Co-ordination chemistry

• Ligand?

  ion or molecule that binds to a central metal ion to form a coordination complex. It contains donor atoms which can donate electron pairs to form dative (not covalent)coordinate bonds.
• What does ‘denticity’ mean?

  Ligand denticity - refers to the number of donor atoms in a single ligand that bind to a central metal ion in a coordination complex
• What is a chelating agent?

  A ligand that forms two or more dative bonds with the same metal ion
• What is a chelate?

  a complex which contains more than one chelating agent
• What is a co-ordination number?

  Coordination number is the number of donor atoms bonded to the central metal ion in the complex
• What is a Lewis acid and a Lewis base?

  Lewis base is a molecule or ion that can donate one or more electron pairs and a Lewis acid is a molecule or ion that is an electron pair acceptor
• What is chelation therapy?


  Chelation therapy is the administration of chelating agents to remove toxic or unwantedmetals from the body
• What gives rise to d orbital splitting?

  Electron-electron repulsion between ligand lone pair of electrons and electrons in metal d orbitals
• What is the spectrochemical series?


  A spectrochemical series is a list of ligands ordered on ligand strength and their ability to cause d orbital splitting
• What are weak field and strong field ligands?

  Ligands which cause a large splitting Δ of the d-orbitals are referred to as strong-field ligands, such as CN− and CO from the spectrochemical series – low spin complexes

  Ligands (like I− and Br−) which cause a small splitting Δ of the d-orbitals are referred to as weak-field ligands – high spin complexes
• Dative bond?

  a covalent bond in which both electrons come from the same atom
• Lewis acid?

  electron pair acceptor
• Lewis base?

  electron pair donor
• Arrhenius acid?

  a substance that ionises to produce H+ in aqueous solution
• Arrhenius base?

  a substance that ionises to produce OH- in aqueous solution
• Bronsted-Lowry acid?

  proton donor
• Bronsted-Lowry base?

  proton acceptor
• Bridging ligand?

  ligand that acts as a bridge between the metal ions
• Chelating agent?

  forms two or more dative bonds with the same metal ion
• Crystal field theory?

  the breaking of d-orbital degeneracy in transition metal complexes due to the presence of ligands
• High spin complex?

  low splitting, electrons fill inter-axial orbitals singly before pairing
• Low spin complex?

  Large splitting, electrons will completely fill inter-axial orbitals first
• Paramagnetic?

  has unpaired electrons
• Diamagnetic?

  has no unpaired electrons
• Three factors of collision theory?


  molecular orientation, energy of collisions, frequency of collisions
• Rate law?

  the dependance of rate on concentration
• Differential rate law?

  rate vs. Concentration of reactant
• Integrated rate law?

  concentration of reactant vs time
• Half-life of a drug?

  the time required for concentration to drop 50%
• Defining reaction order?

  initial rates method, graphical method, half-life method