 °C, (Closed Cup)	[4] Hazardous Substances Data Bank (HSDB)cites International Labour Office. Encyclopedia of Occupational Health and Safety. Vols. I&II. Geneva, Switzerland: International Labour Office, 1983., p. 1812
101 °Cshown	101 °C c.c.	[3] ILO-WHO International Chemical Safety Cards (ICSCs)

Value	As written	Source
480 °C	896 °F (USCG, 1999)	[1] CAMEO Chemicalscites U.S. Coast Guard. 1999. Chemical Hazard Response Information System (CHRIS) - Hazardous Chemical Data. Commandant Instruction 16465.12C. Washington, D.C.: U.S. Government Printing Office.
480 °C	896 °F	[4] Hazardous Substances Data Bank (HSDB)cites Lewis, R.J. Sax's Dangerous Properties of Industrial Materials. 9th ed. Volumes 1-3. New York, NY: Van Nostrand Reinhold, 1996., p. 2853
480 °Cshown	480 °C	[3] ILO-WHO International Chemical Safety Cards (ICSCs)

Each value as its source reports it, with the source's number after it (listed under References). Where several sources report a property, the row shows the value most of them agree on, the rule the app uses; open the values to see every one.

Calculated

Heavy atoms: 10
Rings: 2
Aromatic rings: 2
Fraction sp³ carbons (Fsp3): 0
H-bond donors: 0
H-bond acceptors: 1
Rotatable bonds: 0
TPSA (Å²): 12.9
Formal charge: 0
XLogP3: 2 PubChem
Complexity: 111 PubChem
Stereocenters: None
Double-bond geometry: None specified
Point group: Cs of one 3D conformer with its hydrogens, by Athanor’s engine (as in the app)

Elemental analysis

C83.69%
H5.46%
N10.84%

Isotope pattern

Each peak is a nominal mass with its abundance-weighted exact mass, as a percentage of the tallest, from IUPAC natural isotope abundances.

Computed from the structure with RDKit 2026.09 when this page was built, beside PubChem's own computed values from its record; where the two differ, both are shown.

Predicted

log P: 2.23 Crippen (Wildman and Crippen 1999)
log S (water solubility): -2.79 ESOL (Delaney 2004), log mol/L
Synthetic accessibility: 1.35 SA score, 1 easy to 10 hard (Ertl and Schuffenhauer 2009)

Drug-likeness: Lipinski’s rule of five

Molecular weight ≤ 500: 129.16
log P ≤ 5 (Crippen): 2.23
H-bond donors ≤ 5: 0
H-bond acceptors ≤ 10: 1

Passes all four rules.

¹³C NMR shifts, predicted

Predictions, not measurements; each names its method. A measured log P, where a source reports one, is under Physical properties.

Safety

Danger

Harmonized EU classification (CLP Annex VI). Source [6].

Harmful or irritant
Health hazard
Environmental hazard

NFPA 704[4]

H302Harmful if swallowed
H312Harmful in contact with skin
H315Causes skin irritation
H319Causes serious eye irritation
H341Suspected of causing genetic defects
H350May cause cancer
H411Toxic to aquatic life with long lasting effects

Precautionary statements: P203, P264, P264+P265, P270, P273, P280, P301+P317, P302+P352, P305+P351+P338, P317, P318, P321, P330, P332+P317, P337+P317, P362+P364, P391, P405, P501

View all classifications (2)

[6] Regulation (EC) No 1272/2008 of the European Parliament and of the Council · DangerH302, H312, H315, H319, H341, H350, H411
[7] European Chemicals Agency (ECHA) · 1,783 reports · DangerH302, H312, H315, H319, H341, H350, H411

First aid

Eyes: First check the victim for contact lenses and remove if present. Flush victim's eyes with water or normal saline solution for 20 to 30 minutes while simultaneously calling a hospital or poison control center. Do not put any ointments, oils, or medication in the victim's eyes without specific instructions from a physician. Immediately transport the victim after flushing eyes to a hospital even if no symptoms (such as redness or irritation) develop. Skin: Immediately flood affected skin with water while removing and isolating all contaminated clothing.[1]
General First Aid: · Call 911 or emergency medical service. · Ensure that medical personnel are aware of the material(s) involved, take precautions to protect themselves and avoid contamination. · Move victim to fresh air if it can be done safely. · Administer oxygen if breathing is difficult. · If victim is not breathing: -- DO NOT perform mouth-to-mouth resuscitation; the victim may have ingested or inhaled the substance. -- If equipped and pulse detected, wash face and mouth, then give artificial respiration using a proper respiratory medical device (bag-valve mask, pocket mask equipped…[8]
Fresh air, rest. Refer for medical attention.[3]
Remove contaminated clothes. Rinse and then wash skin with water and soap.[3]

Storage

Provision to contain effluent from fire extinguishing. Separated from strong oxidants, acids, acid anhydrides and food and feedstuffs. Dry. Keep in the dark. Well closed. Store in an area without drain or sewer access.[3]

Incompatibilities

Violent reaction WITH dinitrogen tetraoxide; perchromates.[4]
Potentially explosive reaction with hydrogen peroxide. ... Incompatible with linseed oil + thionyl choride; maleic anhydride.[4]
Pyridine and quinoline are attacked violently by the liquid oxide.[4]

Safety data sheets on the supplier’s page: Xianglong Pharmaceutical Standards (XL Standards), AppChem, Chem-Space.com Database.

Always read the supplier’s safety data sheet before working with it.

Spectra

Experimental spectra held by these sources; each link opens the source's own record.

Literature

Reading PubChem, OpenAlex and GSRS…

Bioactivity

Reading ChEMBL…

References

[1]CAMEO Chemicals · Public domain (NOAA) · via PubChem · retrieved 2026-10-14
[2]EPA Chemical Data Reporting (CDR) · Public domain (US EPA) · via PubChem · retrieved 2026-10-14
[3]ILO-WHO International Chemical Safety Cards (ICSCs) · CC BY 4.0 · via PubChem · retrieved 2026-10-14
[4]Hazardous Substances Data Bank (HSDB) · Public domain (US NLM) · via PubChem · retrieved 2026-10-14
[5]PAC Chemical Database, U.S. Department of Energy · Public domain (US DOE) · via PubChem · retrieved 2026-10-14
[6]Regulation (EC) No 1272/2008 of the European Parliament and of the Council · EU reuse policy, CC BY 4.0 · via PubChem · retrieved 2026-10-14
[7]European Chemicals Agency (ECHA) · ECHA legal notice: reuse with acknowledgement · via PubChem · retrieved 2026-10-14
[8]Emergency Response Guidebook (ERG) · Public domain (US DOT) · via PubChem · retrieved 2026-10-14
[9]NMRShiftDB · Linked only · via PubChem · retrieved 2026-10-14
[10]Human Metabolome Database (HMDB) · Linked only · via PubChem · retrieved 2026-10-14
[11]SpectraBase · Linked only · via PubChem · retrieved 2026-10-14
[12]MassBank of North America (MoNA) · CC BY 4.0 · via PubChem · retrieved 2026-10-14
[13]NIST Mass Spectrometry Data Center · Linked only · via PubChem · retrieved 2026-10-14
[14]MassBank Europe · Linked only · via PubChem · retrieved 2026-10-14
·Calculated values: computed by Athanor with RDKit 2026.09 from the structure.
·Literature on PubChem

Data last updated 2026-10-14.