7466-50-4Relevant articles and documents
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.
Preparation and Properties of New Methano-Bridged Dibenzophenanthrenes
Puls, Carsten,Stolle, Andreas,Meijere, Armin de
, p. 1635 - 1642 (2007/10/02)
Intramolecular Friedel-Crafts alkylation of 1-(hydroxymethyl)helicenes 1-R and 15-Me leads to 10,11-methano-bridged dibenzophenanthrenes 2-R and 16-Me, respectively.These molecules are shaped like the back of a turtle as shown by X-ray crystal structure analysis.Their nonplanarity, however, is not rigid, as revealed by the temperature dependence of their (1)H-NMR spectra.With inversion barriers of about 62.4 and 67.1 kJ mol1- 2-H and 2-Me are surprisingly flexible.A remarkable diastereoselectivity is observed in the addition of methyl- and phenylmagnesium bromide to 1-formylhelicenes 14-Me leading to secondary alcohols 15a,b-Me, which cyclize to bridged hydrocarbons 16a,b-Me, in which the substituents R = Me, Ph are in the thermodynamically less favorable endo-position.Upon heating, endo-16a,b-Me isomerize to exo-16a,b-Me irreversibly. Key Words: Helicenes, methano-bridged/ Aromatic hydrocarbons, polycyclic/ Cycloheptatriene, all-benzoanellated, flexibility of/ Distorted aromatic rings
Phenanthrene derivatives
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, (2008/06/13)
The present invention relates to compounds of formula (1) or a monomethyl ether thereof (the compound of formula (1) including these ethers may contain no more than 30 carbon atoms in total); ethers, esters thereof; acid addition salts thereof; wherein Ar