science · 25 December 1837 · 187 years ago
birth
Born 25 Dec 1837; died 11 Feb 1904 at age 66.
Russian organic chemist who established the Markovnikov addition rule (1869) which predicts the results when a halogen halide reacts with the double bond of alkene. He found that the halogen will attach to the carbon with the most alkyl groups and the hydrogen adds to the carbon with the most hydrogens. (It was not until a half century later that Pauling's resonance theory gave an explanation). Markovnikov also found that carbon forms a four-carbon ring (1879), and a seven-carbon ring (1889) overcoming the popular belief that carbon rings only existed with six carbons. He also discovered that isobutyric and butyric acids are isomers.
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