镧系元素钨硅杂多配合物异构体的合成及性质

SYNTHESES AND CHARACTERIZATION OF HETEROPOLY TUNGSTOSILICATE ISOMERS OF LANTHANIDE ELEMENTS

合成了通式为K_(13)[Ln(β_i-SiW_(11)O_(39))_2]·xH_2O(Ln=La,Ce,Pr,Nd,Sm,Gd,Er;β_i=β_1,β_3)的两个系列的β-异构体。通过元素分析、极谱、循环伏安法,UV和VIS光谱、磁化率以及热分析等手段研究了异构体的组成和性质。

The isomers of K_13[Ln(β_i-SiW_(11)O_(39))_2·xH_2O (Ln=La, Ce, Pr, Nd, Sm, Gd, Er; β_i=β_1 and β_3) have been prepared and characterized by elemental analysis, polarography,CV, UV-VIS, magnetic susceptibility, magnetic moments determination and thermal analysis. It is showed that the polarographic half wave Potential E_(1/2) for the new complexes are in the same order as for the β_i-SiW_(11). In β-isomers the E(1/2) of β_i decreases with the increaoe of the number of unrotated W_3O_(13) group.A linear relationship between E_(1/2)(Ⅰ)and the lowest energy of charge-transfer of the complexes is found. It can be concluded from VIS spectra that Ln(β_i-SiW_(11))_2 and Ln(α-SiW_(11))_2 have an identical geometric structure.