Antimony pentachloride

Antimony pentachloride

Names
IUPAC names Antimony pentachloride Antimony(V) chloride
Other names Antimonic chloride Antimony quintachloride Antimony perchloride
Identifiers
CAS Number	7647-18-9
ChemSpider	10613049
EC Number	231-601-8
Jmol interactive 3D	Image Image
PubChem	24294
RTECS number	CC5075000
InChI InChI=1S/5ClH.Sb/h5*1H;/q;;;;;+3/p-5 Key: PZVOXSCNPLCIRA-UHFFFAOYSA-I InChI=1/5ClH.Sb.3H/h5*1H;;;;/q;;;;;+3;;;/p-5/r5ClH.H3Sb/h5*1H;1H3/q;;;;;+3/p-5 Key: KUGFODPTKMDJNG-MEZDTJOHAL InChI=1/5ClH.Sb/h5*1H;/q;;;;;+3/p-5 Key: PZVOXSCNPLCIRA-AACRGIKGAS
SMILES [Cl-].[Cl-].[Cl-].[Cl-].[Cl-].[SbH3+3] [SbH3+3].[Cl-].[Cl-].[Cl-].[Cl-].[Cl-]
Properties
Chemical formula	Cl5Sb
Molar mass	299.01 g·mol^−1
Appearance	colorless or reddish-yellow (fuming) liquid, oily
Odor	pungent, offensive
Density	2.336 g/cm^3 (20 °C)[1] 2.36 g/cm^3 (25 °C)[2]
Melting point	2.8 °C (37.0 °F; 275.9 K)
Boiling point	140 °C (284 °F; 413 K) decomposes from 106 °C[3] 79 °C (174 °F; 352 K) at 22 mmHg[1] 92 °C (198 °F; 365 K) at 30 mmHg[2]
Solubility in water	reacts
Solubility	soluble in alcohol, HCl, tartaric acid, CHCl3, CS2, CCl4
Solubility in selenium(IV) oxychloride	62.97 g/100 g (25 °C)
Vapor pressure	0.16 kPa (25 °C) 4 kPa (40 °C) 7.7 kPa (100 °C)[4]
Refractive index (nD)	1.59255
Viscosity	2.034 cP (29.4 °C)[1] 1.91 cP (35 °C)
Structure
Molecular shape	Trigonal bipyramidal
Dipole moment	0 D
Thermochemistry
Specific heat capacity (C)	120.9 J/mol·K (gas)[3]
Std molar entropy (S^o298)	295 J/mol·K[3]
Std enthalpy of formation (ΔfH^o298)	-437.2 kJ/mol[3]
Gibbs free energy (ΔfG˚)	-345.35 kJ/mol[3]
Hazards
GHS pictograms	[2]
GHS signal word	Danger
GHS hazard statements	H314, H411[2]
GHS precautionary statements	P273, P280, P305+351+338, P310[2]
EU classification (DSD)	C N
R-phrases	R34, R51/53
S-phrases	(S1/2), S26, S45, S61
Inhalation hazard	Toxic
NFPA 704	0 3 1 W
Flash point	77 °C (171 °F; 350 K)
Lethal dose or concentration (LD, LC):
LD50 (Median dose)	1115 mg/kg, (rat, oral)[3]
US health exposure limits (NIOSH):
PEL (Permissible)	TWA 0.5 mg/m^3 (as Sb)[5]
REL (Recommended)	TWA 0.5 mg/m^3 (as Sb)[5]
Related compounds
Other anions	Antimony pentafluoride
Other cations	Phosphorus pentachloride
Related compounds	Antimony trichloride
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

Antimony pentachloride is a chemical compound with the formula SbCl₅. It is a colourless oil, but typical samples are yellowish due to impurities. Owing to its tendency to hydrolyse to hydrochloric acid, SbCl₅ is a highly corrosive substance and carbonizes non-fluorinated plastics.

Preparation and structure

Antimony pentachloride is prepared by passing chlorine gas into molten antimony trichloride:

SbCl₃ + Cl₂ → SbCl₅

Gaseous SbCl₅ has a trigonal prismatic structure.^[6]

Reactions

Antimony pentachloride hydrolyses readily to give hydrochloric acid:

2 SbCl₅ + 5 H₂O → Sb₂O₅ + 10 HCl

This reaction is suppressed in the presence of a large excess of chloride, owing to the formation of the hexachloroantimonate complex ion:

SbCl₅ + Cl⁻ → [SbCl₆]⁻

The mono- and tetrahydrates are known, SbCl₅·H₂O SbCl₅·4 H₂O.

This compound forms adducts with many Lewis bases. It is used as the standard Lewis acid in the Gutmann scale of Lewis basicity.^[7]

It is also a strong oxidizing agent.^[8]

Applications

Antimony pentachloride is used as a polymerization catalyst and for the chlorination of organic compounds.

Precautions

Antimony pentachloride is a highly corrosive substance that should be stored away from heat and moisture. It is a chlorinating agent and, in the presence of moisture, it releases hydrogen chloride gas. Because of this, it may etch even stainless-steel tools (such as needles), if handled in a moist atmosphere. It should not be handled with non-fluorinated plastics (such as plastic syringes, plastic septa, or needles with plastic fittings), since it melts and carbonizes plastic materials.

References

1. http://www.inchem.org/documents/ukpids/ukpids/ukpid36.htm
2. Sigma-Aldrich Co., Antimony(V) chloride. Retrieved on 2014-05-29.
3. http://chemister.ru/Database/properties-en.php?dbid=1&id=1979
4. Antimony pentachloride in Linstrom, P.J.; Mallard, W.G. (eds.) NIST Chemistry WebBook, NIST Standard Reference Database Number 69. National Institute of Standards and Technology, Gaithersburg MD. http://webbook.nist.gov (retrieved 2014-05-29)
5. "NIOSH Pocket Guide to Chemical Hazards #0036". National Institute for Occupational Safety and Health (NIOSH).
6. Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 0-08-037941-9.
7. V. Gutmann (1976). "Solvent effects on the reactivities of organometallic compounds". Coord. Chem. Rev. 18 (2): 225. doi:10.1016/S0010-8545(00)82045-7.
8. Connelly, N. G. and Geiger, W. E. (1996). "Chemical Redox Agents for Organometallic Chemistry". Chem. Rev. 96: 877–922. doi:10.1021/cr940053x. PMID 11848774.

External links