86396-68-1

Upstream product

• 1692-39-3 (1R,2S)-1,2-bis(4-methoxyphenyl)cyclopropane 
• 6000-10-8 trans-1,2-bis(4-methoxyphenyl)cyclopropane 

Relevant academic research and scientific papers

Generation of Polyphenylene Radical Cations and Their Cosensitization Ability in the 9,10-Dicyanoanthracene-Sensitized Photochemical Chain Reactions of 1,2-Bis(4-methoxyphenyl)cyclopropane

Cosensitization effects of polyphenylene compounds (PP) such as biphenyl (BP), terphenyls (o-, m-, p-TP), and phenanthrene (Phen) in photoinduced electron-transfer reactions were examined. The 9,10-dicyanoanthracene (DCA)-sensitized cis-trans photoisomerization of 1,2-bis(4-methoxyphenyl)-cyclopropane (CP), which proceeds in a chain reaction via free radical cation of CP (CP.+) as a chain carrier, was accelerated by adding PP, particularly by TP. A similar accelerating effect was observed in the DCA-sensitized photooxygenation of CP as another example. BP and TP were more stable under the oxygenation condition than phenanthrene and naphthalene, which also accelerate the photooxygenation CP. CP.+ is generated by the direct electron transfer from CP to the excited singlet state of DCA (1DCA*) and also by the secondary electron transfer from CP to PP.+, which is generated by the primary electron transfer from PP to 1DCA*. The laser flash photolysis study revealed that the quantum yield for the formation of free CP.+ in the direct electron transfer from CP to 1DCA* (ΦCP.+ ≈ 0.1) was smaller than that in the presence of PP. This is due to the high yield of free PP.+ generation by the primary electron transfer and the efficient secondary electron transfer from CP to PP.+. The secondary electron transfers were found to take place in nearly diffusion-controlled rates (0.9-1.5 × 1010 M-1 s-1). The high yield of PP.+ as free radical ions does not seem to be the sole factor of the cosensitization of PP for the DCA-sensitized photoreactions of CP. The ratio of the quantum yields of the photoreactions to that of the initial CP.+ formation (turnover) also increased by the addition of PP from 3 (isomerization) and 15 (oxygenation) to 32-90 for both reactions. The second-order rate constant for the decay of CP.+ in aerated acetonitrile was decreased by a factor of 0.5-0.8 by the addition of PP. We concluded that the cosensitization effect in the photoreaction involves a π-complex formation between CP.+ and PP assisting the chain reaction as well as initial CP.+ formation.

Salt Effect on the 9,10-Dicyanoanthracene-Sensitized Photooxygenation of 1,2-Diarylcyclopropanes and the Photodecomposition of 3,5-Diaryl-1,2-dioxolanes

The 9,10-dicyanoanthracene (DCA)-sensitized photooxygenation of less electron-rich 1,2-diarylcyclopropanes 1 such as 1,2-diphenylcyclopropanes and 1,2-bis(4-chlorophenyl)cyclopropanes in the presence of Mg(ClO4)2 gave cis- and trans-3,5-diaryl-1,2-dioxolanes as major products.However, in the absence of Mg(ClO4)2, the photooxygenation did not afford 1,2-dioxolanes, but their decomposition products, 1,3-diaryl-1-hydroxypropan-3-ones 5, aryl aldehydes 6, and aryl methyl ketones 7.The DCA-sensitized photodecomposition of 1,2-dioxolanes also gave 5-7.This photoreaction was suppressed by addition of Mg(ClO4)2.The DCA-sensitized photooxygenation of 1 proceeds via radical cations that are generated by photoinduced electron-transfer from 1 to the excited singlet 1DCA*.The DCA-sensitized photodecomposition of 1,2-dioxolanes occurs via exciplexes that are formed between 1,2-dioxolanes and 1DCA* or energy-transfer from the excited triplet 3DCA* to 1,2-dioxolanes.