Electron Transfer Function of Metalloporphyrins and Their Fixation in Polymer Gel Beads for Constructing Hydrogen Evolution System.

Abstract

Two series of metal loporphyrins, meso-tetra(p-sulfonatephenyl)porphine and meso-tetra(p-carboxyphenyl) porphine were prepared as their manganese-, tin-, and zinc-complexes for purpose of their fixation in polymer beads. The functions of these metalloporphyrins as an electron carrier instead of viologen derivatives and/or a photosensitizer for constructing the photoinduced hydrogen evolution system were investigated both in free and in polymer-fixed systems. Manganese-and tin-porphyrins could be photoreduced by zinc-porphyrins in the presence of electron donor, and hydrogen was generated efficiently in the system applying tin-porphyrin as an electron car rier in aqueous solutions. Among the beads-fixed heterogeneous systems, only metalloporphyrins / chitosan gel beads could act in the photoinduced hydrogen evolution system.

A Photoinduced Hydrogen Evolution System Using Polymer-Supported Tin Porphyrin

“…The generated hydrogen gas was collected with a syringe and analyzed with a Hitachi G-3000 gas chromatograph, using a Molecular Sieve 5A (60/80) column at 70! [16].…”

Electron Transfer Function of Porphyrin Derivatives and Their Application. (Part 4). A Novel Photoinduced Hydrogen Evolution System Using Bifunctional Polymer-Supported Tin Porphyrins.

“…Considering this result and the previous reult that beads-supported viologen derivative could not work as an electron carrier while non-supported one could work (15), it was assumed that the electron carrier funtion of SnTCPP was lowed by its immobilization in beads.…”

“…We have previously reported an electron transfer function of polymer beads-supported manganese porphyrin, which were incorporated through the membrane (13,14). Considering this results, we have also tried to construct a photoinduced hydrogen evolution system using manganese and tin porphyrins as an electron carrier (15). It was found that tin porphyrin worked as an electron carrier instead of toxic viologen derivatives, though manganese porphyrin could not work in the system.…”