Abstract
Supramolecular photochemistry in crystal state leads to more direct ways of making motions than liquid or thin film states, therefore crystalline supramolecules play essential roles in the photo-induced mechanical motions of molecular machines. Supramolecules involve molecular machines with flexibility, leading to various potential applications. In Chapter 2, design and synthesis of photo-responsive supramolecular pseudorotaxanes are reported. These pseudorotaxanes consist of the ferrocene-containing ammonium cation as an axle molecule and the novel ring molecule having dibenzo[24]crown-8 (DB24C8) with a pendant laser dye. For efficient energy conversion from light to a mechanical motion of crystals of the pseudorotaxanes, coumarin 120 is selected as the laser dye coupled with DB24C8. In the synthesis of the ring molecule, various reaction conditions are attempted changing temperature, solvent, reaction time, and concentration of reactants. After complexation of the new ring molecule and various ferrocene-containing axle molecules in chlorinated solvent such as dichloromethane, crystallization is carried out, in which various crystallization conditions are applied. Obtained compounds are identified by 1H NMR and fast atom bombardment (FAB) mass spectrometry. The photo-mechanical properties of the pseudorotaxanes crystals are characterized by polarizing optical microscopy (POM) with blue laser activation at 405 nm and 445 nm. The new pseudorotaxane crystal comprising DB24C8 with coumarin 120 pendant shows 2 times higher sensitivity to the laser power compared to that without coumarin. Two models are proposed to explain this unique system. In Chapter 3, the new actuating system composed of the combination of polymerfilms and photo-sensitizer is reported. Here poly(n-butyl methacrylate) and ferroceneare used as the polymer matrix and the photo-sensitizer, respectively . The free-standing polymer-ferrocene films are prepared from chloroform solutions of their mixtures varying concentrations of the components and composition ratios, casted on glass plates, Teflon films or petri dishes. The photo-induced expansion motions are observed for the free-standing films. Some elementary properties of the films are established via the measurement of their area changes in adjustment of controllable factors. To further observation, we apply numerical analysis that is used for crystals. In addition, binary films, which have photo active and passive layers, are prepared leading to photo-induced bendable films. Furthermore, we demonstrate some attractive miniature mechanical machines controlled by photoirradiation which are observed using a side view camera.