Biomimetic Assembly of Porphyrinoids

Natural photosynthesis is inspiring feverish research worldwide in order to mimic in artificial devices the capture of sunlight followed by its utilization, either directly as in photovoltaics or for the economic production of fuels. These can be stored and transported to stations different from where the initial light harvesting occurred. Porphyrinoids are extremely versatile molecules with a rather well-combed chemistry enabling to obtain on laboratory-scale sophisticated compounds tailored for either efficient excitation energy transfer (EET) or electron transfer (ET). This article describes biomimetic approaches using porphyrinoids, which can self-assemble into nanostructures with a large photon capture cross section following the model of the antenna system of green and brown photosynthetic bacteria, which strive in deep waters and are able to trap very scarce photons. The natural antenna system of these bacteria is called the chlorosome (or green sac) and represents the most efficient light-harvesting system known. On the other hand, its simple construction by the self-assembly of bacteriochlorophylls c , d , or e occurs in the absence of a complicated protein matrix. We describe herein efforts to mimic this behavior with tailored synthetic porphyrinoid molecules.