模板剂缓释法合成分子筛大单晶

在分子筛的合成中,通过使用四咪唑基取代的硼类化合物(四咪唑硼钠)作为模板剂,在溶剂热条件下,成功得到了磷酸铝盐分子筛AlPO₄-11的大单晶。电喷雾质谱、¹⁹F和¹¹B NMR等研究结果表明,在溶剂热条件下四咪唑硼钠起到了缓释剂的作用,其自身经历缓慢分解,持续释放低浓度咪唑分子的过程。由其释放出来的咪唑分子起到事实上的模板作用。因其浓度较低,限制了分子筛结晶过程中晶核形成的数量,从而易于导向分子筛大单晶的生成。通过引入不同种类的四取代硼类化合物作为模板剂,这种分子筛大单晶的合成策略可潜在应用于其它分子筛材料。     

模板剂缓释法合成分子筛大单晶（英文）

在分子筛的合成中,通过使用四咪唑基取代的硼类化合物(四咪唑硼钠)作为模板剂,在溶剂热条件下,成功得到了磷酸铝盐分子筛AlPO_4-11的大单晶。电喷雾质谱、~(19)F和~(11)B NMR等研究结果表明,在溶剂热条件下四咪唑硼钠起到了缓释剂的作用,其自身经历缓慢分解,持续释放低浓度咪唑分子的过程。由其释放出来的咪唑分子起到事实上的模板作用。因其浓度较低,限制了分子筛结晶过程中晶核形成的数量,从而易于导向分子筛大单晶的生成。通过引入不同种类的四取代硼类化合物作为模板剂,这种分子筛大单晶的合成策略可潜在应用于其它分子筛材料。     

晶种协同廉价有机模板导向合成高纯度MCM-49沸石

采用廉价低毒性的环己胺（CHA）作为有机模板剂,并合理添加少量MCM-49沸石晶种,在静态水热条件下成功合成了高纯度MCM-49沸石.研究了起始凝胶组成（如Al₂O₃/SiO₂,H₂O/SiO₂,CHA/SiO₂,晶种/SiO₂,Na₂O/SiO₂）、晶化温度和时间等因素对合成MCM-49沸石的影响.通过XRD、SEM、N₂吸附、固体²⁷Al和²⁹Si MAS NMR等手段表征产物,结果表明合成的MCM-49沸石具有良好的结晶度、均匀的晶体尺寸、高比表面积和纯的四配位Al³⁺物种.热重差热分析（TG-DTA）和固体¹³C MAS NMR表征结果证实CHA是作为模板剂填充在沸石产物的孔道内.这种合成MCM-49的方法具有廉价和低毒性的特点,对其产业应用有潜在的重要价值.     

一个新颖敞开结构硼磷酸盐的合成、结构、热和磁学性质：NH4Mn(H2O)2BP2O8· H2O

利用新的模板剂在水热条件下合成结构新颖的硼磷酸盐化合物NH₄Mn(H₂O)₂BP₂O₈·H₂O,单晶X射线衍射分析证明化合物属六方晶系,空间群为P6₁22,a = 0.9652(2) nm,c = 1.5792(5) nm,V = 1.2740(5) nm³,Z = 6．化合物所具有的三维敞开结构由硼磷酸盐螺旋带{[BP₂O₈]^3-和八面体MnO₄(H₂O)₂所构成．突出的结构特点是,化合物结构中的氨离子位于螺纹的外侧并与周围的氧原子形成较强的氢键．实验结果表明,顺磁性的标题化合物在较低的温度下表现出微弱的反铁磁性（Ө = -7.3 K）．此外,化合物的IR、元素分析和热分析在文中也被讨论．     

晶种导向干凝胶法制备成型ZSM-5分子筛

在干凝胶法制备ZSM-5 分子筛的体系中添加晶种导向剂, 控制分子筛的生长, 制备了纳米沸石组装的无粘结剂成型多级孔ZSM-5 分子筛, 一步完成纳米分子筛的制备及组装成型, 即克服了传统纳米粒子难以过滤分离的问题, 同时组装所形成的多级孔有助于改善分子在催化剂内的扩散, 从而提高催化反应效率. 以硅胶、薄水铝石为原料, 四丙基氢氧化铵(TPAOH)和ZSM-5 晶种导向胶作为粘结剂, 通过混捏、挤条得到直径2 mm的条状前驱物, 随后通过干凝胶转换法制备成型分子筛. 所用晶种导向剂组成为0.35TPAOH:1SiO₂:20H₂O:4C₂H₅OH. 通过X射线衍射(XRD), 热重(TG)分析和傅里叶变换红外(FTIR)光谱等方法对分子筛晶化过程进行了表征, 结果表明晶种导向剂加入量对分子筛生长速度及多级孔结构均有影响. 当所加晶种导向剂中TPAOH与SiO₂的摩尔比为0.025时, 经过3 h晶化, 分子筛相对结晶度达到100%. 扫描电镜(SEM)结果表明, 合成的分子筛尺寸约为200 nm, 组装形成的多级孔分子筛的介孔体积为0.28 cm³·g^-1. 通过NH₃ 程序升温脱附(NH₃-TPD)考察了所得成型分子筛的酸性, 发现该分子筛酸性与市售的粉末H-ZSM-5分子筛类似.     

微波场中T型分子筛的合成及晶化研究

研究了微波场中T型分子筛的结晶过程。考察了微波加热体系中合成参数如合成时间、溶胶组成、反应压力和模板剂用量对分子筛晶化的影响。微波加热的主要优点是减少合成时间,无模板剂的溶胶在普通加热条件下的晶化时间需要120 h,而在微波场中则仅需要20～25 h。另一方面,由于微波的快速加热特性促进了稳定相钙十字沸石的生成,从而减小了次稳定相T型分子筛的结晶区间。在未添加模板剂条件时,100 ℃下微波水热合成T型分子筛的结晶区间为：20≤n_SiO2/n_Al2O3≤22和0.31≤ n_M2O/n_SiO2≤0.33(其中M₂O=Na₂O+K₂O, n_Na/n_K=3和n_M2O/n_SiO2=11.70)。在普通加热和微波加热合成体系中,添加模板剂均能扩大结晶区间,同时还可以进一步减少合成时间。     

模板剂在分子筛合成过程中的作用机理

启用分子模拟途径,通过Lennard-Jones势对模板剂分子与分子筛骨架间非成键作用的能学分析,论证n=5、6的双季铵盐［(CH₃)₃N(CH₂)_nN(CH₃)₃］Br₂在ZSM-50分子筛骨架合成过程中所起的模板作用。     

CoSAPO-34分子筛的合成、表征及其光催化脱氮性能

利用水热合成法,以三乙烯四胺（TETA）为模板剂,正硅酸乙酯、磷酸、氢氧化铝及乙酸钴为原料,合成了CoSAPO-34分子筛。通过扫描电子显微镜（SEM）、粉末X射线衍射（XRD）、热重（TG）、N2吸附-脱附和紫外-可见漫反射光谱（UV-Vis DRS）等方法对合成的分子筛进行表征。以吡啶-正辛烷体系为模拟油品对分子筛催化剂的脱氮效果进行评价,考察了样品的用量、光催化时间及循环催化次数对其脱氮性能的影响。结果表明：当合成原料的物质的量之比为n_P2O5：n_AL2O3：n_SiO2：n_Co：n_TETA=1：0.26：0.82：0.81：2.05,在200 ℃晶化24 h,合成得到粒径约为50 μm、仍保持了SAPO-34分子筛的骨架结构、形貌为立方体的CoSAPO-34分子筛,而且该分子筛具有较好的热稳定性。在500 W氙灯光照条件下反应150 min,样品对质量分数为100 μg·g^-1模拟油品的脱除率达到70%,循环3次光催化脱氮活性基本保持不变。     

离子热法合成多级孔CuAPO-5分子筛

采用丁二酸、氯化胆碱与四乙基溴化铵三元低共熔体为溶剂和模板剂,借助微波辐射快速合成了具有多级孔结构的CuAPO-5分子筛.系统地考察了P₂O₅/Al₂O₃、HF/Al₂O₃与CuO/Al₂O₃的物质量之比,铝源及铜源对CuAPO-5分子筛合成的影响.利用X射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)和N₂物理吸脱附等检测手段对合成产物的结晶度、形貌和孔结构等进行了表征.通过SEM可知在一定的条件下,可得到具有六角纳米盘状特殊形貌的CuAPO-5分子筛.N₂物理吸脱附、SEM和TEM分析表明该分子筛是一种同时存在微孔和介孔的多级孔磷酸铝分子筛材料.     

高硅SSZ-13分子筛膜二次水热生长过程

采用稀释模板剂合成溶胶在管状莫来石支撑体上制备高硅SSZ-13分子筛膜以研究膜的二次水热生长过程。对433 K下二次生长2~72 h的膜和底料进行表征,XRD表明膜和底料中的SSZ-13特征峰均在6 h后出现。底料中的晶粒尺寸基本不随晶化时间的延长而变化。在298 K和0.4 MPa测试条件下,433 K晶化72 h的SSZ-13分子筛膜CO₂渗透通量为2.08×10^-7 mol·m^-2·s^-1·Pa^-1,CO₂/CH₄理想选择性为24。探讨了SSZ-13分子筛膜的生长过程：涂覆在支撑体上的晶种首先溶解并形成大量有序的结构单元,诱导溶胶中晶粒形成并快速生长,晶粒沉积在支撑体的表面共生形成无缺陷的膜层。     

Crystal structure of Co(III) α-dimethylglyoximates with imidazole

Two new dimethylglyoximate complexes [Co(DmgH)₂(Im)Cl] (I) and (ImH)[Co(DmgH₂)₂Cl₂] (II), where DmgH^? is the dimethylglyoxime residue and Im is the imidazole molecule, are synthesized. The composition and structure of the crystals are determined from the elemental analysis, IR spectra, and single crystal X-ray diffraction. Complex I is molecular, containing the Im molecule as a coordinated ligand; complex II is of the ionic type with (ImH)⁺ involved as an outer-sphere organic cation. The mode of component packing in the crystals mainly depends on the imidazole position in the compounds.     

Two New Hybrid Architectures Based on Polyoxometaloborates and Imidazole Fragments

Two new hybrid compounds based on polyoxometaloborates, (HIm)₁₂[MnBW₁₁O₃₉H]₂ · 13H₂O ( 1 ) and (HIm)(Im)[(Im)₄Zn]₂[BW₁₂O₄₀] · 2H₂O ( 2 ) (Im = imidazole), have been synthesized and characterized by elemental analyses, IR, UV, TG, and single‐crystal X‐ray diffraction. Compound 1 is made up of [MnBW₁₁O₃₉H]^6– polyoxoanions, which are coordinatively linked together by terminal oxygen atoms to yield an unprecedented one‐dimensional chain that represents the first example of one‐dimensional assemblies based on polyoxotungstoborates and transition metal cations. Adjacent inorganic chains are further in close contact by imidazole molecules to form a three‐dimensional supramolecular channel framework by strong hydrogen‐bonding interactions. Compound 2 exhibits a three‐dimensional supramolecular architecture constructed from Keggin‐type polyoxoanions [BW₁₂O₄₀]^5– and zinc‐imidazole coordination units by strong hydrogen‐bonding interactions. Furthermore, both compounds exhibit interesting photoluminescence properties at room temperature.     

Secondary Synthesis and Characterization of Boron-Containing ZSM-5 Zeolites

Under conditions of secondary synthesis and to varying extents, boron can be incorporated into the tetrahedral framework sites of a ZSM-5 zeolite which has been synthesized template-free or in the presence of organic template compounds and subjected to calcination or hydrothermal treatment. Isomorphic incorporation of boron is verified by means of ¹¹B MAS NMR measurements and it is reflected in a contraction of the unit cell volume of the zeolite lattice. A comparative study of the catalytic properties of the boron-containing ZSM-5 in acid catalysed n-hexane cracking revealed that samples based on template synthesis product are more active and show less tendency to deactivation.     

Solution‐Mediated Transformation of a 1D [Zn(Im)(HIm)2(OAc)] Precursor to Several Different 3D Zn(Im)2 Frameworks

1D compound [Zn(Im)(HIm )₂(OAc )] was used as a single precursor of metal and imidazole to prepare several 3‐dimensional (3D ) Zn(Im)₂ frameworks by solution‐mediated transformation. Specifically, three known topologies, zni, coi and crb (BCT ) were obtained using a solution‐mediated transformation with CH₃OH , DMF and DMA as solvent, respectively. Structural studies by ¹³C MAS NMR spectroscopy and TG imply that in the transformation process from 1D compound to coi‐[Zn(Im)₂]•(DMF )_x and crb‐[Zn(Im)₂]•(DMA )_x (ZIF ‐1), DMF and DMA solvent molecules acted as structure‐directing agent and, therefore, were occluded inside the framework, respectively. In contrast, in the formation of zni‐[Zn(Im)₂], no solvent molecules were present in the frameworks; therefore the transformation from 1D compound to zni was induced by temperature. Thus, solution‐mediated transformation of a single precursor (1D compound) approach was established for the synthesis of ZIFs .     

Rhenium‐Dicarbonyl‐Nitrosyl‐Komplexe mit Imidazol

Rhenium Dicarbonyl‐Nitrosyl Complexes with Imidazole Different rhenium‐dicarbonyl‐nitrosyl complexes with imidazole (Im) as monodentate ligand have been synthesized and characterized, starting from [NEt₄][ReCl₃(CO)₂(NO)] and [ReCl(μ?Cl)(CO)₂(NO)]₂. Whereas the complexes [ReCl₂(Im)(CO)₂(NO)] and [ReCl(Im)₂(CO)₂(NO)]⁺ were achieved in high yields, the complex [Re(Im)₃(CO)₂(NO)]²⁺ with three imidazole ligands could only be isolated after complete removal of all halide ions (with AgBF₄) in low yield. The synthesis of a corresponding ^99mTc‐dicarbonyl‐nitrosyl complex with imidazole opens a new perspective for such compounds as potential radiopharmaceuticals and alternatives to the already established ^99mTc‐tricarbonyl complexes.     

Effects of different oxygen-containing anions on the structure of water clusters

Using Ni(Im)₆²⁺ (Im = imidazole) as the structural unit, the effects of oxygen-containing anions, such as SO₄^2-, NO₃^? and CO₃^2- on the structure of water clusters were studied. The crystal structures of three compounds [Ni(Im)₆][SO₄(H₂O)₁₁] (1), [Ni(Im)₆][(NO₃)Cl(H₂O)₄] (2), and [Ni(Im)₆][CO₃(H₂O)₅] (3) were obtained. Using Mercury-3.8 software to analyze the above three crystal structures, find different anion of water clusters had a significant effect on the supramolecular structure. At the same time, it also significantly influences the number of water molecules in the crystal structure.     

Synthesis,crystal structures,and photophysical properties of dibromo-2-(2′-pyridyl)imidazole and its corresponding boron–fluorine complex

2-(2′-Pyridyl)imidazole L1 and its corresponding boron–fluorine complex, 1, were synthesized and their crystal structures correlated with their photophysical properties. L1 forms a rigid supramolecular network through hydrogen bonds and halogen bond in the single crystal, which induces amplified spontaneous emission in crystals; it emits rather poor fluorescence in solution and powder states. Its boron chelate 1 emits intense fluorescence in solution since boron chelate is an excellent chromophore, and it exhibits large Stokes shift (136?nm in acetonitrile), due to the charge-transfer transition from the electron-donating π system to the electron-accepting boron moiety. Interestingly, 1 is also highly fluorescent in amorphous powder and crystal states; C–C rotation between pyridyl and imidazole groups is inhibited by the formation of a five-member ring containing BF₂, and the formation of intermolecular non-covalent bonds is the key factor. Solid emission with large Stokes shift makes it a valuable chromophore for synthesis of functional materials.     

Tailoring Hierarchical Zeolites with Designed Cationic Surfactants and Their High Catalytic Performance

Three hierarchical porous zeolites (H‐*BEA, H‐MTW, and H‐*MRE) were successfully synthesized with the assistance of designed cationic surfactants under hydrothermal synthesis conditions. The as‐synthesized zeolite samples can be easily regulated by changing the number of long hydrophobic n ‐alkyl chains. Also, we investigated the relationship between the length of the surfactant and the formation of the microporous structure of the zeolite. Furthermore, the alkylation of benzene with propene was performed as a probe reaction to evaluate the catalytic performance of the synthesized hierarchical zeolites. The resulting materials were characterized by using a complementary combination of techniques, that is, X‐ray powder diffraction, N₂ adsorption–desorption isotherms, scanning electron microscopy, transmission electron microscopy, Fourier transform IR spectroscopy, ²⁸Si and ²⁷Al MAS NMR spectroscopies, thermogravimetric analysis, and computer simulation. These analysis results indicated that quaternary ammonium surfactants acted as organic structure‐directing agents (OSDAs) in the formation of these hierarchical zeolite samples, whether the surfactant had long hydrophobic tail groups or not. The simulation results indicated that the organic molecules with no long hydrophobic chain could lead to the synthesis of zeolite through charge control, and the hydrophobic molecules with long hydrophobic chains could form zeolites through orbital control. These hierarchical zeolites showed improved catalytic activity towards the industrially relevant alkylation of benzene with propene compared with conventional zeolites with the same frameworks. More importantly, the success of using quaternary ammonium surfactants with no hydrophobic n ‐alkyl tail group in the synthesis of hierarchically structured mesoporous zeolites provides a new pathway for the synthesis of hierarchical porous materials by a soft‐templating method.     

含氟体系中高性能T型分子筛膜的合成

含氟体系中,在负载晶种的大孔莫来石支撑体表面快速合成了高性能且取向生长的T型分子筛膜。采用XRD、SEM和MASNMR等手段对分子筛膜层和粉末进行表征。讨论了添加物、氟硅比、合成温度和合成时间等条件对膜生长与分离性能的影响,并阐述了含氟体系中T型分子筛膜快速晶化的机理。碱金属氟盐的加入促进了T型分子筛晶体层的晶化速率,并对晶体层形貌产生了一定的影响。膜应用于75℃、水/异丙醇（10：90,w/w）体系的平均渗透通量和分离因子分别为（4.91±0.18）kg·m^-2·h^-1和7060±1130。