Hydrogen Evolution from Viologen Radicals and from Photochemically Reduced Tin(IV) Porphyrins in the Presence of Colloidal Platinum

✍ Scribed by Fuhrhop, Jürgen-Hinrich ;Krüger, Wolfgang ;David, Hans Ermann

• Publisher: John Wiley and Sons
• Year: 1983
• Tongue: English
• Weight: 386 KB
• Volume: 1983
• Category: Article
• ISSN: 0947-3440
• DOI: 10.1002/jlac.198319830204

✦ Synopsis

Abstract

The stoichiometry of the platinum‐catalyzed reaction of two methylviologen radical cations and two protons yielding two methylviologen dications and one molecule of hydrogen is demonstrated. ‐Watersoluble tin(IV) porphyrins are reduced by EDTA and visible light, first to give chlorins, then isobacteriochlorins. No isobacteriochlorin is formed in the presence of colloidal platinum, but hydrogen is produced. The conversion is about 25 moles of hydrogen per mole of porphyrin and hour. Isobacteriochlorins are dehydrogenated to give chlorins in the presence of colloidal platinum. The reaction takes place either in the air or under argon.