R-18.104.22.168 Names of symmetrical di- or polyvalent substituent groups are formed by juxtaposing the names of the individual substituent groups starting with the central one, e.g., methylenedioxy, oxydiethylene; or the trivial name, if any, for compound substituent groups may be used.
Examples to R-22.214.171.124
(In the last example, the compound substituent group name is formed by starting with the central substituent group "oxy", followed by "-bis-", and adding successively the names of the substituent groups "ethylene" () and "nitrilo" (), and finally the name of the unit "propanoic acid", preceded by the multiplicative prefix "tetra").
Examples to R-126.96.36.199
Note: In this nomenclature operation, unsymmetrical compound substituent groups are not used for linking identical units because of difficulty in assigning an unambiguous numbering to the complete structure. Instead, simple substitutive nomenclature is used.
R-188.8.131.52 Derivatives of assemblies of identical units. When assemblies names in accordance with R-184.108.40.206 contain substituents in the identical units in addition to the principal characteristic groups, these substituents are named by used of prefixes. These prefixes are assigned the lowest locants available after priority has been given to the principal characteristic groups and the linking di- or polyvalent substituent groups.
Example to R-220.127.116.11
Note: Assemblies of identical units linked by di- or polyvalent substituent groups where the individual units contain different numbers of the principal group are named by simple substitutive nomenclature.
Examples to R-18.104.22.168
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