A Dodecameric Porphyrin Wheel

摘要

The design and synthesis of light-harvesting systems that rival those in photosynthesis has been an important issue, which may require the organization of many pigments in an elaborate arrangement. Inspired by the wheel-like architectures of photosynthetic pigments (LH2 and LH1), particular attention has been focused on the construction of covalently linked cyclic porphyrin arrays, which may aid the understanding of the mechanisms of the energy transfer or find new applications as optoelectronic material.2 The synthetic arrays prepared thus far contain at most six porphyrins,3 whereas B800 and B850 in LH2 consist of eight or nine bacteriochlorophyll a (Bchla) molecules and eight or nine dimeric subunits of Bchla, respectively, and B870 in LH1 has recently shown to consist of 15 pairs of dimeric Bchla, hence posing a further synthetic challenge.