花生状碳酸钡粒子的制备与表征

本文以BaCl2·2H2O和Na2CO3为原料,采用共沉淀法合成了碳酸钡粒子.通过添加合适的晶形控制剂,选择合适的用量,合成了花生状的碳酸钡粒子,利用扫描电子显微镜(SEM)和X射线衍射仪(XRD)进行了表征,结果表明:当控制剂WHB-1用量在85;以上时,生成的花生状碳酸钡粒子为正交晶系,粒度分布均匀,在500nm左右,且粒子分散性良好,几乎没有团聚现象.并对花生状碳酸钡粒子的形成机理进行了初步的探讨.     

不同晶形超细碳酸钡粒子的制备研究

本文分别采用均相沉淀法和共沉淀法合成了碳酸钡粒子.通过添加合适的晶形控制剂,合成了线状、柱状和球状等不同晶形的碳酸钡粉体,利用扫描电子显微镜(SEM)和X射线衍射仪(XRD)进行了表征,并对不同晶形碳酸钡的形成机理进行了初步的探讨.     

乙二胺四乙酸对碳酸钡粒子形貌影响的研究

以硝酸钡和碳酸铵为原料,采用共沉淀法,通过添加和控制乙二胺四乙酸(EDTA)用量,制备出哑铃状、球状和圆柱状等不同形貌的碳酸钡粒子.采用TG/SDTA、SEM 、FT-IR和XRD等对产品进行分析与表征,结果表明:不同形貌碳酸钡粒子均属正交晶系,粒子分布均匀,粒度较小,形貌完整.同时对形貌控制机理进行了初步分析.     

EDTA对超临界二氧化碳法制备碳酸钡粒子形貌影响的研究

以氢氧化钡和二氧化碳气体为原料,采用超临界二氧化碳法,通过添加乙二胺四乙酸(EDTA)并控制其用量,制备出柱状、棒状、椭球状和球状等不同形貌的碳酸钡颗粒.采用TG/SDTA、SEM、XRD和FT-IR等对产品进行分析与表征,结果表明:不同形貌碳酸钡粒子均属于正交晶系.同时对EDTA形貌控制机理进行了初步分析.     

熔盐法制备针状莫来石晶体的研究

本文采用Al2(SO4)3·18H2O和SiO2为原料,以K2SO4,Na2SO4为熔盐,用熔盐法合成了针状莫来石晶体.研究了不同合成温度、熔盐用量和保温时间对合成莫来石晶体的影响,分析了熔盐法合成针状莫来石的反应机理.研究结果表明:以K2SO4为熔盐,熔盐与反应物总量质量比为1: 1,合成温度为1000 ℃,保温时间为3 h时可以合成针状莫来石晶体,针状莫来石的生成符合L-S液固生长机理.     

系列哑铃形BaCO3晶体的制备

以氯化钡、尿素、氢氧化钠和乙二胺四乙酸二钠(EDTA)为原料,通过络合与均相沉淀法成功合成一系列哑铃形碳酸钡晶体,并采用XRD、SEM、SAED和FT-IR对样品进行了表征.结果表明:添加EDTA对碳酸钡晶形有显著影响,随EDTA浓度变化,可得到一系列哑铃型碳酸钡晶体.反应时间和pH值对晶形也有一定影响.研究表明在EDTA浓度为0.025 mol/L,反应时间为5 min,水浴温度为95 ℃,pH=14条件下,制得的哑铃形碳酸钡粒子为亚微米级多晶,具有纯度高,分散性好,晶形完整均一的特点.     

柠檬酸钠作用下碳酸钙的制备

选取柠檬酸钠(Na3C6H5O7)为碳酸钙生长的控制剂,通过气体扩散的方法仿生合成了不同形貌的碳酸钙,并考察矿化时间对碳酸钙晶型和形貌的调控作用.采用扫描电子显微镜(SEM)、透射电子显微镜(TEM)、傅立叶变换红外光谱(FT-IR)以及X射线衍射(XRD)对所得产物进行了表征.结果表明,随着矿化时间的改变所得碳酸钙粒子的形貌发生了显著的变化,出现哑铃状、高尔夫球状、球状等形貌.     

聚合物与表面活性剂混合模板调控碳酸钙结晶

以聚乙烯醇(PVA)和聚苯乙烯磺酸钠(PSSS)分别与十六烷基三甲基溴化铵(CTAB)组成混合模板,在CaCl2、Na2CO3体系中调控合成CaCO3晶体.考察了不同CTAB浓度及结晶温度对碳酸钙晶体的影响.通过扫描电子显微镜(SEM)、红外光谱(FT-IR)及X射线衍射(XRD)等技术对晶体的形貌和结构进行了表征,并对不同形貌碳酸钙的形成机理进行了探讨.结果表明:在PVA和CTAB模板中,5℃为方解石椭球状聚集体,25℃时为菊花状、立方状的方解石和球霰石的混晶,90℃时得到针状文石晶簇.以PSSS和CTAB模板调控下的碳酸钙,5℃时为球状的方解石和球霰石的混晶,25℃为颗粒均匀的球形球霰石,90℃时得到了花朵状文石.不同形貌及晶型碳酸钙的生成源自聚合物与CTAB组成复合物结构的差异.     

Ti,Fe离子掺杂对水热法合成蓝宝石晶体的影响

本文研究了掺杂Fe、Ti离子对水热条件下合成α-Al2O3晶体的颜色和晶体形态的影响.在较低温度(430℃)和较低压力(40MPa)下合成出了蓝色刚玉晶体.在未掺入其他的离子时,水热反应生成透明α-Al2O3六棱柱形晶体.当在反应介质中加入FeSO4*7H2O时,水热反应生成黑色α-Al2O3晶体,晶体呈六棱柱体.加入FeSO4*7H2O和TiCl3时,生成的蓝色宝石晶体显露高指数晶面,晶体长度300μm,另外还生成大量的薄水铝石晶片.加入FeSO4*7H2O和TiCl4时,蓝宝石晶体显露底面{0001},柱面{1120},和菱面{1123},最大的孪晶长度为200μm,最小的晶粒只有2μm;同样有大量的薄水铝石晶片生成,还伴生有少量针状TiO2金红石晶体.     

一维Sm2O3纳米晶的可控合成及其光学性能研究

以有机碱二乙烯三胺(EDTA)为碱源,Sm(NO3)3·6H2O为钐源,在不同模板剂辅助条件下采用水热-热处理相结合的方法进行Sm2O3纳米晶的可控合成.利用X-射线衍射仪(XRD)、扫描电子显微镜(SEM)和Lambda 950分光光度计分别对产物的物相、形貌和光学性能进行表征,并研究了未添加模板剂和分别以六亚甲基四胺(HMTA)、聚乙烯吡咯烷酮(PVP)和十六烷基三甲基溴化铵(CTAB)为模板剂条件下对产物的物相、形貌及光学性能的影响.结果表明:以HMTA为模板剂条件下得到了长条状结构的Sm2O3纳米晶,未添加模板剂和分别以PVP和CTAB为模板剂条件下得到了尺寸可控的棒状结构的Sm2O3纳米晶.不同模板剂会影响产物的微观结构及尺寸,进而对其光学性能产生有较大的影响,其中以HMTA为模板剂时所得长条状结构的Sm2O3纳米晶的禁带宽度较小为4.775 eV.     

Triethyl ammonium salt of O,O′-bis(p-tolyl)dithiophosphate, [Et3NH]+[(4-MeC6H4O)2PS2]−

Triethyl ammonium Salt of O,O′-bis(p-tolyl)dithiophosphate and O,O′-bis(m-tolyl)dithiophosphate have been obtained by reaction of p- and m-cresol, respectively with P₂S₅ in toluene and have been characterized by elemental analysis, IR, ¹H and ³¹P NMR spectroscopy. The molecular structure of O,O′-bis(p-tolyl)dithiophosphate has been determined. Crystal data: [Et₃NH]⁺[(4-MeC₆H₄O)₂PS₂]⁻: Monoclinic, P2₁/c, a=15.2441(9) ?, b=10.415(2) ?, c=3.9726(9) ?, β=91.709(7)°, V=2217.5(1) ?⁻³, Z=4.Supplementary materials Additional material available from the Cambridge Crystallographic Data Centre (CCDC no. 600927 for [Et₃NH]⁺[(4-MeC₆H₄O)₂PS₂]⁻ comprises the final atomic coordinates for all atoms, thermal parameters, and a complete listing of bond distances and angles. Copies of this information may be obtained free of charge on application to The Director, 12 Union Road, Cambridge CB2 2EZ, UK (fax: +44-1223-336033; email: deposit@ccdc.cam.ac.uk or www:http://www.ccdc.cam.ac.uk).     

Crystal structure of Zn4Na(OH)6SO4Cl·6H2O

The structure of Zn₄Na(OH)₆SO₄Cl·6H₂O, a secondary mineral from Hettstedt, Germany, was determined by single-crystal X-ray diffraction. The crystals are hexagonal,a=8.413(8),c=13.095(24) Å, space group $P\bar 3$ , Z=2. The structure was refined to R=0.0554 and R_w=0.0903 for 970 reflections with I≥3σ(I). The structure can be described as zinc hydroxide layers perpendicular toc, from which sulfates and chlorides extend. The layers are held together by a system of hydrogen bonds involving hexaaquo Na⁺ ions which occupy the interlayer space.     

Synthesis and Crystal Structure of 5-[2-(6-bromonaphthalenyloxymethyl)]-3-(4-morpholinomethyl)-1,3,4-oxadiazole-2(3<Emphasis Type="Italic">H</Emphasis>)-thione

Abstract  The title compound, C₁₈H₁₈BrN₃O₃S, a derivative of 1,3,4-oxadiazole, crystallizes in the triclinic space group P-1 with unit cell parameters a = 6.8731(3), b = 8.9994(4), c = 15.7099(6) ?, α = 92.779(3)°, β = 130.575(3)°, γ = 107.868(4)°, Z = 2. The dihedral angle between the mean planes of the planar naphthyl and morpholine (chair) rings with the planar oxadiazol ring is 50.1(8) and 76.8(6)°, respectively. The planar naphthyl ring is twisted 52.2(5)° with the mean plane of the morpholine ring. A group of four intermolecular close contacts are observed between a bromine atom and hydrogen atoms from the closely packed naphthyl, morpholine and oxy–methyl groups in the unit cell. These molecular interactions in concert with an additional series of π–π stacking interactions that occur between the center of gravity of the two 6-membered rings of the naphthalene group influence the twist angles of each of these three groups. A MOPAC AM1 calculation of the conformation energy of the crystal structure [226.0128(9) kcal] compared to that of the minimum energy structure after geometry optimization [29.9744(1) kcal] reveals a significantly reduced value. The twist angles of the three groups above also change after the AM1 calculation giving support to the influence of both intermolecular C–H···Br short-range interactions and Cg π–π stacking interactions on these angles which therefore play a role in stabilizing crystal packing. Graphical Abstract  Crystal structure of 5-{[(6-bromonaphthalen-2-yl)oxy]methyl}-3-(morpholin-4-ylmethyl)-1,3,4-oxadiazole-2(3H)-thione, C₁₈H₁₈BrN₃O₃S, is reported and its geometric and packing parameters described and compared to a MOPAC computational calculation. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Crystal structure of irisolidone from the flowers of Pueraia lobata

Irisolidone (5,7-dihydroxy-6,4′-dimethoxyisoflavone) was isolated from the flowers of Pueraia lobata and its crystal structure was examined by X-ray single crystal diffraction. The crystal structure of irisolidone is monoclinic, space group P2₁/c with a = 15.491(9) ?, b = 7.895(4) ?, c = 13.321(7) ?, β = 110.546(9)° and Z = 4. Hydrogen bonding and aromatic π–π stacking assemble the title compound into a three-dimensional networking structure.     

Synthesis of spinacine and spinacine derivatives: crystal and molecular structures of Nπ-hydroxymethyl spinacine and Nα-methyl spinaceamine

The natural amino acid L-Spinacine (4,5,6,7-tetrahydro-1H-imidazo[4,5-c]pyridine-6-carboxylic acid) has been synthesized following a new pathway which gives a chemically and optically pure product with an excellent yield. The crystal structures of a synthetic intermediate, N^π-hydroxymethyl-spinacine, and a spinacine derivative, N^α-methyl-spinaceamine, have been investigated through X-ray diffraction: Spi(πMeOH)·H₂O, monoclinicP2 _i,a=8.571(1),b=6.682(1),c=8.588(1) Å, and β=94.67(1)^o. Spm(αMe)·2HCl·H₂O, triclinicP l,a=7.492(4),b=10.799(3),c=7.040(2) Å, α=91.88(2), β=98.36(3) and γ=73.34(3)^o. Spi(πMeOH) crystallizes with a water molecule and displays a zwitterionic character. The carboxylate group is in equatorial position and forms a short electrostatic interaction of 2.618(2) Å between one of its oxygens and the protonated nitrogen of the tetrahydropyridine ring. The crystal packing is assured by strong O?H???O, O?H???N, N?H???N intermolecular hydrogen bonds and C?H???O close contacts. The biprotonated compounds Spm(αMe) crystallizes with two Cl^? anions and a water molecule. The positive charge on the imidazole ring is delocalized on the conjugated moiety N=C?N. The crystal is built up by clusters formed by two biprotonated Spm(αMe) molecules, four Cl^? anions and two water molecules linked together by hydrogen bonds.     

X-ray Crystal Structures of [Et3NH][{(CO)5Mo(P(OCH2CMe2CH2O)O)}2H] and (CO)5Mo{μ-Ph2POPPh2}Mo(CO)5, Two Complexes Derived from the Hydrolysis of Coordinated Chloro-Phosphorous-Donor Ligands

Abstract X-ray crystal structures of [Et₃NH][{(CO)₅Mo(P(OCH₂CMe₂CH₂O)O)}₂H], 3, and (CO)₅Mo{μ-Ph₂POPPh₂}Mo(CO)₅, 2, are reported. Crystallization of 3 occurs in P-1 space group with a = 9.6944(19) ?, b = 10.814(2) ?, c = 19.730(4) ?, α = 94.24(3)°, β = 92.23(3)°, γ = 113.47(3)°, Z = 4. Crystallization of 2 occurs in C2/c space group with a = 10.357(2) ?, b = 20.149(4) ?, c = 17.155(3) ?, α = 90°, β = 97.28(3)°, γ = 90°, Z = 8. Compound 2 is a bimetallic complex with a P–O–P bridging group containing bond distances similar to that of other complexes in which two metal centers are bridged by a single R₂POPR₂ ligand. Compound 3 contains intermolecular hydrogen bonded P–O–H–O–P linkages with bond distances comparable to those seen in similar structures with intramolecular hydrogen bonding suggesting that the distance is a function of the nature of the bond and not affected by the cis arrangement of the ligands about the metal center. Graphical abstract X-ray Crystal Structures of [Et ₃ NH][{(CO) ₅ Mo(P(OCH ₂ CMe ₂ CH ₂ O) O)} ₂ H] and (CO) ₅ Mo{μ-Ph ₂ POPPh ₂ }Mo(CO) ₅ , Two Complexes Derived from the Hydrolysis of Coordinated Chloro-Phosphorous-Donor Ligands Samuel B. Owens Jr., Abha A. Kaisare and Gary M. Gray X-ray crystal structures of [Et₃NH][{(CO)₅Mo(P(OCH₂CMe₂CH₂O)O)}₂H], 3, and (CO)₅Mo{μ-Ph₂POPPh₂}Mo(CO)₅, 2, have been determined.      

Preparation,spectral studies and X-ray crystal structure of 1,3,5-triphenyl-1,5-pentanedione,C23H20O2

1,3,5-triphenyl-1,5-pentanedione, C₂₃H₂₀O₂, has been prepared and characterized by spectroscopic methods and single crystal X-ray analysis. Crystals are monoclinic, space groupP2₁/n, a=28.124(4),b=5.997(1),c=10.434(1)Å, -98.42(1)Å,Z=4. The structure has been refined to a finalR-value of 0.040 for 1625 reflections withF _o>3(F _o). The compound contains the two carbonyl groups in a mutuallycis arrangement.     

Isotope Effects in Liquid Crystal Systems: I: Phase Relationships in the Dodecylamine-H2O,Dodecylamine-D2O Systems

The phase diagrams and heats of fusion and transition have been determined for the dodecyl amine (-NH₂)/H₂O and dodecyl amine (-ND₂)/D₂O systems using direct optical observation and differential scanning calorimetry.     

Spherulitic crystallization of β‐In2Te3 by physical vapour deposition

Different morphologies of indium telluride (In₂Te₃) including novel spherulites were crystallized using the physical vapour deposition (PVD) method, by varying the difference in the growth and source zone temperature (ΔT) of a dual zone horizontal furnace assembled indigenously. Whiskers and kinked needles of In₂Te₃were grown at ΔT = 250 K and 300 K respectively, maintaining the growth zone at 500 °C. At high supersaturation (Δ T = 400 K), spherulitic crystals were obtained. The stoichiometric composition of these crystals has been confirmed using energy dispersive analysis by x‐rays (EDAX). The structure of β‐In₂Te₃ spherulitic crystals is identified as zinc blende with lattice parameter a = 6.159 Å, from x‐ray diffraction (XRD) studies. The scanning electron microscope (SEM) images revealed the radial structure of the grown spherulites. The growth mechanism for the spherulitic crystallization of β‐In₂Te₃ crystals has been discussed based on the theoretical models. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)