9202. Tetraethyllead

Nomenclature

CAS number: 78-00-2
Tetraethylplumbane; lead tetraethyl; TEL.
C8H20Pb; mol wt 323.44.
C 29.71%, H 6.23%, Pb 64.06%.

Description and references

Prepd by the action of PbCl2 on zinc ethyl or on a Grignard reagent; by heating C2H5Cl and sodium-lead alloy in an autoclave. Production from lead, ethylene, and hydrogen using triethylaluminum as intermediate was first described by K. Ziegler at the 14th International Congress of Pure and Applied Chemistry (July 1955): Chem. Eng. News 33, 3486 (1955). Alternate synthesis using nonhalide compds: Pearson et al. in Adv. Chem. Ser. 23, entitled “Metal-Organic Compounds,” M. Sittig, Ed. (ACS, Washington DC, 1959) pp 299-305. See also Milde, Beatty, ibid., 306-318. Toxicity study: Schroeder et al., Experientia 28, 923 (1972). Review of toxicology and human exposure: Toxicological Profile for Lead (PB99-166704, 1999) 640 pp.

Chemical structure

Properties

Colorless liq; burns with an orange-colored flame with green margin. Extremely poisonous. d20 1.653. bp ≈200° also stated as 227.7° with decompn. nD20 1.5198. Practically insol in water. Sol in benzene, petr ether, gasoline, slightly in alcohol. LD50 orally in rats: 12.3 mg/kg (Schroeder).

Caution

Potential symptoms of overexposure are insomnia, lassitude and anxiety; tremor, hyper-reflexia and spasticity; bradycardia, hypotension, hypothermia, pallor, nausea, anorexia and weight loss; confusion, disorientation, hallucinations, psychosis, mania, convulsions and coma; eye irritation. See NIOSH Pocket Guide to Chemical Hazards (DHHS/NIOSH 97-140, 1997) p 302. See also Patty's Industrial Hygiene and Toxicology vol. 2A, G. D. Clayton, R. E. Clayton, Eds. (Wiley-Interscience, New York, 3rd ed., 1981) pp 1687-1728; Clinical Toxicology of Commercial Products, R. E. Gosselin et al., Eds. (Williams & Wilkins, Baltimore, 5th ed., 1984) Section II, p 139, Section III, pp 226-239.

Use

As a gasoline additive to prevent “knocking” in motors.