Triethylgallium
Names
IUPAC name
triethylgallane
Systematic IUPAC name
triethylgallium
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.012.939 Edit this at Wikidata
  • CC[Ga](CC)CC
Properties
C6H15Ga
Molar mass 156.9 g/mol
Appearance colourless liquid
Melting point −82.3 °C (−116.1 °F; 190.8 K)
Boiling point 143 °C (289 °F; 416 K)
Reacts[1]
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
 pyrophoric
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Triethylgallium is the organogallium compound with the formul Ga(C2H5)3. Also called TEGa, it is a metalorganic source of gallium for metalorganic vapour phase epitaxy (MOVPE) of compound semiconductors. It is a colorless pyrophoric liquid,[2] typically handled with air-free techniques. It was discovered by Cornell University chemists L. M. Dennis and Winton Patnode in 1931.[3]

Preparation and reactions

The main routes involve alkylation of gallium trichloride. When this alkylation is effected with ethyl Grignard reagent in ether, the product is the diethyl ether adduct of triethylgallium. The ether is not easily removed. Thus an alternative route involves transmetalation with triethylaluminium according to this simplified equation:[4]

GaCl3 + 3 AlEt3 → GaEt3 + 3 AlClEt2

Triethylgallium readily converts to the air-stable, colorless alkoxide by two routes, oxidation and alcoholysis:[4]

GaEt3 + 0.5 O2 → GaEt2(OEt)
GaEt3 + EtOH → GaEt2(OEt) + EtH

The sweet odor associated with triethylgallium is due to the alkoxide.

Redistribution reactions occur with gallium trichloride:[4]

2GaEt3 + GaCl3 → 3 GaEt2Cl

Applications

TEGa can be a useful alternative to trimethylgallium in the metalorganic vapour phase epitaxy of compound semiconductors because films grown using TEGa have been shown to have a lower carbon impurity concentration.[5]

Related compounds

References

  1. ^ amdg.ece.gatech.edu/msds/mo/teg_epichem.pdf
  2. ^ Shenaikhatkhate, D; Goyette, R; Dicarlojr, R; Dripps, G (2004). "Environment, health and safety issues for sources used in MOVPE growth of compound semiconductors". Journal of Crystal Growth. 272 (1–4): 816–821. Bibcode:2004JCrGr.272..816S. doi:10.1016/j.jcrysgro.2004.09.007.
  3. ^ Dennis, L. M.; Patnode, Winton (January 1932). "GALLIUM TRIETHYL MONOETHERATE, GALLIUM TRIETHYL, GALLIUM TRIETHYL AMMINE1". Journal of the American Chemical Society. 54 (1): 182–188. doi:10.1021/ja01340a024. ISSN 0002-7863.
  4. ^ a b c J.J.Eisch, R. B. King, ed. (1981). Organometallic Syntheses Volume 2. Nontransition Metal Compounds. NY, NY: Academic Press.
  5. ^ Saxler, A; Walker, D; Kung, P; Zhang, X; Razeghi, M; Solomon, J; Mitchel, W; Vydyanath, H (1997). "Comparison of trimethylgallium and triethylgallium for the growth of GaN". Applied Physics Letters. 71 (22): 3272–3274. Bibcode:1997ApPhL..71.3272S. doi:10.1063/1.120310.
Categories