Iodobenzene (C6H5I): structure, properties and hazards

Names and identifiers

IUPAC name: iodobenzene
Synonyms: phenyl iodide, cross-coupling partner, Phenyl iodide
+ 36 more
Benzene, iodo-, Benzene iodide, Iodinebenzol, Iodo-benzene, 9HK5L7YBBR, NSC-9244, DTXSID8060452, RefChem:148515, DTXCID9042544, 209-719-6, 4-iodobenzene, 1-Iodobenzene, C6H5I, PHENYLIODIDE, 3-iodobenzene, MFCD00001029, iodiobenzene, phenyl-iodide, Iodo benzene, UNII-9HK5L7YBBR, Iodobenzene--d2, AI3-16898, HSDB 7859, NSC9244, CS-W008603, DB02252, IODOPHENYL, I0050, Iodobenzene, 98%, NSC 9244, EINECS 209-719-6, iodobenezene, benzene, iodo, 2-iodo-benzene, AMY10020, BCP22486
Molecular formula: C₆H₅I
Empirical formula: C₆H₅I
Molecular weight: 204.01 g/mol
Exact mass: 203.94360
CAS number: 591-50-4
PubChem CID: 11575
Canonical SMILES: C1=CC=C(C=C1)I
Isomeric SMILES: C1=CC=C(C=C1)I
InChI: InChI=1S/C6H5I/c7-6-4-2-1-3-5-6/h1-5H
InChIKey: SNHMUERNLJLMHN-UHFFFAOYSA-N
Molfile

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

Physical properties

TemperaturePressureDensity

Boiling point: 188 °C @760 [mmHg][2]
Density: 1.823 @25 °C[2]
Solubility in water: In water, 340 mg/L at 30 °C[1]
2 values
From Hazardous Substances Data Bank (HSDB), the most authoritative source here.
Value As written Source
– Miscible with acetone, benzene, carbon tetrachloride, and ligroin [1] Hazardous Substances Data Bank (HSDB)cites Lide, D.R., G.W.A. Milne (eds.). Handbook of Data on Organic Compounds. Volume I. 3rd ed. CRC Press, Inc. Boca Raton ,FL. 1994., p. V1: 998
–shown In water, 340 mg/L at 30 °C [1] Hazardous Substances Data Bank (HSDB)cites Chio CT et al; Environ Sci Technol 11: 475-8 (1977)
log P: log Kow = 3.25[1]
Vapor pressure: 1.06 mmHg at 25 °C (extrapolated)[1]
Flash point: 77 °C (171 °F) - closed cup[1]

Value	As written	Source
–	Miscible with acetone, benzene, carbon tetrachloride, and ligroin	[1] Hazardous Substances Data Bank (HSDB)cites Lide, D.R., G.W.A. Milne (eds.). Handbook of Data on Organic Compounds. Volume I. 3rd ed. CRC Press, Inc. Boca Raton ,FL. 1994., p. V1: 998
–shown	In water, 340 mg/L at 30 °C	[1] Hazardous Substances Data Bank (HSDB)cites Chio CT et al; Environ Sci Technol 11: 475-8 (1977)

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: 7
Rings: 1
Aromatic rings: 1
Fraction sp³ carbons (Fsp3): 0
H-bond donors: 0
H-bond acceptors: 0
Rotatable bonds: 0
TPSA (Å²): 0
Formal charge: 0
XLogP3: 3.2 PubChem
Complexity: 46 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

C35.32%
H2.47%
I62.20%

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: 2.29 Crippen (Wildman and Crippen 1999)
log S (water solubility): -3.18 ESOL (Delaney 2004), log mol/L
Synthetic accessibility: 1.48 SA score, 1 easy to 10 hard (Ertl and Schuffenhauer 2009)

Drug-likeness: Lipinski’s rule of five

Molecular weight ≤ 500: 204.01
log P ≤ 5 (Crippen): 2.29
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

Warning

Most widely reported: 57 company reports to ECHA. Source [3].

Harmful or irritant

H302Harmful if swallowed (98.2% of reports)
H319Causes serious eye irritation (77.2% of reports)
H332Harmful if inhaled (12.3% of reports)

Precautionary statements: P261, P264, P264+P265, P270, P271, P280, P301+P317, P304+P340, P305+P351+P338, P317, P330, P337+P317, P501

View all classifications (2)

[3] European Chemicals Agency (ECHA)This chemical does not meet GHS hazard criteria for 1.8% (1 of 57) of reports.
[3] European Chemicals Agency (ECHA) · 57 reports · WarningH302, H319, H332

Storage

Keep container tightly closed in a dry and well-ventilated place. Containers which are opened must be carefully resealed and kept upright to prevent leakage. Light sensitive.[1]

Safety data sheets on the supplier’s page: Matrix Scientific, Biorbyt, Alfa Chemistry.

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]Hazardous Substances Data Bank (HSDB) · Public domain (US NLM) · via PubChem · retrieved 2026-10-14
[2]PAC Chemical Database, U.S. Department of Energy · Public domain (US DOE) · via PubChem · retrieved 2026-10-14
[3]European Chemicals Agency (ECHA) · ECHA legal notice: reuse with acknowledgement · via PubChem · retrieved 2026-10-14
[4]NMRShiftDB · Linked only · via PubChem · retrieved 2026-10-14
[5]SpectraBase · Linked only · via PubChem · retrieved 2026-10-14
[6]Human Metabolome Database (HMDB) · Linked only · via PubChem · retrieved 2026-10-14
[7]MassBank of North America (MoNA) · CC BY 4.0 · via PubChem · retrieved 2026-10-14
[8]NIST Mass Spectrometry Data Center · Linked only · via PubChem · retrieved 2026-10-14
[9]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.