Term: class (b) metal ion
https://doi.org/10.1351/goldbook.C01095

Definition:
A metal ion that combines preferentially with ligands containing ligating atoms other than the lightest of their Periodic Group.

Related Terms:
1) class (a) metal ion (http://doi.org/10.1351/goldbook.C01094).
2) hard acid (http://doi.org/10.1351/goldbook.H02740).
3) ligands (http://doi.org/10.1351/goldbook.L03518).

Source: PAC, 1994, 66, 1077. 'Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994)' on page 1097 (https://doi.org/10.1351/pac199466051077)

Citation: 'class (b) metal ion' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. https://doi.org/10.1351/goldbook.C01095

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