Dimer Cation Formation in Anionic Microemulsion Media. Duroquinone-Sensitized Photooxidation of 2,6-Dimethylnaphthalene and Tetrathiafulvalene

Article abstract of DOI:10.1021/j100243a037

Flash photolysis studies using a ruby laser (λ=347 nm, doubled line) were performed on the systems duroquinone (DQ)/2,6-dimethylnaphthalane (DMN) and DQ/tetrathiafulvalene (TTF) principally in sodium hexadecyl sulfate (SCS) microemulsion media.Electron transfer from both DMN and TTF to triplet duroquinone with efficient charge separation to produce the product cations and anion was observed in these media.Identical experiments performed in homogeneous media demonstrated electron transfer but with less efficient charge separation and consequently lower product ion yields.Dimer cation formation of both DMN and TTF, i.e., (DMN)₂⁺ and (TTF)₂⁺, in the anionic microemulsion media was readily detected.The formation of (TTF)₂⁺ was reverified by pulse radiolysis experiments.Although tetrathiafulvalene stacks easily in organic conducting salts and thus should have no difficulty in obtaining the supposed sandwichlike configuration of the dimer, no previous reports announce its detection.Dimer cation formation of aromatic compounds in microemulsion media is unique in itself since the majority of previous studies of this type involved γ irradiation of substrate solubilized in glassy alkane matrices at low temperatures (77 K).The dimer formation constant for DMN was evaluated graphically as K=4.76*10².