Coordination Compounds

• Introduction

  • Definition of Coordination Compounds
  • Difference between Addition Compounds and Double Salts
  • Werner’s Theory of Coordination Compounds
    • Primary Valency (Ionizable, ionic bonds)
    • Secondary Valency (Non-ionizable, directional, coordination number)

• Basic Terminology

  • Coordination Entity
  • Central Atom / Ion (Lewis acids)
  • Ligands
    • Monodentate, Dientate, Polydentate
    • Chelate Ligands & Chelate Effect
    • Ambidentate Ligands
  • Coordination Number (CN)
  • Coordination Polyhedra
  • Oxidation Number of central atom
  • Homoleptic and Heteroleptic complexes

• Nomenclature (IUPAC System)

  • Rules for naming cationic, anionic, and neutral complexes
  • Order of naming ions and ligands (alphabetical order)
  • Use of prefixes (di-, tri-, bis-, tris-)
  • Oxidation state representation in Roman numerals

• Isomerism in Coordination Compounds

  • Stereoisomerism
    • Geometrical Isomerism (Cis-Trans, Fac-Mer)
    • Optical Isomerism (d and l forms)
  • Structural Isomerism
    • Linkage Isomerism
    • Coordination Isomerism
    • Ionisation Isomerism
    • Solvate (Hydrate) Isomerism

• Bonding in Coordination Compounds

  • Valence Bond Theory (VBT)
    • Hybridization ($sp^3$, $dsp^2$, $sp^3d^2$, $d^2sp^3$)
    • Inner orbital vs Outer orbital complexes
    • Magnetic properties (paramagnetic vs diamagnetic)
    • Limitations of VBT
  • Crystal Field Theory (CFT)
    • Splitting of $d$-orbitals in octahedral fields ($\Delta_o$, $e_g$ and $t_{2g}$)
    • Crystal field splitting energy ($\Delta_o$) and Spectrochemical Series
    • Pairing energy ($P$) and strong/weak field ligands
    • Splitting in tetrahedral fields ($\Delta_t$)
    • Colour in coordination complexes (due to $d-d$ transitions)
    • Limitations of CFT

• Stability of Coordination Compounds

  • Stability constant ($ estabilidad$) in aqueous solution
  • Factors affecting stability (charge on metal ion, nature of ligand)

• Organometallic Compounds

  • Definition and classification
  • Metal Carbonyls (Synergic bonding, $d\pi-p\pi$ back bonding)

• Importance and Applications

  • Biological systems (Chlorophyll, Hemoglobin, Vitamin $B_{12}$)
  • Medicinal chemistry (Cisplatin in cancer treatment)
  • Metallurgy (Extraction of Gold and Silver via cyanide process)
  • Analytical chemistry (Qualitative and quantitative estimation)