190-81-8Relevant articles and documents
Charge Transfer Complexes, Gas-liquid Chromatographic and Photochemical Characteristics, and Solvent Adduct of Polyphenes and Related Linear Polyphenyls
Fujioka, Yasuhiro
, p. 481 - 489 (1985)
The absorption spectra of the charge-transfer (CT) complexes formed by two acceptors (tetracyanoethylene and 2,3-dichloro-5,6-dicyano-p-benzoquinone) with thirteen macrocyclic polyphenylenes and with thirty-eight linear polyphenyls were measured in dichloromethane.A linear relationship existing between the first transitions of the CT-complexes and those of the uncomplexed donor hydrocarbons made it possible to predict the CT-bands of new polyphenylenes and polyphenyls.By the gas-liquid chromatography using a glass capillary column, forty-nine polyphenyls and polyphenylenes, containing a large number of isomers, were successfully analyzed.The relationship between the retention times and the structure of linear polyphenyls was expressed by means of a simple empirical equation, and the equation was also applicable to the polyphenylenes by adding a correction factor.These equations are extremely useful for the estimation of the retention time and elution order and the structure of unknown polyphenyls and polyphenylenes.The reductive irradiation of m,m,o,p,o-pentaphenylene provided the bridged annulene compound.For six polyphenylenes and the related compounds, the criteria for the occurence of the intramolecular photocoupling reaction were discussed.Among the examined polyphenylene m,o,o,m,o,o-hexaphenylenes and o,p,p,o,p,p,o,p,p-nonaphenylene formed the adducts with several solvents.
The Rolling-Up of Oligophenylenes to Nanographenes by a HF-Zipping Approach
Steiner, Ann-Kristin,Amsharov, Konstantin Y.
, p. 14732 - 14736 (2017)
Intramolecular aryl–aryl coupling is the key transformation in the rational synthesis of nanographenes and nanoribbons. In this respect the C?F bond activation was shown to be a versatile alternative enabling the synthesis of several unique carbon-based nanostructures. Herein we describe an unprecedentedly challenging transformation showing that the C?F bond activation by aluminum oxide allows highly effective domino-like C?C bond formation. Despite the flexible nature of oligophenylene-based precursors efficient regioselective zipping to the target nanostructures was achieved. We show that fluorine positions in the precursor structure unambiguously dictate the “running of the zipping-program” which results in rolling-up of linear oligophenylene chains around phenyl moieties yielding target nanographenes. The high efficiency of zipping makes this approach attractive for the synthesis of unsubstituted nanographenes which are difficult to obtain in pure form by other methods.
Systematic investigations on fused π-system compounds of seven benzene rings prepared by photocyclization of diphenanthrylethenes
Fujino, Shota,Yamaji, Minoru,Okamoto, Hideki,Mutai, Toshiki,Yoshikawa, Isao,Houjou, Hirohiko,Tani, Fumito
, p. 925 - 934 (2017/07/10)
We studied the photoproducts of 1-(n-phenanthryl)-2-(m-phenanthryl)ethenes (nEm; n, m = 1, 3 and 9) for understanding photocyclization patterns based on NMR spectroscopy. The crystal structures of the photoproducts were analyzed by X-ray crystallography, and the photophysical features of the photocyclized molecules were investigated based on emission and transient absorption measurements. Phenanthrene derivatives substituted at the 1- and 3-positions were prepared for synthesizing nEm by photocyclization of stilbene derivatives. We obtained four types of primary photoproducts (n@m) from the corresponding nEm. Two of them were found to have racemic molecular structures in the single crystal determined by X-ray crystallography. Besides the primary photoproducts, two types of secondary photoproducts (n@mPP) were isolated. Fluorescence quantum yields and lifetimes of the obtained photoproducts were determined in solution whereas the definite fluorescence quantum yields were obtained in the powder. Observation of the triplet-triplet absorption spectra in solution by laser photolysis techniques showed that intersystem crossing to the triplet state competes with the fluorescence process.
Photochemical Intramolecular Acylation of Polycyclic Aromatic o-Dicarboxylic Anhydrides
Bunte, Reinhard,Gundermann, Karl-Dietrich,Leitich, Johannes,Polansky, Oskar E.,Zander, Maximilian
, p. 3521 - 3527 (2007/10/02)
The light-induced Diels-Alder addition of maleic anhydride to naphthochrysene (1) yields the same dicarboxylic anhydrides 2 and 4 as the thermal Diels-Alder addition. 4 is further isomerized by light to give the fluorenone carboxylic acid 6, as was revealed by isolation of compounds 7 and 8 after decarboxylation of the mixture 2 + 4.Analogously, 12 is formed by irradiation of the dicarboxylic anhydride 10; decarboxylation of 12 yields 13 and 14.The simpler systems 15 and 17 did not undergo an analogous light-induced isomerization.Photophysical examination of 4, 10, 15, and 17 gave no clue to the reasons for this difference in behaviour.
