Prefixes omission

These problems are easily overcome with parentheses names such as poly(chlorostyrene) and poly(ethylene oxide) clearly indicate the part of the name to which the prefix poly refers. However, the omission of parentheses is, unfortunately, still common in the literature. 

McBain s term Sorption applies to all cases when a gas or solute is taken up by a solid. Adsorption means strictly the formation of a layer on an impermeable surface a sorption to penetration, or solution, into the interior. With the zeolites, there are pores of quite regular shape and size, only a few A. across. With charcoal there are irregular pores of similar size, as well as larger ones. Foreign substances, finding their way into these very fine pores may be said to be adsorbed on the walls of the pores, but as they permeate the whole structure of the solid more or less uniformly, they may equally be said to be absorbed by the solid. McBain avoids this difficulty simply by omission of the prefix. 

Omission of amino adds is shown by the prefix des, e.g. des-3-proline-bradykinin (abb. des-Pro -bradyki-... 

Coupling this rule with those for numerals (p. 10), and not forgetting the provisions for omission of numerical prefixes, we then have a host of familiar names, of which the following list, based on one in the lUPAC rules, is representative ... 

There is also in Great Britain less tendency to use multiplicative prefixes (bis, tris, etc.) than in USA. Chemical Abstracts have a rigid rule that if any compound radical name is replicated the numeral prefix should be of the replicative type. Thus, bis(2 -chloroethyl)benzene and 3,4-bis(trichloromethyl)-l,6-hexanediol would be prescribed. In Great Britain bis-2 -chloroethylbenzene or di-(2-chloroethyl)benzene would be considered sufficiently unambiguous. I ote also the omission of the prime (dash) after 2 in parentheses in British but not in American practice. 

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