Two new receptors, 9 and 13, have been prepared, utilising a pyridyl aryl e
ther unit in the rim of the macrobicyclic structure, and the crystal struct
ures for both of these receptors are reported. The presence of the pyridyl
unit provides additional hydrogen bonding functionality in comparison to ea
rlier structures of this type, and 9 is an effective receptor for N-acetyl
L-asparagine carboxylate in CH2Cl2. (C) 2000 Elsevier Science Ltd. All righ
ts reserved.