M. Mortimer et al., AB-INITIO CALCULATION AND NMR SPIN-ECHO MEASUREMENT OF F-19 CHEMICAL SHIELDING IN THE ALKALI-METAL FLUORIDES, Journal of the Chemical Society. Faraday transactions, 92(7), 1996, pp. 1117-1120
Citations number
30
Categorie Soggetti
Chemistry Physical","Physics, Atomic, Molecular & Chemical
Experimental values of F-19 chemical shielding in the series of anhydr
ous alkali-metal fluorides LiF to CsF are reported. An NMR spin-echo t
echnique is used for the measurements and the results are shown to com
pare favourably with others, in particular those determined by magic-a
ngle spinning (MAS) techniques, reported in the literature. Ab initio
methods of calculating F-19 chemical shielding in these primarily ioni
c materials are then discussed in terms of simplified model systems. F
or all the alkalimetal fluorides, values of absolute F-19 chemical shi
elding are calculated which are significantly less than the free fluor
ide ion value. In the specific cases of LiF and NaF reasonable agreeme
nt between ab initio calculation and experiment is achieved.