Conformational Studies of Substituted Chromans: Crystal Structures of 2,2′-(1E,1′E)-(2,3-Dimethylchroman-2,4-diyl)bis(Azan-1-yl-1-ylidene)bis(Methan-1-yl-1-ylidene)Diphenol (I) and 2,2′-(1E,1′E)-(2-Ethyl-3-Methylchroman-2,4-diyl)bis(Azan-1-yl-1-ylidene)bis(Methan-1-yl-1-ylidene)Diphenol (II)

Abstract  

The title compounds C₂₅H₂₄N₂O₃ (I) and C₂₆H₂₆N₂O₃ (II) crystallize in the triclinic space group P-1 with cell parameters a = 8.981(1), b = 9.933(1), c = 12.369(2) ?, α = 78.537(2), β = 84.515(2), γ = 73.561(2)° Z = 2 (I) and a = 11.4630(9), b = 12.955(1), c = 16.154(1) ?, α = 70.425(1), β = 87.403(1), γ = 71.850(1)°, Z = 4 (II). In both compounds the phenolic groups in the Schiff base substituents form intramolecular hydrogen bonds with the imine nitrogen atoms thereby rendering these substituents nearly planar. A detailed analysis of the amount by which the heterocyclic ring deviates from planarity (extent of puckering) in these and a series of related molecules shows that the extent of the deviation is largely unaffected by the number, size and placement of substituents on this ring.     

Preparation and crystal structure of spiro(5,7-dimethoxy-1(1H)oxo-2-benzopyran-3(4H),1′-cyclohexane)

Spiro(5,7-dimethoxy-1(1H)oxo-2-benzopyran-3(4H),1-cyclohexane) (C₁₆H₂₀O₄) was prepared by alkylation of o-lithio 3,5-dimethoxy-N-methyl benzamide with methylene cyclohexane oxide followed by alkaline hydrolysis and its crystal structure was determined by X-ray crystallographic techniques. The compound crystallizes into monoclinic space group P2₁/c with unit cell parameters: a = 11.914(3) Å, b = 9.861(3) Å, c = 12.508(7) Å, = 91.34(3), Z = 4. The structure has been solved by direct methods and refined to R = 0.039 for 1870 observed reflections. The heterocyclic ring adopts distorted sofa conformation while cyclohexane ring assumes a highly symmetric chair conformation. The dihedral angle between the mean planes of isocoumarin nucleus and cyclohexane ring is 105.51(5). Molecules are held together in the crystal by C=H ... O hydrogen bonds.     

X-ray and NMR structural investigations of (±) (u) N-(1-phenylethyl)-1-t-butylsulfinyl-1-propenyl-2-amine,C15H23NOS

The structure of the title compound has been investigated in the solid state and in solution by X-ray and NMR-NOE methods, respectively. The crystals are monoclinic:P2₁/c,a=9.828(1),b=12.326(2),c=13.976(2) Å,=107.36(1)°. The structure was solved by direct methods, and refined against 2495 unique reflections by a full-matrix, least-squares procedure givingR=0.046. In the solid state the compound exists as theE isomer with unlike relative configurations on asymmetric atoms. In solution the compound is found as a mixture of a single enamine and two imine forms. The MM calculations suggest that of the two possible geometrical isomers of both diastereoisomersu andl of the enamine, theZ forms should be of lower energy. The total recognition of the homonuclear¹H NMR-NOE data interpreted in terms of their distance dependence in the two geometrical forms also favors theZ isomer in both diastereomers.     

Crystal and molecular structures of (±)cadinene dihydrochloride (1) and (−)cadinene dihydrochloride (2)

Two compounds, racemic (±)cadinene dihydrochloride C₁₅H₂₆C1₂ (1) and (–)cadinene dihydrochloride C₁₅H₂₆Cl₂ (2), prepared by treating germacrene D fromSolidago canadensis L, and sesquiterpene fraction of essential oil fromPinus silvestris L, respectively, with gas HCl were investigated. Compound (1) crystallizes in monoclinic system, but (2) in orthorhombic (Table 1). The structures were found by direct methods and were refined with full matrix least-squares techniques to R value of 0.039 and 0.044, respectively, for (1) and (2).     

(1-x)Ba_(0.998)La_(0.002)TiO_3+xBi_4Ti_3O_(12)陶瓷电性能的研究

采用固相法制备了(1-x)Ba0.998La0.002TiO3+xBi4Ti3O12(0≤x≤0.03)陶瓷,研究了Bi4Ti3O12掺杂量以及烧结气氛对Ba0.998La0.002TiO3陶瓷显微结构、居里温度Tc及介电性能的影响。结果表明:Bi4Ti3O12在Ba0.998La0.002TiO3陶瓷中的掺杂抑制了陶瓷晶粒的生长,使居里温度提高到约150℃。在空气中烧结的陶瓷的介电常数随Bi4Ti3O12掺杂量的增加先减小后增大,当Bi4Ti3O12掺杂量为1.5 mol%时,陶瓷的介电常数最小(还原再氧化陶瓷的介电常数为6.0×103,空气中烧成的陶瓷的介电常数为9.0×102)。     

Growth and characterization of lead-free Ba(1−x)CaxTi(1−y)ZryO3 single crystal

A lead-free Ba_(1?x)Ca_xTi_(1?y)Zr_yO₃ (BCZT) single crystal (x=0.08, y=0.26) was grown by the Czochralski (CZ) method in a mixed flux of TiO₂ and ZrO₂. The composition of as-grown BCZT was analyzed by electron probe micro-analysis. The structure, dielectric properties and phase transition were investigated at different temperatures. The X-ray diffraction results confirmed that the structure of the as-grown BCZT crystal was cubic both at 25 °C and 500 °C. The temperature dependence of the dielectric constant and Raman spectra characterization revealed that there was a phase transition from cubic to tetragonal, which happened between 200 K and 250 K. With increasing frequency, the Curie temperature shifted towards high temperature.     

Pb(Zn,Nb)O3-(Pb(Zn,Ti)O3)1-x(LaySr1-y MnO3)x 固溶体系磁电特性研究

采用常规陶瓷制备工艺制备了xLaySr(1-y)MnO3+(1-x) [0.2PbZn0.5Yb0.5O3-0.8Pb0.33Zr0.67TiO3](x=0.025、0.05、0.075、0.1、0.15、0.2,y=0.7、0.9)三元体系陶瓷,系统研究了不同成分LSMO掺杂对FZN-PZT磁学及电学性能影响.结果表明,掺入不同比例的LSMO均溶解入PZN-FZT晶格,导致PZN-PZT峰位偏移;随着LSMO掺杂量的提高,陶瓷的矫顽场E及剩余极化强度Pr降低;原本分别呈现铁磁性和反铁磁性的LyS(1-y) MO3(y=0.7、0.9)磁性消失;随着LMSO掺杂量的提高,晶粒尺寸变大.     

Sb2(S1-x Sex)3(0≤x≤1)薄膜太阳能电池的研究进展

Sb2(S1-xSex)3(0≤x≤1)化合物是重要的半导体材料,主要包括Sb2Se3、Sb2Se3及Sb2(S,Se)3三种材料,元素储量丰富且环境友好、组分简单、价格低廉,同时其禁带宽度合适(1.1～1.8 eV),吸光系数大(＞105 cm-1),非常适合用作新型低成本低毒的薄膜太阳能电池的吸收层,有可能成为下一个研究热点.本文综述了近几年来Sb2Se3、Sb2Se3及Sb2(S,Se)3薄膜太阳能电池的研究进展,并对其发展趋势进行了展望.     

Structure of sodium bis(pentadecatungstodiphosphato)diaquatetrazincate hydrate (16∶1∶50)

Crystals of Na₁₆[Zn₄(H₂O)₂(-P₂W₁₅O₅₆)₂]·50H₂O are triclinic, , witha+14.670(5),b+14.661(5),c+19.817(3)Å, =84.95(3), =81.51(3), =65.73(3)^o. Least-squares refinement converged atR+0.053 for 5906 independent data withl>3(I). The centrosymmetric anion consists of two -P₂W₁₅O ₅₆ ^12– ligands attached to a planar group of four Zn²⁺, two of which also carry water molecules. The distortions in the ZnO₆ octahedra and in the W₁₅ framework of the ligands are smaller than the corresponding distortions in the otherwise similar [Cu₄(H₂O)₂(P₂W₁₅O₅₆)₂]^16– anion.     

Molecular structure of N-(2-phenylethyl)amide of α-(1,1-ethylenedioxy)-ethyl γ-hydroxybutyric acid (I) and1H NMR spectra of (I) and N-(p-methoxybenzyl)derivative (III)

The spectroscopic and X-ray investigation of the N-(2-phenylethyl) amide of -(1,1-ethylenedioxy)-ethyl--hydroxybutyric acid are reported. The¹H NMR spectra for the title structure and for the N-(p-methoxybenzyl) amide of -(1,1-ethylenedioxy)-ethyl--hydroxybutyric acid are given. The N-(2-phenylethyl)amide of -(1,1-ethylenedioxy)-ethyl--hydroxybutyric acid, C₁₆H₂₃O₄N, crustallizes in the monoclinic space groupP2 ₁/c witha=21.547(5),b=6.333(2),c=11.822(3) Å and =101.01(2)°. The dioxolane ring has a half-chair conformation with C₂(O3)=2.4° and ||_av=18.2°. The inconsiderable deviations from planarity of the six atoms of the amide group are caused mainly by twist around the C4–N1 bond and out-of-plane bending at the N1 atom ((C4–N1)=4°, X_N =7°, X_c =0.4° ). The amide group plane is nearly coplanar with the phenyl ring. The molecules are connected by two intermolecular hydrogen bonds.     

Sr_xLa_(1-x)MgAl_(11)O_(19-0.5x)热障涂层材料的固相合成

利用固相法在1600℃左右制备出LaMgAl11O19和Sr0.5La0.5MgAl11O18.75片体,研究SrxLa1-xMgAl11O19-0.5x的合成反应过程,掺杂元素Sr对合成过程以及材料微观结构的影响。用X射线衍射仪(XRD)及场发射扫描电镜(SEM)表征材料的相结构和微观形貌。结果表明:合成出的材料皆为单相的具有磁铁铅矿晶型的六铝酸盐,材料是由许多片状小板随机排列而成;Sr降低了该材料的最终生成温度。     

Synthesis, crystal structure, and spectroscopy of (azido-N1)bis(2,2′-bi-imidazoline)copper(II) perchlorate

The compound [Cu(biz)₂(N₃)](ClO₄) (biz = 2,2-bi-imidazoline) has been synthesized and characterized by X-ray crystallography and infrared spectroscopy. In addition, EPR and magnetic measurements have been performed. The compound crystallizes in the monoclinic space group P2₁/c, with a = 9.2716(2), b = 27.6454(4), c = 7.4285(1) Å, = 102.1417(6)°, V = 1861.46(5) ų, and Z = 4. The coordination geometry around the Cu(II) ion is distorted square pyrimidal, with 4 nitrogen atoms of 2 bis-chelating ligand molecules in the basal plane and one nitrogen of the azide molecule in the apical position. The perchlorate ion is noncoordinating. In the infrared the vibrations of the coordinated azide anion are observed at 2050, 1286, and 620 cm^–1, while the vibrations of the free perchlorate anion are observed at 1071, 1035, and 919 cm^–1; Cu—N vibrations are observed at 418 and 336 cm^–1. The molecules are connected in the lattice via relatively strong hydrogen bonding between the N—H groups at the back of the biz ligand and the N1 and N3 atoms of the azide ligand forming layers. No intermolecular magnetic interaction was observed for this compound.     

Properties of high nitrogen content mixed alkali earth oxynitride glasses (AExCa1−x)1.2(1)SiO1.9(1)N0.86(6), AE = Mg,Sr, Ba

Mixed alkali earth element containing high nitrogen content oxynitride glasses (Ca_1?xAE_x)_1.2(1)SiO_1.9(1)N_0.86(6), with AE = Mg, Sr, Ba, x ≤ 0.30 for Mg and x ≤ 0.46 for Sr and Ba, and nominally constant (Ca/AE):Si:O:N ratios were prepared in order to investigate the compositional dependencies of physical properties on alkali earth element composition. The glasses were prepared by melting mixtures of AEH₂, CaH₂, SiO₂ and Si₃N₄ powders in nitrogen atmosphere at 1600–1700 °C and characterized by X-ray powder diffraction and scanning and transmission electron microscopy. Cation and anion glass compositions were determined by respectively energy dispersive X-ray analysis and combustion analysis. The determined physical properties were density, glass transition temperature, Vickers hardness, and refractive index. The physical properties were found to vary linearly with the degree of substitution of Ca by the AE elements. The density of the glasses increases substantially upon substitution by Sr and Ba, up to 3.99 g/cm³. Glass transition temperatures are found to be higher for Mg and Sr substituted glasses, ca. 900 °C, in comparison with Ba substituted glasses, ca. 850 °C. The hardness increases upon substitution by Mg, up to 12.2 GPa at x = 0.46, and decreases upon substitution by Sr and Ba. The refractive index increases upon substitution by Sr and Ba, up to 1.97 for Ba at x = 0.46, and decreases upon substitution by Mg. The transparency of the glasses was found to increase upon increasing substitution by Mg and completely transparent glasses were obtained for x = 0.24.     

Crystal and Molecular Structures of 2-Amino-4-Nitrobenzoic Acid and Its Cocrystals with 2,2′-Bipyridine (2/1) and Bis(pyridin-2-yl)ketone (1/1)

Abstract  

The eight-membered {···HOC=O}₂ synthon featured in the crystal structure of 2-amino-4-nitrobenzoic acid (1) is replaced by carboxylic acid···N-pyridine hydrogen bonds in its cocrystals with 2,2′-bipyridine (2/1; 2) and bis(pyridin-2-yl)ketone (1/1; 3) indicating the robust nature of the latter synthon. Disruption of the three-dimensional architecture based on O–H···O and N–H···O(nitro) hydrogen bonds in (1) is evident in the cocrystals which form supramolecular tubes (2) and chains (3) based on O–H···N and N–H···O hydrogen bonding. Compound (1) crystallizes in the monoclinic space group P2₁/n with a = 3.6291(1) ?, b = 7.7339(3) ?, c = 26.561(1) ?, β = 91.385(2)°, and Z = 4. Compound (2) crystallizes in the monoclinic space group C2/c with a = 27.562(3) ?, b = 6.8300(6) ?, c = 12.923(1) ?, β = 110.593(5)°, and Z = 4. Compound (3) crystallizes in the monoclinic space group P2₁/c with a = 3.795(3) ?, b = 12.024(8) ?, c = 35.65(2) ?, β = 92.131(6)°, and Z = 4 (determined from synchrotron data).     

合成方式对(1-x)Ba_(0.998)La_(0.002)TiO_3-xBi_4Ti_3O_(12)陶瓷性能影响的研究

采用固相法制备了Bi4Ti3O12(BIT)与La2O3共掺杂的(1-x)Ba0.998La0.002TiO3-xBi4Ti3O12(0.001≤x≤0.03)系统陶瓷,研究了不同合成工艺(一步合成法:BIT与La2O3直接掺杂到BaTiO3陶瓷中;两步合成法:先将La2O3和BaTiO3预合成Ba0.998La0.002TiO3陶瓷,再将BIT掺杂到Ba0.998La0.002TiO3陶瓷中)对(1-x)Ba0.998La0.002TiO3-xBi4Ti3O12陶瓷显微结构、居里温度Tc及电性能的影响。结果表明:BIT对两种方式合成的(1-x)Ba0.998La0.002TiO3-xBi4Ti3O12陶瓷的晶粒长大均有抑制作用,而随着BIT加入量的增加晶粒又逐渐长大;一步合成法制备的(1-x)Ba0.998La0.002TiO3-xBi4Ti3O12陶瓷存在晶粒异常长大,而两步合成法制备的BLIT陶瓷晶粒较小;一步合成法对(1-x)Ba0.998La0.002TiO3-xBi4Ti3O12陶瓷的居里温度没有影响,而两步合成法制备的(1-x)Ba0.998La0.002TiO3-xBi4Ti3O12陶瓷居里温度提高到约150℃。     

(Ti1-xAlx)N硬质涂层的研究进展

TiAlN作为一种三元复合纳米涂层材料,具有非常好的性能.该涂层克服了TiN涂层所存在的一些缺陷,其硬度远远高于TiN涂层,最高可达47GPa, 并且具有很好的热稳定性,在700℃高温下仍很稳定,而TiN涂层在500℃时就已被氧化.TiAlN涂层还具有抗磨损,摩擦系数小,热膨胀系数及热传导系数低等特性,这些特性与涂层中Al含量的多少有关,Al含量的改变会导致涂层微观结构的改变,从而使其性能发生变化.氮分压和基底温度对TiAlN涂层的性质有着极其重要影响.本文结合国内外对TiAlN涂层的最新研究进展,对TiAlN涂层的应用,制备方法,结构,抗氧化性及硬度作了简要论述.     

xPMnS-(1-x)PZN陶瓷极化特性研究

本文研究了xPMnS-(1-x)PZN四元系压电陶瓷的极化性能、谐振频率附近的介电性能及谐振频率温度稳定性.结果表明,xPMnS-(1-x)PZN陶瓷中以取向极化为主,具有很好的谐振频率温度稳定性.组成为x=0.6时,xPMnS-(1-x)PZN陶瓷具有最好的综合压电性能,可用于在谐振频率附近应用的水声换能器.     

Ravil Vagizovich Galiulin (January 1, 1940–February 1, 2010)

Obituaries

Ravil Vagizovich Galiulin (January 1, 1940–February 1, 2010)     

La_(1-x)Sr_xMnO_3电极的制备及其对Ba_(1-x)Sr_xTiO_3薄膜介电性能的影响

采用溶胶-凝胶法在Si(100)基底上制备了La_(1-x)Sr_xMnO_3电极材料.采用XRD、SEM对材料的晶体结构、表面形貌、薄膜厚度进行了表征,研究了退火温度对薄膜结构及电阻率的影响,以及介电常数与介电损耗随频率变化的关系.结果表明:在x=0.5,退火温度为800 ℃时,La_(0.5)Sr_(0.5)MnO_3薄膜的电阻率为1.2×10~(-2) Ω·cm.La_(0.5)Sr_(0.5)MnO_3薄膜与Ba_(1-x)Sr_xTiO_3匹配性较好,实现了BST薄膜的外延生长,其介电性能比在Pt上制备的Ba_(1-x)Sr_xTiO_3得到了明显的改善.