Light-harvesting arrays

Fig. 14 Energy transfer cascade in self-assembling anthracene-Ru complex-Os complex light harvesting array linked by cydodextrins [88]...

Li J, Lindsey JS. Efficient synthesis of light-harvesting arrays composed of eighth porphyrins and one phthalocyanine. / Org Chem 1999 64 9101-8. 

Van Patten PG, Shreve AP, Lindsey JS, Donohoe RJ. Energy transfer modelling for the rational design of multiporphyrin light-harvesting arrays. J Phys Chem B 1998 102 4209-16. 

Prathapan, S., Johnson, T. E., Lindsey, J. S. (1993). Building-block synthesis of porphyrin light-harvesting arrays, J. Am. Chem. Soc., 115 1519. 

Fig. 1 (a) A star-like light-harvesting array (antenna) synthesized by modular approach (Ref. [8]). (b) The carotene-free-base... 

An excellent example of employing secondary pigment to enhance the absorption properties of the porphyrin was reported by Lindsey, Holten, Bocian, Birge and coworkers. They designed and. synthesized light-harvesting arrays... 

The simplest approach to branched or denritic multiporphyrin structures is the combination of two arrays connected at one point. This has been successfully attempted by Osuka to produce the so-called windmill porphyrinic arrays 58-60 represented in Figure 13.40. The properties of these light harvesting arrays are adjusted taking into account previous results that show that the excitation energy of the Si state in the central meso-meso coupled species is smaller (2.07 eV) than that of the weakly coupled peripheral porphyrins (2.13 eV). To increase this... 

A light-harvesting array was attempted in a five-porphyrins system linked by a diphenylethyne group [638,639] (23). The center-to-center distance was around 20 A. Excitation of the surrounding four Zn porphyrins induced singlet energy transfer with 90% efficiency to emit fluorescence m the central free-base poiphyrin. 

A light-harvesting system in solid state has been studied [651] and a molecular design for a novel light-harvesting array has been proposed [652]. 

A major current effort in our lab is to develop corrole-based dye-sensitized solar cells (DSSCs), which you ve surely heard about from your Uncle Carl, with whom I ve had a wonderful collaboration these last few years. DSSCs are ultimately modeled after photosynthetic light-harvesting arrays, albeit rather crudely. Like others in the business, we prefer to use synthetic porphyrins (or, in our case, corroles) instead of chlorophylls because the synthetic stuff is considerably more rugged and processable. DSSCs in essence consist of an organic dye bonded to titania or another nanostructured semiconductor, and, in principle, they are far cheaper to manufacture than conventional solar cells based on crystalline silicon. Assuming they live up to their promise, they could revolutionize solar energy conversion. 

---