Monodisperse Giant Porphyrin Arrays

Abstract

Our synthetic attempts for the preparation oligo- and polyporphyrin arrays were reviewed in comparison with recent accomplishment in the related field. Especially, the synthesis and structural characteristics of huge monodisperse meso-meso linked porphyrin arrays with multidimensional architectures were focused. The AgI-promoted meso-meso coupling reaction of 5,15-diaryl and 5,10,15-triaryl ZnII-porphyrins is advantageous in light of its high regioselectivity, as well as its easy extension to large porphyrin arrays. When applied to 1,4-phenylene-bridged linear porphyrin substrates, the coupling reaction gave three-dimensionally arranged windmill-shaped and grid-shaped porphyrin arrays. The meso-meso coupling doubling reaction was repeated up to the synthesis of a discrete 128-mer. During these attempts, many porphyrin arrays were isolated in a discrete form by repetitive gel-permeation chromatography and, interestingly, all the arrays exhibited high solubility in common organic solvents in spite of their giant molecular size. Furthermore, the AgI-promoted coupling reaction was extended to the preparation of long polyporphyrinylenes under slightly modified conditions by either adding N,N-dimethylacetamide (DMA) or heating slightly.