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Principles of Organic Nomenclature

R-1.1 Bonding Number

The concept of a standard valence state is fundamental to organic nomenclature. Since most organic names are derived by formal exchange of atoms or groups for hydrogen atoms of a parent structure, it is necessary to know exactly how many hydrogen atoms are implied by the name of the parent structure. For example, does the name phosphane refer to PH3 or to PH5? This is a problem only when an element can occur in more than one valence state; in such cases the "standard" state is normally not specified, but any other valence state is noted by citation of the appropriate bonding number. A more detailed treatment of bonding number, including selection rules, is given in separate publications, .

See Also:
R-1.0 Introduction
R-1.2 Nomenclature Operations
R-1.3 Indicated Hydrogen

This HTML reproduction is as close as possible to the published version [see IUPAC, Commission on Nomenclature of Organic Chemistry. A Guide to IUPAC Nomenclature of Organic Compounds (Recommendations 1993), 1993, Blackwell Scientific publications, Copyright 1993 IUPAC]. If you need to cite these rules please quote this reference as their source.

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