CH/pi interactions as demonstrated in the crystal structure of host/guest compounds. A database study

Crystal structures deposited in the Cambridge Structural Database (CSD) wer e examined, by use of our program CHPI, for several kinds of clarhrates in order to know the role of the CH/pi interaction in host/guest chemistry. Th ese include cyclodextrin complexes, calix[4]arene complexes, cryptophane co mplexes and pseudorotaxanes. A number of short CH/pi distances have been sh own in the crystal structure of these compounds. Tho result was discussed i n view of the role of the CH/pi interaction in controlling the specific str ucture of supramolecules. (C) 2000 Elsevier Science Ltd. All rie;hts reserv ed.