Course Contents

1. Ultraviolet and Visible Spectroscopy Nature of electronic excitation, Principles of absorption spectroscopy, Instrumentations, Chromophores: Effect of conjugation, Woodwords Fieser rules of dienes, Calculations of λmax, α-β unsaturated compounds, Substituents with unshared electrons and problems. 2. IR Spectroscopy Electromagnetic radiations: IR; modes of vibration, sampling techniques, factors influencing the vibration frequencies, functional group determination and factors affecting the absorption frequencies. Identification of the following organic compounds by IR: Alkanes, Alkenes, Alkynes, Aromatic compounds, Aldhydes, Ketones, Alcohols, Acids and its derivatives; Amines, Esters, Alkyl halides and Nitro compounds; Problems using UV and IR. 3. Nuclear Magnetic Resonance Spectroscopy Introduction, Magnetic properties of nuclei-Resonance condition, Nuclear spin, population of nuclear spin levels and NMR isotopes, Relaxation methods, Instrumentation and sampling handling; Chemical shift, Factors influencing chemical shifts : electronegativity and electrostatic effects; Mechanism of shielding and deshielding in alkanes, alkyl halides, alkenes, aromatic compounds, carbonyl compounds and annulenes. Pascals triangle and Magnetic anisotropy. Equivalence of protons-chemical and magnetic equivalence; Spin systems: First order and second order coupling of AB systems, Simplification of complex spectra. Problems. Spin-spin interactions: Homonuclear coupling interactions - AX, AX2, AX3, AMX, AB types. Vicinal, germinal and long range coupling-spin decoupling; Chemical shift reagents and deuterium exchange; Stereochemistry and hindered rotations. Temperature effects. CIDNP, Nuclear Overhauser effect (NOE), 2-D NMR, COSY and HETCOR, HMBC, HMQC, 4. 13C NMR Spectroscopy 13C-Nucleus, Interpretation of 13C Spectra (Peak assignment), Chemical Shifts, Calculations of 13C Chemical shifts, Proton-coupled 13C-spectra; spin-spin splitting of 13C, proton decoupled, Off-resonance decoupled (SFORD),Selectively decoupled and gated decoupled spectra. 13 C chemical shifts of alkanes, alkyl halides, alkenes, alkynes, alcohols, ethers, carbonyl compounds and aromatic compounds; Factors affecting the chemical shifts.C-13 NMR solvent, Hetero-nuclear coupling of carbon to deuterium and problems (elucidation of structures of organic compounds by 1H or 13C-NMR spectra). 5. Mass Spectrometry Basic concepts; mass spectrometers, ionization techniques, ;Ion production : Soft ionization methods: Low energy electron ejection; Chemical ionization; Ionization of large molecules : Fast-atom bombardment (FAB), Plasma desorption (PD) and Matrix Assisted Laser Desorption/ionization (MALDI); Electrospray ionization (ESI); Pyrolysis Isotopic abundance, molecular and metastable ions Exact mass measurements (high resolution spectra); Classification of mass spectrometers: Magnetic field deflection: magnetic field only (unit resolution) and double focusing (electrostatic field and magnetic field); High resolution; Quadrapole mass spectrometers: i. quadrupole mass filter and quadrupole ion storage (ion trap) Time of flight mass spectrometers; FT-ICR (ion cyclotron resonance spectrometers); MS/MS (tandem mass spectrometry). Mass spectrum: Unit mass molecular ion and isotope peaks; High resolution molecular ion; recognition of the molecular ion peak; Use of molecular formula; Fragmentation of alkanes, alkenes, alkyl halides, alcohols, aldehydes, ketones (cyclic and acyclic compounds), acids, esters, ethers, amines, nitro and halo compounds, peptides; Nitrogen rule; Factors affecting cleavage patters; McLafferty rearrangement; Composite problems; Use of HRMS to determine exact molecular weight of compounds; Application of UV, IR, NMR and mass methods in the structural elucidation of organic compounds

Course Synopsis

All spectroscopic techniques which is used to characterized the organic compounds is the part of this course.There are four spectroscopic techniques which is include here to identify organic molecules: infrared (IR), mass spectroscopy (MS) UV/visible spectroscopy (UV/Vis) and nuclear magnetic resonance (NMR). Each functional group is discussed in each spectroscopy through spectrum.

Course Learning Outcomes

this course aim to learn theory, instrumentation and application of different spectroscopic techniques. .This course is enough content through which a learner is able to elucidate the structure of organic molecules.