Crystal Structure of β‐Cyclodextrin‐Felbinac Inclusion Complex

Abstract The crystal structure of the inclusion complex of β‐cyclodextrin (β‐CD) synthesized with felbinac (4‐biphenylacetic acid) was determined by single crystal X‐ray diffraction at 150 K. The complex contains two β‐CDs, two felbinac molecules, twenty‐two water molecules in the asymmetric unit, and could be formulated as (C42H70O35)2·(C14H12O2)2·22(H2O). In the crystal lattice, the two β‐CD moieties form a head‐to‐head dimer jointed through hydrogen bonds, and the felbinacs that interact by face‐to‐face Π‐Π stacking are included in the β‐CD dimer cavity with their carboxyl groups protruding out from cavity opening. In crystals the dimer units of β‐CD are stacked in an intermediate type (IM) that consists of closely packed β‐CD dimer layers.