Crystal structures of 2:1 inclusion complexes of xylidine isomers with 1,1,6,6-tetraphenylhexa-2,4-diyne-1,6-diol:: the importance of weak intermolecular interactions in crystal stability

Molecular structures of inclusion complexes of the title host with 2,5-, 2,6- and 3,4-xylidines were determined by X-ray analysis. In addition to the relatively strong hydrogen bonds, intermolecular C-H . . . pi, N-H . . . pi and pi . . . pi interactions were found in the structures. The importance of these weak interactions is discussed in relation to the stability of the inclusion complexes.