Coordination and Organometallic Compounds — DU B.Sc (hons) Chemistry Previous Year Question Papers

The questions should be numbered in accordance to the number in the question paper. (b) Draw the structure of methyl lithium. In which category of organometallic compounds will you place it? What are the coordination numbers of Li and C in the tetramer? (c) What is the cause of distortion with some octahedral complexes? The high-spin octahedral complexes of Ni?* ion are not expected to show distortion, whereas low-spin octahedral complexes of Ni?+ show strong distortion. Explain. 4. (a) Differentiate between ionic and covalent sigma bonded organometallic compounds giving suitable example. (b) Write IUPAC names of the following complexes. (c) Give two examples for the preparation of metal carbonyls by reductive carbonylation. (6,5,4) 5. (a) What are inner and outer orbital complexes? Give two examples of each. (b) Define 18-electron rule. Show that Fes(CO)12 obeys 18 electron rule. (c) Write a short note on valence bond theory. (6,5,4) 6. (a) [FeF6] has higher magnetic moment than [Fe(CN)6]*, though both are octahedral complex ions. Explain on the basis of CFT. Draw the crystal field splitting of d- orbitals for both the complex ions. (b) Calculate the crystal field stabilization values for high spin and low spin octahedral complexes of (i) d* ion and (ii) d' ion. (c) Answer the following: (i) Apart from CO give an example of a it - acid ligand. Through which atom does CO act as an eiectron pair donor? (iv) Why is CO a it acid ligand? (6,5,4)