TOWARD A MIMIC OF PHOTOSYNTHESIS

Abstract

A NEW ARTIFICIAL LIGHT-HARvesting system has taken scientists one step closer to capturing photons and converting them into chemical energy as efficiently as nature does in photosynthesis. The self-assembling supramolecular system can also rearrange into an ion channel upon the addition of an intercalating molecule ( Science 2006,313, 84). The helical photosystem's architecture features π stacks of fluorescent naphthalene diimides. These novel electron-deficient chromophores are held together by a scaffold of four rigid p -octiphenyl units. Designed and synthesized by an international team from Switzerland's University of Geneva and Germany's University of Wurzburg, the assembly can span lipid bilayer membranes. To study the assembly's photosynthetic properties, the researchers embedded the photosystem in the wall of a vesicle containing the electron acceptor quinone. Outside the vesicle sphere, they added a sacrificial electron donor. Irradiation with visible light produces electrons that quickly move fr...