Semi-Quantitative Studies On Processes Of Molecular Recognition Utilizing Thermodynamic Method

Summarizing the experience by themselves and the facts in many reports, Professors Jin Songshou, Zheng Xiaoming, and Tang Xinshuo proposed the concept of Selective Intermolecular Force (SIF ) and the theory of Adaptability of Group Structure (AGS).The main point of SIF and AGS is that: some atoms in a molecule distributing in adaptable space may construct some groups with various forms, the selective interaction between two molecules may be caused by the interaction of some group(s) of one molecule with some group(s) of another molecule, which happens only when the two type of groups are mutually adaptable. Strength of SIF can not be estimated and expressed by formula of Van der Waals forces. Under the direction of their own theory(SIF and AGS), they have succeeded in catalytic and other physicochemical researches. Recently, we have noticed that SIF and AGS are of great significance for supramolecular chemistry. Lehn, the father of supramolecular chemistry called the new field "chemistry beyond the molecule" . In fact, molecular recognition, transport, and catalytic activity represent the three basic functional features of supramolecular species, among which molecular recognition is the most important function. For examples, when a substrate binds to an enzyme, a drug sticks to its target, signals propagate between cells or a reactant accepted and activated by catalysts, highly selective interactions occur between the partners to control the process. In many cases the so called selective interactions are selective intermolecular forces(SIF) caused by adaptability of group structure (AGS). When SIF occurs between two substances and causes some changes of physical and chemical properties, the thermodynamic functions such as enthalpy and entropy of the system certainly change.