Thiophene

Athanor · official

C₄H₄S · 84.14 g/mol

Also called thiofuran, thiole

Rings

Open in Athanor

Drawn from its SMILES with RDKit

DangerHighly Flammable liquid and vapor · Harmful if swallowed · Harmful in contact with skin · Causes skin irritation · Causes serious eye damage · Causes serious eye irritation · Toxic if inhaled · Harmful if inhaled · May cause respiratory irritation · Harmful to aquatic life with long lasting effects

Names and identifiers

IUPAC name: thiophene
Synonyms: thiofuran, thiole, Thiofuran
+ 36 more
Thiole, Thiophen, Thiotetrole, Thiacyclopentadiene, Thiofurfuran, Divinylene sulfide, Thiaphene, Thiofuram, Furan, thio-, Huile HSO, Thiofen, Huile H50, CP 34, USAF EK-1860, CCRIS 2935, HSDB 130, NSC 405073, DTXSID8026145, UNII-SMB37IQ40B, EINECS 203-729-4, SMB37IQ40B, BRN 0103222, AI3-15417, NSC-405073, DTXCID006145, CHEBI:30856, EC 203-729-4, Divinylene sulphide, RefChem:6305, HUILE HS0, CP34, 203-729-4, MFCD00005413, Hopkin's lactic acid reagent, Thiofen [Czech], Thiophenes
Molecular formula: C₄H₄S
Empirical formula: C₄H₄S
Molecular weight: 84.14 g/mol
Exact mass: 84.00337
CAS number: 110-02-1
PubChem CID: 8030
Canonical SMILES: C1=CSC=C1
Isomeric SMILES: C1=CSC=C1
InChI: InChI=1S/C4H4S/c1-2-4-5-3-1/h1-4H
InChIKey: YTPLMLYBLZKORZ-UHFFFAOYSA-N
Molfile

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

Physical properties

TemperaturePressureDensity

Appearance: Thiophene appears as a colorless liquid with an unpleasant odor. Insoluble in water and slightly denser than water. Flash point -1 °C (30 °F). Vapors heavier than air. Irritates the skin, eyes, and mucous membranes. Used to make pharmaceuticals and dyes.[1]
3 values
From CAMEO Chemicals, the most authoritative source here.
Value As written Source
–shown Thiophene appears as a colorless liquid with an unpleasant odor. Insoluble in water and slightly denser than water. Flash point 30 °F. Vapors heavier than air. Irritates the skin, eyes, and mucous membranes. Used to make pharmaceuticals and dyes. [1] CAMEO Chemicals
– COLOURLESS LIQUID WITH PUNGENT ODOUR. [2] ILO-WHO International Chemical Safety Cards (ICSCs)
– COLORLESS LIQUID [3] Hazardous Substances Data Bank (HSDB)cites Lewis, R.J., Sr (Ed.). Hawley's Condensed Chemical Dictionary. 12th ed. New York, NY: Van Nostrand Rheinhold Co., 1993, p. 1145
Melting point: -38.2 °C (-36.8 °F, NTP 1992)[1]
2 values
2 of 2 sources agree on it (most common value).
Value As written Source
−38.2 °Cshown -36.8 °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.
−38 °C -38 °C [2] ILO-WHO International Chemical Safety Cards (ICSCs)
Boiling point: 84.4 °C (183.9 °F) at 760 mmHg (NTP, 1992)[1]
2 values
2 of 2 sources agree on it (most common value).
Value As written Source
84.4 °Cshown 183.9 °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.
84 °C 84 °C [2] ILO-WHO International Chemical Safety Cards (ICSCs)
Density: 1.0649 at 20 °C (68 °F) (NTP, 1992) - Denser than water[1]
2 values
2 of 2 sources agree on it (most common value).
Value As written Source
–shown 1.0649 at 68 °F (NTP, 1992) - Denser than water [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.
– Relative density (water = 1): 1.06 [2] ILO-WHO International Chemical Safety Cards (ICSCs)
Solubility in water: Solubility in water: none[2]
3 values
From ILO-WHO International Chemical Safety Cards (ICSCs), the most authoritative source here.
Value As written Source
– less than 1 mg/mL at 75 °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.
– water solubility = 3,020 mg/l @ 25 °C [3] Hazardous Substances Data Bank (HSDB)cites Yalkowsky SH, Dannenfelser RM; The AQUASOL dATAbASE of Aqueous Solubility. Fifth ed, Tucson, AZ: Univ Az, College of Pharmacy (1992)
–shown Solubility in water: none [2] ILO-WHO International Chemical Safety Cards (ICSCs)
log P: 1.81[2]
2 values
2 of 2 sources agree on it (most common value).
Value As written Source
– log Kow = 1.81 [3] 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. 8
–shown 1.81 [2] ILO-WHO International Chemical Safety Cards (ICSCs)
Vapor pressure: Vapor pressure, kPa at 12.5 °C: 5.3[2]
5 values
Sources disagree; from ILO-WHO International Chemical Safety Cards (ICSCs), the most authoritative.
Value As written Source
20 mmHg 20 mmHg at 32 °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.
60 mmHg 60 mmHg at 68.2 °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.
760 mmHg 760 mmHg at 183.9 °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.
79.7 mmHg 79.7 mm Hg @ 25 °C [3] Hazardous Substances Data Bank (HSDB)cites Boublik, T., Fried, V., and Hala, E., The Vapour Pressures of Pure Substances. Second Revised Edition. Amsterdam: Elsevier, 1984.
39.8 mmHgshown Vapor pressure, kPa at 12.5 °C: 5.3 [2] ILO-WHO International Chemical Safety Cards (ICSCs)
Flash point: -1 °C[2]
3 values
3 of 3 sources agree on it (most common value).
Value As written Source
−1 °C 30 °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.
−1 °C 30 °F (-1 °C) (CLOSED CUP) [3] Hazardous Substances Data Bank (HSDB)cites Fire Protection Guide to Hazardous Materials. 12 ed. Quincy, MA: National Fire Protection Association, 1997., p. 325-87
−1 °Cshown -1 °C [2] ILO-WHO International Chemical Safety Cards (ICSCs)
Autoignition temperature: 395 °C[2]
Viscosity: Reported, but no value passed the checks.
The value and why
0.621 mPa.s (no temperature given; source [3])

Value	As written	Source
–shown	Thiophene appears as a colorless liquid with an unpleasant odor. Insoluble in water and slightly denser than water. Flash point 30 °F. Vapors heavier than air. Irritates the skin, eyes, and mucous membranes. Used to make pharmaceuticals and dyes.	[1] CAMEO Chemicals
–	COLOURLESS LIQUID WITH PUNGENT ODOUR.	[2] ILO-WHO International Chemical Safety Cards (ICSCs)
–	COLORLESS LIQUID	[3] Hazardous Substances Data Bank (HSDB)cites Lewis, R.J., Sr (Ed.). Hawley's Condensed Chemical Dictionary. 12th ed. New York, NY: Van Nostrand Rheinhold Co., 1993, p. 1145

Value	As written	Source
−38.2 °Cshown	-36.8 °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.
−38 °C	-38 °C	[2] ILO-WHO International Chemical Safety Cards (ICSCs)

Value	As written	Source
84.4 °Cshown	183.9 °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.
84 °C	84 °C	[2] ILO-WHO International Chemical Safety Cards (ICSCs)

Value	As written	Source
–shown	1.0649 at 68 °F (NTP, 1992) - Denser than water	[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.
–	Relative density (water = 1): 1.06	[2] ILO-WHO International Chemical Safety Cards (ICSCs)

Value	As written	Source
–	less than 1 mg/mL at 75 °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.
–	water solubility = 3,020 mg/l @ 25 °C	[3] Hazardous Substances Data Bank (HSDB)cites Yalkowsky SH, Dannenfelser RM; The AQUASOL dATAbASE of Aqueous Solubility. Fifth ed, Tucson, AZ: Univ Az, College of Pharmacy (1992)
–shown	Solubility in water: none	[2] ILO-WHO International Chemical Safety Cards (ICSCs)

Value	As written	Source
–	log Kow = 1.81	[3] 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. 8
–shown	1.81	[2] ILO-WHO International Chemical Safety Cards (ICSCs)

Value	As written	Source
20 mmHg	20 mmHg at 32 °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.
60 mmHg	60 mmHg at 68.2 °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.
760 mmHg	760 mmHg at 183.9 °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.
79.7 mmHg	79.7 mm Hg @ 25 °C	[3] Hazardous Substances Data Bank (HSDB)cites Boublik, T., Fried, V., and Hala, E., The Vapour Pressures of Pure Substances. Second Revised Edition. Amsterdam: Elsevier, 1984.
39.8 mmHgshown	Vapor pressure, kPa at 12.5 °C: 5.3	[2] ILO-WHO International Chemical Safety Cards (ICSCs)

Value	As written	Source
−1 °C	30 °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.
−1 °C	30 °F (-1 °C) (CLOSED CUP)	[3] Hazardous Substances Data Bank (HSDB)cites Fire Protection Guide to Hazardous Materials. 12 ed. Quincy, MA: National Fire Protection Association, 1997., p. 325-87
−1 °Cshown	-1 °C	[2] 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: 5
Rings: 1
Aromatic rings: 1
Fraction sp³ carbons (Fsp3): 0
H-bond donors: 0
H-bond acceptors: 1
Rotatable bonds: 0
TPSA (Å²): 0 computed here · PubChem 28.2
Formal charge: 0
XLogP3: 1.8 PubChem
Complexity: 22 PubChem
Stereocenters: None
Double-bond geometry: None specified
Point group: C2v of one 3D conformer with its hydrogens, by Athanor’s engine (as in the app)

Elemental analysis

C57.10%
H4.79%
S38.11%

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: 1.75 Crippen (Wildman and Crippen 1999)
log S (water solubility): -2.2 ESOL (Delaney 2004), log mol/L
Synthetic accessibility: 3.19 SA score, 1 easy to 10 hard (Ertl and Schuffenhauer 2009)

Drug-likeness: Lipinski’s rule of five

Molecular weight ≤ 500: 84.14
log P ≤ 5 (Crippen): 1.75
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

Most widely reported: 391 company reports to ECHA. Source [4].

Flammable
Corrosive
Acute toxicity
Harmful or irritant

NFPA 704[3]

H225Highly Flammable liquid and vapor (98.5% of reports)
H302Harmful if swallowed (67% of reports)
H312Harmful in contact with skin (19.7% of reports)
H315Causes skin irritation (68.8% of reports)
H318Causes serious eye damage (36.1% of reports)
H319Causes serious eye irritation (51.2% of reports)
H331Toxic if inhaled (13.6% of reports)
H332Harmful if inhaled (30.2% of reports)
H335May cause respiratory irritation (36.1% of reports)
H412Harmful to aquatic life with long lasting effects (57% of reports)

Precautionary statements: P210, P233, P240, P241, P242, P243, P261, P264, P264+P265, P270, P271, P273, P280, P301+P317, P302+P352, P303+P361+P353, P304+P340, P305+P351+P338, P305+P354+P338, P316, P317, P319, P321, P330, P332+P317, P337+P317, P362+P364, P370+P378, P403+P233, P403+P235, P405, P501

View all classifications (2)

[4] European Chemicals Agency (ECHA)This chemical does not meet GHS hazard criteria for 1.5% (6 of 391) of reports.
[4] European Chemicals Agency (ECHA) · 391 reports · DangerH225, H302, H312, H315, H318, H319, H331, H332, H335, H412

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…[5]
Fresh air, rest. Refer for medical attention.[2]
Remove contaminated clothes. Rinse and then wash skin with water and soap.[2]

Storage

Fireproof. Separated from oxidizing materials.[2]

Incompatibilities

Explosive reaction with N-nitrosoacetanilide. Violent or explosive reaction with nitric acid. Incompatible with oxidizing materials.[3]

Safety data sheets on the supplier’s page: TargetMol, Cooke Chemical Co., Ltd, Ambinter.

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]ILO-WHO International Chemical Safety Cards (ICSCs) · CC BY 4.0 · via PubChem · retrieved 2026-10-14
[3]Hazardous Substances Data Bank (HSDB) · Public domain (US NLM) · via PubChem · retrieved 2026-10-14
[4]European Chemicals Agency (ECHA) · ECHA legal notice: reuse with acknowledgement · via PubChem · retrieved 2026-10-14
[5]Emergency Response Guidebook (ERG) · Public domain (US DOT) · via PubChem · retrieved 2026-10-14
[6]NMRShiftDB · Linked only · via PubChem · retrieved 2026-10-14
[7]Human Metabolome Database (HMDB) · Linked only · via PubChem · retrieved 2026-10-14
[8]SpectraBase · Linked only · via PubChem · retrieved 2026-10-14
[9]NIST Mass Spectrometry Data Center · 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.