BETA-CYCLODEXTRIN NONANOIC ACID 1 1 COMPLEX

The structure of the complex of cyclomaltoheptaose (beta-CD) with nona noic acid, beta-cyclodextrin-nonanoic acid (1/1) water solvate, 2C(42) H(70)0(35).1.6C(9)H(18)O(2).23.9H(2)O, has been determined at room tem perature. Two independent molecules of beta-CD form a dimer which encl oses two molecules of nonanoic acid. The guest molecules penetrate the beta-CD cavities to different depths. Their carboxylic groups point t owards the primary hydroxyl region of beta-CDs forming direct dimers t hrough hydrogen bonds with the carboxylic groups of adjacent guests al ong the a axis and interact with water molecules and disordered primar y hydroxyl O atoms.