Here we meet with a great diversity of types: oxygen, nitrogen, sulphur and other elements may, in addition to carbon, combine together in a great number of arrangements to form cyclic nuclei, which exhibit characters closely resembling open-chain compounds in so far as they yield substitution derivatives, and behave as compound radicals.
If we accept Kekule's formula for the benzene nucleus, then we may expect the double linkages to be opened up partially, either by oxidation or reduction, with the formation of di-, tetra-, or hexa-hydro derivatives, or entirely, with the production of open chain compounds.
Generally rupture occurs at more than one point; and rarely are the six carbon atoms of the complex regained as an open chain.
These compounds retain their aliphatic nature, and are best classified with open-chain compounds, into which, in general, they are readily converted.
Systems which are generally unsaturated compounds, often of considerable stability, and behave as nuclei; these compounds constitute a well-individualized class exhibiting closer affinities to benzenoid substances than to the open-chain series.
Thelfirst four substances are readily formed from, and converted into, the corresponding dihydroxy open-chain compound; these substances are truly aliphatic in character.
This open chain structure is challenged in the views put forward by T.
It is convenient to distinguish between aliphatic and aromatic acids; the first named being derived from open-chain hydrocarbons, the second from ringed hydrocarbon nuclei.
OLEFINE, in organic chemistry, the generic name given to open chain hydrocarbons having only singly and doubly linked pairs of carbon atoms. The word is derived from the French olefiant (from olefier, to make oil), which was the name given to ethylene, the first member of the series, by the Dutch chemists, J.
group is very reactive and behaves in a similar manner to the grouping CO CH 2 CO in open chain compounds, e.g.
In addition to these, a series of open-chain olefine terpenes is known.
Two distinct types of hydrocarbons exist: (1) those consisting of an open chain of carbon atoms - named the " aliphatic series " (i.XEicAap, oil or fat), and (2) those consisting of a closed chain - the " carbocyclic series."
As to the stability of these compounds, most trimethylene derivatives are comparatively unstable, the ring being broken fairly readily; the tetramethylene derivatives are rather more stable and the pentaand hexa-methylene compounds are very stable, showing little tendency to form open chain compounds under ordinary conditions (see Chemistry: Organic).
In contrast, open chain exercises such as the leg extension machine isolate one muscle group.
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