Synthesis and Study of Aluminum Hexamolybdenocobaltate(III) and Hexamolybdenochromate(III)

Aluminum hexamolybdenocobaltate and hexamolybdenochromate of the Al[MMo₆O₁₈(OH)₆] · 16H₂O composition, where M = Co(III) or Cr(III), were synthesized for the first time. X-ray diffraction study shows that the crystals of the compounds are triclinic; space group P1, Z = 1, and _calcd = 2.665 and 2.611 g/cm³, respectively. The compounds were studied by IR spectroscopy and thermogravimetry.     

X-Ray Diffraction Study of Aluminum Monoxycarbide

The structural characteristics of aluminum monoxycarbide Al₂OC are refined and systematized. Based on our X-ray diffraction data, three modifications of Al₂OC: -Al₂OC, '-Al₂OC, and '-Al₂OC have been revealed. Structural models are suggested for them.     

面粉中滑石粉的X射线衍射分析

通过四氯化碳分离或高温灰化,X射线衍射分析测定面粉中掺入的滑石粉。其中灰化处理适宜温度为500~750℃。该方法简便、快速,灵敏度高,样品用量少,准确可靠,可推广为检测面粉质量的一种较理想的手段。     

Thermal Analysis and X-Ray Diffraction of Roasting of Egyptian Molybdenite

Molybdenite is the main ore mineral for the molybdenum industry and the production of molybdenum. The industrial processing of molybdenite is based on its oxidized roasting to technical grade molybdenum oxide, followed by its purification by distillation or its ammonia leaching.The present work reports a thermal analysis study of the oxidized roasting of Egyptian molybdenite, using a derivatograph. The reaction products were identified microscopically and by using a Siemens Crystalloflex diffractometer.The DTA curves of the roasting of molybdenite show that its oxidation begins at 360–370°C, as indicated by the small exothermic peak at such temperatures. This is followed immediately by a large, wide exothermic peak with maximum at 510–520°C, representing the intensive oxidation of molybdenite. The medium endothermic peak at 795–800°C reflects the melting and sublimation of molybdenum oxide. The vigourous vaporization of molybdenum oxide and its boiling are associated with the large, sharp endothermic peak at 1150°C. This is accompanied by a large loss in mass (TG).The study includes calculation of the thermodynamic constants and the kinetics of the reaction of oxidation of molybdenite.The oxidized roasting of molybdenite results in the production of molybdenum oxide, which is the essential starting material of the molybdenum industry. The molybdenum oxide produced has the molybdite structure and crystallizes in the orthorhombic system in the form of elongated, thin, light-green crystals.This revised version was published online in November 2005 with corrections to the Cover Date.     

Chloromethylthio-Substituted Chromium(III), Cobalt(III), and Aluminum(III) Acetylacetonates

SCl-Substituted chromium(III), cobalt(III), and aluminum(III) acetylacetonates react with carbenes similarly to organylsulfenyl chlorides, with insertion of the carbenes into the S-Cl bond. Reaction with diazomethane gave chloromethylthio-substituted complexes whose structure was proved by IR, ¹H NMR, and mass spectroscopy. The thermal oxidative degradation of the complexes was studied. Chlorination of SCH₃-substituted acetylacetonates does not yield such complexes.     

X-Ray Diffraction Analysis and Luminescent Study of the Structure of the Tb2(CF3COO)6(H2O)6 Dimer Obtained from Terbium(III) Carbonate

The molecular and crystal structure of the terbium(III) trifluoroacetate trihydrate dimer synthesized from terbium(III) carbonate was studied by X-ray diffraction (XRD) analysis. Luminescent data unambiguously show that the compound is one of the isomers of Tb₂(CF₃COO)₆(H₂O)₆ composition. Evidence has been found for the presence of another isomer in the terbium(III) dimer obtained from terbium(III) hydroxide.     

X射线衍射分析的微量粉末制样法

在X射线衍射法中,一般制备粉末样品比较简单。但对微量样品,如还需经过研磨和制样等操作手续,会使样品进一步损失,这就给制样带来了困难。为了达到以最少粉末获得足够衍射强度的要求,为此,对微量粉末的制样法进行了试验,并取得了良好的效果。     

Aluminum(III), gallium(III), and indium(III) 4-hydroxyacridinato complexes

4-Hydroxyacridine (HAcr) is an O,N-chelating ligand whose coordination chemistry toward group 13 M(III) ions has received little attention. The molecular structure of HAcr consists of a 2,3-disubstituted-8-hydroxyquinoline; thus, in order to compare 8-hydroxyquinoline (HQ), 2-methyl-8-hydroxyquinoline (HMeQ′), and 2,3-disubstituted-8-hydroxyquinoline (HAcr) for steric and/or electronic influence, HAcr chelating ability toward the Al(III), Ga(III), and In(III) triad has been investigated. Irrespective of the nature of M(III), only complexes containing two equivalents of deprotonated HAcr are obtained. This article describes the synthesis and characterization of different series of bis-chelated pentacoordinated (Acr)₂MY (M = Al, Ga, In; Y = Cl, Br, I, NCS, N₃) or (Acr)₂MZ (M = Ga or In; HZ = C₆H₅OH, C₆H₁₃OC₆H₄OH, C₆H₅COOH, or C₆H₁₃OC₆H₄COOH) six-coordinate neutral (Acr)₂In(acac) (H(acac) =acetylacetone), or ionic [(Acr)₂In(N,N)][CF₃SO₃] (N,N = 2,2′-bipyridine or 1,10-phenanthroline) complexes. These results significantly contribute to elucidating the complexation capability of HAcr.     

Interactions of Aluminum(III) with Phosphates

In order to obtain information about aluminum(III)-phosphate interactions, potentiometric measurements were carried out to characterize the complex forming properties of Al(III) with organic phosphates, phosphonates, and nucleoside-5'-monophosphates. The aluminum(III)-orthophosphate system is difficult to study due to AlPO(4) precipitation. To overcome this problem, the stability constant logarithms of the 1:1 Al(III) complexes of ligands with the same donor groups (log K(1:1)) were plotted against the basicities of the ligands (log K(PO)3(H)). The resulting linear free energy relation (LFER) indicates that organic phosphates, phosphonates, and uridine-, thymidine-, and guanosine 5'-monophosphates similarly bind Al(III). Adenosine and cytidine 5'-monophosphate fall above the LFER owing to the presence of a second microform with the nucleic base protonated and a hydroxide bound to the Al(III). From the LFER the log stability constant for Al(III) binding to HPO(4)(2-) is estimated as 6.13 +/- 0.05. From the weakness of any soluble orthophosphate complexes of Al(III) we confirm the importance of citrate as the main small molecule Al(3+) binder in the blood serum. The study includes investigation of Al(III) binding to di- and triphosphates, which bind metal ion differently than monophosphates. Structures of the complexes were supported by (31)P NMR measurements.     

Synthesis, Characterization, and X-Ray Diffraction Analysis of Triethylenetetraammonium Tetrathiomolybdate

The reaction of gaseous H₂S with aqueous ammonium heptamolybdate in the presence of triethylenetetramine (trien) gave a red complex. The complex was recrystallized in hot water and characterized by element analysis and UV, visible, IR, and ¹H NMR spectroscopy. PMR has revealed accidental magnetic equivalence, resulting from the proximity of [MoS₄]^2- species in one complex molecule to the open triethylenetetramine ligand of another molecule. (TrienH₂)[MoS₄] crystallizes in the orthorhombic crystal system, space group Pca2₁, a=13.045(2), b=16.461(3), c=13.754(2) , =90, =90, =90°, V=2953.5(9) ³, Z=8, R₁=0.0323, wR₂=0.0730. The structure consists of the tetrahedral tetrathiomolybdate anions, forming an extended 3D framework in solids due to the interactions with triene cations via Mo-S...H-N hydrogen bonds.     

中国茜草与欧茜草的X射线粉末衍射分析

对植物中国茜草（ＲｕｂｉａｃｏｒｄｉｆｏｌｉａＬ．）和欧茜草（Ｒ．ｔｉｎｃｔｏｒｕｍ）首次采用Ｘ射线粉末衍射分析方法进行了鉴定研究,获得令人满意的结果。该法快速、准确、重现性好,样品前处理简单易行     

DSC And X-Ray Diffraction Coupling

A new technique, that allows simultaneous time-resolved synchrotron X-ray diffraction as a function of temperature (XRDT) and high sensitivity DSC to be carried out in the same apparatus, has been developed. Microcalorimetry and XRDT scans can be performed at any rate between 0.01 and 10°C min^?1 with a 0.01°C temperature resolution in the temperature range, 30–130°C and at lower cooling rates but the same heating rates in the ?30–+30°C range. The use of a single and very small sample (1 to 20 μl) contained in a thin glass capillary for both measurements and simultaneous data collection prevents any temperature shift between recordings and any possible difference in the thermal histories of the samples.     

Synthesis and X-Ray Diffraction Study of 2-(2-Acyl-1-phenylethenyl)pyrroles

Pyrroles add to 2-acyl-1-phenylacetylenes on the surface of silicon dioxide at 20-90°C affording structurally stable Z-isomers of 2-(2-acyl-1-phenylethenyl)pyrroles containing a strong intramolecular hydrogen bond. The geometry of these molecules was established by X-ray diffraction analysis of a single crystal of 2-(2-benzoyl-1-phenylethenyl)-4,5,6,7-tetrahydroindole.     

中草药板蓝根粉末的X射线衍射傅立叶指纹图谱分析

对来自不同地区的板蓝根粉末样品用X射线衍射傅立叶(Fourier)指纹图谱技术进行鉴定.由于不同产地的板蓝根样品的指纹图谱不同,因此,采用这一技术可对板蓝根样品作出区别和鉴定.试验结果表明该方法尚可应用于其他中药的鉴别.     

X-Ray Diffraction and Raman Spectroscopic Study of Bis-(Pyridine Base) Complexes of Cadmium(II) Halogenides

Summary.  The molecular structures of bis-(pyridine base) complexes of cadmium(II) chloride and bromide, where the pyridine base is pyridine ( py), 3-methylpyridine (3-Me-py), 4-methylpyridine (4-Me-py), and 4-ethylpyridine (4-Et-py), were investigated by means of single-crystal X-ray diffraction and Raman spectroscopy. The crystal structures of CdCl₂ py ₂ (1), CdCl₂(3-Me-py)₂ (2), and CdCl₂(4-Me-py)₂ (3) were determined. All crystals are monoclinic; 1: a = 17.784(2), b = 8.666(1), c = 3.8252(7) ?, β = 91.54(1)°, space group: P2₁/n; 2: a = 11.89(1), b = 14.41(1), c = 3.874(6) ?, β = 92.3(1)°, space group: P2₁/a; 3: a = 21.091(2), b = 3.8884(5), c = 18.2317(3) ?, β = 113.64(1)°, space group: C2/c. The structures were refined to R/R _w values (%) of 3.2/5.5, 3.0/5.0, and 3.4/5.1 for 1–3. All cadmium atoms are octahedrally coordinated with the chloride ions forming infinite di-μ-chloro polymeric linear chains and the nitrogen atoms of the pyridine base in trans configuration. The Cd chains are oriented along the c-axis in 1 and 2 and along the b-axis in 3. The crystal structures indicate the absence of a peculiar interaction between the polymeric chains. The Raman spectra of eight complexes were measured in the range of 550–50 cm⁻¹, and the Raman peaks originating from cadmium-halogen vibrations were assigned. The Raman spectra of 1 and 2 are quite alike in the lattice mode vibration region. The resemblance of the cadmium-halogen vibration peaks indicates the same halogenide ion bridged octahedral structure for all complexes. Received March 27, 2001. Accepted (revised) June 19, 2001     

用热重分析与X-射线衍射法探究中国花鲈耳石的微结构

为表征中国花鲈耳石的微结构,应用数码照相机、热重分析仪与X-射线衍射仪对中国花鲈耳石的外观形貌、化学组成与晶体结构进行记录及表征。结果显示:中国花鲈耳石为较厚的宽叶形,表面有不同大小的晶状突,边缘有叶形晶状突,内弯面有中央突,弯曲背面有嵴突及几乎贯穿整个耳石的主凹槽;TGA曲线分为晶体间隙水的挥发,有机质和无机盐的灰化与分解,碳酸钙热分解为氧化钙等三个平台,化学组成中碳酸钙含量为97.92%,水、有机质和其它无机盐含量为2.08%;XRD晶体结构属于稳定性较差的含很少量第二相的霰石。组成与结构的表征有助于鱼类耳石的化学生物学分类数据库的建立,也丰富了耳石的研究内涵。