Multiplicative prefixes

The number of identical chemical entities in a name is expressed by a multiplicative prefix (see Table IV). 

In the case of simple entities such as monoatomic ligands the multiplicative prefixes di, tri, tetra, penta, etc., are used. 

The multiplicative prefixes bis, tris, tetrakis, pentakis, etc. are used with composite ligand names or in order to avoid ambiguity. The modified entity is placed within parentheses. 

Composite multiplicative prefixes are built up by citing units first, then tens, hundreds and so on, e.g. 35 is written pentatriaconta (or pentatriacontakis). 

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Submultiple Prefix Symbol Multiple Prefix Symbol... 

Multiplicative Prefixes. The multiplicative prefixes bis, tris, etc., are used with certain anions for indicating stoichiometric proportions when di, tri, etc., have been preempted to designate condensed anions for example, A1K(S04)2 I2H2O, aluminum potassium bis(sulfate) 12-water (recall that disulfate refers to the anion S20jfi. 

The number of atoms of a given kind is indicated, if there is more than one, by the usual multiplicative prefixes. A final a in such a prefix is elided if the following syllable begins with a vowel thus tetrazole rather than tetraazole , and pentoxepane rather than pentaoxepane . 

Derivatives with the same substitution pattern on each residue can be named semisystematically by assigning a single multiplicative prefix (e.g. hexakis, hep-takis etc.) to the substituent prefixes as a group. 

If there is more than one electropositive constituent, the names should be spaced and cited in alphabetical order of the initial letters, or of the second letters if the first letters are the same. Multiplicative prefixes are ignored for purposes of ordering. 

The names of polyatomic electronegative groups are derived in various ways. Homoatomic species are designated using an appropriate multiplicative prefix. 

Qualification by both charge number and oxidation number is not allowed. It should be evident that there are several ways of conveying the same stoichiometric information, employing charge number, oxidation number and multiplicative prefixes. Employing them all would create redundancies. In general, one uses whichever devices are both necessary and sufficient, and no more. 

If structural information is available, it can be conveyed using the devices already discussed. Bridging ligands are cited as above, unless the symmetry of the system allows a simplification using multiplicative prefixes. Bonding between metal atoms may be indicated in names by italicised element symbols of the appropriate metal atoms, separated by a long dash, and enclosed in parentheses after the list of central atoms and before the ionic charge. 

However, higher members of the series are named systematically by combining the ending -ane, characteristic of the first four members and implying complete saturation, with a multiplicative prefix of the series penta-, hexa-, etc. of Table 4.2, which indicates the number of carbon atoms constituting the chain. The letter a , which ends the name of the multiplicative prefix, is elided. 

Multiplicative prefixes. Multiplicative prefixes (Table 4.2) are used when more than one substituent of a given kind is present in a compound or group. The name of the substituent is cited as a prefix, and two sets of multiplicative prefixes are used, depending on whether the substituent is simple or complex. 

Basic multiplicative prefixes di-, tri-, tetra-, etc. are used with the names of simple substituents and retained names. Different or modified prefixes are used with complex substituents bis-, tris-, tetrakis- from tetrakis- onwards the ending -kis is attached to the basic multiplicative prefix, giving pentakis-, hexakis-, etc. (compare the use in coordination nomenclature). 

The assembly of the components to construct a full name starts by attaching the names of the detachable prefixes in alphabetical order to the name of the parent hydride. Then, and only then, necessary multiplicative prefixes are introduced, without changing the alphabetical order obtained previously. Finally, locants are inserted. 

When one heteroatom is present, the locant 1 is attributed to the heteroatom. In many cases, an indicated hydrogen is necessary to describe the structure with accuracy. The presence of more than one heteroatom of any type is indicated by a multiplicative prefix (di-, tri-, etc.). If two or more kinds of heteroatom occur in the same name, the order of citation is the order of their appearance in descending Table 4.8. The numbering starts from the heteroatom cited first in Table 4.8, giving the lowest possible locants to other heteroatoms. 

Some fused systems are named systematically by using a multiplicative prefix in front of an ending representing a well-defined arrangement of cycles. For instance, the ending -acene, taken from anthracene, indicates a linear arrangement of benzene rings, as in tetracene, pentacene, etc. 

Assemblies of identical rings are named by using a unique set of multiplicative prefixes, bi-, ter-, quater-, etc., to indicate the number of rings. The name phenyl is used instead of benzene for the aromatic C5 ring. 

In one method, the non-detachable prefixes hydro- and dehydro- (in the case of mancudes only) can be used to indicate the addition or subtraction of one hydrogen atom. As even numbers of hydrogen atoms are involved when a carbon-carbon single bond becomes a double or triple bond, the multiplicative prefixes di-, tetra-, etc., as well as the appropriate locants, are used. The prefix dehydro- is always used to indicate the subtraction of hydrogen atoms from saturated heterocycles having Hantzsch-Widman names. 

In the other method, the ending -ane is changed to -ene or -yne to indicate the presence of a double or triple bond. This is used for alkanes and mono- and polycyclic alkane parent hydrides. In alkanes and cycloalkanes, the change of the -ane ending to -ene or -yne indicates the presence of one double or triple bond. Multiplicative prefixes di-, tri-, tetra-, etc. are used to signal the multiplicity of unsaturated bonds. Locants placed immediately in front of the endings -ene and -yne are used as needed. 

The names of polynuclear hydrides (i.e. compounds with molecules consisting of chains) are obtained by prefixing the -ane names of Table 5.2 with the appropriate multiplicative prefixes of di-, tri-, tetra-, etc. 

The preferred names are also obtained by applying the principles of substitutive nomenclature. Substituents, considered as replacing hydrogen atoms, are named using prefixes of the appropriate group names and are cited, if there is more than one, in alphabetical order before the name of the parent hydride, using parentheses and multiplicative prefixes as necessary. 

Hvmoatnmic electronegative constituents. These have the name of the monoatomic parent, but qualified by a multiplicative prefix, if appropriate, ft may be necessary to use parentheses to emphasize subtle points of structure. 

However, when the name of the constituent itself starts with a multiplicative prefix (as in disulfate, dichrdmate. triphosphate, and tetraborate), two successive multiplicative prefixes may be necessary. When this happens, and in other cases simply to avoid confusion, the alternative multiplicative prefixes, bs-. Ins-, tetrakis-. pentakis-. etc. are used [see Table 1-3] and the name of the group acted upon by the alternative prefix is placed m parentheses. 

Names cfoligonttclear hydrides derived from elements of standard bonding number. Names are constructed by prefixing the ane names of the corresponding mononuclear hydride with the appropriate multiplicative prefix (di-, tri-.letra-. etc.) corresponding to the number of atoms of the chain bonded in series. 

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