Pentaphenylantimony - Misplaced Pages

Pentaphenylantimony
Names

Preferred IUPAC name Pentaphenyl-λ-stibane
Identifiers
CAS Number	2170-05-0
3D model (JSmol)	Interactive image
ChemSpider	9987829
PubChem CID	11813170
CompTox Dashboard (EPA)	DTXSID60473337
InChI InChI=1S/5C6H5.Sb/c51-2-4-6-5-3-1;/h51-5H;Key: XJQGITRIKZCKRF-UHFFFAOYSA-N
SMILES C1=CC=C(C=C1)(C2=CC=CC=C2)(C3=CC=CC=C3)(C4=CC=CC=C4)C5=CC=CC=C5
Properties
Chemical formula	C₃₀H₂₅Sb
Molar mass	507.290 g·mol
Related compounds
Other cations	PPh₅ AsPh₅ BiPh₅
Related compounds	Pentamethylantimony Pentaethylantimony
Except where otherwise noted, data are given for materials in their standard state (at 25 °C , 100 kPa). Infobox references

Chemical compound

Pentaphenylantimony is an organoantimony compound containing five phenyl groups attached to one antimony atom. It has formula Sb(C₆H₅)₅ (or SbPh₅).

Structure

The 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. When dissolved, molecules are also trigonal bipyramidal. According to solution NMR measurements, the phenyl groups all appear to be equivalent, indicating fluxionality.

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.

Reactions

Pentaphenylantimony reacts with a variety of protic reagents (hydrogen halides, carboxylic acids, methanol, etc). Benzene is one product as well as a tetraphenylantimony(V) compound:

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.

A reaction with carbon tetrachloride yields tetraphenylstibonium chloride, chlorobenzene, and benzene. Some of these reactions may proceed by radical pathways.

Formation

Pentaphenylantimony can be formed by reacting dichlorotriphenylantimony with phenyl lithium.

References

^ 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.
^ 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.
^ 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.

Structure

Reactions

Formation

References

Further reading