Couper invented a symbolic language to represent carbon linkage. Both made significant contributions to the field of structural chemistry. This finding explained the very multiplicity of carbon compounds that had been puzzling chemists. Couper, in his paper—and in another paper on salicylic acid that appeared earlier in —indicated valence bonds as straight lines linking the symbols for the elements, which is still the practice in most modern structural diagrams. Jerry Allison, oil on canvas, ca.
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Kirkintilloch, Dumbartonshire, Scotland, 31 March ; d. Kirkintilloch, 11 March chemistry. Couper, at the same time as F. He also introduced into organic chemistry lines to represent valence bonds in chemical formulas. All his papers were published in barely over a year, after which ill health terminated his scientific career.
Couper was the only surviving son of Archibald and Helen Dollar Couper. His father was proprietor of a large cotton-weaving business that had been owned by the family for several generations. Couper received most of his early education at home and then went to Glasgow University for study in the humanities and classical languages. The summers of and he spent in Germany, and in August he entered the University of Edinburgh, studying logic and metaphysics under Sir William Hamilton while continuing his language studies.
During the year — Couper moved to Berlin, where, sometime before his departure for Paris in , he chose chemistry as his field of major interest.
After moving to Paris in August , Couper engaged in independent research in the laboratory of Charles Adolphe Wurtz. His first publication—on the bromination of benzene—appeared in August His other experimental paper, on salicylic acid , was published in Dumas in June and was published soon thereafter. Couper complained to Wurtz about the delay in presenting his paper and was asked to leave the laboratory.
He returned to Scotland in the fall of and accepted a position as second laboratory assistant to Lyon Playfair , professor of chemistry at Edinburgh University. Soon after beginning his duties he suffered a mental breakdown, underwent treatment, apparently recovered, and went on a fishing expedition, during which, reportedly due to extended exposure to the sun, his illness returned.
He never fully recovered and lived in retirement for the remaining thirty-four years of his life. Wurtz had just prepared ethylene glycol, C2H4 OH 2, from ethylene via the iodide C2H4I2 reacted with silver acetate, followed by treatment with potassium hydroxide. Couper reacted benzene with bromine and isolated two new compounds, bromo-benzene, C6H5Br, and p-dibromobenzene, C6H4Br2. The first showed only very slight reactivity with silver acetate, while the second led to an explosion.
This represented the first time that the relations between the individual carbon atoms of benzene had been depicted in a formula. Having ascertained these, the composition and structure of every possible word is revealed. These two principles are the foundation of the structural theory of organic chemistry.
Couper then devised a pictorial representation of chemical compounds using dotted lines, solid lines, or brackets to show the linkings between atoms in the molecule. These formulas represent the first introduction of the valence line into organic formulas.
Since Couper used an atomic weight of eight for oxygen, his formulas always contain a pair of oxygen atoms instead of the single atom used today. Couper maintained that several elements, such as carbon, notrogen, and phosphorous, exhibit multiple valence. Formulas in this paragraph are those now in use. Pinkus, P. Walrep, and W. Benfey, ed. Original Works. Anschutz, ed. Secondary Literature. On Couper or his work, see R. Great Chemists New York , , pp.
Archibald Scott Couper Facts
He developed the concepts of tetravalent carbon atoms linking together to form large molecules, and that the bonding order of the atoms in a molecule can be determined from chemical evidence. Life and work[ edit ] Couper was the only surviving son of a wealthy textile mill owner near Glasgow. He studied at the universities of Glasgow and Edinburgh and intermittently in Germany during the years Couper published his "New Chemical Theory" in French in a condensed form on 14 June ,  then in detailed papers simultaneously in French  and English  in August When Couper angrily confronted Wurtz, Wurtz expelled him from the laboratory. In December , Couper received an offer of an assistantship from the University of Edinburgh.
Archibald Scott Couper
Archibald Scott Couper was born on March 31, , at Kirkintilloch in Dumbartonshire, Scotland, the son of a prosperous cotton weaver. He commenced his university studies at Glasgow mainly in classics, spent the summer semester of in Berlin, and returned to Scotland to complete his university course in logic and metaphysics at Edinburgh. He spent the period in Berlin and during this time decided to study chemistry. Couper entered the laboratory of Charles Wurtz in Paris in the autumn of and remained there until his return to Scotland in ; during these 2 years he made all his contributions to chemistry: two papers containing experimental contributions and his now famous memoir "On a New Chemical Theory. He retired to Kirkintilloch and lived there incapable of intellectual work and completely lost to chemistry until his death 34 years later. Couper protested to Wurtz about his procrastination but was, it is said, shown out of the laboratory.
August Kekulé and Archibald Scott Couper