| Summary: | 碩士 === 國立成功大學 === 化學系碩博士班 === 101 === Dibenzo[de,mn]naphthacene annelated derivatives has been generated by nickel-catalyzed cyclodimerization. These structure which has been comfirmed by X-ray single-crystal diffraction analysis is non-planar and twist angle about 43.8-66.6o. The bond length and bond alternation in the crystal structures and HOMA theoretical calculations reveal that the central two six-membered rings lack aromaticity.
Systematic studies of reaction conditions reveal that nickel-catalyst, the amount of zinc powder, slovent and temperature all play key roles in this reaction. The reaction conditions have been optimized. Upon heating 1-bromo-(phenylethynyl)acene with mixture of NiBr2(dppe) and zinc powder in 1,4-dioxane at temperature between 130 to 150 ℃ for 14 hours, we generated 6 kinds of Dibenzo[de,mn]naphthacene annelated derivatives, the isolated yield is between 30% to 69%.
These Dibenzo[de,mn]naphthacene annelated derivatives show similar perfermoce in oxidation-reduction potential as most PAHs compounds show. In optical physical properties, the maximum absorption wavelenth of these compound is between 551 nm to 647nm, which shows small HOMO-LUMO energy gap(1.81-2.12 eV).
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