Review Sheet for Pulsed NMR Spectroscopy Theory and Practice | CHEM 781, Study notes of Chemistry

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Important constants: h = 6.6260755:10*J s" h=h/(2T) c = 2.99792458- 108m s" k = 1.380658:1073 JK" N,=6.022-10 mol Yu = 2.67522: 108 rad T* $1 Yo = 6.728310" rad T's! Planck’s constant speed of light in vacuum Boltzmann constant Avogadro constant @=2T Vv Important definitions and relations: Symbol description By main magnetic field (static along z axis) B, rotating RF field, in rotating frame along x (or y) Tp length of RF pulse Vo, Wo precession frequency of spins in laboratory frame @ pr — frequency of the RF field B,. Normally =, @,,V, rotation rate of spins during pulse about rf field B, Q free precession in rotating frame: Q = W)- @ proton gyromagnetic ratio carbon gyromagnetic ratio Relation between angular frequency and frequency Relationship to experiment Field of superconducting magnet pll (power level of pulse) pl, p2, ... signal that induces voltage in receiver coil sfol, set with olp determines length of pulse Observed NMR signal after mixing with reference frequency @, depends on main field (precession @, = —B, or Y= Bo in laboratory frame) @, depends of strength of B, field . . B, (rotation during pulse) @, =-7B, or Y= mn flip angle depends on strength and duration of B, field 6 = Qt, = B,Tp