Protolytic Properties and Molecualr Structure of 2,8,14,20-Tetramethyl-5,11,17,23-tetrakis(N-morpholino)-methylcalix[4]resorcinolarene

摘要

The protolytic properties of 2,8,14,20-tetramethyl-5,11,17,23-tetrakis(N-morpholino)methylcalix[4]resorcinolarene were studied by pH-potentiometric titration. Its crystal and molecular structure was determined by single crystal X-ray diffraction and UV spectroscopy. In solution the macrocycle exists as a zwitter-ion. In the crystal, the calixresorcinolarene molecule is in the cone conformation; two pairs of the opposite morpholine substitutents are oriented inside and outside the macrocycle cavity and therefore show different acid properties.