Supramolecular host recognition process

Supramolecular Host Recognition Processes with Biological Compounds, Organometallic Pharmaceuticals, and Alkali-metal Ions as Guests... 

Clearly, molecular recognition processes are the prototypical supramolecular reactions on which the other aspects are based. Without molecular recognition, there are no template effects, no self-assembly, and certainly no self-replication. In contrast to opinions sometimes encountered among chemists from other areas, supramolecular chemistry did not come to a halt with the examination of hosts and guests and their interactions. Sophisticated molecular devices are available which not only are based on, but go far beyond mere molecular recognition. 

A host-guest molecular recognition process of L-tryptophan, with the above various triangular, bowl-shaped Cp Rh-nucleobase/nucleoside/nucleotide cyclic trimer molecular receptors, was also detected in a gas phase by electrospray ionization mass spectrometry.In this case, the supramolecular complex formation was found to occur predominately via non-covalent tt-tt interactions non-covalent hydrophobic forces apparently being weak or nonexistent. Trp-Met-Asp-Phe tetrapeptide with the trimeric-rhodium host [Cp Rh(2 -deoxyadenosine)]3[OTf]3 also formed a host-guest complex in water that is detected in the gas phase. 

The host-guest association process, incorporating structured solvent molecules (with water as the best example), is illustrated in Scheme 4. It is widely recognized that water is a unique solvent capable of playing active roles in supramolecular and biological recognition processes the detailed information and discussion on this topic may be found in a recent review. ... 

---