H. Tsukube et al., Porphyrinatoerbium-crown ether conjugate for synergistic binding and chirality sensing of zwitterionic amino acids, CHEM COMMUN, (11), 1999, pp. 1007-1008
A porphyrinatoerbium-benzo-18-crown-6 conjugate offers efficient extraction
and chirality sensing of amino acids under neutral conditions via synergis
tic binding of zwitterions.