The combined application of two-dimensional nuclear magnetic resonance (2-D NMR) correlation experiments and gauge-including atomic orbital (GIAO) 13C NMR chemical shift calculations allowed reliable and simple determination of regioisomeric structure of heterocyclic substituents on the calixarene lower rim. Moreover, the 1-D double pulsed field gradient nuclear Overhauser effect technique allows quick and efficient measurement of small nuclear Overhauser effects and, in doing so, establishes a 3-D structure of calixarene simply and unequivocally. In general, these methods may find application in the regio- and stereoisomeric structure determination of complicated macrocyclic compounds.
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics