Bismuth chloride

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Bismuth chloride
Bismuth chloride
Bismuth-trichloride-xtal-1982-3D-balls.png
Identifiers
CAS number 7787-60-2 YesY
PubChem 24591
ChemSpider 22993 YesY
RTECS number EB2690000
Jmol-3D images Image 1
Properties
Molecular formula BiCl3
Molar mass 315.34 g/mol
Appearance hygroscopic white to yellow crystals
Density 4.75 g/cm3
Melting point 227 °C (441 °F; 500 K)
Boiling point 447 °C (837 °F; 720 K)
Solubility in water Decomposes to bismuth oxychloride (BiOCl)
Solubility soluble in methanol, diethyl ether, acetone
Thermochemistry
Specific
heat capacity
C
0.333 J/(g K)
Std enthalpy of
formation
ΔfHo298
-1.202 kJ/g
Hazards
MSDS JT Baker
NFPA 704
Flammability code 0: Will not burn. E.g., water Health code 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g., chloroform Reactivity code 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g., liquid nitrogen Special hazards (white): no codeNFPA 704 four-colored diamond
LD50 3324 mg/kg, oral (rat)
Related compounds
Other anions bismuth fluoride, bismuth subsalicylate, bismuth trioxide
Other cations iron(III) chloride, manganese(II) chloride, cobalt(II) chloride
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
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Infobox references

Bismuth chloride is an inorganic compound with the chemical formula BiCl3. It is a common source of the Bi3+ ion. In the gas phase and in the crystal, the species adopts a pyramidal structure, in accord with VSEPR theory.

Preparation[edit]

Bismuth chloride can be synthesized directly by passing chlorine over bismuth.

2 Bi + 3 Cl2 → 2 BiCl3

or by dissolving bismuth metal in aqua regia, evaporating the mixture to give BiCl3.2H2O, which can be distilled to form the anhydrous trichloride.[1]

Alternatively, it may be prepared by adding hydrochloric acid to bismuth oxide and evaporating the solution.

Bi2O3 + 6 HCl → 2 BiCl3 + 3 H2O

Also, the compound can be prepared by dissolving bismuth in concentrated nitric acid and then adding solid sodium chloride into this solution.[2]

Bi + 6 HNO3 → Bi(NO3)3 + 3 H2O + 3 NO2
Bi(NO3)3 + 3 NaCl → BiCl3 + 3 NaNO3

Structure[edit]

In the gas phase BiCl3 is pyramidal with an Cl-Bi-Cl angle of 97.5° and a bond length of 242 pm.[3] In the solid state each Bi atom has three near neighbors at 250 pm, two at 324 pm and three at a mean of 336 pm,[4] the image above highlights the three closest neighbours. This structure is similar to that of AsCl3, AsBr3, SbCl3 and SbBr3.

Chemistry[edit]

Bismuth chloride is hydrolyzed readily to bismuth oxychloride, BiOCl:[5]

Bi3+
+ Cl
+ H
2
O
→ BiOCl (s) + 2 H+

This reaction can be reversed by adding an acid, such as hydrochloric acid.[6]

Reaction of solid BiCl3 with water vapour below 50 °C has been shown to produce the intermediate monohydrate, BiCl3.H2O.[7]

Bismuth chloride is an oxidizing agent, being readily reduced to metallic bismuth by reducing agents.

Chloro complexes[edit]

In contrast to the usual expectation by consistency with periodic trends, BiCl3 is a Lewis acid, forming a variety of chloro complexes such as [BiCl6]3− that strongly violates the octet rule. Furthermore the octahedral structure of this coordination complex does not follow the predictions of VSEPR theory, since the lone pair on bismuth is unexpectedly stereochemically inactive. The dianionic complex [BiCl5]2− does however adopt the expected square pyramidal structure.[8]

Tricaesium-hexachlorobismuthate-xtal-1986-3D-balls.png
Tricaesium-hexachlorobismuthate-xtal-1986-3D-SF.png
Hexachlorobismuthate-from-tricaesium-xtal-1986-3D-balls.png
Cs3[BiCl6]
Cs3[BiCl6]
[BiCl6]3−

Organic catalysis[edit]

Bismuth chloride is used as a catalyst in organic synthesis. In particular, it catalyzes the Michael reaction and the Mukaiyama-aldol reaction. The addition of other metal iodides increases its catalytic activity.[9]

Safety[edit]

Bismuth chloride is toxic. It causes irritation to the gastrointestinal and respiratory tract. Contact with skin may cause burns.

References[edit]

  1. ^ Godfrey, S. M.; McAuliffe, C. A.; Mackie, A. G.; Pritchard, R. G. (1998). Nicholas C. Norman, ed. Chemistry of arsenic, antimony, and bismuth. Springer. p. 90. ISBN 0-7514-0389-X. 
  2. ^ Pradyot Patnaik. Handbook of Inorganic Chemicals. McGraw-Hill, 2002, ISBN 0-07-049439-8
  3. ^ Töke, Orsolya, and Magdolna Hargittai. "Molecular structure of bismuth trichloride from combined electron diffraction and vibrational spectroscopic study." Structural Chemistry 6.2 (1995): 127-130.
  4. ^ Wells A.F. (1984) Structural Inorganic Chemistry 5th edition, pp. 879 - 884, Oxford Science Publications, ISBN 0-19-855370-6
  5. ^ Joel Henry Hildebrand (2008). Principles of Chemistry. BiblioBazaar, LLC. p. 191. ISBN 0-559-31877-4. 
  6. ^ Frank Welcher (2008). Chemical Solutions. READ BOOKS. p. 48. ISBN 1-4437-2907-8. 
  7. ^ Wosylus, Aron; Hoffmann, Stefan; Schmidt, Marcus; Ruck, Michael (2010). "In-situ Study of the Solid-Gas Reaction of BiCl3 to BiOCl via the Intermediate Hydrate BiCl3·H2O". European Journal of Inorganic Chemistry 2010 (10): 1469–1471. doi:10.1002/ejic.201000032. ISSN 1434-1948. 
  8. ^ Holleman, A. F.; Wiberg, E. "Inorganic Chemistry" Academic Press: San Diego, 2001. ISBN 0-12-352651-5.
  9. ^ Hitomi Suzuki; Yoshihiro Matano (2001). Organobismuth chemistry. Elsevier. pp. 403–404. ISBN 0-444-20528-4.