混合价化合物中桥配位体对其电子性质的影响

由桥配位体(bridged ligand)所联结的双金属离子所构成的混合价化合物如(NH_3)_5Ru(Pyr)Ru(NH_3)_5]~(5+)近年来引起物理学家和化学家广泛的兴趣和重视.直至目前为止,对于该种混合价化合物的电子性质仍存很多争论,不同的理论只能解释某些特性.在所有的模型中都把桥配位体看作一个格点,而忽略了它的内部结构.本文第一次考虑了桥配位体的结构,在此基础上提出了一个6模模型,然后定义一组键合(B),非键合(N),反健合(A)基,把6模哈密顿(Hamiltonian)量变换到这个新的基中去,可得到一组三维势表面,而把所观察到的某些吸收谱和磁的圆振二色向性(MCD)谱解释为三维势表面问能级之间的跃迁,所得到的结果比不考虑桥配位体结构的结果都更符合实验事实.

The Effect of the Bridged Ligand on Electronic Properties in Mixed-Valence Complexes

The effect of the bridged ligand on electronic properties in mixed-valence complexes is investigated. Based on analyzing the structure of bridged ligand, a six-mode model which includes the Interaction between electron-lattice vibration is presented. After defining a new (b, n, a) basis set, we transform the six-mode Hamiltonian into this basis set, whieh is appropriate for delocalized complexes. Then the three-dimensional adiabatic potential surfaces could be constructed as the functions of vibrational sum and difference coordinates q? Therefore some observed absorption spectra could be explained as the transition between the vibronic levels of corresponding potential surfaces. It is found that the theoretical prediction is more precise than the previous results which didn't include the effect of the bridge ligand.