Page 25 - Nomenclature of Inorganic Chemistry (IUPAC Recommendations 2005)
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G R A M  M  A R                                                     I  R-2.1





                       IR-2.15  O  rdering principles
                         IR-2.15.1 Introduction
                         IR-2.15.2 Alphabetical order
                         IR-2.15.3 Other ordering  r ules
                           IR-2.15.3.1 Element ordering on the basis of the periodic table
                           IR-2.15.3.2 Ordering of parent hydrides
                           IR-2.15.3.3 Ordering characteristic groups for substitutive nomenclature
                           IR-2.15.3.4 Ordering ligands in formulae and names
                           IR-2.15.3.5 Ordering components in salt formulae and names
                           IR-2.15.3.6 Isotopic  m  odification
                           IR-2.15.3.7 Stereochemical priorities
                           IR-2.15.3.8 Hierarchical ordering  o f  p unctuation marks
                       IR-2.16  F  inal remarks
                       IR-2.17  R  eferences




           IR-2.1      I N T R O D U C T I O N

                       Chemical n omenclature may be considered to be a  l anguage. As such, it consists of words
                       and it should  o bey the rules of syntax.
                          In the language of chemical nomenclature, the simple names of atoms are the words. As
                       words are assembled to form a s entence, s o  n ames of atoms are assembled to form names of
                       chemical compounds. S yntax  i s  t he set of grammatical rules for building sentences  o ut of
                       words. In nomenclature, syntax includes  t he use of symbols,  s uch as dots, commas  a nd
                       hyphens, t he use of numbers for appropriate reasons in given places, and the order of citation
                       of various words, syllables and symbols.
                          Generally, nomenclature systems require a  r oot on which to construct the name. This
                       root can be an element name  ( e.g. ‘ cobalt’ or ‘silicon’) f or use in additive nomenclature, or
                       can be derived from an element name (e.g. ‘sil’ from ‘silicon’, ‘ plumb’ f rom ‘plumbum’ for
                       lead) and elaborated to yield a  p arent hydride name  ( e.g. ‘ silane’ or ‘plumbane’) f or use  i n
                       substitutive nomenclature.
                          Names are constructed  b y  j oining other units to these roots. Among the most important
                       units are affixes. These are syllables added to words or roots and can be suffixes, prefixes o r
                       infixes a ccording to whether they are placed after, before or within a  w  ord or root.
                          Suffixes and endings are of many different kinds (Table III)*, each of which conveys
                       specific information. The following examples illustrate particular u ses. They may specify the
                       degree of unsaturation of a  p arent compound in substitutive nomenclature: hexane, h exene;
                       and phosphane, d iphosphene, d iphosphyne. O  ther endings indicate  t he nature of the charge
                       carried by the whole compound; cobaltate refers to an anion. Further suffixes can indicate
                       that a  n ame refers to a  g roup, as in hexyl.
                          Prefixes i ndicate, for example, substituents in substitutive nomenclature, as in the name
                       chlorotrisilane, and ligands in additive nomenclature, as in the name aquacobalt.
                       Multiplicative prefixes (Table IV) can be used to indicate  t he number of constituents or
                       ligands, e.g. hexaaquacobalt. Prefixes  m  ay also be used to describe the structural t ypes or

                       *  T  ables numbered with a  R  oman numeral are collected together at the end of this book.


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