Based on our recent reinvestigation of the disproportionation reaction of 3,3′,5,5′‐tetraphenyl‐4,4′‐biphenoquinone, which exhibited drastic color change, we performed the synthesis and characterization of 3,3′′,5,5′′‐tetraphenyl‐4,4′′‐terphenoquinone with the aim of obtaining enhanced physical properties, such as lower reduction potentials and bathochromic shift in light absorption, and realizing a disproportionation reaction at a lower temperature. To construct the terphenyl and/or terphenoquinone skeletons, the Suzuki‐Miyaura coupling, which involves coupling between 1,4‐diiodobenzene and the boronic acid ester with phenyl and oxygen moieties attached was carried out. The subsequent hydroquinone formation reaction and oxidation reaction yielded a brilliant ultramarine‐blue terphenoquinone. The quinone showed properties typical of π‐expanded quinones, namely, positively shifted reduction potential, small on‐site Coulomb repulsion, and lower excitation energy. DSC measurement of this product showed an exothermic process at 212.5 °C and this temperature was much lower than that of the corresponding biphenoquinone, 289.5 °C. The products of this reaction were similar to those of the biphenoquinone reaction, i. e., two benzofurans and the corresponding hydroquinone.

中文翻译：

---

3,3''，5,5''-四苯基-4,4''-对苯二酚的合成及其还原歧化反应

基于我们最近对3,3'，5,5'-四苯基-4,4'-联苯醌的歧化反应进行的重新研究，该反应表现出剧烈的颜色变化，我们进行了3,3''，5的合成和表征， 5'′-四苯基-4,4'-对苯二酚旨在获得增强的物理性能，例如较低的还原电势和吸光度的红移，并在较低的温度下实现歧化反应。为了构建三联苯和/或三苯醌骨架，进行了Suzuki-Miyaura偶联，该偶联涉及1,4-二碘代苯与硼酸酯与苯基和氧部分的偶联。随后的对苯二酚形成反应和氧化反应产生了亮丽的深蓝色对苯二酚醌。醌表现出π扩展醌的典型特性，即正位移还原电位，小的库仑排斥力和较低的激发能。该产物的DSC测量显示在212.5℃下有放热过程，该温度比相应的联苯醌289.5℃低得多。该反应的产物与联苯醌反应的产物相似，即。例如，两个苯并呋喃和相应的氢醌。