468083-02-5Relevant articles and documents
Practical synthesis of perylene-monoimide building blocks that possess features appropriate for use in porphyrin-based light-harvesting arrays
Tomizaki, Kin-Ya,Thamyongkit, Patchanita,Loewe, Robert S.,Lindsey, Jonathan S.
, p. 1191 - 1207 (2007/10/03)
Perylene-monoimide dyes with solubilizing aryloxy substituents at the perylene perimeter and a synthetic handle on the N-aryl group are valuable building blocks for incorporation as accessory pigments in porphyrin-based light-harvesting arrays. A family of such dyes has been prepared by reaction of 1,6,9-tris(4-tert-butylphenoxy)perylene-3,4-dicarboxylic anhydride with a set of 4-iodo/ethynyl anilines (with or without 2,6-diisopropyl substituents) in the presence of Zn(OAc)2·2H2O in imidazole/mesitylene at 130°C. The workup procedures throughout the synthesis have been streamlined for scale-up purposes, minimizing chromatography. Two bis(perylene)porphyrin building blocks were prepared in a rational manner and examined in Sonogashira and Glaser polymerizations. The two isopropyl groups on the N-aryl group and the three 4-tert-butylphenoxy groups at the perylene perimeter are essential for high solubility of the bis(perylene)porphyrins and corresponding oligomers in organic solvents.
Synthesis and photophysical properties of light-harvesting arrays comprised of a porphyrin bearing multiple perylene-monoimide accessory pigments
Tomizaki, Kin-ya,Loewe, Robert S.,Kirmaier, Christine,Schwartz, Jennifer K.,Retsek, Jennifer L.,Bocian, David F.,Holten, Dewey,Lindsey, Jonathan S.
, p. 6519 - 6534 (2007/10/03)
We present the synthesis and characterization of new light-harvesting arrays containing two, four, or eight perylene-monoimide accessory pigments attached to a zinc porphyrin. Each perylene is substituted with one or three 4-tert-butylphenoxy substituents. A 4,3′- or 4,2′-diarylethyne linker joins the perylene N-imide position and the porphyrin meso-position, affording divergent or convergent architectures, respectively. The architectures are designed to provide high solubility in organic media and facile perylene-to-porphyrin energy transfer, while avoiding charge-transfer quenching of the excited porphyrin product. For the array containing four perylenes per porphyrin in both nonpolar (toluene) and polar (benzonitrile) media and for the array containing eight perylenes per porphyrin in toluene, the photoexcited perylene-monoimide dye (PMI*) decays rapidly (～3.5 ps) and predominantly (≥90%) by energy transfer to the zinc porphyrin to form the excited zinc porphyrin (Zn*), which has excited-state characteristics (lifetime, fluorescence yield) comparable (within ～10%) to those of the isolated chromophore. For the array containing eight perylenes in benzonitrile, PMI* decays ～80% by energy transfer (forming Zn*) and ～20% by hole transfer (forming PMI- Zn+); Zn* subsequently decays ～20% by electron transfer (also forming PMI- Zn+) and ～80% by the normal routes open to the porphyrin monomer (intersystem crossing, internal conversion, fluorescence). In addition to rapid and efficient perylene-to-porphyrin energy transfer, the broad blue-green to yellow absorption of the perylene dyes complements the blue absorption of the porphyrin, resulting in excellent light harvesting across a significant spectral region. Collectively, the work described herein identifies multiperylene-porphyrin arrays that exhibit suitable photochemical properties for use as motifs in larger light-harvesting systems.
