BENZO-9-CROWN-3 ETHER - X-RAY CRYSTAL-STRUCTURE, NMR-STUDIES IN SOLUTION AND THE SOLID-PHASE, AND AB-INITIO CALCULATIONS OF ISOTROPIC C-13 CHEMICAL-SHIFTS USING LORG WITH A D95V BASIS-SET
Gw. Buchanan et al., BENZO-9-CROWN-3 ETHER - X-RAY CRYSTAL-STRUCTURE, NMR-STUDIES IN SOLUTION AND THE SOLID-PHASE, AND AB-INITIO CALCULATIONS OF ISOTROPIC C-13 CHEMICAL-SHIFTS USING LORG WITH A D95V BASIS-SET, Canadian journal of chemistry, 71(12), 1993, pp. 1983-1989
Using the X-ray crystal geometry as input, the C-13 NMR chemical shift
s of benzo-9-crown-3 ether have been calculated via ab initio methods
using a localized orbital local origin (LORG) approach. Reasonable agr
eement is found between the calculated values for an isolated molecule
in the gas phase and those obtained in the C-13 CPMAS NMR spectrum. S
olid phase C-13 spectra of the C7,10-d(4), derivative confirm the exis
tence of a 7.9 ppm shift difference between these sites in the solid,
whereas in solution they are conformationally averaged to one resonanc
e. The effects of C-H bond length variation on calculated C-13 shifts
have been explored.