【摘要】 通过对铀采用相对赝势基组,其它原子使用6-31+G(d)基组,应用密度泛函理论(DFT)以及B3LYP方法对UO22+离子与F-、CO23-和NO-3的各配位结构进行优化和频率计算.计算考虑了气相和水溶剂化两种状态,其中溶剂化模型采用连续导体介质理论模型(CPCM).计算结果显示配体的配位数与O襒U襒O对称伸缩振动频率存在线性关系.配体在气相和水溶液中存在的关系基本符合通式:νs=-Agasn+983和νs=-Aaqn+821(Agas和Aaq为常数,表示每增加一个配体振动频率的变化值;n为配体配位数).其中F-对应Agas=53cm-1,Aaq=11cm-1;CO230-对应Agas=85cm-1,Aaq=19cm-1;NO-3对应Agas=48cm-1,Aaq=-10cm-1.并且Aaq值与实验值一致.更多还原

【Abstract】 The geometries and IR frequencies of uranyl complexes were calculated by B3LYP method in density functional theory (DFT) using the relative effective core potential (RECP) on uranium and 6-31+G(d) basis set on other elements. Both gaseous and aqueous phases were considered and conductor-like polarized continuum model(CPCM) was used to consider the solvation effect of water. Ligands investigated in the present paper were F-,CO230-,and NO3-. A linear correlation between the frequency of the O=U=O symmetrical stretching vibration and the number (n) of ligands was established for the above-mentioned ligands according to the following two equations:νs=-Agasn+983 and νs=-Aaqn+ 821,where Agas and Aaq are characteristic coefficients that represent the shift in vibrational frequency for the addition of each ligand to the uranyl center. Results obtained for F-fit the equations with Agas=53 cm-1 and Aaq=11 cm-1; CO230-with Agas=85 cm-1 and Aaq=19 cm-1; NO3-with Agas=48 cm-1 and Aaq=-10 cm-1. The value of Aaq was found to correspond to the experimental results.更多还原