类水滑石主体层板与客体CO_3^(2-)、H_2O间的超分子作用  

Supra-molecular Interaction between Host Layer and Guest CO_3^(2-),H_2O of Layered Double Hydroxides

作　　者：潘国祥[1] 倪哲明[1] 李小年[1] 

机构地区：[1]浙江工业大学化学工程与材料学院,催化新材料研究所,杭州310032

出　　处：《物理化学学报》2007年第8期1195-1200,共6页Acta Physico-Chimica Sinica

基　　金：浙江省自然科学基金(Y406069)资助项目

摘　　要：通过构建类水滑石双层计算模型,采用混合密度泛函B3LYP/6-31G(d)//B3LYP/3-21G方法计算类水滑石(LDHs-CO3-yH2O)的结构与能量,探讨LDHs限域空间中客体阴离子及水分子的分布形态以及主客体超分子作用.计算结果表明,客体阴离子与水分子以平行层板的方式存在于水滑石层间.主客体发生作用时,CO23-的HOMO轨道向层板的LUMO轨道转移电子.所形成的LDHs-CO3主客体作用要强于LDHs-F以及LDHs-Cl,与其离子交换性能相一致.水滑石去水结构(LDHs-CO3)水合过程,氢键作用较静电作用更占优势,并且layer-water型氢键要强于anion-water型氢键.此外,水合能计算表明LDHs水合具有一定的饱和量.A two-sheets model of layered double hydroxides （LDHs） was proposed. The structure parameters and energy of LDHs were calculated using density functional theory at the B3LYP/6-31 G（d）//B3LYP/3-21 G level. Distribution of guest anion and water in the interlayer and the supra-molecular interaction between the host layer and guest had been investigated. The results showed that the optimized guest anion and water paralleled to the host layer. The frontier CO3 to orbital of the host layer interacted with that of the guest anion, and the electron was transferred from HOMO of 2 LUMO of the host layer. Moreover, LDHs-CO2 was more stable than LDHs-F and LDHs-Cl, calculating results remained consistent with the ion exchange ability reported. In the process of hydration of LDHs-CO3, hydrogen- bonding was superior to electrostatic interaction, and layer-water type hydrogen-bonding was stronger than anionwater type hydrogen-bonding between H2O and the rest of the structure. Moreover, the calculated hydration energy indicated that the hydration of LDHs-CO3 could achieve a definite saturation state.

关 键 词：密度泛函理论 类水滑石 超分子作用 水合能 

分 类 号：O641.1[理学—物理化学]