Pentaphenylantimony is an organoantimony compound containing five phenyl groups attached to one antimony atom. It has formula Sb(C6H5)5 (or SbPh5).
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| Preferred IUPAC name
Pentaphenyl-λ5-stibane | |
| Identifiers | |
3D model (JSmol)
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PubChem CID
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CompTox Dashboard (EPA)
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| Properties | |
| C30H25Sb | |
| Molar mass | 507.290 g·mol−1 |
| Related compounds | |
Other cations
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PPh5 AsPh5 BiPh5 |
Related compounds
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Pentamethylantimony Pentaethylantimony |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Structure
editThe structure of pentaphenylantimony has been the subject of several studies, and a definite ground state remains uncertain. The molecule adopts a roughly square pyramidal shape in the unsolvated crystal. In crystals of the solvate with cyclohexane or tetrahydrofuran, the compound adopts a trigonal bipyramid shape.[1] When dissolved, molecules are also trigonal bipyramidal.[1] According to solution NMR measurements, the phenyl groups all appear to be equivalent, indicating fluxionality.[2]
Solid pure pentaphenylantimony forms triclinic crystals in the P1 space group. The unit cell has a=10.286 b=10.600 and c=13.594 Å, α=79.20° β=70.43° γ=119.52°. The basal Sb-C bond length is 2.216 Å whereas the apex Sb-C length is 2.115 Å.[3]
Reactions
editPentaphenylantimony reacts with a variety of protic reagents (hydrogen halides, carboxylic acids, methanol, etc). Benzene is one product as well as a tetraphenylantimony(V) compound:[4]
- Ph5Sb + HOR → PhH + Ph4SbOR
- Ph5Sb + HX → PhH + Ph4SbX
Halogens also cleave one Sb-phenyl bond:
- Ph5Sb + X2 → PhX + Ph
When heated, pentaphenylantimony forms triphenylstibine, biphenyl and p-quaterphenyl.[5]
A reaction with carbon tetrachloride yields tetraphenylstibonium chloride, chlorobenzene, and benzene. Some of these reactions may proceed by radical pathways.[5]
Formation
editPentaphenylantimony can be formed by reacting dichlorotriphenylantimony with phenyl lithium.[3]
References
edit- ^ a b Lindquist-Kleissler, Brent; Weng, Monica; Le Magueres, Pierre; George, Graham N.; Johnstone, Timothy C. (2021-06-21). "Geometry of Pentaphenylantimony in Solution: Support for a Trigonal Bipyramidal Assignment from X-ray Absorption Spectroscopy and Vibrational Spectroscopic Data". Inorganic Chemistry. 60 (12): 8566–8574. doi:10.1021/acs.inorgchem.1c00496. ISSN 0020-1669. PMID 34087066. S2CID 235346648.
- ^ Beattie, I. R.; Livingston, K. M. S.; Ozin, G. A.; Sabine, R. (1972). "The shape of pentaphenylantimony and pentaphenylarsenic in solution". Journal of the Chemical Society, Dalton Transactions (7): 784. doi:10.1039/DT9720000784.
- ^ a b Beauchamp, A. L.; Bennett, Michael J.; Cotton, F. Albert (November 1968). "A reinvestigation of the crystal and molecular structure of pentaphenylantimony". Journal of the American Chemical Society. 90 (24): 6675–6680. doi:10.1021/ja01026a020.
- ^ Sharutin, V. V.; Sharutina, O. K.; Gubanova, Yu. O.; El'tsov, O. S. (September 2019). "Specific Features of the Reaction between Pentaphenylantimony and Bifunctional Acids: Structures of Bis(tetraphenylantimony) Glutarate, Benzene Solvate of Bis(tetraphenylantimony) 1,4-Cyclohexanedicarboxylate, Dioxane Solvate of Triphenylantimony Hydroxybenzoate, and Triphenylantimony 3-Hydroxybenzoate Adduct with Tetraphenylantimony Tetraphenylstiboxybenzaote and Toluene". Russian Journal of Inorganic Chemistry. 64 (9): 1138–1145. doi:10.1134/S0036023619090195. S2CID 203852991.
- ^ a b Shen, Kei-Wei; McEwen, William E.; Wolf, Alfred Peter (March 1969). "Photolysis and thermolysis of pentaphenylantimony in benzene". Journal of the American Chemical Society. 91 (6): 1283–1288. doi:10.1021/ja01034a003.
Further reading
edit- Smirnova, N.N.; Letyanina, I.A.; Larina, V.N.; Markin, A.V.; Sharutin, V.V.; Senchurin, V.S. (January 2009). "Thermodynamic properties of pentaphenylantimony Ph5Sb over the range from T→0K to 400K". The Journal of Chemical Thermodynamics. 41 (1): 46–50. doi:10.1016/j.jct.2008.08.002.
- Brock, C. P.; Ibers, J. A. (1976-01-01). "The role of crystal packing forces in the structure of pentaphenylantimony". Acta Crystallographica Section A. 32 (1): 38–42. Bibcode:1976AcCrA..32...38B. doi:10.1107/S0567739476000065.