Nuclear Magnetic Spectroscopy

Nuclear Magnetic Spectroscopy Introduction NMR - A technique 0 for determining the magnetic moments of nucles by subjecting a substance to high- frequency radiation and a large magnetic field. NMR Nuclear - Properties of atome nuclei. Magnetic T Magnetic field Ps required Resonance - Interaction b/w magnetic field and radio treavencu

Introduction Powerful analytical technique used to characterize organic molecules by identifying Carbon- hydrogen frameworks within molecules. two type 'H -NMR 13C-NMR The source of energy in NMR is radio waves which have long wavelengths, and thue low energy and ficquency - This waves can change the nuclear spins of some element including 'H and 13c. Frequency in the range of 300 Mhz -500 Mhz. Birth of NMR Principle of Magnetic Resonance When molecules are placed in a strong magnetic field the magnetic moments of the nucles align cartiqued with the field. 2 UP This equilibrium alignment can be changed to an excited State by applying radio frequency (RF) pulses /

When the nuclei revert to the equilibrium, they emit RF radiation that can be detected A spinning Proton With no external mag field creates a mag field In a magnet field 0 The nuclear magnets are randomly oriented The nuclear Magical are oriented with or against B NMR Phenumenon far Bo N N S +1/2(0) x) 2 (or B) 1 Spinning change. generals a magnetic put Spin energy Stat u In the presence of an actional magich field (Bo) / two spin state exist, +1/2 and -1/2