层状水滑石对吡啶二甲酸异构阴离子的选择性插层行为

本文采用焙烧复原法研究了镁铝水滑石与吡啶二甲酸异构阴离子单体及其混合体的插层反应，实验发现镁铝水滑石对吡啶二甲酸异构阴离子存在着明显的选择性，有机酸异构体优先进入层间的顺序是：2,3-吡啶二甲酸>2,5-吡啶二甲酸>2,4-吡啶二甲酸>3,5-吡啶二甲酸>3,4-吡啶二甲酸>2,6-吡啶二甲酸。利用XRD、IR和TG测试技术对样品进行了表征，同时采用Gaussian-98软件包中ab initio 分子轨道法（HF/6-31G）计算了吡啶二甲酸异构阴离子的分子结构，理论结合实验探讨了阴离子在水滑石层间可能的空间构型，分析了其结构与插层行为的关系。研究表明镁铝水滑石层状材料插层过程中具有分子识别能力，可用于分离有机异构阴离子。     

水滑石无机阴离子交换剂的合成与表征

采用水热法制成了镁铝碳酸盐型、镁铝硝酸盐型、镁铝盐酸盐型、镁铝羟基型等插层镁铝类水滑石,比较了层间含不同阴离子类水滑石的结构差异和高温热处理后的结构稳定性.通过离子交换方式以镁铝羟基型为基材插层组装无机阴离子基团MoO42-、WO42-、CO32-和NO3-制得不同的阴离子插层类水滑石.通过XRD、TEM、XPS和热分析方法对镁铝类水滑石和阴离子插层类水滑石进行了表征.     

基于主-客体相互作用的插层水滑石光敏特性研究

本文基于水滑石类插层材料(LDHs)特有的超分子结构及其功能可调控性,采用离子交换法成功合成了邻、间、对硝基苯甲酸阴离子(o-、m-、p-NBA-)插层的锌铝水滑石,并研究了插层产物的光敏性能。插层后这3种异构体化合物都在紫外光照射下表现出不同的光响应程度,即光敏作用:m-NBA-LDHo-NBA-LDH≈p-NBA-LDH。用PXRD、FTIR、UV/Vis和理论计算研究了光敏性能,并提出了可能的光敏机理,为其应用于新型感光材料提供了一定的理论基础。     

类水滑石及其杂多阴离子柱撑物的合成与表面酸性研究

合成了一些类水滑石和过渡金属取代型杂多酸盐，并由此制备了相应杂多阴离子柱撑水滑石层柱材料。用ＸＲＤ，ＩＲ和元素分析等手段对合成产物进行组成和结构表征，用ＮＨ３－ＴＰＤ，Ｐｙ－ＩＲ研究了合成产物的表面酸性和酸类型，并在异丙醇反应中考察了合成物的酸碱催化行为，结果表明，水滑石和柱撑水滑石均同时存在酸碱中心，且酸碱相对强度与柱阴离子类型密切相关。杂多阴离子进入水滑石层，同时改变了水滑石和杂多酸盐的酸强度     

层间阴离子对四元水滑石超分子作用力的影响

构建一价阴离子(X=F^?, Cl^?, Br^?, I^?, NO₃^?, OH^?)插层铜锌镁铝四元水滑石(CuZnMgAl-X)周期性计算模型, 采用密度泛函理论(DFT), 选取CASTEP程序模块, 对体系进行几何全优化, 从结合能、结构参数、Mulliken布居、氢键布居、态密度等角度研究了不同层间阴离子的分布形态以及其对主客体间超分子作用的影响. 结果表明, 随着CuZnMgAl-X体系层间阴离子电负性的减弱, 电子逐渐从层间阴离子向层板发生转移, 主客体间静电作用力逐渐减小, 氢键强度逐渐降低, 禁带宽度逐渐变窄, 体系电子更易向高能级发生跃迁, 稳定性逐渐下降. 此外, Cu的掺杂使得CuZnMgAl-X 体系的价带顶向高能量处发生偏移, 禁带宽度较传统水滑石体系更窄,稳定性更低, 进一步解释了含铜水滑石较难合成的原因.     

二元类水滑石层板组成、结构与性能的理论研究

采用晶体学理论建立二元类水滑石(LDHs)微观结构模型与静电势能模型，将层板金属离子间距、层板电荷密度、层间阴离子间距等微观结构参数定量化，并将层间阴离子的静电势能表示成层板金属离子半径和物质的量之比、插层阴离子尺寸和电荷的函数。研究结果表明：LDHs层板金属离子间距应用离子紧密堆积来估算和孔径按阴离子平面六方点阵分布来计算是可行的；调变层板金属离子种类与物质的量之比影响层间阴离子的稳定性，势能计算值与文献报道的LDHs热稳定性次序一致。所以该模型可用于预测LDHs的微观结构参数以及热稳定性，为新型层状双羟基材料的定向合成提供思路。     

酸性橙插层锌铝水滑石的组装及其结构与性能

采用共沉淀法合成酸性橙阴离子插层锌铝水滑石(Zn/Al-AO7 LDHs),研究不同pH值及原料金属离子配比对产物结构的影响,利用X射线粉末衍射(XRD),热分析(TG-DTA),傅里叶变换红外(FT-IR)等表征手段,对插层产物的结构进行表征,确定了制备酸性橙插层锌铝水滑石的最适宜条件.用量子化学的B3PW91/6-31G(d,p)方法对Zn/Al-AO7 LDHs模型分子的空间几何构型进行了优化,通过结构组合得到的层间距为2.33 nm,接近XRD测试得到的层间距,从而说明了酸性橙离子在水滑石层板间的排列方式.进一步以甲酰胺为溶剂对水滑石层板进行剥离,得到澄清溶液,根据剥离产物的XRD谱可以确定剥离实验成功.     

P—W系杂多阴离子柱水滑石的制备及表征

本文采用微波法，首次制了第四周期系过滤金属取代三元杂多阴离子（ＰＺＷ１１）柱水滑石。经ＸＲＤ、ＤＴＡ、ＩＲ、ＵＶ－ＤＲＳ和ＥＳＲ表征。结果表明插入层间的柱高约为１．０ｎｍ，进入水滑石层间的杂多阴离子与其盐的ＩＲ振动类型和振动频率很相近，并且在水滑石层间ＰＷ１２基团不能稳定存在，可能已部分发生降解，而ＰＺＷ１１则能稳定的存在于水滑石层间。ＵＶ结果表明，进入水滑石层间的杂多阴离子的桥氧与钨（Ｏｂ／Ｏｃ     

镍铁类水滑石对偶氮阴离子染料的吸附脱色作用

采用镍铁类水滑石作为吸附剂,对偶氮阴离子染料酸性大红G、活性艳红X-3B和直接耐酸大红4BS废水进行脱色处理,研究了时间、镍与铁的物质的量之比、初始pH和无机电解质添加剂等因素对脱色率的影响,并结合红外光谱和X射线衍射分析结果讨论了其吸附脱色机理.结果表明,三种染料在镍铁类水滑石上的吸附均为层间的阴离子交换吸附和外表面的吸附.通过阴离子交换进入层间后,不同于直接耐酸大红4BS阴离子,酸性大红G和活性艳红X-3B两种阴离子与水滑石层间水分子之间产生氢键作用;在化学键合过程中,染料分子被镍铁类水滑石表面Fe3+氧化,同时偶氮键断裂导致脱色.     

超分子结构水杨酸根插层水滑石的组装及结构与性能研究

以锌铝水滑石ZnAl-CO3 LDHs为前体（主体），以乙二醇为分散介质，用离子 交换法组装了水杨酸根（客体）插层水滑石ZnAl-[o-HO(C6H4)COO]LDHs，并用XRD ，FT-IR，TG-DTA等手段对样品进行了表征。结果表明，能过控制离子交换条件， 水杨酸根阴离子可取代锌铝水滑石前体层间的CO3^2-离子，组装得到晶体结构良好 的水杨酸根插层水滑石。通过研究发现，主体水滑石层板与客体以静电力和氢键相 互作用，得到的超分子结构材料紫外阻隔作用增强并具有较好的稳定性，从而成为 一种集屏蔽和吸收双重功能的新型无机-有机得合紫外阻隔材料。     

meta-Substituted benzamide oligomers that complex mono-, di- and tricarboxylates: folding-induced selectivity and chirality

meta-Substituted arylamide trimer, pentamer and heptamer have been prepared from simple benzene-1,3-diamine, benzene-1,3-dicarboxylic acid, and 3-aminobenzoic acid units. 2D NOESY (1)H NMR experiments reveal that these flexible oligomers form folded conformations to complex di- and tricarboxylate anions of varying sizes and shapes in DMSO of high polarity, which is driven by multiple intermolecular N-H···O=C and C-H···O=C hydrogen-bonds between the amide and aromatic hydrogens of the oligomers and the carboxylate oxygens of the anions. Generally, tricarboxylate anions display an increased binding affinity compared with the dicarboxylate anions and the complexes formed by 1,3-benzenedicarboxylate anion are more stable than those formed by 1,2- or 1,4-benzenedicarboxylate anions. Circular dichroism experiments show that chiral glutamic acid dianion can induce the oligomers to produce chiral bias, leading to the formation of chiral supramolecular complexes.     

Rationally designed, polymeric, extended metal-ciprofloxacin complexes

Reactions of the antimicrobial fluoroquinolone ciprofloxacin (cfH) with metal salts in the presence of aromatic polycarboxylate ligands or under basic conditions produce fourteen new metal-cfH complexes, namely, [Ba2(cf)2(1,4-bdc)(H2O)2] x H2O (1), [Sr6(cf)6(1,4-bdc)3(H2O)6] x 2H2O (2), [M2(cfH)2(bptc)(H2O)2] x 8H2O (M = Mn3 and Cd4), [M(cfH)(1,3-bdc)] (M = Mn5, Co6, and Zn7), [Zn2(cfH)4(1,4-bdc)](1,4-bdc) x 13H2O (8), [Ca(cfH)2(1,2-Hbdc)2] x 2H2O (9) and [M(cf)2] x 2.5H2O (M = Mn10, Co11, Zn12, Cd13, and Mg14) (1,4-bdc = 1,4-benzenedicarboxylate, bptc = 3,3',4,4'-benzophenonetetracarboxylate, 1,3-bdc = 1,3-benzenedicarboxylate, 1,2-bdc = 1,2-benzenedicarboxylate). Their structures were determined by single-crystal X-ray diffraction analyses and further characterized by elemental analyses, IR spectra, and thermogravimetric analyses. The structures of 1 and 2 consist of unique two-dimensional arm-shaped layers. Compounds 3 and 4 are isostructural and feature one-dimensional structures formed from the interconnection of [M2(cfH)2(H2O)2] dimers with bptc ligands. Compounds 5-7 are isostructural and contain double-chain-like ribbons constructed from [M2(cfH)2(CO2)2] dimers and 1,3-bdc. Compound 8 consists of a pair of [Zn(cfH)2]2+ fragments bridged by a 1,4-bdc into a dinuclear dumbbell structure. Compound 9 is a neutral monomeric complex. To the best of our knowledge, compounds 1-9 are the first examples of metal-quinolone complexes that contain aromatic polycarboxylate ligands. Compounds 10-14 are isostructural and exhibit interesting two-dimensional rhombic grids featuring large cavities with dimensions of 13.6x13.6 A. Up to now, polymeric extended metal-cfH complexes have never been reported.     

Ab initio and DFT study of the geometric structures and static dipole (hyper)polarizabilities of aromatic anions

The geometries and the static dipole (hyper)polarizabilities (alpha, beta, gamma) of a series of aromatic anions were investigated at the ab initio (HF, MP2, and MP4) and density functional theory DFT (B3LYP) levels of theory. The anions chosen for the present study are the benzenethiolate (Ph-S-), benzenecarboxylate (Ph-CO2-), benzenesulfinate (Ph-SO2-), benzenesulfonate (Ph-SO3-), and 1,3-benzenedicarboxylate (1,3-Ph-(CO2)2(2-)). For benzenethiolate anion, additional alpha, beta, and gamma calculations were performed at the coupled cluster CCSD level with MP2 optimized geometries. The standard diffuse and polarized 6-31+G(d,p) basis set was employed in conjunction to the ab initio and DFT methods. Additional HF calculations were performed with the 6-311++G(3d,3p) basis set for all the anions. The correlated electric properties were evaluated numerically within the formalism of finite field. The optimized geometries were analyzed in terms of the few reports about the phenolate and sulfonate ions. The results show that electron correlation effects on the polarizabilities are very important in all the anion series. Was found that Ph-SO2- is highly polarizable in terms of alpha and beta, and the Ph-S- is the highest second hyperpolarizable in the series. The results of alpha were rationalized in terms of the analysis of the polarization of charge based in Mulliken atomic population and the structural features of the optimized geometries of anions, whereas the large differences in the beta and gamma values in the series were respectively interpreted in terms of the bond length alternation BLA and the separation of charge in the aromatic ring by effects of the substitution. These results allowed us to suggest the benzenesulfinate and benzenethiolate anions as promising candidates that should be incorporated in ionic materials for second and third-order nonlinear optical devices.     

Neutral species from "non-protic" N-heterocyclic ionic liquids

Possible isomerisation of 1,2,3-trialkylimidazolium and 1-alkylpyridinium ion pairs by proton transfer and by the nucleophilic addition of the anion to the cation have been investigated at the B3LYP/6-31+G* and B3LYP/6-311+G** levels of density functional theory. The deprotonation energies of 1,2,3-trialkylimidazolium and 1-alkylpyridinium cations to diaza-pentafulvene and pyridinium-ylide, respectively, were only slightly larger than that of 1,3-dialkylimidazolium salts yielding N-heterocyclic carbenes. Accordingly, in the case of 1,2,3-dialkylimidazolium salt ion pairs the stability of the H-bonded complex between the fulvene and the corresponding acid can be comparable to that of the ion pair in the presence of sufficiently basic anions, such as acetate. In the case of the pyridinium salts the nucleophilicity of the cation dominates over the acidity, and the formation of 1,2- or 1,4-dihydropyridine derivatives is preferred over proton transfer.     

Ab initio calculations including solvent effects of the structure of pyrazine, 4-nitropyridine and dicyanobenzenes ion pairs

The potential surfaces of pyrazine, 4-nitropyridine, 1,2-, 1,3-, 1,4- dicyanobenzene radical anions have been calculated within theab initio and electrostatic molecular potential formalism, including the effect of the solvent. These potential surfaces suggest models of ion pairs with alkali cations, which are in agreement with those deduced from related ESR spectra.     

Reactions of 1,2-diaza-1,3-dienes with thiol derivatives: a versatile construction of nitrogen/sulfur containing heterocycles

The synthesis of substituted 2,3-dihydro-1,4-thiazines, fused cycloalkyl-1,4-thiazines, 1,4-benzothiazines and fused cycloalkyl-1,4-benzothiazines by 1,4-addition of 1,2-aminothiols to 1,2-diaza-1,3-dienes bearing carboxylate, carboxamide, or phosphorylated groups and subsequent internal heterocyclization is described. The reaction of carboxylated 1,2-diaza-1,3-butadienes with 2-(butylamino)ethanethiol affords 1,4-thiazinan-3-ones. The solid-phase reaction of polymer-bound 1,2-diaza-1,3-butadienes with 1,2-aminothiols produces 2,3-dihydro-1,4-thiazines and 1,4-benzothiazines.     

Open layers based on metal-oxide chains linked by cyclohexanedicarboxylate ligands

Three layered metal-oxide organic compounds, In(OH)(1,4-chdc), (1), Cr(OH)(1,4-chdc), (2), and In(OH)(1,2-chdc), (3), (H₂chdc = cyclohexanedicarboxylic acid) were synthesized and characterized by thermogravimetric analysis, infrared spectroscopy, and X-ray diffraction. All three structures are formed by stacking electro- neutral layers in a simple AA sequence. The layers are built by cross-linking –OH–M–OH–M– chains with the chdc anions. Unlike the flat 1,4-benzenedicarboxylate ligand which was previously shown to connect similar metal-oxide chains into porous 3D frameworks, the bent chdc ligands link the chains to form open layers with narrow intra-layer channels. From a mixture of cis- and trans- conformations of 1,4-chdc, only the e,a-cis conformation is incorporated in 1 and 2.     

Design and synthesis of a near infra-red luminescent hexanuclear Zn-Nd prism

The use of the Schiff-base ligand N,N'-bis(5-bromo-3-methoxysalicylidene)propylene-1,3-diamine (H2L) and 1,4-benzenedicarboxylate (BDC) enables the construction of the hexanuclear luminescent Zn-Nd complex [Zn4Nd2L4(1,4-BDC)2].[Nd(NO3)5(H2O)].Et2O.2EtOH.3H2O.     

Coordination polymers derived from gallium and zinc metal–metal bonded species

The reaction of (dpp-bian)Ga–Zn(dpp-bian) (dpp-bian is 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene) with 1,3-di(4-pyridyl)propane results in 1D coordination polymer [(dpp-bian)Ga–Zn(dpp-bian)(μ²-1,3-Py₂(CH₂)₃)]_n with the retained Ga–Zn bond. In contrast, the coordination of 1,3-di(4-pyridyl)propane to Zn atoms in the (dpp-bian)Zn–Zn(dpp-bian) complex induces the cleavage of the Zn–Zn bond which is accompanied by reduction of dpp-bian radical anions to dianions. The reaction product represents 1D coordination polymer [{(dpp-bian)Zn}(μ²-1,3-Py₂(CH₂)₃)]_n.