Phenylacetylene

Athanor · official

C₈H₆ · 102.13 g/mol

IUPAC name: ethynylbenzene

Also called ethynylbenzene, Sonogashira partner

Reagents Rings

Open in Athanor

Drawn from its SMILES with RDKit

DangerFlammable liquid and vapor · May be fatal if swallowed and enters airways · Causes skin irritation · Causes serious eye irritation · May cause respiratory irritation

Names and identifiers

IUPAC name: ethynylbenzene
Synonyms: ethynylbenzene, Sonogashira partner, Ethynylbenzene
+ 35 more
Phenylethyne, Benzene, ethynyl-, 1-Phenylethyne, Phenylacetylide, phenyl-acetylene, 239WSR2IBO, NSC-4957, DTXSID1060211, RefChem:596816, DTXCID1041477, 208-645-1, ethynyl-benzene, phenyl acetylene, Ethyne, phenyl-, Acetylene, phenyl-, ethynyl benzene, Phenylacethylene, MFCD00008570, C8H6, 1-ethynylbenzene, 1-phenylacetylene, NSC 4957, EINECS 208-645-1, UNII-239WSR2IBO, ethynylbenzen, phenylacetylen, Ethinylbenzene, AI3-24180, 1-ethynyl-benzene, Phenylacetylene, 98%, Ph-C=CH, ETHYNYL-D-BENZENE, Phenylacetylene, ~98%, ETHYNYLBENZENE [MI], SCHEMBL4884
Molecular formula: C₈H₆
Empirical formula: C₄H₃
Molecular weight: 102.13 g/mol
Exact mass: 102.04695
CAS number: 536-74-3
PubChem CID: 10821
Canonical SMILES: C#CC1=CC=CC=C1
Isomeric SMILES: C#CC1=CC=CC=C1
InChI: InChI=1S/C8H6/c1-2-8-6-4-3-5-7-8/h1,3-7H
InChIKey: UEXCJVNBTNXOEH-UHFFFAOYSA-N
Molfile

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

Physical properties

TemperaturePressureDensity

Melting point: -45 °C[1]
Boiling point: 142 °C @760 [mmHg][1]
Density: 0.94 @25 °C[1]
Vapor pressure: 17.6 [mmHg] @37.700000000000003 °C[1]

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: 8
Rings: 1
Aromatic rings: 1
Fraction sp³ carbons (Fsp3): 0
H-bond donors: 0
H-bond acceptors: 0
Rotatable bonds: 0 computed here · PubChem 1
TPSA (Å²): 0
Formal charge: 0
XLogP3: 2.5 PubChem
Complexity: 98 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

C94.08%
H5.92%

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: 1.67 Crippen (Wildman and Crippen 1999)
log S (water solubility): -2.08 ESOL (Delaney 2004), log mol/L
Synthetic accessibility: 1.78 SA score, 1 easy to 10 hard (Ertl and Schuffenhauer 2009)

Drug-likeness: Lipinski’s rule of five

Molecular weight ≤ 500: 102.14
log P ≤ 5 (Crippen): 1.67
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: 224 company reports to ECHA. Source [2].

Flammable
Harmful or irritant
Health hazard

H226Flammable liquid and vapor
H304May be fatal if swallowed and enters airways (87.5% of reports)
H315Causes skin irritation (94.6% of reports)
H319Causes serious eye irritation (97.3% of reports)
H335May cause respiratory irritation (18.3% of reports)

Precautionary statements: P210, P233, P240, P241, P242, P243, P261, P264, P264+P265, P271, P280, P301+P316, P302+P352, P303+P361+P353, P304+P340, P305+P351+P338, P319, P321, P331, P332+P317, P337+P317, P362+P364, P370+P378, P403+P233, P403+P235, P405, P501

Safety data sheets on the supplier’s page: LGC Standards, 001Chemical, Enamine.

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]PAC Chemical Database, U.S. Department of Energy · Public domain (US DOE) · via PubChem · retrieved 2026-10-14
[2]European Chemicals Agency (ECHA) · ECHA legal notice: reuse with acknowledgement · via PubChem · retrieved 2026-10-14
[3]NMRShiftDB · Linked only · via PubChem · retrieved 2026-10-14
[4]SpectraBase · Linked only · via PubChem · retrieved 2026-10-14
[5]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.