阴离子插层镁铝水滑石结构及相互作用的理论研究

摘要

采用密度泛函理论(DFr)计算了MgAl-LDHs层板与无机阴离子(F-、C1-、NO3、CO23-、SO24-)和有机阴离子(水杨酸根离子([HO(C6H4)COO]-)、苯甲酸根离子([(C6H5)COO]-)、对二甲氨基苯甲酸根离子([p-(CH3)2N(C6H4)COO]-)、十二烷基磺酸根离子[C12H25SO3]-、己烷基磺酸根离子[C6H13SO3]-、丙烷基磺酸根离子[C3H7SO3]-)间的相互作用,获得稳定超分子几何结构及相互作用能.层板主体与客体间存在较强的超分子作用,包括主客体间静电作用和氢键等.主、客体间相互作用能数值大小顺序为CO23-＞ SO24-＞F-＞ Cl-＞ NO3-；[p-(CH3)2N(C6H4)COO]-＞ [(C6H5)COO]-＞[HO(C6H4)COO]-和[C12H25SO3]-＞[C6H13SO3]-＞[C3H7SO3]-.另外,还采用自然键轨道(NBO)计算和分析了LDHs层板与阴离子间作用机理,从二阶微扰理论计算得到的稳定化能变化趋势与相互作用能数据基本吻合.%The structure of anion-intercalated MgAl-layered double hydroxides (MgAl-LDHs) and the interaction between the anion and host layer were investigated by density functional theory (DFT) ; the anions considered were inorganic ones like F-,CI-,NO3-,CO23-and SO24-,as well as organic ones like [p-(CH3)2N(C6H4)COO]-,[(C6H5)COO]-,[HO(C6H4)COO]-,[C12H25SO3]-,[C6H13SO3]-and [C3H7SO3]-.The geometric structures and interactional energies between the anions and host layer were obtained.The results showed that there is a strong supra-molecular interaction between anions and host layer of MgA1-LDHs and the interactional energy values followed the orders of CO32-＞ SO42-＞ F-＞ Cl-＞ NO3-,[p-(CH3) 2N(C6H4) COO]-＞ [(C6H5)COO]-＞ [HO(C6H4)COO]-,and [C12H25SO3]-＞ [C6H13SO3]-＞ [C3H7SO3]-.In addition,the interaction mechanism between anions and host layer was considered by the natural bond orbital (NBO) analysis; the trend of stability energies calculated by the second order perturbation agrees well with that of the interactional energies.