ABSTRACT
The output of any natural and artificial job requires control; similarly, control of reactivity can modulate ON and OFF states in catalysis. This is particularly true in the case of supramolecular assemblies due to reversible weak interactions. The concern of this chapter is to delineate the regulatory aspects of catalytic systems by using interlocked systems. The dynamic aspects of catalysis based on conformational, regional and stereochemical changes affecting the movement of one component over another in systems like rotaxane, catenanes and molecules with geometrical changes are illustrated. Modulation of reactivity by movement of rings to show ON and OFF states of catalysts in rotaxanes, with emphasis on cooperative binding with urea, squaramide and amine units, is demonstrated. The metallacycles and gridlike structures assisting in size-selective catalysis are discussed. Stimuli-guided catalytic activities, the crown effect, coordination changes, changes in composition through a combinatorial approach and changes in molecular rotor due to orientation changes are presented in this chapter to suggest that a molecular-level understanding has an impact on new catalyst design.
