Alkyl group nomenclature

Tabular summaries of the lUPAC rules for alkane and alkyl group nomenclature appear on pages 96-98... 

The following alkanes show the use of alkyl group nomenclature. 

Structure and Physical Properties Alkyl Groups Nomenclature Constitutional or Structural Isomers An Environmental Perspective ... 

An alkyl group lacks one of the hydrogens of an alkane A methyl group (CH3 —) is an alkyl group derived from methane (CH4) Unbranched alkyl groups m which the point of attachment is at the end of the chain are named m lUPAC nomenclature by replac mg the ane endings of Table 2 2 by yl... 

The lUPAC rules permit alkyl halides to be named m two different ways called func twnal class nomenclature and substitutive nomenclature In functional class nomencla ture the alkyl group and the halide (fluoride chloride bromide or iodide) are desig nated as separate words The alkyl group is named on the basis of its longest continuous chain beginning at the carbon to which the halogen is attached... 

Ethers are named m substitutive lUPAC nomenclature as alkoxy derivatives of alkanes Functional class lUPAC names of ethers are derived by listing the two alkyl groups m the general structure ROR m alphabetical order as separate words and then adding the word ether at the end When both alkyl groups are the same the prefix di precedes the name of the alkyl group... 

Section 16 1 Ethers are compounds that contain a C—O—C linkage In substitutive lUPAC nomenclature they are named as al/coxy derivatives of alkanes In functional class lUPAC nomenclature we name each alkyl group as a separate word (m alphabetical order) followed by the word ether... 

Alkylamines are named m two ways One method adds the ending amine to the name of the alkyl group The other applies the principles of sub stitutive nomenclature by replacing the e ending of an alkane name by amine and uses appropriate locants to identify the position of the ammo group Arylammes are named as derivatives of aniline... 

A single alkane may have several different names a name may be a common nfflne, or it may be a systematic name developed by a well-defined set of rules. The most widely used system is lUPAC nomenclature. Table 2.6 summarizes the rules for alkanes and cycloalkanes. Table 2.7 gives the r-ules for naming alkyl groups. 

TABLE D.4 Alkane Nomenclature Number of carbon atoms Formula Name of alkane Name of alkyl group... 

Which will generally correspond to the RJt isomer when Rl and RM are simple alkyl groups and Rl takes precedence over RM in the R,S nomenclature. 

The nomenclature of the RP is not consequent. The RP most often used contains octyl (RP C8) or octadecyl (RP C18) groups. There is no differentiation even when two methyl groups are introduced additionally with the silane (as with monofunctional silanes) or only one (difunctional) or none (trifunctional silane). Some manufacturer use silanes with bulky side groups (e.g., isopropyl groups) to improve the hydrolytic stability of the bonded phases, but here also, only the longest alkyl group is used in nomenclature. RP C8 and RP C18 are the work horses in HPLC. Shorter chains (RP4) are used in protein separations, and special selectivity can be obtained with bonded phenyl, cyano, amino or fluoro groups. 

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