Accession Number : ADA266492


Title :   High-Valent Oxo, Methoxorhenium Complexes: Models for Intermediates and Transition States in Proton-Coupled Multi-Electron Transfer Reactions


Descriptive Note : Technical rept. Jun 1992-Jun 1993


Corporate Author : NORTHWESTERN UNIV EVANSTON IL DEPT OF CHEMISTRY


Personal Author(s) : Ram, M S ; Skeens-Jones, Lisa M ; Johnson, Christopher S ; Zhang, Xiao L ; Hupp, Joseph T


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a266492.pdf


Report Date : 30 May 1993


Pagination or Media Count : 50


Abstract : Dioxorhenium(V) tetrapyridyl species are currently under active investigation as model systems for interfacial two-electron, two-proton transfer reaction sequences We now find that the corresponding oxo, methoxo complexes can be prepared from dioxo species and methyl trifluoromethanesulfonate. The new complexes behave nearly identically to the analogous oxo, hydroxo complexes-with one important exception: CH3(+), unlike H(+), does not dissociate from the oxo ligand. As a direct consequence, the usually elusive rhenium oxidation state, IV, is stabilized with respect to redox disproportionation and is observable for several complexes at high pH. The ability to detect this state, in turn leads to: (1) direct access to the formal reduction potentials for the isolated 1e(-) redox couples comprising the overall two electron transfer (key information for understanding multi-ET kinetics) (2) elucidation of the profound structural and energetic consequences of the initial protonation (methylation) step in the dioxorhenium(V) reduction kinetics.


Descriptors :   *COMPLEX COMPOUNDS , *PROTONS , *VALENCE , *RHENIUM COMPOUNDS , *METAL COMPLEXES , *ELECTRON TRANSFER , MODELS , METHYL RADICALS , OXIDES , CHEMICAL REACTIONS , MOLECULAR STRUCTURE , TRANSITIONS , EPOXIDATION , ALKENES , COUPLINGS , OXIDATION REDUCTION REACTIONS , PH FACTOR , ENERGETIC PROPERTIES , METHANE , KINETICS , CATALYSIS , SULFONATES , LIGANDS , FLUORINE , HYDROGEN , INTERFACES , ELECTROCHEMISTRY


Subject Categories : Inorganic Chemistry
      Organic Chemistry
      Physical Chemistry
      Solid State Physics


Distribution Statement : APPROVED FOR PUBLIC RELEASE