911.1 - Monoazo compounds RN=NR, in which the azo group -N=N- links radicals derived from parent molecules that, when unsubstituted, are identical, are named by adding the prefix "azo-" to the name of the unsubstituted parent molecule. Substituents are denoted in the usual way by prefixes and suffixes. The azo group has priority for lowest available numbers; one set of locants is distinguished by primes.
911.2 - Monoazo compounds , in which the azo group links radicals derived from parent molecules that, when unsubstituted, are different, are named by placing "azo" between the complete names of the (substituted) parent molecules; when locants are needed to indicate the position of the azo group they are placed between the affix "azo" and the names of the molecules to which each respectively refers. Preference is given to the more complex parent molecule for citation as the first component. The azo group has priority for lowest permissible numbers. All substituents in the component named first are denoted by prefixes unless their presence is indicated in the trivial or semi-trivial name of that component. Locants for substituents in the first-named component are not primed; the others are primed.
Examples to Rule C-911.1
911.3 - Bisazo compounds and more complex analogues are similarly named by citing the components serially, starting with the more complex terminal component; or, when the molecule consists of a central component from which identical RN=N- groups radiate, by citing these radiating groups as substituents of the central component.
Examples to Rule C-911.2
See Recommendations'93 R-5.3.3
Examples to Rule C-911.3
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