Learning objectives
The course provides the bases required to examine thoroughly the chemistry of coordination compounds in terms of bonds, spectra, magnetism, structures and reactions and to discuss the descriptive chemistry of the transition elements considering comparatively in the periodic classification the chemical properties of theirs compounds.
Course unit content
1) General part
Introduction to the chemistry of coordination compounds (complexes). Werner's theory (primary and secondary valence). Nomenclature of coordination compounds. Ligands: denticity, coordination modes (ambidentate ligands, bridging ligands), cyclic ligands. Coordination number, coordination sphere, coordination geometry of a metal ion. Kepert model of point charges, Berry pseudorotation. Isomerism in complexes: structural isomers, stereoisomers (geometric isomers, optical isomers), chirality on the ligand.
The bond in coordination compounds:
- crystalline field theory (energy separation of d orbitals: octahedral, tetrahedral and square planar fields)
- stabilization energy of the crystalline field. Strong and weak fields, spectrochemical series of ligands, low and high spin complexes (spin transitions).
Jahn-Teller effect. Outline of the theory of molecular orbitals (covalent model): sigma / pi bond. Sigma donor ligands. Pi- donor/acceptor ligands, backdonation. Electronic and magnetic properties of complexes. Solvatocroism.
Thermodynamic aspects of the chemistry of coordination compounds: formation constants, hard and soft acids and bases (HSAB) theory, "absolute" hardness, Irving-Williams series, chelating effect, ligand pre-organization, macrocyclic effect, polycyclic ligands. Selectivity of a ligand for a metal ion. Ionophores (siderophores).
Thermodynamic and kinetic templating effect.
Kinetic aspects of the chemistry of coordination compounds, associative / dissociative mechanism, substitution reactions, substitution reactions in square-planar complexes, factors affecting the rate of substitution, nucleophilicity, trans effect.
Redox reactions (internal sphere mechanism, external sphere mechanism), dependence of the redox potentials of metal ions on coordination.
2) Coordination chemistry and bioinorganic chemistry
Chelation therapy for the removal of toxic or essential metals in abnormal concentrations. Ligands that inhibit the activity of a metalloenzyme. Metal complexes such as drugs or supplements. Metal complexes in radiodiagnostics and radiotherapy. General characteristics of the coordination chemistry of lanthanides; “antenna” effect. Metal complexes in Nuclear Magnetic Resonance imaging. Fluorescent probes (molecular probes).
Bibliography
J.R. Gispert, Coordination Chemistry, Wiley
J.E. Huheey, E.A. Keiter, R.L. Keiter, Chimica Inorganica. Principi, strutture, reattività, Piccin
D.F. Shriver, P.W. Atkins, C.H. Langford, Chimica Inorganica, Zanichelli
F. Basolo, R. Johnson, Chimica dei composti di coordinazione, Zanichelli
