A comparative study of the electronic spectra, fluorescence quantum yields, cyclic voltammograms and theoretical calculations of phenanthrene-type benzodifurans

作者：Hayashi Naoto^*; Saito Yoko; Zhou Xiaoxi; Yoshino Junro; Higuchi Hiroyuki; Mutai Toshiki^*

来源：Tetrahedron, 2016, 72(29): 4159-4168.

DOI：10.1016/j.tet.2016.05.019

• Benzodifurans
• Oxidation potentials
• Fluorescence quantum yields
• HOMO/LUMO energy levels

Three isomeric difuran analogs of phenanthrene, including benzo[1,2-b;6,5-b']difuran (30), benzo[1,2-b;4,3-b']difuran (40) and benzo[1,2-b;3,4-b']difuran (50) have prepared and their properties investigated systematically. Compared with benzo[1,2-b;4,5-b']difuran (10) and benzo[1,2-b;5,4-b']difuran (20), there were pronounced differences in the fluorescence quantum yields of 30-50. Consideration of the absorption and fluorescence spectra, cyclic voltammograms and B3LYP/6-31G(d,p) calculations revealed that 40 had the highest electron-donating/accepting characteristics of all of the compounds prepared in this study. The lower electron-donating/accepting properties of 50 were attributed to the shorter chain length of it pi-conjugated system. The unexpectedly high electron-donating and low electron-accepting properties of 30 were attributed to changes in the radical cationic and anionic states, respectively. The energy levels of the highest occupied and lowest unoccupied molecular orbitals of the thiophene and selenophene analogs of 30-50 have also been calculated, and their relative energies explained in a similar manner.

• 出版日期2016-7-21