Nomenclature of Cationic Complexes
Applying IUPAC rules to correctly name coordination compounds where the complex ion carries a positive charge.
What is Nomenclature of Cationic Complexes?
A coordination compound in which the complex ion carries a positive charge.
Key points
- To systematically name cationic coordination complexes.
- To identify and correctly name ligands.
- To determine the oxidation state of the central metal atom.
- To apply IUPAC nomenclature rules for coordination compounds.
Common exam trap
Incorrect alphabetical ordering of ligands.
Definitions
- Term
Cationic Complex
- Meaning
A coordination compound in which the complex ion carries a positive charge.
- Term
Ligand
- Meaning
An atom, ion, or molecule that binds to a central metal atom or ion to form a coordination complex.
- Term
Coordination Number
- Meaning
The number of ligand donor atoms directly bonded to the central metal atom.
- Term
Oxidation State
- Meaning
The hypothetical charge that an atom would have if all bonds to atoms of different elements were 100% ionic.
Learning objectives
To systematically name cationic coordination complexes.
To identify and correctly name ligands.
To determine the oxidation state of the central metal atom.
To apply IUPAC nomenclature rules for coordination compounds.
Prerequisites
Werner's Theory of Coordination Compounds
Understanding of oxidation states
Basic knowledge of chemical nomenclature
Common mistakes
Incorrect alphabetical ordering of ligands.
Using simple prefixes (di-, tri-) for complex ligands.
Forgetting to indicate the oxidation state of the metal.
Naming the complex ion after the counter ion when the complex is cationic.
Incorrectly naming simple ligands like 'ammine' or 'aqua'.
Keywords
Coordination Compound
Cationic Complex
IUPAC Nomenclature
Ligand
Central Metal Atom
Oxidation State
Prefixes
Alphabetical Order
Werner's Theory
Practice preview
The IUPAC name of [Cr(H₂O)₄Cl₂]⁺ is:…
medium
Consider the complex [Co(en)₂(NH₃)₂]³⁺. Which of the following is the correct IUPAC name?…
hard
What is the IUPAC name for [Cr(en)₂Cl₂]Cl?…
easy