N. Kitaguchi
Mar 1, 1989
Citations
0
Influential Citations
18
Citations
Journal
Bulletin of the Chemical Society of Japan
Abstract
Electronic spectra of substituted 9,10-dihydro-9,10-o-benzenoanthracene-1,4-diones (triptycenequinones) in various solvents and that of benzo- and dibenzotriptycenequinones were investigated in this paper. Intramolecular charge-transfer (CT) bands ware observed in triptycenequinone system as a result of intramolecular interaction between benzene ring and benzoquinone moiety. Substituents on the benzene rings strongly affected the CT bands. Electron-donating groups gave absorption maxima at long wavelength. Naphthalene ring gave similar but stronger CT bands than benzene ring. Hammett σ+ value of substituents gave good linear relationship with the energy of the CT bands. Calculations of reduced charge matrix of triptycenequinones by extended Huckel theory showed that the charge of aromatic ring(s) were transferred to benzoquinone moiety accompanying HOMO–LUMO excitation. Especially, absorption maxima of the methyl-substituted triptycenequinones gave good correlation with the amounts of charge transferred f...