Hydrogen atom abstraction and electron transfer of triplet 2,3-dihalo-1,4-naphthoquinones studied by the cidep technique and laser flash photolysis |
| |
Authors: | Iwao Amada Minoru Yamaji Masami Sase Haruo Shizuka Takuji Shimokage Shozo Tero-Kubota |
| |
Institution: | (1) Department of Chemistry, Gunma University, 376 Kiry Gunma , Japan;(2) Institute for Chemical Reaction Science, Tohoku University, Katahira, Aobaku, 980-77 Sendai, Japan |
| |
Abstract: | Investigations using CIDEP techniques showed that an H-atom abstraction from phenol and the electron transfer from 1,2,4,5-tetramethoxybenzene
to photoexcited 2,3-dibromo-1,4-naphthoquinone (DBNQ) and 2,3-dichloro-1,4-naphthoquinone (DCNQ) in the polar media originated
from their triplet states. Nanosecond laser photolysis at 355 nm was carried out to determine the absorption spectra and coefficients
of the corresponding triplet states, semiquinone, and anion radicals for a quantitative investigation of the mechanisms involved
in the H-atom abstraction and the electron transfer. The steric hindrance of the substituted groups was indifferent to H-atom
abstraction. The electronic structures of triplet DBNQ and DCNQ at 295 K were both revealed to be the mixed states of 3(n,π*) with a 3(π,π*) character. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|