Self-Assembled Molecular Rafts at Liquid|Liquid Interfaces for Four-Electron Oxygen Reduction
The self-assembly of the oppositely charged watersoluble porphyrins, cobalt tetramethylpyridinium porphyrin (CoTMPyP4+) and cobalt tetrasulphonatophenyl porphyrin (CoTPPS4−), at the interface with an organic solvent to form molecular “rafts”, provides an excellent catalyst to perform the interfacial four-electron reduction of oxygen by lipophilic electron donors such as tetrathiafulvalene (TTF). The catalytic activity and selectivity of the self-assembled catalyst toward the four-electron pathway was found to be as good as that of the Pacman type cofacial cobalt porphyrins. The assembly has been characterized by UV−visible spectroscopy, Surface Second Harmonic Generation, and Scanning Electron Microscopy. Density functional theory calculations confirm the possibility of formation of the catalytic CoTMPyP4+/ CoTPPS4− complex and its capability to bind oxygen.
Keywords: Immiscible Electrolyte-Solutions ; Polarizable Continuum Model ; Water-Soluble Porphyrins ; 2Nd-Harmonic Generation ; Liquid/Liquid Interface ; Cobalt Porphyrins ; 2Nd Derivatives ; Radical Cation ; Energy ; Dioxygen
Record created on 2012-02-07, modified on 2016-08-09