Syntheses of cyanide bridged-mixed valent complexes with dynamic electronic state

合成了一种氰根桥联的分子正方体[Ru <II>^2Fe ^<II>2（μ-CN）4（bpy）8]（PF 6）4CHCl 3 H2O，简称[Ru <II>^2Fe ^<II>2]（PF 6）4，并用光谱电化学方法研究了其电化学混合价态。[Ru^<II>_2Fe^<II>_2]^&lt;4+&gt;的配位阳离子是由Ru（II）和Fe（II）离子通过四个氰根离子交替桥接而成的近正方形。[Ru <II>^2Fe ^<II>2]（PF 6）4在乙腈中的循环伏安图在0.69、0.94、1.42和1.70 V（vsSSCE）处显示出四个准可逆波，对应于[Ru <II>^2Fe ^<II>2]^&lt;4+&gt; [双箭头] [Ru <II>^2Fe <II>^^<III>]^&lt;5+&gt; [双箭头][Ru <II>^2Fe ^<III>2]^&lt;6+&gt; [双箭头][Ru^<II>Ru^<III>Fe^<III>2]^&lt;7+&gt; [双箭头][Ru <III>^2Fe ^<III>2]^&lt;8+&gt;的四个单电子氧化还原过程。电化学生成的[Ru^<II>_2Fe^<II>Fe^<III>]^&lt;5+&gt;和[Ru^<II>_2Fe^^<III>_2]^&lt;6+&gt;分别在2350 nm（ε= 5500 M^<-1>cm^<-1>）和1560 nm（ε= 10500 M^<-1>cm^<-1>）处显示出新的吸收带，分别归属于Fe^<II>到Fe^<III>和Ru^<II>到Fe^<III>的分子内IT（价间转移）带。电子相互作用矩阵元（H_<AB>）和电子离域度（α^2）分别为1090 cm ~ 2<-1>和0.065（[Ru^<II>_2Fe <II>^<III>_2]^&lt;5+&gt;态）和1990 cm ~ 2<-1>和0.065（[Ru^<II>_2Fe^<III>_2]^&lt;6+&gt;态）。

A cyanide bridged molecular square of [Ru^<II>_2Fe^<II>_2(μ-CN)_4(bpy)_8](PF_6)_4 CHCl_3 H_2O, abbreviated as [Ru^<II>_2Fe^<II>_2](PF_6)_4, was synthesized and electrochemically generated mixed valence states were studied by spectroelectrochemical methods. The complex cation of [Ru^<II>_2Fe^<II>_2]^<4+> is nearly square composed of Ru(II) and Fe(II) ions alternately bridged by four cyanide ions. The cyclic voltammogram (CV) of [Ru^<II>_2Fe^<II>_2](PF_6)_4 in acetonitrile showed four quasi-reversible waves at 0.69, 0.94, 1.42, and 1.70 V (vs SSCE), which correspond to the four one-electron redox processes of [Ru^<II>_2Fe^<II>_2]^<4+> 【double arrow】 [Ru^<II>_2Fe^<II>Fe^<III>]^<5+> 【double arrow】 [Ru^<II>_2Fe^<III>_2]^<6+> 【double arrow】 [Ru^<II>Ru^<III>Fe^<III>_2]^<7+> 【double arrow】 [Ru^<III>_2Fe^<III>_2]^<8+>. Electrochemically generated [Ru^<II>_2Fe^<II>Fe^<III>]^<5+> and [Ru^<II>_2Fe^<III>_2]^<6+> showed new absorption bands at 2350 nm (ε= 5500 M^<-1>cm^<-1>) and 1560 nm (ε= 10500 M^<-1>cm^<-1>), respectively, which were assigned to the intramolecular IT (intervalence transfer) bands from Fe^<II> to Fe^<III> and from Ru^<II> to Fe^<III> ions, respectively. The electronic interaction matrix elements (H_<AB>) and the degrees of electronic delocalizafcon (α^2) were estimated to be 1090 cm^<-1> and 0.065 for the [Ru^<II>_2Fe^<II>Fe^<III>_2]^<5+> state and 1990 cm^<-1> and 0.065 for the [Ru^<II>_2Fe^<III>_2]^<6+> states.