Page 74 - Nomenclature of Inorganic Chemistry (IUPAC Recommendations 2005)
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IR-4.6                                                       F O R M  U L A E





                       Examples:
                                36
                           1. H[ Cl]
                               32
                           2. [ P]Cl 3
                                     2
                               15
                           3. [ N]H 2 [ H]
                                    17
                               13
                           4. [ C]O[ O]
                                    18
                               32
                           5. [ P]O[ F 3 ]
                                 2
                           6. Ge[ H 2 ]F 2
           IR-4.5.3.3  Selectively labelled compounds
                       A  s electively labelled compound may be considered as a  m  ixture of specifically labelled
                       compounds. It is indicated by prefixing the formula  b y  t he nuclide symbol(s) preceded by
                       any necessary locant(s) (but without multiplying subscripts) enclosed in square  b rackets.

                       Examples:
                               36
                           1. [ Cl]SOCl 2
                               2
                           2. [ H]PH 3
                               10
                           3. [ B]B 2 H 5 Cl

                       The numbers of possible labels for a g iven p osition may be indicated by subscripts separated
                       by semicolons  a dded to the atomic symbol(s) in the isotopic descriptor.


                       Example:
                                2
                           4. [1- H 1;2 ]SiH 3 OSiH 2 OSiH 3

           IR-4.6      O P T I O N A L  M  O D I F I E R S  O  F  F  O R M  U L A E


           IR-4.6.1    Oxidation state
                       The oxidation state of an element in a  f ormula may be indicated by an oxidation number
                       written  a s  a  right superscript in Roman numerals. Oxidation state zero may be represented
                       by the numeral 0  b ut is not usually shown. If an element occurs with more  t han one
                       oxidation state in the same  f ormula, the element symbol is repeated, each symbol being
                       assigned a  n umeral, a nd the symbols cited in order of these numerals.

                       Examples:

                                V
                           1. [P 2 Mo 18 O 62 ] 6
                           2. K[Os VIII (N)O 3 ]
                                 V
                           3. [Mo 2 Mo VI 4 O 18 ] 2
                                II  IV
                           4. Pb 2 Pb O 4
                                 0
                           5. [Os (CO) 5 ]
                                  I
                           6. [Mn (CO) 5 ]

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