具有八-环开放骨架结构的Ni3(PO4)2·8H2O的水热合成与表征

由于开放骨架结构的金属酸盐具有潜在的应用前景，因此合成具有开放骨架结构的金属磷酸盐一直是研究的热点［1~3］. 自从第一个具有微孔结构的磷酸铝［4］被报道以来，许多其它具有开放骨架结构的金属磷酸盐被合成出来［5~14］. 然而有关磷酸镍研究的报道很少，仅有几个具有开放骨架结构的磷酸镍［15,16］和一些碱金属的磷酸镍［17~19］(大部分是通过固相法合成的). 本文通过水热法合成了一个新的具有层状结构的磷酸镍［Ni3(PO4)2·8H2O］，并通过X射线单晶衍射测定了其结构，其结构中包含共角的多面体连接成的四元环和八元环.     

非水体系中磷酸锌的合成与表征

非水体系中磷酸锌的合成与表征宋天佑，徐家宁，徐如人，岳勇（吉林大学化学系，长春，１３００２３）（中国科学院武汉物理研究所）关键词无机合成，非水体系，磷酸锌，Ｘ射线衍射非水体系中合成磷酸铝的工作开展得较为广泛［１，２］，在水溶液中合成磷酸锌的工作亦有报...     

磺化苯膦酸-磷酸锆的制备及其对甲醛羰基化反应的催化性能

合成了苯膦酸锆及其混合配体形式的苯膦酸.磷酸锆和苯膦酸-亚磷酸锆,并通过层间苯环磺化制备了不同组成的磺化苯膦酸-磷酸锆(SZrPP-n).利用电感耦合等离子体、X射线衍射、热重、红外光谱等手段对样品磺化前后的结构和性质进行了表征,考察了SZrPP-n对甲醛羰基化反应的催化性能.结果表明.苯膦酸.磷酸锆具有典型的层状结构,改变合成条件可以得到层间距不同的晶体.磺化后,SZrPP-n样品层间距增大,具有丰富的酸性位,热稳定性可以达到200℃以上.SZrPP-n对甲醛羰基化制乙醇酸甲酯反应具有较高的催化活性和稳定性.     

以1,6-己二胺为模板剂的层状磷酸锆晶体的合成与表征

 采用水热法合成了以1,6-己二胺(HDA)为模板剂的层状磷酸锆晶体0.5·1.5H2O,并用单晶及粉末XRD,IR和TG-DTA等对其结构和性质进行了表征. 该晶体是由磷酸锆无机层、有机胺以及水分子三部分构成的层状结构,层间距约为1.77 nm,无机层结构为γ-型. 位于有机胺两端的氮与无机层表面部分羟基的氧以氢键连接,水分子占据磷酸锆层间的两种位置. 单晶结构模拟得到的XRD谱与从粉末样品采集的XRD谱基本吻合. 此晶体在180 ℃下脱去水分子,在220 ℃下加热3 h其结构未发生明显变化; 有机胺模板剂在250 ℃下开始分解.     

Na2ZnSiO4的中温水热合成和离子导电性质研究

Ｎａ_２ＺｎＳｉＯ_４的中温水热合成和离子导电性质研究崔得良，傅戈妍，庞广生，徐秀廷，冯守华，徐如人（吉林大学无机水热合成开放研究实验室，长春，１３００２３）关键词水热合成，硅酸锌钠，离子导体在硅酸盐中，人们已得到了如特种玻璃［１］、微孔晶体［２］“及...     

氧化硅柱撑磺化磷酸-苯膦酸锆的合成及性能

以磷酸-苯膦酸锆为层板,合成并表征了硅柱撑的层柱磷酸-苯膦酸锆,并磺化了其中的苯环.磺化后的产物具有较高的酸量,在酯化反应中催化活性与硫酸相当.     

无定形（磷酸氢－二苯基次膦酸）锆－氯化铁复合物催化烷基化反应

制得无定形（磷酸氢－二苯基次膦酸）锆－氯化铁复合物Ｚｒ（ＨＰＯ＿４）＿（１．５）［Ｏ＿２Ｐ（Ｃ＿６Ｈ＿５）＿２］·［ＦｅＣｌ＿２（ＯＨ）］．该复合物不易吸潮，不冒烟，在空气中稳定，对卤代烷与芳香烃在液相的烷基化反应有较好的催化活性；反应条件温和，产物收率高，操作方便，后处理简单，并可多次重复使用。     

草酸/四丙基溴化铵体系中磷酸锆晶体的离子热合成与表征

采用离子热合成方法, 在草酸/四丙基溴化铵离子型低共熔混合物中对磷酸锆骨架材料的合成进行了系统地研究, 通过改变反应条件合成了2种不同的磷酸锆, α-Zr(HPO₄)₂•H₂O和 (NH₄)Zr₂(PO₄)₃. 体系中的四丙基季铵阳离子对磷酸锆骨架没有体现出模板作用, 后者是在较高的反应温度下(220 ℃)以四丙基季铵离子的热分解产物( )作为模板而生成. 通过向该体系中添加少量的氮杂环化合物(哌嗪), 合成了一种三维开放骨架的8-元环磷酸锆微孔材料, 位于孔道中的质子化哌嗪起到模板作用并平衡骨架负电荷. 研究结果表明, 草酸/四丙基溴化铵低共熔混合物可以作为一种离子热反应介质, 通过向体系中引入少量的有机碱可以起到模板作用来诱导磷酸锆骨架的生成.     

二茂锆杂环羧酸衍生物的合成

二茂锆杂环羧酸衍生物的合成陈宏明（北京医科大学药学院１０００８３）应卫，周耀坤（兰州大学化学系７３００００）１９６１年ＮａｔｉｏｎａｌＬｅａｄＣｏ．［１］首先以专利形式报导了一些二茂钛羧酸衍生物的合成，并发现这类化合物可作为烯烃的聚合催化剂。近几年又...     

新型层状结构磷钼酸盐的水热合成与表征

新型层状结构磷钼酸盐的水热合成与表征于龙，黄晓威（辽宁大学化学系，沈阳１１００３６）微孔晶体材料领域由于磷酸铝，磷酸镓，磷酸铍等新型微孔晶体的合成而得到极大的拓展。磷钼酸盐除可以形成具有经典结构（如Ｋｅｇｇｉｎ结构）的杂多酸型阴离子骨架外。近来又发现...     

二钼酸铵晶体饱和水溶液Raman光谱的变异现象及其机理

记录了常温下二钼酸铵晶体饱和水溶液的Raman光谱，并分别与二钼酸铵晶体、仲钼酸铵晶体、仲钼酸铵晶体饱和水溶液、水溶液状态下单钼酸根离子的Raman光谱进行了比较研究。结果表明：二钼酸铵晶体饱和水溶液Raman光谱相对二钼酸铵晶体Raman光谱，明显地发生了变异现象。二钼酸铵晶体饱和水溶液Raman光谱其主要特征峰最高振动频率937.6 cm^-1与仲钼酸铵晶体饱和水溶液Raman光谱主要特征峰最高振动频率937.6 cm^-1完全吻合，而其次高振动频率893.9 cm^-1，恰好介于水溶液中单钼酸根离子Raman光谱主要特征峰最高振动频率895.1 cm^-1与仲钼酸铵晶体饱和水溶液Raman光谱主要特征次高峰振动频率891.0 cm^-1之间，而且三者彼此接近。二钼酸铵晶体饱和水溶液Raman光谱主、次特征峰强度之比值为2.1，与仲钼酸铵晶体饱和水溶液Raman光谱主、次特征峰强度之比值4.4相比，一半不足。提出了一种利用Raman光谱主要特征峰振动频率及其主、次特征峰强度之比值对二钼酸铵晶体饱和水溶液组分同时进行定性和半定量分析的新方法。发现了常温下二钼酸铵晶体饱和水溶液中二钼酸根离子Mo₂O₇^2-已经不复存在，完全转变成了优势组分仲钼酸根离子Mo₇O₂₄^6-和次要组分单钼酸根离子MoO₄^2-；证明了常温下含钼水溶液酸化过程中溶液Raman光谱离散性变化现象的存在。运用结构化学和物理化学原理同时讨论了二钼酸铵晶体饱和水溶液Raman光谱发生变异现象的机理。     

Crystal growth, spectral, optical, and thermal characterization of glycyl-l-alanine hydrochloride (GLAH) single crystal

A new semi-organic nonlinear optical material glycyl-l-alanine hydrochloride (GLAH) was grown successfully by slow evaporation solution growth method. The solubility of GLAH was estimated for a wide range of temperatures. Large size single crystal of size 15?×?9?×?6?mm³ was grown at room temperature. The grown crystal was subjected to single crystal X-ray diffraction study which confirms that the grown crystal is monoclinic in nature with the space group P2₁. The molecular weight of the title compound was estimated by mass spectrometry. Functional groups and the modes of vibrations were identified by FT-IR spectral analysis. The UV?Cvisible spectral study reveals that the percentage of optical transmission of the sample is very high in the entire visible and UV regions. The second harmonic generation of the crystal was confirmed by the Kurtz and Perry technique. The hardness of the sample was tested by microhardness test which shows that the grown crystal belongs to the soft category of materials. The thermal stability of the compound was studied by TG?CDTA analyses which indicate that the crystal is thermally stable up to 248.6?°C.     

Physico-chemical characterization of an active pharmaceutical ingredient

The physico-chemical properties and polymorphism of a new active pharmaceutical ingredient entity has been analyzed and the gain of knowledge during the chemical development of the substance is described. Initial crystallization revealed an anhydrous crystal form with good crystallinity and a single, sharp DSC melting peak at 171°C and a straightforward development of this crystal form seemed possible. However, during polymorphism screening, new crystalline forms were detected that were often analyzed as mixtures of crystal forms. The process of characterization and identification of the different crystalline forms and its thermodynamical relationship has been supported by a combination of experimental and computational work including determination of the three-dimensional structures of the crystal forms. The crystal structure of one polymorphic form was solved by single crystal X-ray structure analysis. Unfortunately, Mod B resisted in formation of suitable single crystals, but its structure could be solved by high resolution powder diffraction data analysis using synchrotron radiation. Calculation of the theoretical X-ray powder diffraction pattern from three dimensional crystal coordinates allowed an unambiguous identification of the different crystalline forms. Two polymorphic crystal forms of the API-CG3, named Mod A and Mod B, are enantiotropic whereas Mod B is the most stable polymorph at room temperature up to about 50°C and Mod A at temperatures above 50°C. The mechanism of the solid-solid transition can be explained by analyzing the molecular packing information gained from the single crystal structures. A third crystalline form with the highest melting peak turned out to be not a polymorphic or pseudopolymorphic crystal modification of our API-CG3 but a chemically different substance. This revised version was published online in July 2006 with corrections to the Cover Date.     

Synthesis,growth and characterization of hydrogen bonding organic complex for SHG conversion: 3-hydroxyanilinium-2,5-dimethylbenzenesulphonate single crystal

The new hydrogen bonding single crystal of 3-hydroxyanilinium-2,5-dimethylbenzenesulphonate (3HADB) complex has been synthesized and grown by slow evaporation solution growth technique. The grown crystal was confirmed by single crystal X-ray diffraction, Fourier Transform Infrared (FT-IR) and proton Nuclear Magnetic Resonance (¹HNMR) spectral studies. Single crystal X-ray diffraction study shows that 3HADB crystallizes in the orthorhombic crystal system with noncentrosymmetric Pna2₁ space group. The title compound was characterized by UV–Vis–NIR absorption and TG/DTA thermal analysis studies. The second harmonic generation efficiency of powdered 3HADB was determined by Kurtz and Perry method.     

A new polymorphic form and crystal solvates of N-(3-methylthio-1,2,4-thiadiazol-5-yl-aminocarbonylmethyl)cytisine

By the single-crystal X-ray diffraction the structures of a new polymorphic form and crystal solvates of N-(3-methylthio-1,2,4-thiadiazol-5-yl-aminocarbonylmethyl)cytisine (C₁₆H₁₉N₅O₂S₂) with dioxane and pyridine have been determined. The crystal structures of solvates are isostructural to previously investigated benzene solvated crystal. Crystal solvates are formed at 2:1 ratio of “host” and solvents. Conformations of the host molecules found in the asymmetric unit of crystal solvates are different like it was observed in benzene solvated crystal. A new polymorphic form is obtained from ethyl acetate.     

Synthesis,characterisation and liquid crystal properties of 2,5‐bis[5‐alkyl(alkoxy)phenyl‐1,3,4‐oxadiazole]bromobenzenes

A series of new thermal bilateral liquid crystal compounds with the phenylenebis‐1,3,4‐oxadiazole structure was synthesised. The molecular structures of the oxadiazole compounds were confirmed by FT‐IR and ¹H NMR spectroscopy, elemental analysis and mass spectrometry. Thermogravimetric analysis indicates that the compounds in an atmosphere of nitrogen have good thermal stability. Measurements using differential scanning calorimetry, polarising optical microscopy and temperature‐dependent wide‐angle X‐ray diffraction indicated that the liquid crystalline properties are related to the length of the end groups. When the end group was tert‐butyl or alkoxy with four and six carbons, the compounds exhibit no liquid crystal phase. However, compounds with end groups containing more than eight carbons show significant bidirectional thermally‐induced liquid crystal properties and the structure of the liquid crystal phase is the lamellar smectic A phase. All the compounds exhibit blue fluorescence.     

Determination of the Crystal Structure of a New Polymorph of Theophylline

A new approach to crystal structure determination, combining crystal structure prediction and transmission electron microscopy, was used to identify a potential new crystal phase of the pharmaceutical compound theophylline. The crystal structure was determined despite the new polymorph occurring as a minor component in a mixture with Form II of theophylline, at a concentration below the limits of detection of analytical methods routinely used for pharmaceutical characterisation. Detection and characterisation of crystallites of this new form were achieved with transmission electron microscopy, exploiting the combination of high magnification imaging and electron diffraction measurements. A plausible crystal structure was identified by indexing experimental electron‐diffraction patterns from a single crystallite of the new polymorph against a reference set of putative crystal structures of theophylline generated by global lattice energy minimisation calculations.     

Tl2Te and its relationship with Tl5Te3

The crystal structure of Tl₂Te, dithallium telluride, has been determined by single‐crystal X‐ray diffraction. The analysis of the structure shows that this compound is the first known representative of a new crystal structure type. The structural relationship with the related Tl₅Te₃ phase is discussed.     

Palladium and the electrochemical quartz crystal microbalance: a new method for the in situ analysis of the precious metal in aqueous solutions

A new method for the quantitative determination of palladium(II) by the electrochemical quartz crystal microbalance (EQCM) technique has been developed. Using a bare carbon-coated quartz crystal, Pd(II) ions are directly deposited from aqueous solution as palladium metal onto the crystal surface, and the Pd(II) concentration is determined with a detection limit of 0.0156 mM, or 1.66 ppm. No complexing agent or preconcentration of palladium is required for the analysis. The palladium is stripped from the crystal through its electrochemical oxidation, regenerating the crystal for subsequent multi-cycle palladium analyses. A conventional gold-coated quartz crystal was incapable of carrying out the same measurements. The EQCM technique presented is simple, sensitive, and reproducible for the detection of this widely used precious metal.     

Preparation,Crystal Structure and Properties of a New Crystal Form of Diammonium 5,5′‐bistetrazole‐1,1′‐diolate

A new crystal form of diammonium 5,5′‐bistetrazole‐1,1′‐diolate ( 1 ) was prepared by two novel methods and fully characterized by using IR, NMR spectroscopy, elementary analysis, single crystal X‐ray crystallography and thermal gravity/differential thermal analysis (TG/DTA). Crystalline 1 was found as monoclinic and space group of P21/c (14). The TG/DTA analysis showed that the decomposition temperature of 1 was 287.8°C with a mass loss of 91.2% in the range of 220–300°C at a heating rate of 5°C/min. The sensitivities test towards impact, friction of 1 indicated that 1 has much lower sensitivities than those of RDX/HMX and is comparable to those of TNT, which suggested that 1 could be used as a good candidate of new insensitive energetic compound.