Anomalous fluorescence from the azaxanthone ketyl radical in the excited state.
Anomalous fluorescence from the azaxanthone ketyl radical in the excited state.
复制标题
DOI：
10.1021/ja043212v
复制
发表时间：
2005-03
影响因子：
15
通讯作者：
M. Sakamoto;Xichen Cai;M. Hara;S. Tojo;M. Fujitsuka;T. Majima
中科院分区：
文献类型：
--
作者：
M. Sakamoto;Xichen Cai;M. Hara;S. Tojo;M. Fujitsuka;T. Majima
研究了氮杂蒽酮（AX）酮自由基（AXH）的时间分辨吸收光谱和荧光光谱。在激发态（AXH. (Dn)（n = 1或2））。AXH在460和645 nm处显示出双荧光峰，分别归属于D2 -> D 0和D1 -> D 0跃迁。发现D2 -> D 0荧光的寿命（1.0 ns）比D1 -> D 0荧光的寿命（0.4 ns）长。D1 --> D 0和D2 --> D 0荧光的荧光量子产率估计分别为0.0008 +/- 0.0002和0.05 +/- 0.02。这些异常的发光性质可以归因于AX中的吡啶环。AXH是违反Kasha规则的中性基的一个新例子。
The time-resolved absorption and fluorescence spectra of the azaxanthone (AX) ketyl radical (AXH.) in the excited state (AXH.(Dn) (n = 1 or 2)) were observed during the nanosecond-picosecond two-color two-laser flash photolysis. AXH. showed dual fluorescence peaks at 460 and 645 nm, which were assigned to the D2 --> D0 and D1 --> D0 transitions, respectively. It was found that the lifetime of the D2 --> D0 fluorescence (1.0 ns) was longer than that of the D1 --> D0 fluorescence (0.4 ns). The fluorescent quantum yields of the D1 --> D0 and D2 --> D0 fluorescence were estimated to be 0.0008 +/- 0.0002 and 0.05 +/- 0.02, respectively. These anomalous emitting properties can be attributed to the pyridine ring in AX. AXH. is a new example of a neutral radical which violates Kasha's rule.