Coordination Number
| Formula / Notation | CN = number of donor atoms bonded to central metal; common: 2, 4, 6 |
|---|---|
| Also Known As | CN (coordination), ligand number, denticity context, coordination index |
What is Coordination Number?
The coordination number in a coordination compound is the number of donor atoms (from ligands) directly bonded to the central metal ion. Common coordination numbers are 2 (linear), 4 (tetrahedral or square planar), and 6 (octahedral). In crystal structures, coordination number refers to the number of nearest neighbours surrounding a particular atom or ion.
Formula & Notation
Other Names / Synonyms: CN (coordination), ligand number, denticity context, coordination index
Properties & Characteristics
Uses & Applications
Safety Information
Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.
Key Facts
Frequently Asked Questions
The coordination number in a coordination compound is the number of donor atoms (from ligands) directly bonded to the central metal ion. Common coordination numbers are 2 (linear), 4 (tetrahedral or square planar), and 6 (octahedral). In crystal structures, coordination number refers to the number of nearest neighbours surrounding a particular atom or ion.
Coordination number determines molecular geometry and is central to VSEPR application in coordination chemistry, Crystal Field Theory analysis, and ligand field stabilisation energy (CFSE) calculations. It guides the design of selective chelating agents and metal-based drugs.
No direct safety concern. Knowing the coordination number helps predict whether all sites on a toxic metal ion (e.g., Pt²⁺ in cisplatin) are occupied by protective ligands vs. available for binding to DNA or proteins.
The formula or notation for Coordination Number is: CN = number of donor atoms bonded to central metal; common: 2, 4, 6