Page 53 - Nomenclature of Inorganic Chemistry (IUPAC Recommendations 2005)
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G R A M  M  A R                                                    I  R-2.16





                       Example:
                           1. [Cr 2 (m-O)(OH) 8 (m-OH)]  5
                              m-hydroxido-octahydroxido-m-oxido-dichromate(5 )

                       Thus, for both formulae and names the terminal ligands are closer to the central atom, with
                       the multiplicity of the bridging  l igands increasing further away from the metal.

           IR-2.15.3.5  Ordering components in salt formulae and names

                       In formulae and names of salts, double salts and coordination compounds, cations precede
                       anions. Ordering within each of these groups is alphabetical, cf. S ection IR-2.15.2.


           IR-2.15.3.6  Isotopic  m  odification
                       In isotopically modified compounds, a  p rinciple governs the order of citation  o f  n uclide
                       symbols. ( See Section II-2.2.5 of Ref. 2.)

           IR-2.15.3.7  Stereochemical priorities

                       In the stereochemical nomenclature of coordination compounds, the procedure for assigning
                       priority numbers to the ligating atoms of a  m  ononuclear coordination system is based upon
                       the standard  s equence rules developed for chiral carbon compounds (the Cahn, Ingold,
                                       6
                       Prelog or CIP rules , s ee Section IR-9.3.3.2).
           IR-2.15.3.8  Hierarchial ordering of punctuation marks

                       In the names of coordination compounds and boron compounds, t he punctuation marks used
                       to separate the symbols of atoms from the numerical locants, the locants indicating bridging
                       atoms, and the various other sets of locants which may be present,  a re arranged in the
                       following hierarchy:

                                               semicolon 4 colon 4 comma:

                       The colon is only used for bridging  l igands, s o  t hat the more  r estricted general hierarchy is
                       simply comma 5 semicolon. The  s equence when  b ridging ligands are being specified is
                       comma 5 colon. (See Example 2  i n  S ection IR-2.5.2, and Section IR-9.2.5.5.)



           IR-2.16     F I N A L  R  E M  A R K S

                       In this chapter, the various uses of letters, numerals and symbols in names and formulae
                       have been gathered under common headings to provide an easy check to ensure that the
                       constructed name  o r  f ormula is in accord with agreed practice. However, this chapter is
                       not sufficient to make clear all the rules needed  t o  b uild a  n ame  o r  a  formula, and the
                       reader is therefore advised to consult other  a ppropriate chapters for the more  d etailed
                       treatment.





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