Conjugated porphyrinic polymers

B. Jiang, S.-W. Yang, and W.E. Jones, Jr., Conjugated porphyrin polymers control of chromo-phore separation by oligophenylene vinylene bridges, Chem. Mater., 9 2031-2034, 1997. 

Anderson et al. synthesized the soluble conjugated porphyrin polymer of 5,10,15,20-diethylnyl zinc porphyrin (DEtyP)n using Glaser-Hay coupling (Figure 34). The real and imaginary components of / (—0,0, to) of the.se polymers were calculated from the electroabsorption spectra. The / (-m 0,0, (o) on the order of 7.3 x 10 esu was obtained at the peak resonance due to resonance enhancement. 

Figure 118. Synthesis of conjugated porphyrin polymers via the Wittig reaction. Reprinted with permission from Jiang, B. Szu-Wei, Y. Jones Jr., W. E. Chem. Mater. 1997, 9, 2031. 1997 American Chemical Society.

LDMS is particularly well suited for the analysis of porphyrins.35-39 The heme molecule—a 22 rc-electron conjugated protoporphyrin system (Figure 8.1)—is an efficient photo-absorber in the visible and near UV (with an absorption maximum—the Soret band—near 400nm). This feature, concurrently with its low ionization potential, warrants that direct LDMS will possess extremely low limits for heme detection. The uses of IR or UV LDMS for structural characterization of natural porphyrins and their metabolites, synthetic monomeric porphyrins (e.g., used in photodynamic therapy), porphyrin polymers, and multimeric arrays, have been well documented.41148 In addition fast atom bombardment MS has been used to characterize purified hemozoin, isolated from the spleens and livers of Plasmodium yoelii infected mice.49... 

Yamamoto, T., et al. 2000. Synthesis and chemical properties of pi-conjugated zinc porphyrin polymers with arylene and aryleneethynylene groups between zinc porphyrin units. Macromolecules 33 5988. 

Anderson and coworkers [81] have extended this approach of metal-ligand mediated self-assembly of dyes to construct double-stranded, conjugated ladders 30 through cofacial bridging of metalloporphyrins. The zinc porphyrin polymer 29, which is soluble in chloroform even in aggregated form, is transformed into the ladder complex by the addition of the ditopic hgand 4,4 -... 

When the -C=C- unit is directly bonded to the zinc porphyrin unit (polymer of type B), the Soret and Q-bands are shifted to a longer wavelength, suggesting the formation of a highly 71-conjugated system along the main chain, due to the lack of steric hindrance around the zinc porphyrin ring. 

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