Synthesis and Molecular Design of Ruthenium Polynuclear Complexes Responding Logically to Trigger Signals

我们将重点放在Ru多核配合物的分子设计上，它可以对触发信号做出逻辑上的响应，比如质子运动。本项目的主要工作总结如下：(1)有机苯并咪唑桥连双核和四核配合物的合成。我们发展了质子诱导氧化还原电位转换的化学原理，即2-(2-吡啶基)苯并咪唑Ru双核和四核配合物中非配位氮中心的可逆质子化。在Ru-Rh双核异核配合物中，在Rh位的去质子态观察到了发射，而当Rh位发生质子化时，没有观察到发射。因此，在这个二核复合体中观察到了发射开关。我们正在将这种化学扩展到树状大分子类型的四核配合物。报道了当四种金属离子通过桥联配体…连接时，配体桥联的树枝状大分子四核配合物中的两种氧化模式更多的是以星爆的方式，每一种金属与金属的相互作用都很弱。模式A包括在中心金属离子单电子氧化之前，以几乎相同的电位同时氧化三种外围金属。第二种模式B与之相反。在目前的RuOS混合金属四核配合物[{Os(Bpy)_2(BbbpyH_2)}_3Ru](ClO_4)_8(bpy=2，2‘-联吡啶)中，A和B两种氧化还原模式可以通过碱性中心的质子化而互换。在去质子化配合物2^+(Ru^&lt；III&gt；Os^&lt；II&gt；_3)的单电子氧化形式中，电子从外围的Os^&lt；II&gt；向中心的Ru^&lt；III&gt；发生了质子化。(2)RuOS络合物中光致电荷分离态的形成：双核Ru(II)-NdI-Os(III)络合物的皮秒激光闪光光解表明，MLCT带漂白，然后在650 nm处出现了新的带。这些新谱带对应于Ru(III)-NdI-Os(II)态的形成。光致电子从Ru(Bpy)部分逐步转移到二羧亚胺，进而产生Os(III)。(3)电喷雾电离质谱学是四核Ru络合物表征和纯度检验的有力工具。较少

We are focusing on the molecular design of the Ru polynuclear complexes which can respond logicaly to the trigger signal such proton movements. The summary of this project during the term is the following :(1) Synthesis of Ru di- and tetranuclear complexes bridged by organice benzimidazole. We have developed the chemical principle underlying the proton-induced switching of redox potential, i.e., reversible protonation of uncoordinated nitrogen site in 2- (2-pyridyl) benzimidazole Ru di- and tetranuclear complexes. In heteronuclear Ru-Rh dinuclear complex, the emission was observed at the deprotonated state of Rh site, however when the protonation occurred at Rh site, no emission was observed. Thus, the emission switching was observed in this dinuclea complex. We are extending this chemistry to the dendrimer type tetranuclear complexes. Two oxidation patterns have been reported in ligand-bridged dendrimer tetranuclear complexes when the four metal ions are connected by bridging ligands … More in the star-burst like manner and each metal-metal interaction is weak. Pattern A consists in simultaneous oxidation of three peripheral metals at almost same potentials prior to one-electron oxidation of the central metal ion. The second pattern B is the reverse. In the present RuOs mixed metal tetranuclear complex, [ {Os (bpy)_2 (bbbpyH_2) }_3 Ru] (CIO_4)_8 (bpy=2,2'-bipyridine) , the two redox patterns A and B can be interchanged by protonation of basic sites. Within the one-electron oxidized form of the deprotonated complex 2^+ (Ru^<III>Os^<II>_3) , the electron transfer from peripheral Os^<II> to central Ru^<III> moiety has occurred on protonation.(2) Formation of photoinduced charge separated state in RuOs Complex : The picosecond laser flash photolysis of dinuclear Ru (II) -NDI-Os (III) complex shows that the bleaching of MLCT band and then the appearance of new bands at 650 nm were observed. These new bands corresponds to the fprmation of Ru (III) -NDI-Os (II) state. The stepwise photoinduced electron transfer from the Ru (bpy) moiety to the dicarboximide, and then Os (III) occurred.(3) We showed that electrospray ionization mass spectra is a powerful tool for the characterization and purity check of tetranuclear Ru complexes. Less