镁铝水滑石层板与层间阴离子相互作用的理论研究

本文采用以ASED-MO(含原子对排斥的EHMO法)为基础的结构自动优化的EHTOPT程序,对镁铝水滑石(LDHs)层板与层间阴离子相互作用进行了理论研究.以Mg6Al2(OH)16X@H2O为分子结构单元,计算并分析了与不同层间阴离子形成稳定结构的能量变化、成键状况及电荷转移情况,揭示了层间作用力的本质.结果表明,LDHs层板与层间阴离子间存在静电吸引、氢键等非共价键弱相互作用,且氢键作用为主,其强弱与阴离子电荷分布、空间排布方式密切相关;层间阴离子电荷分布同时还影响着层板酸碱性的变化.

Theoretical Study of the Layer-Anio n Interactions in Magnesium Aluminum Layered Double Hydroxides

The interaction of the intercalated anions with the cationic sheets in ma gnesium aluminum layered double hydroxides has been in vestigated using the ASED-MO method.The energy changes,and the nature of the bonding have been studied during the formation of the layered structure with different anions,based on the model Mg₆Al₂(OH)₁₆ X·H₂ O.The calculations have shown that both Coulombic and hydrogen bonding inte ractions exist in the layered structure,and the strength of the hydrogen bonding interaction is con nected with the charge distribution of the anion and its orientation in space.Furthermore,it indicates that the variation in acid-base prop erties of the layers is affected by the charge distribution of the int ercalated anion.