1-Butyne
Athanor · official
C4H6 · 54.09 g/mol
IUPAC name: but-1-yne
Also called ethylacetylene
DangerExtremely flammable gas · Contains gas under pressure; may explode if heatedNames and identifiers
- IUPAC name
- but-1-yne
- Synonyms
- ethylacetylene, but-1-yne, Ethyl acetylene
+ 36 more
Butyne-1, UN2452, UNII-A6B47CPN6W, EINECS 203-451-3, A6B47CPN6W, Ethylacetylene, inhibited, Ethyl acetylene, inhibited, C2H5C.$.CH, DTXSID4029141, CHEBI:48087, UN 2452, ETHYL ACETYLENE, (STABILIZED), ETHYL ACETYLENE, [STABILIZED], Etilacetileno, inhibido, RefChem:75284, Ethylacetylene, stabilise, DTXCID709141, ETHYL ACETYLENE, STABILIZED, Etilacetileno, inhibido (Spanish DOT), Ethylacetylene, stabilise (French DOT), InChI=1/C4H6/c1-3-4-2/h1H,4H2,2H, KDKYADYSIPSCCQ-UHFFFAOYSA-N, Ethylacetylene, Ethylethyne, MFCD00039944, Butyne, n-but-1-yne, 1-Butyne 98%, SCHEMBL3342, SCHEMBL3343, SCHEMBL4736, 1-Butyne, >=98%, SCHEMBL20344, SCHEMBL37868, SCHEMBL141281, SCHEMBL600739
- Molecular formula
- C4H6
- Empirical formula
- C2H3
- Molecular weight
- 54.09 g/mol
- Exact mass
- 54.04695
- CAS number
- 107-00-6
- PubChem CID
- 7846
- Canonical SMILES
- CCC#C
- Isomeric SMILES
- CCC#C
- InChI
- InChI=1S/C4H6/c1-3-4-2/h1H,4H2,2H3
- InChIKey
- KDKYADYSIPSCCQ-UHFFFAOYSA-N
- Molfile
Names, InChI and the identifiers from PubChem, retrieved 2026-10-14.
Physical properties
- Appearance
- Ethyl acetylene, stabilized appears as a colorless gas. Denser than air. Prolonged exposure to intense heat may cause the containers to rupture violently and rocket.[1]
2 values
From CAMEO Chemicals, the most authoritative source here.
Value As written Source –shown Ethyl acetylene, stabilized appears as a colorless gas. Denser than air. Prolonged exposure to intense heat may cause the containers to rupture violently and rocket. [1] CAMEO Chemicals – Liquid; Gas Vapor [2] EPA Chemical Data Reporting (CDR)
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
- 4
- Rings
- 0
- Aromatic rings
- 0
- Fraction sp³ carbons (Fsp3)
- 0.5
- H-bond donors
- 0
- H-bond acceptors
- 0
- Rotatable bonds
- 0
- TPSA (Ų)
- 0
- Formal charge
- 0
- XLogP3
- 1.3 PubChem
- Complexity
- 35 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
- C88.82%
- H11.18%
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
- 1.03 Crippen (Wildman and Crippen 1999)
- log S (water solubility)
- -0.82 ESOL (Delaney 2004), log mol/L
- Synthetic accessibility
- 3.1 SA score, 1 easy to 10 hard (Ertl and Schuffenhauer 2009)
Drug-likeness: Lipinski’s rule of five
- Molecular weight ≤ 500: 54.09
- log P ≤ 5 (Crippen): 1.03
- H-bond donors ≤ 5: 0
- H-bond acceptors ≤ 10: 0
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: 164 company reports to ECHA. Source [3].
- Flammable
- Compressed gas
- H220Extremely flammable gas (97% of reports)
- H280Contains gas under pressure; may explode if heated (97% of reports)
Precautionary statements: P203, P210, P222, P280, P377, P381, P403, P410+P403
View all classifications (2)
- [3] European Chemicals Agency (ECHA)This chemical does not meet GHS hazard criteria for 3% (5 of 164) of reports.
- [3] European Chemicals Agency (ECHA) · 164 reports · DangerH220, H280
First aid
- Excerpt from ERG Guide 116 [Gases - Flammable (Unstable); polymerization hazard]: Refer to the "General First Aid" section. Specific First Aid: In case of contact with liquefied gas, only medical personnel should attempt thawing frosted parts. In case of burns, immediately cool affected skin for as long as possible with cold water. Do not remove clothing if adhering to skin. (ERG, 2024)[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…[4]
Safety data sheets on the supplier’s page: BenchChem, Molport, MuseChem.
Always read the supplier’s safety data sheet before working with it.
Spectra
- NMRNMRShiftDB
- 13C NMRSpectraBase (BRUK HX-90)
- GC-MSNIST Mass Spectrometry Data Center · NIST Mass Spectrometry Data Center · SpectraBase
- Vapor Phase IRSpectraBase (Vapor Phase)
- RamanSpectraBase
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]European Chemicals Agency (ECHA) · ECHA legal notice: reuse with acknowledgement · via PubChem · retrieved 2026-10-14
- [4]Emergency Response Guidebook (ERG) · Public domain (US DOT) · via PubChem · retrieved 2026-10-14
- [5]NMRShiftDB · Linked only · via PubChem · retrieved 2026-10-14
- [6]SpectraBase · Linked only · via PubChem · retrieved 2026-10-14
- [7]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.