Structure of the partial cone conformer of 25,26,27,28-tetrakis[(2-pyridylmethyl)oxy]calix[4]arene

Abstract

The partial cone conformer of tetrakis[(2-pyridylmethyl)- oxy]pentacyclo[ 19.3.1.13'7.19'13.115,19]octacosa- 1 (25),- 3,5,7 (28),9,11,13 (27), 15,17,19(26),21,23-dodecaene, (I), adopts a conformation in which the pendant OCH2py group of the rotated aryl ring is oriented away from the calixarene cavity produced by the other three aryl rings, with its N atom exo to the calixarene cup. The orientation of the four aromatic rings is such that two rings are almost parallel to each other and the other two are at an angle of 42 ° . This conformation precludes any solvent molecule being enclathrated within the small molecular cavity.