Organometallic Chemistry and Bio-catalysis, Application of Reagents in Organic Synthesis and Crystalline Solids & their Magnetic Properties (DSC-20) — DU B. Sc. Life Science (Chemistry) Previous Year Question Papers

Name o.f the Course DSC: ORGANOMETALLIC CHEMISTRY AND BIOCATALYSIS, APPLICATION OF REAGENTS IN ORGANIC SYSTHESIS AND CRYSTALLINE SOLIDS & THEIR MAGENETIC PROPERTIES B.Sc.(Prog) Life Science Attempt six questions in total and any two questions from each section: (A, 8, Q 1 (i) How do you rationalize the increase in the C{ bond length from 133.7 pin in ethenc to 137.5 pin in Zcisc's salt, accompanied by a decrease in C-C stretching frequency from 1623 (ii) Discuss the challenges in developing organometallic radiopharmaccuticals, including toxicity and biological compatibility. (iii)) Hxpalin how ferroconc conjugation can jmprovc the efficacy of an existing drug with suitable example. (5,5,5) Q2. (i) Describe the effect of temperature in enzyme-catalyzed reactions. (ii) The CO stretching frequency in IR spectra (Vco values), in pro(CO)412- , [Co(CO)4]- and LNi(COM are 1788,1918 and 2121 cm-I respectively while the Vco value for CO(g) is 2143cm-I . Explain the trend. (iii) Write a short note on nano biocatalysis with examples and discuss their advantages over traditional catalysis? (5£5) Q3. (A) Using the 18 electron rule, find/ identify: (i) The number of CO ligands in (a) [Fe(NO)(CO), (b) [V(NO)(CO).] (c) [W(n-CH) (CO)n] (d) [Con-CsHs)(CO),] (ii) The number of metal-metal bonds in (ii1) The charge on the species (iv) The number of ligands (m and n) in [(n°-C.H6),Cr(CO)m] (B) Explain the structure of ferrocene and explain its staggered and eclipsed conformations. Q4. (i) Why Hydroboration of an alkene is highly regioselective process? Explain an example with plausible reaction mechanism. (il) Outline the mechanism of the following transformations: (ili) Write the product of given reactions and explain each step. (i) BUL, THE A B Q5. (i) Write the method of synthesis for methyl lithiurn and ethyl magnesium bromide, and why alkyl lithium reagent is more reactive in comparison of alkyl magnesium bromide. (ii) Write the most suitable reagent for the given reaction and explain the reaction mechanism. (iii) Write the product in the following reactions. Q6. (i) Write one application of following reagents: (b) Jones Reagent (ii) Give the preparation and applications of the following reagents: (b) Thalliun Nitrate (iii) (a) Write the product of given reaction with stereochemical outcome. Os04, NMO acetone, H20 Q7. (i) What are the symmetry elements found in any crystalline solid? Which rotational axes of rotation is present of a cubic unit cell. (ii) What is magnetic anisotropy? Explaln its type. (iii) Define Miller indices. Determine the Miller indices for a plane, Q8. (i) What is .space lattice. Differentiate between monoclinic and triclinic crystal systems. (ii) A crystal preferentially diffracts monochromatic X-rays having a wavelength of 10.4 A 2905 4-at an angle of 25.50. (a) Assuming that this is the first-order diffraction, what is the d spacing between the crystalline planes? (b) At what angle would the second-order diffraction be found