Square brackets nesting order

The name of the polymer is simply the name of the preferred CRU enclosed in curves, square brackets or braces and prefixed by poly. The nesting order of enclosing marks is curves, square brackets, braces, then curves, square brackets, braces, etc., i-6- [( [( )] )] This is well illustrated in Examples 21 and 31 in Section 9. 

Uses of cnclii,sinj> murks. The formula for the entire coordination enlily. whether charged or not. is enclosed in square brackets. When ligands are polyatomic, their formulae are enclosed in parentheses. Ligand abbreviations are also enclosed in parentheses. In the special case of coordination entities, the nesting order of enclosures is as given [on page A-5I. There should be no space between representations of ionic species within a coordination formula. 

In formulae, these enclosing marks are used in the following nesting order [],[()],[ () ], [( () )], [ ( () ) ], etc. Square brackets are normally used only to enclose entire formulae parentheses and braces are then used alternately (see also Sections IR-4.2.3 and IR-9.2.3.2). There are, however, some specific uses of square brackets in formulae, cf. Section IR-2.2.2.1. 

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