Multiple-quantum coherences of molecular groups: F-19 in CF3COOAg
: Kaikkonen A, Ylinen EE, Punkkinen M
Publisher: SPRINGER VERLAG
: 1998
Applied Magnetic Resonance
APPLIED MAGNETIC RESONANCE
: APPL MAGN RESON
: 15
: 3-4
: 509
: 518
: 10
: 0937-9347
DOI: https://doi.org/10.1007/BF03162033
The three (3Q) and six (6Q) quantum coherences of two proximate methyl groups were studied to find out if they can be used to determine the possible nonequivalence of the groups relative to chemical shifts. Numerical calculations of the efficiency of excitation and detection of 3Q and 6Q coherences in reorienting and static methyl group pairs were performed. The crystal orientation, resonance offset, chemical shifts and finite value of the RF field were taken into account. Experimental F-19 2D NMR spectra were obtained from a single crystal of CF3COOAg. To record 6Q spectra in pure absorption mode in presence of chemical shifts, the data were acquired according to the hypercomplex method. 3Q spectra of the same sample were recorded in absolute-value mode.