TPPTS

3,3′,3″-Phosphanetriyltris(benzenesulfonic acid) trisodium salt

Names
Other names Tris(3-sulfophenyl)phosphine trisodium salt
Identifiers
CAS Number	63995-70-0 Y
3D model (Jmol)	Interactive image
ChemSpider	3552062 N
ECHA InfoCard	100.058.706
PubChem	4348292
InChI InChI=1S/C18H15O9PS3.3Na/c19-29(20,21)16-7-1-4-13(10-16)28(14-5-2-8-17(11-14)30(22,23)24)15-6-3-9-18(12-15)31(25,26)27;;;/h1-12H,(H,19,20,21)(H,22,23,24)(H,25,26,27);;;/q;3*+1/p-3 N Key: MYAJTCUQMQREFZ-UHFFFAOYSA-K N InChI=1/C18H15O9PS3.3Na/c19-29(20,21)16-7-1-4-13(10-16)28(14-5-2-8-17(11-14)30(22,23)24)15-6-3-9-18(12-15)31(25,26)27;;;/h1-12H,(H,19,20,21)(H,22,23,24)(H,25,26,27);;;/q;3*+1/p-3 Key: MYAJTCUQMQREFZ-DFZHHIFOAA
SMILES C1=CC(=CC(=C1)S(=O)(=O)[O-])P(C2=CC(=CC=C2)S(=O)(=O)[O-])C3=CC(=CC=C3)S(=O)(=O)[O-].[Na+].[Na+].[Na+]
Properties
Chemical formula	P(C6H4SO3Na)3
Molar mass	568.42 g/mol
Appearance	White microcrystalline solid
Solubility in water	Soluble in water
Hazards
R-phrases	R36/37/38
S-phrases	S26
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

3,3′,3″-Phosphanetriyltris(benzenesulfonic acid) trisodium salt (abbreviated TPPTS when isolated and tppts as a ligand), is an organic compound that is also known as sodium triphenylphosphine trisulfonate. The compound has the formula P(C₆H₄SO₃Na)₃. This white microcrystalline solid is an unusual example of a water-soluble phosphine. Its complex with rhodium is used in the industrial production of butyraldehyde.^[1]

Synthesis

Tppts is synthesized by sulfonation of triphenylphosphine. The sulfonation occurs at one meta-position of each of the three phenyl rings. The sulfonation agent is oleum, a solution of sulfur trioxide in sulfuric acid. The resulting trisulfonic acid is then treated with triisooctylamine and sodium hydroxide. Immediately upon dissolving in the reaction medium, the phosphine is protonated. It is the phosphonium salt that undergoes the sulfonation:

HP(C₆H₅)₃⁺ + 3 SO₃ → [HP(C₆H₄SO₃H)₃]⁺

[HP(C₆H₄SO₃H)₃]⁺ + 4 N(C₈H₁₇)₃ → [HN(C₈H₁₇)₃]₃[P(C₆H₄SO₃)₃] + [HN(C₈H₁₇)₃]⁺

[HN(C₈H₁₇)₃]₃[P(C₆H₄SO₃)₃] + 3 NaOH → P(C₆H₄SO₃Na)₃ + 3 N(C₈H₁₇)₃ + 3 H₂O

As a Lewis base, tppts is stronger than triphenylphosphine.

Uses in hydroformylation

Complexes of tppts are very soluble in water, which is the basis of its industrial application. Tppts-based rhodium catalysts were introduced in 1984 for a two-phase hydroformylation of propene by Ruhrchemie. Hydroformylation, also known as oxo synthesis, is the reaction of an alkene with carbon monoxide and hydrogen. Traditionally, hydroformylation is catalyzed by rhodium and cobalt complexes in nonaqueous solution.^[2]

References

1. ↑ Herrmann, W.A.; Kohlpaintner, C.W. (1998). "Synthesis of Water-Soluble Phosphines and Their Transition Metal Complexes". Inorganic Syntheses. New York: John Wiley & Sons. 32: 8–25. doi:10.1002/9780470132630.ch2. ISBN 0-471-24921-1. OCLC 219831361. 
2. ↑ Boy Cornils, Richard W. Fischer, Christian Kohlpaintner "Butanals" in Ullmann's Encyclopedia of Industrial Chemistry, 2000, Wiley-VCH, Weinheim. doi:10.1002/14356007.a04_447