Abstract:

In physical chemistry, the model of solvent cage is used to describe the relationship between reactant and solvent. In this model, the reactant molecule is surrounded by the cage constructed with solvent molecules. The solvent cage is flexible, and its size and shape are determined by the central reactant molecule. The encounter, collision and reaction between reactant molecules proceed in solvent cages. With the advancement of synthetic techniques, molecular cages, which are constructed by covalent and coordination bonds, are developed. Relative to the solvent cages connected with van der Waals force, molecular cages show much higher rigidity, thus, their effects on the reactions is expected to be more remarkable. Different from traditional catalysts that participate the reaction through the binding with reactants or intermediates, molecular cages could affect the reaction through a physical manner. By enriching reactants, altering the configuration of reactants, changing the structure of intermediates and limiting the growth of products, molecular cages could exert a profound influence on the rate and selectivity of the reaction. The research on this field is significant for the elucidation of reaction mechanism and the modulation of reaction proceeding.

Key words: Solvent cage, Molecular cage, Chemical reaction, Structural rigidity