Work
Markovnikov is best known for Markovnikov's rule, elucidated in 1869 to describe addition reactions of H-X to alkenes. According to this rule, the nucleophilic X- adds to the carbon atom with fewer hydrogen atoms, while the proton adds to the carbon atom with more hydrogen atoms bonded to it. Thus, hydrogen chloride (HCl) adds to propene, CH3-CH=CH2 to produce 2-chloropropane CH3CHClCH3 rather than the isomeric 1-chloropropane CH3CH2CH2Cl. The rule is useful in predicting the molecular structures of products of addition reactions. Why hydrogen bromide exhibited both Markovnikov as well as reversed-order, or anti-Markovnikov, addition, however, was not understood until Morris S. Kharasch offered an explanation in 1933.
Hughes has discussed the reasons for Markovnikov's lack of recognition during his lifetime. Although he published mostly in Russian which was not understood by most Western European chemists, the 1870 article in which he first stated his rule was written in German. However the rule was included in a 4-page addendum to a 26-page article on isomeric butyric acids, and based on very slight experimental evidence even by the standards of the time. Hughes concludes that the rule was an inspired guess, unjustified by the evidence of the time, but which turned out later to be correct (in most cases).
Markovnikov also contributed to organic chemistry by finding carbon rings with more than six carbon atoms, a ring with four carbon atoms in 1879, and a ring with seven in 1889.
Markovnikov also showed that butyric and isobutyric acids have the same chemical formula (C4H8O2) but different structures; i.e., they are isomers.
Read more about this topic: Vladimir Markovnikov
Famous quotes containing the word work:
“The truth of the thoughts that are here set forth seems to me unassailable and definitive. I therefore believe myself to have found, on all essential points, the final solution of the problems. And if I am not mistaken in this belief, then the second thing in which the value of this work consists is that it shows how little is achieved when these problems are solved.”
—Ludwig Wittgenstein (1889–1951)
“You haf slafed your life away in de bosses’ mills and your fadhers before you and your kids after you yet. Vat is a man to do with seventeen-fifty a week? His wife must work nights to make another ten, must vork nights and cook and wash in day an’ vatfor? So that the bosses can get rich an’ the stockholders and bondholders. It is too much... ve stood it before because ve vere not organized. Now we have union... We must all stand together for union.”
—John Dos Passos (1896–1970)
“Meanwhile, if the fear of falling into error sets up a mistrust of Science, which in the absence of such scruples gets on with the work itself, and actually cognizes something, it is hard to see why we should not turn round and mistrust this very mistrust.... What calls itself fear of error reveals itself rather as fear of the truth.”
—Georg Wilhelm Friedrich Hegel (1770–1831)