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|Section2= |Section3= |Section4= |Section8= }} Tetraethyllead (commonly styled tetraethyl lead), abbreviated TEL, is an organolead compound with the formula (CH3CH2)4Pb. TEL was mixed with gasoline (petrol) beginning in the 1920s as a patented octane rating booster that allowed engine compression to be raised substantially, which in turn increased vehicle performance or fuel economy. TEL in automotive fuel was phased out starting in the U.S. in the mid-1970s because of its cumulative neurotoxicity and its damaging effect on catalytic converters. When present in fuel, TEL is also the main cause of spark plug fouling. TEL is still used as an additive in some grades of aviation gasoline, and in some developing countries. Innospec has claimed to be the last firm still making TEL, but it is apparently being produced illegally by several companies in China.〔(【引用サイトリンク】url=http://www.lead.org.au/TEL_for_MOGAS_manufacture_in_China_20130816.pdf )〕 ==Synthesis and properties== TEL is produced by reacting chloroethane with a sodium–lead alloy. : 4 NaPb + 4 CH3CH2Cl → (CH3CH2)4Pb + 4 NaCl + 3 Pb The product is recovered by steam distillation, leaving a sludge of lead and sodium chloride. TEL is a viscous colorless liquid. Because TEL is charge neutral and contains an exterior of alkyl groups, it is highly lipophilic and soluble in petrol (gasoline). Despite decades of research, no reactions were found to improve upon this rather difficult process that involves metallic sodium and converts only 25% of the lead to TEL. A related compound, tetramethyllead, was commercially produced by a different electrolytic reaction.〔 A process with lithium was developed, but never put into practice. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Tetraethyllead」の詳細全文を読む スポンサード リンク
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