Tetrabutylammonium

Tetrabutylammonium is a quaternary ammonium cation with the formula [N(C₄H₉)₄]⁺. It is used in the research laboratory to prepare lipophilic salts of inorganic anions. Relative to tetraethylammonium derivatives, tetrabutylammonium salts are more lipophilic but crystallize less readily.

Derivatives

Some tetrabutylammonium salts of simple anions include:

• tetrabutylammonium fluoride, a desilylation reagent.
• tetrabutylammonium bromide, a precursor to other tetrabutylammonium salts via salt metathesis reactions.
• tetrabutylammonium hydroxide, a precursor to other tetrabutylammonium salts via acid-base reactions.
• tetrabutylammonium hexafluorophosphate, an electrolyte for nonaqueous electrochemistry.

Some tetrabutylammonium salts of more complex examples include:

• polyoxometalates.^[1]
• NS₄^-.^[2]
• metal carbonyl anions.^[3]
• Synthetic iron-sulfur clusters such as [Fe₄S₄(SPh)₄]^2-[4]
• Octachlorodirhenate ([Re₂Cl₈]^2-).^[5]

References

1. W. G. Klemperer, "Tetrabutylammonium Isopolyoxometalates" Inorganic Syntheses, 1990, Vol. 27, pp. 74–85. doi:10.1002/9780470132586.ch15
2. J. Bojes, T. Chivers, I. Drummond "Heptathiazocine(Heptasulfurimide) and Tetrabutylammonium Tetrathionitrate" Inorganic Syntheses, 1978, Vol. 18, pp. 203–206. doi:10.1002/9780470132494.ch36
3. A. Ceriotti, G. Longoni, M. Marchionna "Bis(Tetrabutylammonium) Hexa-μ-Carbonyl-Hexacarbonylhexaplatinate(2-), [N(C₄H₉)₄]₂[Pt₆(CO)₆(μ-CO)₆]" Inorganic Syntheses, 1989, Vol. 26, pp. 316–319. doi:10.1002/9780470132579.ch57
4. George Christou, C. David Garner, A. Balasubramaniam, Brian Ridge, H. N. Rydon, "Tetranuclear Iron-Sulfur and Iron-Selenium Clusters" Inorganic Syntheses, 1982, Vol. 21, pp. 33–37. doi:10.1002/9780470132524.ch9.
5. T. J. Barder, R. A. Walton "Tetrabutylammonium Octachlorodirhenate(III)" Inorganic Syntheses, 1990, Vol. 28, pp. 332–334. doi:10.1002/9780470132593.ch83