CHEMICAL SPECTROSCOPY

Electromagnetic radiation, quantization of energy, regions of electromagnetic spectrum, Born –Oppenheimer approximation.

Diatomic molecule, energy levels of a rigid rotor (semi-classical principles), selection rules, spectral intensity, distribution using population distribution (Maxwell-Boltzmann distribution), determination of bond length, qualitative description of non-rigid rotor, isotope effect.

Different regions of IR spectrum (finger print and functional group region), Hooke’s law, energy levels of simple harmonic oscillator, selection rules, pure vibrational spectrum, intensity, determination of force constant, qualitative relation of force constant and bond energies, effect of anharmonic motion and isotope on the spectrum, rotational- vibrational spectrum.
Idea of vibrational frequencies of different functional groups, molecular vibrations, characteristic intensity and position of IR bands of various functional groups (alkanes, alkenes, alkyl halides, alcohols, ethers, carbonyl compounds, primary and secondary amines, carboxylic acids and its derivatives); effect of solvent and hydrogen bonding.

Raman effect, Classical and quantum theory of Raman effect, Concept of polarizability, pure rotational Raman and pure vibrational Raman spectra of diatomic molecules, rotational vibrational Raman spectroscopy, selection rules, mutual exclusion principle, applications of Raman spectroscopy.

Concept of potential energy curves for bonding and antibonding molecular orbitals, Franck–Condon principle, different electronic transitions and selection rules, Lambert – Beer law, molar absorptivity, effect of solvent on transitions, effect of conjugation, concept of chromophores and auxochromes, bathochromic, hypsochromic, hyperchromic and hypochromic shift. Woodward Fieser rules and its applications on enes, dienes, α,β-unsaturated carbonyls and extended conjugations.
Jablonski diagram depicting various processes occurring in the excited state, qualitative description of fluorescence, phosphorescence, non-radiative processes (internal conversion, intersystem crossing).

Introduction, principle of nuclear magnetic resonance, nuclear shielding and deshielding, energies of nuclei in magnetic fields, chemical shift, spin-spin coupling and coupling constant, proton spectra of simple compounds like ethanol, ethyl acetate, 1,2-dibromoethane.