Abstract
Abstract The photoelimination of hexamethyleneammonium hexamethylenedithiocarbamate (HMTC) can be sensitized by xanthene dyes, such as rose bengal and eosine yellowish. In contrast to the direct photolysis results, the presence of HMTC in the dye-sensitized decomposition produces no carbon disulfide and consumes oxygen during the irradiation. The quantum yield of photoelimination in an aerated ethanol solution was measured. The quantum yield was almost unchanged on the variation of the xanthene dye concentration from 10−5 to 10−6m. This is different from the former observation that there was an apparent tendency for the quantum yield to decrease monotonously with an increase in the thiazine dye concentration. The singlet oxygen mechanism, in which the photochemical reaction is initiated by the interaction between the triplet dye and the ground-state oxygen molecules, has been inferred for the dye-sensitized photoelimination of HMTC. It has been explained in terms of the effect of 1,4-diazabicyclo [2.2.2] octane, β-carotene, and tetramethylethylene in reducing the quantum yield. The photooxygenation of HMTC by dyes seemed to be caused by attack of the singlet oxygen on the thiocarboxyl-ion group, which has a rate constant of 108m−1sec−1 in ethanol.
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call