Antimony pentachloride

Antimony pentachloride

Antimony pentachloride
Names
IUPAC names Antimony pentachloride Antimony(V) chloride
Other names Antimonic chloride Antimony perchloride
Identifiers
CAS Number	7647-18-9  Y
3D model (JSmol)	Interactive image Interactive image
ChemSpider	10613049  Y
ECHA InfoCard	100.028.729
EC Number	231-601-8
PubChem CID	24294
RTECS number	CC5075000
UNII	0S9308207L  Y
CompTox Dashboard (EPA)	DTXSID30893043
InChI InChI=1S/5ClH.Sb/h5*1H;/q;;;;;+3/p-5 Y Key: PZVOXSCNPLCIRA-UHFFFAOYSA-I Y 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/cm3 (20 °C) [1] 2.36 g/cm3 (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]
Magnetic susceptibility (χ)	−120.0·10−6 cm3/mol
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 [3]
Heat capacity (C)	120.9 J/mol·K (gas)
Std molar entropy (S⦵298)	295 J/mol·K
Std enthalpy of formation (ΔfH⦵298)	−437.2 kJ/mol
Gibbs free energy (ΔfG⦵)	−345.35 kJ/mol
Hazards
Occupational safety and health (OHS/OSH):
Inhalation hazards	Toxic
GHS labelling: [2]
Pictograms
Signal word	Danger
Hazard statements	H314, H411
Precautionary statements	P273, P280, P305+P351+P338, P310
NFPA 704 (fire diamond)	4 0 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]
NIOSH (US health exposure limits):
PEL (Permissible)	TWA 0.5 mg/m3 (as Sb) [5]
REL (Recommended)	TWA 0.5 mg/m3 (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). N  verify  (what is  YN ?) Infobox references

Antimony pentachloride is a chemical compound with the formula SbCl₅. It is a colourless oil, but typical samples are yellowish due to dissolved chlorine. Owing to its tendency to hydrolyse to hydrochloric acid, SbCl₅ is a highly corrosive substance and must be stored in glass or PTFE containers.

Preparation and structure

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

SbCl₃ + Cl₂ → SbCl₅

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

Reactions

This compounds reacts with water to form antimony pentoxide and hydrochloric acid: ^[7]

2 SbCl₅ + 5 H₂O → Sb₂O₅ + 10 HCl

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

This compound forms adducts with many Lewis bases. SbCl₅ is a soft Lewis acid and its ECW model parameters are E_A = 3.64 and C_A = 10.42. It is used as the standard Lewis acid in the Gutmann scale of Lewis basicity. ^{[8] [9]}

It is also a strong oxidizing agent. ^[10] For example aromatic ethers are oxidized to their radical cations according to the following stoichiometry: ^[11]

3 SbCl₅ + 2 ArH → 2 (ArH+)(SbCl₆⁻) + SbCl₃

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. ^[12]

References

1. "Antimony pentachloride (UK PID)".
2. Sigma-Aldrich Co., Antimony(V) chloride. Retrieved on 2014-05-29.
3. "Antimony(V) chloride".
4. Antimony pentachloride in Linstrom, Peter J.; Mallard, William G. (eds.); NIST Chemistry WebBook, NIST Standard Reference Database Number 69, National Institute of Standards and Technology, Gaithersburg (MD) (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   978-0-08-037941-8.
7. Pradyot Patnaik. Handbook of Inorganic Chemicals. McGraw-Hill, 2002, ISBN   0-07-049439-8
8. V. Gutmann (1976). "Solvent effects on the reactivities of organometallic compounds". Coord. Chem. Rev. 18 (2): 225–255. doi:10.1016/S0010-8545(00)82045-7.
9. Cramer, R. E.; Bopp, T. T. (1977). "Graphical display of the enthalpies of adduct formation for Lewis acids and bases". Journal of Chemical Education. 54: 612–613. doi:10.1021/ed054p612. The plots shown in this paper used older parameters. Improved E&C parameters are listed in ECW model.
10. Connelly, N. G.; Geiger, W. E. (1996). "Chemical Redox Agents for Organometallic Chemistry". Chem. Rev. 96 (2): 877–922. doi:10.1021/cr940053x. PMID   11848774.
11. Rathore, R.; Kumar, A. S.; Lindeman, S. V.; Kochi, J. K. (1998). "Preparation and Structures of Crystalline Aromatic Cation-Radical Salts. Triethyloxonium Hexachloroantimonate as a Novel (One-Electron) Oxidant". The Journal of Organic Chemistry. 63 (17): 5847–5856. doi:10.1021/jo980407a. PMID   11672186.
12. Shekarchi, M.; Behbahani, F. K Catal. Lett.2017147 2950. doi:10.1007/s10562-017-2194-2