含氧酸盐熔盐Raman光谱V_(1)峰位移的解释

On the Explanation of the Shift of Raman Frequency of Oxyanions in Molten Salts

若干含氧酸盐熔盐Raman光谱表明:含氧酸根离子的v_(1)峰(对称伸缩振动散射)位置随阳离子不同而异,James在解释NO_(3)^(-)在熔盐中的Raman光谱时,认为正电场较强的阳离子可能使NO_(3)^(-)中N—O键电子云密度增加,从而使力常数增大,v_(1)峰频率上升。为了探讨这一观点是否正确以及它对其它含氧酸根离子是否适用,我们用EHMO方法计算了若干由碱金属离子Me+和含氧酸根离子XOmm-(包括NO_(3)^(-)、NO_(2)^(-)、IO_(3)^(-)等)组成的原子簇(Me+)x(XOnm-)中的X—O键的重叠集居数和原子净电荷,并考察其与相应的熔盐的Raman光谱v_(1)峰位置的关系。以探讨v_(1)峰位移的物理实质。

A quantum chemical interpretation of the shifts of v_(1) peaks of Ramanspectra of the oxyanions in molten salt systems has been proposed, based on thecalculation by EHMO method. It can be seen that the cations of alkaline metalswith higher Z/r values make the electron overlap population of X-O bondincreased, and give rise to the Raman spectra with higher v_(1) frequency.