Tetra-n-butylammonium iodide

Tetra-n-butylammonium iodide

Names
Preferred IUPAC name N,N,N-Tributylbutan-1-aminium iodide
Other names TBAI
Identifiers
CAS Number	311-28-4  Y
3D model (JSmol)	Interactive image
ChemSpider	60875  Y
ECHA InfoCard	100.005.656
EC Number	206-220-5
PubChem CID	329769349
CompTox Dashboard (EPA)	DTXSID30878092
InChI InChI=1S/C16H36N.HI/c1-5-9-13-17(14-10-6-2,15-11-7-3)16-12-8-4;/h5-16H2,1-4H3;1H/q+1;/p-1 Y Key: DPKBAXPHAYBPRL-UHFFFAOYSA-M Y InChI=1S/C16H36N.HI/c1-5-9-13-17(14-10-6-2,15-11-7-3)16-12-8-4;/h5-16H2,1-4H3;1H/q+1;/p-1
SMILES [I-].CCCC[N+](CCCC)(CCCC)CCCC
Properties
Chemical formula	C16H36IN
Molar mass	369.3716 g/mol
Appearance	White powder
Melting point	147 °C (297 °F; 420 K)
Hazards
Occupational safety and health (OHS/OSH):
Main hazards	Harmful
Related compounds
Other anions	Tetrabutylammonium bromide, Tetrabutylammonium chloride, Tetrabutylammonium fluoride, Tetrabutylammonium hydroxide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Tetra-n-butylammonium iodide (TBAI) is a quaternary ammonium salt with an iodide counterion. It is used for synthesizing tetra-n-butylammonium triiodide by mixing with iodine. TBAI is also commonly used as a catalyst for the protection of alcohols as benzyl ethers with benzyl bromide. ^[1]

Properties

The solid crystal of tetra-n-butylammonium iodide is in the monoclinic crystal system. It has space group C2/c. The unit cell has dimensions a=14.2806 b=14.1864 c=19.5951 β=111.149. There are eight formulae in the unit cell (Z=8), which has volume 3702.4 Å³. ^[2]

The enthalpy of formation Δ_fH⁰ of tetra-n-butylammonium iodide is −499 kJ/mol, which is lower than that for the bromide or chloride (−540, −564 kJ/mol). ^[3]

At lower temperatures with water tetra-n-butylammonium iodide forms a clathrate hydrate. ^[3] The tetra-n-butylammonium cation is large and hydrophobic. The absolute enthalpy of hydration (from gas phase) is −260 kJ/mol. ^[3]

The He(I) photoelectron spectrum of tetra-n-butylammonium iodide contains a peak at 11 eV due to the tetra-n-butylammonium cation, and at 7 and 8 eV due to iodide. ^[4]

See also

• Iodide
• Tetrabutylammonium triiodide

References

1. Czernecki, S.; Georgoulis, C.; Provelenghiou, C. (September 1976). "Nouvelle methode de benzylation d'hydroxyles glucidiques encombres" . Tetrahedron Letters. 17 (39): 3535–3536. doi:10.1016/s0040-4039(00)71351-7. ISSN   0040-4039.
2. Prukała, Wiesław; Marciniec, Bogdan; Kubicki, Maciej (28 February 2007). "Tetra-n-butylammonium iodide: a space-group revision". Acta Crystallographica Section E. 63 (3): o1464 –o1466. Bibcode:2007AcCrE..63O1464P. doi:10.1107/S1600536807008446.
3. Nagano, Yatsuhisa; Mizuno, Hideki; Sakiyama, Minoru; Fujiwara, Tadayuki; Kondo, Yasuhiko (March 1991). "Hydration enthalpy of tetra-n-butylammonium ion". The Journal of Physical Chemistry. 95 (6): 2536–2540. doi:10.1021/j100159a079.
4. Ballard, R.E.; Jones, Jimmy; Sutherland, Elizabeth (December 1984). "He(I) photoelectron spectrum of tetra-N-butylammonium iodide and bromide in solution. The effects of surface activity". Chemical Physics Letters. 112 (4): 310–312. Bibcode:1984CPL...112..310B. doi:10.1016/0009-2614(84)85747-4.