Prefixes multiplying

Both remaining CgHi4 isomers have two methyl groups as substituents on a four carbon chain Thus the parent chain is butane When the same substituent appears more than once use the multiplying prefixes di tri tetra and so on A separate locant is used for each substituent and the locants are separated from each other by commas and from the words by hyphens... 

If the same alkyl group occurs more than once as a side chain, this is indicated by the prefixes di-, tri-, tetra-, etc. Side chains are cited in alphabetical order (before insertion of any multiplying prefix). The name of a complex radical (side chain) is considered to begin with the first letter of its complete name. Where names of complex radicals are composed of identical words, priority for citation is given to that radical which contains the lowest-numbered locant at the first cited point of difference in the radical. If two or more side chains are in equivalent positions, the one to be assigned the lowest-numbered locant is that cited first in the name. The complete expression for the side chain may be enclosed in parentheses for clarity or the carbon atoms in side chains may be indicated by primed locants. 

In the case of complex entities such as organic ligands (particularly if they are substituted) the multiplying prefixes bis-, tris-, tetrakis-, pentakis-,. . . are used, i.e.,-kis is added starting from tetra-. The modified entity is often placed within parentheses to avoid ambiguity. 

Two or more cyclic units linked by single or double bonds in such a way that no new rings are formed can be named by placing the appropriate multiplying prefix (bi-, ter-, quater-, etc.) before either the name of the cyclic unit or that of the corresponding radical. Locants before the name indicate the points of attachment (examples 67 and 68). 

Use hyphens to separate the different prefixes, and use commas to separate numbers. If two or more different substituents are present, cite them in alphabetical order. If two or more identical substituents are present, use one of the multiplier prefixes d, fn -, tetra-, and so forth, but don t use these prefixes for alphabetizing. Full names for some of the examples we have been using follow. 

It should be noted that italicised hyphenated prefixes which indicate structure, such as cis-. o-, m-, tert-, mixo-, N-. 0-, etc., have been ignored during the alpha-sorting routine used on this index and the group-lists, while the roman character structural prefixes iso and neo, and roman multiplying prefixes such as di, tris, tetra and hexakis, have been included in the indexing procedure. 

In deciding on alphabetically order disregard multiplying prefixes such as di and tri ... 

Where a succession of blocks, such as -Ar B -Cm- is repeated, the appropriate multiplying prefix is used. 

Two or more identical hetero-atoms are indicated by use of the multiplying prefixes di-, tri- or tetra-. When more than one distinct hetero-atom is present, the appropriate prefixes are cited in the name in descending order of group number in the periodic table, e.g. oxa- takes precedence over aza-. If both lie within the same group of the periodic table, then the order is determined by increasing atomic number, e.g. oxa- precedes thia-. 

When there are two or more different substituents present, the question arises as to what order they should be cited in naming the compound. The system adopted by TUPAC and long practiced by Chemical Abstracts cites them in alphabetical order without regard for whether there is a multiplying prefix such as di- or tri-. Examples are given below. 

When the benzene ring carries different substituents we shall cite them in alphabetical order (disregarding multiplying prefixes) and assign their posi-... 

Prefix Abbr. Multiplier Prefix Abbr. Multiplier... 

Prefix Abbreviation Multiplier Prefix Abbreviation Multiplier... 

If there are two or more of the same type of branch, give each branch a position number. Also, use multiplying prefixes such as di- (meaning 2), tri- (meaning 3), and tetra- (meaning 4) to indicate the number of branches. 

If there is more than one type of branch, name the branches in alphabetical order. Determine the alphabetical order by using the first letter of the root (for example, -methyl-or-ethyl-), not the multiplying prefix (for example, di- or tri-). 

For very large numbers with units of measure, use scientific notation or choose an appropriate multiplying prefix for the unit to avoid numbers of more than four digits. 

Leave no space between the multiplying prefix and the unit, whether abbreviated or spelled out. 

Multiplying affixes are integral parts of the chemical name they are set in roman type and are always closed up to the rest of the name (without hyphens). Use hyphens only to set off intervening locants or descriptors. Use enclosing marks (parentheses, brackets, or braces) to ensure clarity or to observe other recommended nomenclature conventions. Multiplying prefixes include the following ... 

The kilogram is the standard SI base unit for mass, even though it includes a multiplier prefix. However, for the application of other prefix multipliers the base word is the gram thus 1000 kilograms is 1 Mg, not 1 kkg. 

In chemistry, we use Multiplying Prefixes instead of using very smaii or very iarge numbers (Tabie 2). 

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