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Pulse Sequences
CPMAS
The
CPMAS experiment is generally used to assist in the observation of dilute
spins (most commonly 13C) by the transfer of magnetization from a nearby network
of abundant spins (such as 1H). The whole time the sample is undergoing magic
angle spinning which is an invaluable line narrowing technique. CPMAS is one
of the most widely used experiments in solid-state NMR.
13C
CP/MAS spectrum of caffeine. At 21.1 T note absence of the line splitting
due to the dipolar coupling with the quadrupolar 14N. At lower magnetic fields
such coupling results in very complicated spectra.
September, 2005
13C
CP/MAS spectrum of tetracycline hydrochloride. Resonances from all 22 carbon
atoms are resolved.
September, 2005
19F-13C CP MAS spectrum recorded for a hydrated Nafion film. In such high-resolution
spectra various C-F species can readily be identified. Experiments performed
by Shane Pawsey (the 900 Facility) with the 2.5 mm MAS probe.
October, 2006
