Spectral Techniques in Organic Chemistry

General principles Introduction to absorption and emission spectroscopy.

UV Spectroscopy: Types of electronic transitions, λ_max, chromophores and auxochromes, bathochromic and hypsochromic shifts, intensity of absorption, application of Woodward Rules for calculation of λ_max for the following systems: α,β unsaturated aldehydes, ketones, carboxylic acids and esters; Conjugated dienes: alicyclic, homoannular and heteroannular; Extended conjugated systems (aldehydes, ketones and dienes); Distinction between cis and trans isomers.

Fundamental and non-fundamental molecular vibrations; IR absorption positions of O, N and S containing functional groups; Effect of H- bonding, conjugation, effect of resonance and ring size on IR absorptions; Fingerprint region and its significance; Applications in functional group analysis.

Basic principles of Proton Magnetic Resonance, chemical shift and factors influencing it; Spin – Spin coupling and coupling constant; Anisotropic effects in alkene, alkyne, aldehydes and aromatics; Interpretation of NMR spectra of simple compounds like ethyl acetate, ethyl alcohol, acetaldehyde, 1,2 dibromo ethane, ethyl bromide etc.

¹³C NMR spectroscopy: general considerations, chemical shift, (aliphatic, olefinic, alkyne, aromatic, heteroaromatic & carbonyl carbon), proton (¹H) coupled ¹³C NMR spectrum,off resonance(elementary idea of ²D NMR spectroscopy)

Introduction, instrumentation, molecular ion-production, determination of molecular  weight – molecular ion peak, base peak, nitrogen rule, isotope peak, metastable ions; fragmentation – basic fragmentation types and rules, factors influencing fragmentation, McLafferty rearrangement, fragmentation pattern of hydrocarbons, alcohols, ethers, ketones, aldehydes, carboxylic acids, amines, nitro compounds, alicyclic and heterocyclic compounds.

Combined applications of IR, UV, NMR and Mass spectral techniques  for identification of simple organic molecules.