Guest molecule electron donor/acceptor interaction

Interactions between 7t-systems have long been observed in crystal structures of aromatic molecules and, for example, play a role in stabilising DNA through vertical base-pair interactions. They are also involved in the intercalation of drugs into the grooves of DNA. Such interactions have also been exploited in many synthetic host-guest systems. Previous rationales for the occurrence of k-k interactions have included explanations based on solvophobic,electron donor-acceptor as... 

For binding to occur, a host must possess suitable binding sites with favourable electronic properties such as polarity and hydrogen bond donor/acceptor abilities that complement those of the guest. Cyclophanes such as I, calixarenes II, homocalixarenes IH, and resor-cinarenes FV fulfil these requirements (Scheme 12.1). Cucurbiturils V are water soluble container molecules without aromatic subunits. Therefore, both electrostatic interaction other than cation- r interaction and hydrophobic interaction play a dominant role. 

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