Coordination Compounds Cheatsheet

Cheat Codes & Shortcuts

• Definition: Coordination compounds consist of a central metal atom/ion bonded to surrounding molecules or ions called ligands.
• Coordination Number: Number of ligand donor atoms bonded to the metal center.
• Ligands: Classified as monodentate, bidentate, polydentate (chelating agents).
• Complex Ion: Charged species formed by central metal and ligands.
• Oxidation State: Charge assigned to the central metal after ligands are assigned.
• Geometry: Common structures include octahedral, tetrahedral, square planar.
• Isomerism: Coordination compounds show structural and stereoisomerism (cis-trans, optical).
• Naming: Ligands named first (alphabetical order), metal named last with oxidation state in Roman numerals.
• Chelate Effect: Stability increases with polydentate ligands due to ring formation.
• CBC Theory: Describes bonding with sigma donation and pi back bonding.

Quick Reference Table

Concept	Example / Form	Description
Monodentate Ligand	\( \text{NH}_3 \)	Donates one lone pair to the metal.
Bidentate Ligand	Ethylene diamine (\( \text{en} \))	Donates two lone pairs, chelates metal.
Coordination Number	6 (in \( \text{[Co(NH}_3)_6]^{3+} \))	Six ligands coordinate to central metal.
Geometry	Octahedral	Coordination number 6, common geometry.
Isomerism	Cis-trans in \( \text{[Pt(NH}_3)_2Cl_2] \)	Different spatial arrangements of ligands.
Oxidation State	\( \text{Fe}^{3+} \) in \( \text{[Fe(CN)}_6]^{3-} \)	Metal charge after assigning ligands.

Advice

Coordination Compounds Quick Tips

• Central Metal: Usually a transition metal with variable oxidation states.
• Ligands: Can be neutral or charged; monodentate or polydentate.
• Coordination Number: Often 4 or 6, determines geometry.
• Isomerism: Different types like geometric and optical isomers exist.
• Stability: Chelate complexes are more stable due to entropy effects.

Coordination Compounds Speed Quiz

Test your knowledge with 5 coordination compounds questions! You have 30 seconds per question.