GIAO chemical shifts calculations of some polycyclic cage compounds: Unambiguous assignment of NMR signals and stereoisomers

摘要

GIAO model at DFT/B3LYP level of theory using the cc-pVTZ basis set was employed for calculations of ~1H and ~(13)C NMR chemical shifts (δ) for various rigid polycyclic compounds. The data obtained were used as an auxiliary tool to an unequivocal assignment of all ~1H and ~(13)C NMR signals and the endo/exo stereochemistry of the strained compounds studied. For these compounds the theoretical model adopted was sufficient to obtain a good description of chemical shifts.