Non-classical [14]metaheterophanes containing betaine units. Synthesis, NMR spectroscopy and X-ray crystallography

Abstract
The N-diphenylmethyl derivative 4 is the immediate precursor of the N-substituted dipolar [14]metaheterophane 3, and allows the convenient synthesis of the unsubstituted macrocycle 5, which can be transformed into the quadrupolar or dipolar heterophanes 1 and 2; the molecular structures of 1 and 2 were confirmed by single-crystal X-ray analysis.