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Functionalization of rho-ZMOF with photosensitizers for singlet oxygen generation

Paper ID Volume ID Publish Year Pages File Format Full-Text
27540 44029 2011 6 PDF Available
Title
Functionalization of rho-ZMOF with photosensitizers for singlet oxygen generation
Abstract

Here we report the functionalization of a zeolite-like-metal organic framework of RHO topology with two cationic photosensitizers, methylene blue (MB+) and phenosafranine (PS+). The spectroscopic properties of encapsulated MB+ are strongly influenced by host–guest interactions. At low MB+ loading levels, the photo-sensitizer remains monomeric and exhibits absorption and emission spectra that are red-shifted with respect to MB+ spectra in aqueous solution. Strong interactions between MB+ and the framework are clearly evident from the long fluorescence lifetime of the functionalized material, τ = 3.2 ns, that is nearly an order of magnitude longer relative to MB+ in aqueous solutions. Unlike MB+, the larger diameter of PS+ dye prevents its incorporation within the ZMOF framework and PS+ molecules weakly bind to the external surface of the framework and exhibit absorption and emission properties similar to those measured for PS+ in methanolic solution. The immobilized photosensitizers partially preserve their capacity to generate singlet oxygen as determined indirectly using diphenylanthracene as a chemical trap.

► We functionalized rho-ZMOF with methylene blue and phenosafranine. ► Methylene blue penetrates into internal cavities. ► Phenosafranine reminds adsorbed on the surface. ► Altered properties of methylene blue indicate strong host-guest interactions. ► Photo-excitation of dyes leads to the generation of singlet oxygen.

Keywords
ANA, analcime net; MER, merlinoite net; MB+, methylene blue; PS+, phenosafranine; RHO, zeolite Rho net; SOD, sodalite net; AOT, sodium bis(2-ethylhexyl) sulfosuccinate; ZMOF, zeolite like metal organic frameworkMetal organic framework; Porous materials; P
First Page Preview
Functionalization of rho-ZMOF with photosensitizers for singlet oxygen generation
Publisher
Database: Elsevier - ScienceDirect
Journal: Journal of Photochemistry and Photobiology A: Chemistry - Volume 221, Issue 1, 10 June 2011, Pages 84–89
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Bioengineering