Spectroscopy and Photochemical Laws

Diatomic molecules, 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.

Infrared spectrum: energy levels of simple harmonic oscillator, selection rules, pure vibrational spectrum, intensity, determination of force constant and qualitative relation of force constant and bond energies, effect of anharmonic motion and isotope on the spectrum, idea of vibrational frequencies of different functional groups.

Raman Spectrum: concept of polarizability, pure rotational and pure vibrational Raman spectra of diatomic molecules, selection rules.

Concept of potential energy curves for bonding and antibonding molecular orbitals, qualitative description of selection rules and Franck–Condon principle, qualitative description of σ, π and n molecular orbital, their energy levels and respective transitions.

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

Interaction of radiation with matter, difference between thermal and photochemical processes, laws of photochemistry- Grothus-Drapper law, Stark-Einstein law; Jablonski diagram depicting various processes occurring in the excited state, qualitative description of fluorescence, phosphorescence, non-radiative processes (internal conversion, intersystem crossing);  quantum yield; energy transfer processes – photosensitization.