Reaction of magnesium, calcium, strontium, and barium salts with a range of dicarboxylic acids [benzene-1,4-dicarboxyl ic acid (H2BDC), naphthalene-2,6-dicarboxylic acid (H2NDC), 4,5,9, 10-tetrahydropyrene-2,7-dicarboxylic acid (H-2)TPDC), pyrene-2,7-dicarboxylic acid (H2PDC), 5, 1 0-dihydroanthracene-2,7-dicarboxylic acid (H(2)DADC] in N,N'-dimethylformamide (DMF) or N,N'-diethylformamide (DEF) in Teflon-lined stainless steel autoclaves produces a range of metal-organic framework materials. Single crystal X-ray analysis has confirmed that the predominant building block in these materials is a chain of metal centers bridged either by carboxylate moieties alone as in [M(DMF)(mu-BDC](infinity) (M = Mg or Sr), [Ca-1.5(DEF)(mu-BDC](1.5)](infinity), and [Sr(DEF)(OH2)(mu-BDC](infinity) or bridged by both carboxylate ligands and DMF/DEF molecules as in [M(mu-DMF)(mu-NDQC](infinity) (M = Ca, Sr, or Ba), [M(mu-DEF)(mu-TPDC](infinity) (M = Ca or Sr), [M(mu-DMF)(mu-DADC](infinity) (M = Ca or Sr), and [Sr(mu-DEF)(mu-PDC)](infinity). In contrast, the isomorphous complexes [Mg-3(DMF)(4)(mu-NDC)(3)](infinity) and [Mg-3(DEF)(4)(mu-NDC](3)](infinity) contain centrosymmetric trinuclear moieties in which each pair of cations is bridged by three carboxylate anions with two pendant solvent molecules coordinated to each of the terminal Mg2+ cations. These trinuclear building blocks act as six-connected nodes and generate a tilted alpha-Po type structure. Eleven of the 12 structures based upon cationic chains adopt a common extended architecture in which the aryldicarboxylate anions link the chains to generate diamond-shaped channels. However, in the material [Sr(DMF)(mu-BDC)](infinity), the chains are linked to generate a hexagonal motif of triangular channels. In all 12 compounds based on cationic chains, the space within the channels is occupied by coordinated solvent molecules, leading to nonporous materials.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据