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Hydrogen Evolution from Viologen Radicals and from Photochemically Reduced Tin(IV) Porphyrins in the Presence of Colloidal Platinum
Author(s) -
Fuhrhop JürgenHinrich,
Krüger Wolfgang,
David Hans Ermann
Publication year - 1983
Publication title -
liebigs annalen der chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 0170-2041
DOI - 10.1002/jlac.198319830204
Subject(s) - chemistry , platinum , photochemistry , dehydrogenation , porphyrin , tin , hydrogen , radical , catalysis , inorganic chemistry , viologen , organic chemistry
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.