LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034
M.Sc. DEGREE EXAMINATION – CHEMISTRY
THIRD SEMESTER – APRIL 2008
CH 3802/ 921 – COORDINATION CHEMISTRY
Date : 29-04-08 Dept. No. Max. : 100 Marks
Time : 1:00 – 4:00
Part – A
Answer all the questions (10 x 2 = 20)
- What are polydentate ligands? Give an example.
- What is the ground term of 3d7 configuration?
- Why the magnetic moment of Co(II) octahedral complexes are much higher than that of tetrahedral complexes?
- Explain why CrO42- ion with d0 configuration is coloured?
- What are Π-acceptor ligands? Give two examples.
- Explain SN1CB mechanism with an example.
- What is meant by hapticity of a ligand? How is it designated?
- Differentiate the types of cytochromes.
- What are cryptands? Mention any one application.
- What is Wilkinson catalyst? What type of reaction can make use of this catalyst?
Part – B
Answer any eight questions (8 x 5 = 40)
- What is tetragonal distortion? Which dn configurations lead to strong Jahn teller distortion in octahedral and tetrahedral complexes?
- What are the basic postulates of valence bond theory? How does valence bond theory explain the geometry and magnetic properties of (i) [Co(NH3)6]3+ and (ii) [CoF6]3-
- Explain how optical rotatory dispersion study is useful to determine the absolute configuration of chiral complexes.
- Discuss the bonding in ferrocene on the basis of molecular orbital energy level diagram.
- Explain the variations in the stretching frequency of the isoelectronic species, Cr(CO)6, V(CO)6– and Mn(CO)6+.
- Explain the trans effect in the substitution reactions of square planar complexes.
- Explain the fluxional isomerism with two examples.
- Explain the crystal structures of Fe3O4, ZnFe2O4 as spinel or inverse spinel
- Explain the synergic effect of metal-ligand bonding in metal carbonyls.
- Apply Wade’s rule to predict the geometry of
a)[Fe5(CO)15C] b) [h5C5H5RhFe3(CO)11]
- Briefly explain the significances of metal complexes in nitrogen fixation
- Write short notes on
- a) Wacker’s process b) Fischer Tropsch process
Part – C
Answer any four questions. (4 x 10 = 40)
- Explain the d orbital spilitting of square planar complexes using crystal field theory. Why does the metal ion with d8 configuration in a strong field form square planar complexes?
- Explain Why Cl– acts as a weak ligand whereas CN– acts as strong ligand in octahedral transition metal complexes with the help of MO theory.
- Explain the features of Tanabe- Sugano and Orgel diagram. Construct orgel diagram for d3and d7, tetrahedral and octahedral complexes.
- Explain the principles involved in the Mossbauer spectral analysis of metal complexes and explain how do the Mossbauer spectra of K4[Fe(CN)6] and K3[Fe(CN)6] differ.
- a) Discuss in detail the mechanisms of outer and inner sphere electron transfer in metal complexes. (10)
- b) Why is the electron transfer in the system [Co(NH3)6]2+ – [Co(NH3)6]3+ slower than that in the system [Fe(CN)6]4- and [Fe(CN)6]3- . .
- Describe the essential structure of haemoglobin and explain its cooperativity in its oxygenation.