Equations used in the NMR tutorial
(see below for some sample calculations)
(see below for some sample calculations)
where:
E is the energy difference between spin states
- h is Planck's constant
is the frequency of the B1 field
- Be is a small magnetic field generated by the circulation of electrons of the molecule (see below)
- Bo is the strength of the external homogeneous magnetic field
(gyromagnetic ratio) is a constant which is a property of the particular nucleus
(Discussed in Spin states)
(obtained by dividing eq 1 by h)
(Discussed in Spin states)
- TMS) is the frequency difference between the resonance of the signal of interest and the resonance of TMS. Note that ( - TMS) will always be in units of Hz (from 1 Hz to a few thousand Hz).
is the center frequency of the B1 field in megahertz (MHz).
= 300 MHz for 1H nuclei or 75 Mz for 13C nuclei.
= 500 MHz for 1H nuclei or 125 Mz for 13C nuclei.
(Discussed in Chemical shift)
Copyright information: Original content © University of Colorado, Boulder, Chemistry and Biochemistry Department, 2011. The information on these pages is available for academic use without restriction.
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