Page 76 - Nomenclature of Inorganic Chemistry (IUPAC Recommendations 2005)

IR-4.7 F O R M U L A E

IR-4.6.4 Indication of excited states
Excited electronic states may be indicated by an asterisk as right superscript. This practice
does not differentiate between different excited states.

Examples:

1. He*
2. NO*

IR-4.6.5 Structural descriptors

Structural descriptors such as cis, trans, etc., are listed i n T able V. Usually such descriptors
are used as italicized p refixes a nd are connected to the formula by a h yphen.

Examples:
1. cis-[PtCl 2 (NH 3 ) 2 ]
2. trans-[PtCl 4 (NH 3 ) 2 ]

The descriptor m designates an atom or group bridging c oordination centres.

Example:

3. [(H 3 N) 5 Cr(m-OH)Cr(NH 3 ) 5 ] 5þ

IR-4.7 R E F E R E N C E S

1. This is the so-called Hill order. S ee E.A. Hill, J. Am. Chem. Soc., 22, 4 78–494 (1900).
2. For intermetallic compounds, earlier recommendations prescribed alphabetical ordering
rather than by electronegativity (see Section I-4.6.6 of Nomenclature of Inorganic
Chemistry, IUPAC Recommendations 1990, e d. G.J. L eigh, Blackwell Scientific
Publications, Oxford, 1990).
3. For example, the ordering o f B and C i n f ormulae was inconsistent in Nomenclature of
Inorganic Chemistry, IUPAC Recommendations 1990, e d. G.J. Leigh, Blackwell
Scientific Publications, Oxford, 1990.
4. Nomenclature of Organic Chemistry, IUPAC R ecommendations, e ds. W.H. P owell and
H. Favre, R oyal Society of Chemistry, in preparation.
5. Chapter I I-2 o f Nomenclature of Inorganic Chemistry II, IUPAC R ecommendations
2000, e ds. J.A. M cCleverty and N.G. Connelly, Royal Society of Chemistry, 2001. (Red
Book I I.)

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