A new Os
II
complex, Os(tap)
3
2+
(tap=1,4,5,8-tetraazaphenanthrene) has been prepared and
characterized. Its spectroscopic properties in absorption and
luminescence and its electrochemical behaviour are compared with those
of Ru(tap)
3
2+
and
Os(phen)
3
2+
. The analysis of the dependence of
the luminescence lifetime of Os(tap)
3
2+
as a
function of temperature shows that the
3
MC state (metal
centred) is not reached at room temperature; therefore the complex is
photostable. In the presence of GMP (guanosine
5′-monophosphate), the emission of
Os(tap)
3
2+
is quenched with a rate constant of
6×10
8
dm3 mol
-1
s
-1
. A photoinduced electron transfer, evidenced by laser
flash photolysis, is shown to be the origin of this inhibition
process. Moreover this primary charge transfer induces the formation
of a photoproduct, as observed by absorption spectroscopy and HPLC;
this photoproduct corresponds to an adduct of the complex to GMP
without loss of ligand. Os(tap)
3
2+
should thus
behave as a new photoreagent for the DNA guanine bases without the
disadvantages caused by photoinstability, as observed with
Ru(tap)
3
2+
.
一个新的操作系统
二
复杂,Os(tap)
3
2+
(tap=1,4,5,8-四氮杂
菲)已制备并
特点。其吸收和光谱特性
发光及其电
化学行为与
钌(丝锥)
3
2+
和
奥斯(苯)
3
2+
。依赖性分析
Os(tap)的发光寿命
3
2+
作为
温度的函数表明
3
MC状态(
金属
居中)在室温下未达到;因此复合体是
耐光。在 GMP(
鸟苷
5′-单
磷酸盐),发射
操作系统(点击)
3
2+
淬灭速率常数为
6×10
8
dm3摩尔
-1
s
-1
。激光证明光诱导电子转移
闪光光解被证明是这种抑制的根源
过程。此外,这种初级电荷转移诱导形成
通过吸收光谱和 HPLC 观察到的光产物;
该光产物对应于 GMP 复合物的加合物
不损失
配体。操作系统(点击)
3
2+
因此应该
作为 DNA
鸟嘌呤碱基的新型光试剂,无需
如所观察到的,由光不稳定性引起的缺点
钌(
水龙头)
3
2+
。