Accession Number : ADA114443


Title :   Sensitized Photo-Reduction of Methyl Viologen by Metalloporphyrins.


Descriptive Note : Technical rept.,


Corporate Author : YORK UNIV DOWNSVIEW (ONTARIO) DEPT OF CHEMISTRY


Personal Author(s) : Lever,A B P ; Ramaswamy,B S ; Licoccia,S


Full Text : http://www.dtic.mil/get-tr-doc/pdf?AD=ADA114443


Report Date : 01 May 1982


Pagination or Media Count : 23


Abstract : We report the sensitized photo-reduction of methyl viologen by a series of porphyrins and metalloporphyrins, by visible light, in the presence of triethanolamine. Electrochemical studies and absorption and emission spectra are used to identify the redox potentials of the relevant photo-excited states and to calculate thermodynamic driving forces for quenching and subsequent thermal reactions. Electron spin resonance data are used to confirm the occurrence of oxidative and/or reductive quenching in these various systems. In general, the quantum yields for methyl viologen reduction parallel the thermodynamic driving force in a regular manner. The complex (L) (OAc) Rh(III)TPP (L equal solvent molecule) is shown to be an effective catalyst, photoreducing methyl viologen via an oxidative pathway with a quantum yield as high as 51%. LIfetimes and quenching constants are also reported for these species. (Author)


Descriptors :   *ELECTROCHEMISTRY , *ORGANOMETALLIC COMPOUNDS , *PHOTOCHEMICAL REACTIONS , *PORPHYRINS , EMISSION SPECTRA , REACTION KINETICS , CATALYSTS , ELECTRON SPIN RESONANCE , QUENCHING , CONSTANTS , ABSORPTION , THERMODYNAMICS , LIFE EXPECTANCY(SERVICE LIFE) , QUANTUM THEORY , REDUCTION(CHEMISTRY)


Subject Categories : Atomic and Molecular Physics and Spectroscopy


Distribution Statement : APPROVED FOR PUBLIC RELEASE