Bonding in Co-ordination Chemistry and Inorganic Reaction Mechanism

Paper Code: 
CHY- 121
Credits: 
4
Contact Hours: 
60.00
Objective: 

To learn about kinetics and reaction mechanism of transition metal complexes and acquaint them with the nature of metal-ligand bonding in coordination compounds.

10.00
Unit I: 
Stability of Complex ions in Solutions

Thermodynamic and kinetic stability, Stepwise and overall formation constants, factors affecting the stability constants of complexes, chelate effect; determination of the composition and formation constants of complexes – mole ratio method, solubility method, spectral methods (slope-ratio and Job’s method) and Bjerrum’s method (pH-metry).

Self Study: Kinetic and thermodynamic stability of complex ions.

 

14.00
Unit II: 
Reaction Mechanism of Transition Metal Complexes-I

Ligand Substitution Reactions: patterns of reactivity, classification of mechanisms- associative and dissociative and interchange mechanism of substitution, energy profile of reaction transition states; inert and labile complexes (according to VBT and CFT),  kinetics of substitution reactions in octahedral complexes, acid hydrolysis(SN1 mechanism) and factors affecting acid hydrolysis, base hydrolysis, conjugate base mechanism( SN1CB mechanism), direct and indirect evidence in favour of conjugate mechanism, reaction of trigonal bipyramidal and square pyramidal complexes,  anation reactions; reactions without metal ligand bond cleavage, berrys’s pseudo rotation mechanism, swain scott equation.

12.00
Unit III: 
Reaction Mechanism of Transition Metal Complexes-II

Mechanism of substitution in square planar complexes, trans effect, theories of trans effect and its uses, factors affecting substitution reactions in square planar complexes(SN2 reaction), cis effect, cis-trans isomerization.

Redox Reactions: classification, homo and lumo of oxidants and reductant, nature of bridge ligands,  mechanism of one electron transfer reaction – outer sphere type reactions, cross reactions and Marcus-Hush theory, inner sphere type reactions, two electron transfer reaction (brief idea).

12.00
Unit IV: 
Molecular Orbital Theory-I (σ-bonding)

Pre requisite: Crystal field theory.

Ligand field theory; introduction to the molecular orbital diagrams of some simple polyatomic molecules like BeH2, H2O, NH3 , walsch diagrams complexes involving only σ bonding, LCAO’s approximation; σ-only molecular orbital energy levels for octahedral, tetrahedral and square planar complexes.

12.00
Unit V: 
Molecular Orbital Theory-II (π-bonding)

π-only molecular orbital energy levels for octahedral, tetrahedral and square planar complexes; effect of pi-bonding (π- type ligands); experimental evidences for pi-bonding (crystallography, Infra red spectroscopy); angular overlap model – principles, angular overlap and geometry.

References: 

1.          Mechanism of Inorganic Redox Reactions, Second Edition; F. Basalo and R.G. Pearson; Wiley Eastern Pvt. Ltd., New Delhi, 1973.

2.         Inorganic Chemistry; Third Edition; D.F. Shriver and P.W. Atkins; Oxford University Press, New York, 1999.

3.         Inorganic Chemistry, Principles of Structure and Reactivity; Fourth Edition; J.E. Hueey, E.A. Keiter and R.L. Keiter; Addison-Wesley Publishing Company, New York, 1993.

4.         Advanced Inorganic Chemistry, Fifth Edition; F.A. Cotton and G. Wilkinson; John Wiley and Sons, USA, New York, 1988.

5.         Inorganic Chemistry; Third Edition; Gary L. Miessler and Donald A. Tarr; Pearson Education Inc. Singapore, 2005.

6.         Coordination Compounds; S.F.A Kettle; Thomson Nelson and Sons Limited, 1975.

7.         The Determination of Stability Constants and other Equilibrium Constants in Solution; Francis.J.C.Rossotti; Mc Graw Hill Company, 1961.

Academic Year: 
2014-2015
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