In this review article, we cast doubt on true necessity of complicated organic synthesis for development of functional materials. Instead of synthesizing many molecules, one particular molecule may exhibit varieties of functions just through selecting appropriate environment and its dynamic structural changes. For example, molecular recognition capabilities can be significantly enhanced by placing the molecules at appropriate interfacial environments. Binding constants between phosphate and guanidinium are enhanced by 100-10000 times simply by shifting media from dispersed solution to mesoscopic interfaces of micelles and vesicles. The corresponding constants are further enlarged by 1000000-10000000 times at macroscopic interfaces such as the air-water interfaces. This surprising fact is proved both by experimental and theoretical approaches. Mechanical deformation of particular molecules at interfacial environments makes it possible to freely tune recognition of chiral amino acids and highly enhance discrimination of very similar substances, thymine and uracil derivatives. Further more, such mechanical process at interfaces enable us to operate molecular machines by hand-motion-like macroscopic stimuli. These examples demonstrated that medium-selection and molecular deformations can result in modification and tuning of molecular functions incredibly and could make impossible functions really possible. Now we have to think about aggressive introductions of surface science concepts and supramolecular essences to traditional organic syntheses for further developments of functional molecular sciences.
Fabrication of functional materials through self-assembly and coordination chemistry at interface becomes hot topics in recent research activities. However, supramolecular chemistry at interface including molecular recognition and self-assembly has fundamental meanings in understanding of biological events and investigation on functions of organic materials. In this account, various aspects in supramolecular chemistry are briefly introduced from origin to future. For example, molecular recognition efficiency at interfaces are incredibly enhanced as compared with those observed in bulk aqueous solutions. It would be a key to understand several mysteries in biological systems. In addition, interfacial environments as confined interfacial media offer opportunities for formation of complicated receptor sites and precisely controlled nanostructures. As another view point, twodimensional systems can bridge macroscopic actions and nano-level functions. For example, controls of molecular machines with incredible functions such as capture and release of desired molecules can be done through hand-motion-like macroscopic mechanical motions. Furthermore, tuning-type molecular recognition as a new mode of molecular recognition has been proposed. The latter characteristics would open a new methodology to explore hidden functions of organic molecules through soft manipulations.