Solvate Isomerism (Hydrate Isomerism)
A specific type of ionisation isomerism where water molecules are involved as either a ligand or as solvent molecules outside the coordination sphere.
What is Solvate Isomerism (Hydrate Isomerism)?
A type of structural isomerism in coordination compounds where solvent molecules are incorporated differently, either as ligands or as solvent molecules of crystallisation.
Key points
- Define solvate isomerism and hydrate isomerism.
- Identify examples of solvate isomerism.
- Differentiate between coordinated solvent molecules and solvent molecules of crystallisation.
- Explain how solvate isomerism affects the properties of coordination compounds.
Common exam trap
Confusing solvate isomerism with ionisation isomerism (where anions are exchanged).
Definitions
- Term
Solvate Isomerism
- Meaning
A type of structural isomerism in coordination compounds where solvent molecules are incorporated differently, either as ligands or as solvent molecules of crystallisation.
- Term
Hydrate Isomerism
- Meaning
A specific type of solvate isomerism where the solvent molecule involved is water.
- Term
Coordination Sphere
- Meaning
The central metal atom/ion and the ligands directly bonded to it, enclosed in square brackets.
- Term
Solvent of Crystallisation
- Meaning
Solvent molecules trapped within the crystal lattice of a solid compound, not directly bonded to the central metal ion.
Learning objectives
Define solvate isomerism and hydrate isomerism.
Identify examples of solvate isomerism.
Differentiate between coordinated solvent molecules and solvent molecules of crystallisation.
Explain how solvate isomerism affects the properties of coordination compounds.
Prerequisites
Coordination compounds: definition, nomenclature.
Coordination sphere, ligands, central metal ion.
Types of isomerism (structural isomerism).
Common mistakes
Confusing solvate isomerism with ionisation isomerism (where anions are exchanged).
Not distinguishing between coordinated solvent molecules and solvent molecules of crystallisation.
Assuming all water molecules in a hydrated salt are coordinated.
Keywords
Solvate Isomerism
Hydrate Isomerism
Coordination Compounds
Structural Isomerism
Ligands
Solvent of Crystallisation
Coordination Sphere
Chromium(III) chloride hexahydrate
Practice preview
Which of the following pairs of complexes are solvate isomers?…
hard
Which of the following complexes exhibits solvate isomerism?…
easy
Identify the type of isomerism shown by the complex [Co(NH₃)₅(H₂O)]Cl₃ and [Co(NH₃)₅Cl]Cl₂·H₂O.…
easy