Molecular Systems and Their Applications to Energy Conversion

Abstract

A number of molecular energy conversion systems can be seen in biological organisms, e.g., photosynthesis, vision, muscular movements, and photophobic/ phototactic responses. A particular form of energy, e.g., photonic energy, electric energy, mechanical energy, or chemical energy, is received as a stimulus from the external environment by sensor molecules and then converted to another form of energy. The initial steps in these energy conversions are driven by the transfer of an electron, excitation energy, or a soliton through a molecular channel in which functional molecules are arranged in a specific spatial configuration within polypeptide networks. These processes are characterized by high efficiencies and ultrafast reaction rates. To interprete the mechanisms of such sequential and cooperative reactions, it may be necessary to develop a new theoretical description of the intermolecular interactions which spread the functional molecules along the reaction channel. This description is being sought by detailed analyses of the biological systems, and also by research into artificial molecular systems based on synthesized supramolecules or planned solid complex superstructures. This chapter first considers sequential reactions in biological molecular systems, and then those in artificial systems.