The CH⋯π interaction as an important factor in the crystal packing and in determining the structure of clathratesA comprehensive literature list for the CH⋯π interaction is available on the following website: http://www.tim.hi-ho.ne.jp/dionisio

Abstract

Crystal structures in the Cambridge Structural Database (CSD) were examined to investigate the role of the CH⋯π interaction in the crystal packing and the structure of clathrates. More than 77% of organic crystals have been found to bear CH⋯π interatomic distances shorter than 3.05 Å. Database subsets were edited by monitoring the entire CSD with the structure of included solvents (CHCl3, CH2Cl2, MeNO2, MeCN, MeOH, Me2CO, DMSO, DMF, 1,4-dioxane, benzene, toluene and p-xylene). A great many of the examined compounds have been shown to bear short CH⋯π distances among themselves and between supramolecular components. A variety of different solvents (protic, dipolar aprotic as well as non-polar) has been found to be included by CH⋯π interactions. The crystal structures were retrieved and examined in detail for clathrates of 1,1,6,6-tetraphenylhexa-2,4-diyne-1,6-diol and 1,1′-binaphthyl-2,2′-dicarboxylic acid in complexation with their specific guests. The results are discussed in the context of the CH⋯π interaction in controlling the specific structure of supramolecular aggregates.