Synthesis and crystal structure of [{V3(μ-Cl)4(μ 3-Cl) (μ 3-OH)(thf)2(teeda)}2]·2(thf) (teeda = N,N,N′N′-tetraethylethane-1,2-diamine)

The title complex was prepared from the reaction of [V₂(-Cl)₃(thf)₃]₂[Zn₂Cl₆] with N,N,NN-tetraethylethane-1,2-diamine (teeda) in refluxing thf and its crystal structure exhibits two triangulo-[V₃(-Cl)₃(-Cl)( ₃-OH)(thf)₂(teeda)]⁺ cations bridged by two chlorides. The molecular structure (monoclinic, space group P2 ₁/n, Z = 2, a = 11.8005(7) Å, b = 18.7492(14) Å, c= 15.6253(9) Å, = 103.600(4) shows each vanadium site in a distorted octahedral geometry. V1 and V2 have two thf molecules bounded in cis configuration, and V3 completes the hexa-coordination with the diamine teeda. Main bond distances are 2.5149(12) Å for V(1)--Cl(1), 2.062(3) Å for V(1)- ₃-O(3), 2.5554(12) Å for V(1)- ₃-Cl(4), 2.140(3) Å for V(1)–O(1)(thf), 2.243(4) Å for V(3)–N(1)(teeda), and 3.0437(9) for V(1)···V(2).     

Crystal structure of [Yb(L(NO3)2(H2O)2](NO3), L = bromo-N,N,N′,N′-tetraethylmalonamide

[Yb(L(NO₃)₂(H₂O)₂](NO₃), L = bromo-N,N,N,N-tetraethylmalonamide crystallizes in the triclinic spacegroup P-1 with cell dimensions a = 9.030(9), b = 12.036(12), c = 12.392(13) Å, = 84.52(1), = 77.58(1), = 67.21(1)° , d_calc = 1.935 g cm^-3 for Z = 2. The ytterbium atom in the complex cation is nine-coordinate being bonded to two oxygen atoms from the malonamide ligand, two nitrate anions, and three water molecules.     

Structure of N,N′-bis[3-(aminocarbonyl)propyl]sulfamide

The title compound, C₈H₁₈N₄O₄S, possesses C₂ symmetry, with the S atom lying on a twofold rotational axis in the unit cell. The sulfamide group of each molecule forms four identical hydrogen bonds with those of its four neighboring molecules, resulting in a rhombic two-dimensional hydrogen bonded network. This network assembles in the third dimension via hydrogen bonds between the primary amide groups of the substituents that extend from the 2D sulfamide sheets. The primary amide groups form a hydrogen-bonded eight-membered cyclic dimer around a two-fold rotational axis. These cyclic dimers are linked into a ribbon-like network via hydrogen bonding interaction between the trans-H and the carbonyl of the amide groups. The compound crystallizes in C2/ca with a = 8.6162(1), b = 57716(1), c = 24.8344(b) Å, = 96.298(1)°, D _calc = 1.441 g cm^–3, and Z = 4.     

Nonpreorganized neutral acyclic anion receptors: Structural investigations of N,N′-diphenyl-1, 3-benzenedisulfonamide and N,N′bis(4-t-butylphenyl)-1, 3-benzenedisulfonamide

The structure of N,N-diphenyl-1,3-benzenedisulfonamide (1) was determined by single crystal X-ray diffraction. It crystallizes in P2₁/n with cell dimensions: a = 11.8390(6) Å, b = 12.3950(10) Å, c = 12.1184(10) Å, = 94.388(6)°, and V = 1773.1(2) ų. Its di-t-butyl derivative, N,N-bis(4-t-butylphenyl)-1,3-benzenedisulfonamide (2), was prepared and structurally characterized as two solvated structures. Both crystallize in P with cell dimensions: 2 CF₃CH₂OH, a = 9.469(2) Å, b = 10.0039(18) Å, c = 16.385(3) Å, = 85.561(16)°, = 83.035(18)°, = 72.459(16), and V = 1467.7(5) ų; 2 ClCH₂CH₂Cl, a = 9.559(2) Å, b = 9.8125(12) Å, c = 17.100(6) Å, = 82.495(19)°, = 83.47(2)°, = 70.100(15), and V = 1491.1(6) ų. The structures exhibit hydrogen-bonding, and are evaluated in terms of preorganization for anion binding.     

Crystal structures of bis(cyanido)bis(N,N′-diethylthiourea-κS) mercury(II) and bis(cyanido)bis(N,N′-dipropylthiourea-κS) mercury(II)

Two mercury(II) complexes containing cyanide and, N,N′-diethylthiourea (detu) and N,N′-dipropylthiourea (dprtu) ligands, [(detu)₂Hg(CN)₂] (1) and [(dprtu)₂Hg(CN)₂] (2), respectively, have been prepared and characterized by X-ray crystallography. In the both complexes Hg atom lies on a 2-fold rotation axis, and is coordinated to the sulfur atoms of two thiourea ligands and to two cyanide carbon atoms. Both have a distorted tetrahedral environment with bond angles about the Hg atoms in the range of 93.41(4)°–146.75(19)°. In the crystal structures symmetry related molecules are linked via N-H-N hydrogen bonds resulting in the formation of a two-dimensional network in 1, while in 2 a double stranded one-dimensional chain is formed.     

Crystal structure of (ethylenediammonium-N,N′-di-3-propanoic acid) tetrachloropalladate(II) complex

The title compound was obtained by a synthesis from ethylenediamine-N,N-di-3-propanoic acid dihydrochloride (H₂eddp2HCl) and potassium hexachloropalladate(IV) (molar ratio 1:1, in water). Its structure has been determined by single-crystal X-ray diffraction: monoclinic space group P2₁/n, a = 8.198(1), b = 10.282(1), c = 9.080(1) Å, = 103.62(1)°, V = 743.9(2) ų, and Z = 2. The dianionic complex has a square-planar coordination geometry with four chloro ligands, and ethylenediamine-N,N-di-3-propanoic acid as dication in the second coordination sphere. This is the first reported Pd(II) structure with uncoordinated H₂eddp.     

Crystal and molecular structure of the spin-crossover complex bis(pyridine) [N,N′-ethylenebis (3-carboxysalicylaldimine)] cobalt (II)

The average structure of the title compound, Co(H₂fsa₂en)(py)₂, which has been shown previously to exhibit a thermally induced high-spin low-spin crossover, has been investigated by single-crystal X-ray diffraction. This structure has been solved in the monoclinic space groupC2/c (No. 15), with cell dimensionsa=16.641(5),b=9.496(4),c=16.329(6) Å, and=95.47(3)°;V=2569(3) ų,M _r =571.46,Z=4,D _x =1.478 mg m^–3; MoK radiation (graphite crystal monochromator),=0.71073 Å,(MoK)=7.138 cm^–1;T=295 K andR=0.081 for 681 observed [I>3(I)] independent reflections. The cobalt(II) ion resides on a twofold axis in an elongated octahedral environment, the length of the apical bond (formed with pyridine) being 2.262(12) Å and the mean length of the equatorial bonds (formed with the Schiff base) 2.079(12) Å. These values are consistent with the magnetic behavior, which suggested a distorted surrounding for the metal atom. The packing is essentially governed by the parallelism of the salicylaldimine ligands. The two pyridine rings of the molecule are twisted by ~98° on each side of the basal plane; they are probably affected by orientational disorder or, if ordered, they might be described in a superstructure not yet established.     

Distortions in nitramine substituted cubanes: The structures of N,N′-dinitro-1,4-diaminocubane,N,N′-dinitro-N,N′-(2-pyridyl)-1,4-diaminocubane,and 1,2,4,7-tetrakis(N-methoxycarbonylnitramino)cubane

The structures of three nitramine substituted cubane molecules, N,N-dinitro-1,4-diaminocubane (1), N,N-dinitro-N,N-(2-pyridyl)-1,4-diaminocubane (2), and 1,2,4,7-Tetrakis(N-methoxycarbonylnitramino)-cubane (3), have been determined.1 crystallized in the space group P2₁/a with cell dimensionsa=6.545(1),b=9.331(1),c=7.459(1) Å, =105.80(1),2 crystallized in the monoclinic space group P2₁/a with cell dimensionsa=7.545(2),b=8.697(3),c=12.406(4 Å, =96.28(3)°, while3 crystallized in the monoclinic space group P2₁/c with cell dimensionsa=10.866(3),b=6.866(2),c=16.167(6) Å, =108.79(3)°. The metrical parameters of the cubane skeleton showed no significant deviations from those found in other similarly substituted cubane molecules. For2 and3 there were considerable distortions of the nitramine moiety from planarity in contrast to1 where the nitramine moiety was almost exactly planar. The bond distances and angles for the nitramine group in1 indicates a substantial introduction of double bond character into the N–N bond in1, achieved by delocalization of the amine lone pair, compared with2 and3.     

The structure of N,N′-bis(2-hydroxyphenyl)butanediamide

The structure of N,N-bis(2-hydroxyphenyl)butanediamide has been determined. The molecule consists of two 2-hydroxyphenyl moieties which are attached (at the 2 position) to the two nitrogens of the butanediamide. The compound C₁₆H₁₆N₂O₄ crystallizes in the monoclinic space group P2₁/c witha=5.576(1),b=4.8853(6),c=25.397(6) Å and =90.58(1)°.     

Structure of N,N′,N″-tris(carboxymethyl)-1,3,5-benzenetricarboxamide trihydrate

The title compound, C₁₅H₁₅N₃O₉·3H₂O, crystallizes in the centrosymmetric space group R with a = 13.642(5), b = 13.642(5), c = 18.692(5) Å, D _calc = 1.440 g cm³, and z = 6. An extensive three-dimensional hydrogen bonded network is observed. The network arises from 15 hydrogen bonds per asymmetric unit. Six identical N—H···O hydrogen bonds are formed between two triacid molecules, which results in the face-to-face dimerization of the two triacid molecules. The dimers form extended sheets through hydrogen bond interaction with water molecules. The sheets are held together by hydrogen bonds via the water molecules. The planes of the benzenoid ring are parallel to each other.     

(K,Na)3La2(BO3)3固溶体系的晶体结构

本文合成了一系列的(K,Na)3La2(BO3)3硼酸盐,通过自发结晶得到了组分为K1.34,Na1.66La2(BO3)3的单晶.单晶X射线结构分析表明该晶体与Na3La2(BO3)3同构,并且当K+取代Na+的数量小于2/3时,晶体结构仍为Na3La2(BO3)3构型.该晶体的基本结构单元为孤立的(BO3)3-基团.一个单胞中含有6个BO3基团,其中两个沿c方向一致平行排列,而剩余的4个BO3基团的排列方向与c方向呈一定的角度,从而减小了BO3基团对非线性效应的贡献.粉末倍频测试该晶体的有效非线性系数约为KDP的2.4倍.此外,研究表明用适量的Rb+,Li+取代Na+时,固溶晶体结构也不发生改变.     

自蔓延高温合成Ti(C,N)材料

采用Ti粉和一种CNx前驱物粉体为原料,通过自蔓延高温合成技术,制备了单相Ti(C,N)材料.并研究了添加过量Ti对反应合成Ti(C,N)材料的影响.研究结果表明,自蔓延反应会产生很高的温度,温度达2782 K.燃烧产物组织均匀,Ti(C,N)颗粒平均大小约为3μm.当原料中Ti含量过量时,容易生成多种C和N配比不同种类的Ti(C,N)材料.最后,通过淬熄实验提出了一种自蔓延反应合成Ti(C,N)的机理.     

Al2O3/Cr3 C2/Ti(C,N)复合材料摩擦磨损性能研究

采用热压烧结技术制备了Al2O3/Cr3 C2/Ti(C,N)复合陶瓷材料,对其力学性能、摩擦磨损性能进行测试,用扫描电镜(SEM)对其磨损表面进行观察.结果表明:Al2O3/Cr3 C2/Ti(C,N)复合陶瓷材料具有良好的综合力学性能,在与硬质合金YG8环块摩擦中表现出较高的减摩抗磨性能,摩擦系数与磨损率较单相Al2O3降低近一半.对其磨损机理研究认为,磨粒磨损为主要磨损机制,高的强度和韧性是其具有良好耐磨性能的主要原因.     

A crystallographic study of (2-acetylpyridine-κN 4-phenylthyosemicarbazonate-κ2N1,S) methyl-trans-dichlorotin(IV)

The preparation and characterization of [Sn(C₁₄H₁₃N₄S)(CH₃)Cl₂], an organotin(IV) complex containing 2-acetylpyridine(4)-phenylthiosemicarbazone, is described. The molecular structure was studied by single crystal X-ray diffraction, and IR and Mössbauer spectroscopies. The title compound crystallizes in the centric triclinic space group, P , as discrete neutral complexes, with the Sn(IV) ion in a distorted octahedral coordination geometry, with the thiosemicarbazone derivative in a meridional configuration and the chlorides in trans positions.     

三维孔道结构钒磷酸盐[H3N(CH2)3NH3]2[H3N(CH2)3NH2][H2N(CH2)3NH2]-[V(H2O)2(VO)8(OH)4(PO4)4(HPO4)4]·4H2O的水热合成和结构表征

以1,3-丙二胺为模板,水热合成了三维孔道结构钒磷酸盐[H3N(CH2)3NH3]2[H3N(CH2)3NH2][H2N(CH2)3NH2][V(H2O)2(VO)8(OH)4(PO4)4(HPO4)4]·4H2O(DAP-V9P8).用单晶X射线衍射、红外光谱和热重法对该化合物的晶体结构进行了表征.DAP-V9P8的无机骨架由[VO5]、[VO6]、[PO4]和[HPO4]通过共顶点连接而成.孔道中充填的丙二胺分子随所处结晶学位置不同,有三种完全不同的分子构象.其中,位于//b轴直径达1.82nm椭圆形孔道中心的丙二胺分子碳链呈独特的直线状分布.晶体学参数:a=1.4820(9)nm,b=1.0255(4)nm,c=1.8181(9)nm,β=90.391(8)°;P21/n(No.14);R1=0.0772,wR2=0.2004(I＞(2σI)).与等结构的其它化合物进行了系统的结构比较.     

Synthesis,Spectral, Thermal and Structural Study of Monoaquabis(Acetylsalicylato-κO)bis(Nicotinamide-κN)Copper(II)

Abstract  

The compound has been formed by mononuclear [Cu(C₉H₇O₄)₂(C₆H₆N₂O)₂(H₂O)] units in which the metal ion as well as the water ligand lies on a twofold symmetry axis, so that only one acetylsalicylate ligand and one nicotinamide ligand are independent. The distortion from ideal five-coordinate geometries can be described best by the degree of trigonality τ. For a regular square-pyramidal (SQP) geometry the trigonality parameter is 0 and for a trigonal–bipyramidal (TBP) structure it increases to 1. The copper coordination geometry is that of a square pyramid (τ = 0.23), with the N atoms from nicotinamide ligands and the bonded carboxylate O atoms from acetylsalicylate ligands defining the quasi-planar square base. The apical site is occupied by the aqua ligand, a bond which coincides with the twofold symmetry axis and is thus exactly perpendicular to the basal plane. The thermal decomposition takes place in four steps: removing of moisture, dehydration of aqua ligand, the elimination of the nicotinamide (na) ligand and the decomposition of acetyl-groups and oxidation of salicylate ion ligands. In complex, all ligands are coordinated to the metal ion as monodendate. The IR spectra of the intermediate products showed similar results.     

Synthesis and crystal structure of (+)-(2R,3R)-N, N′-bis-trityl-2,3-bis-aziridine

A new C₂ symmetric bis-aziridine derivative was synthesized starting from L-(+)-tartaric acid. The molecular structure of (+)-(2R, 3R)-N, N-bis-trityl-2,3-bis-aziridine 4, was determined by ¹H, ¹³C NMR and elemental analysis and was confirmed by single-crystal X-ray diffraction. Crystal data for 4: C₄₂H₃₆N₂, orthorhombic, space group: P2₁2₁2₁, a = 12.7633(14), b = 14.5661(6), c = 17.4184(14) Å, and Z = 4.     

Synthesis and structural characterization of a (N,N′-bis[2(S)-pyrrolidylmethyl]-propane-1,3-diamine) nickel (II) complex

The nickel(II) complex [Ni(C₄H₃NCH=N–(CH₂)₃–N=CHC₄H₃N)], (1) containing the symmetrical N₄ tetradentate Schiff base ligand, which is the 2:1 condensation product of pyrrole-2-carboxaldehyde and 1,3-diaminopropane respectively, was prepared. Structural investigation shows that it is monomeric, having space group P2₁/c, a = 7.989(7), b = 17.406(14), c = 9.193(5) Å, = 90, = 100.39(6), = 90, and Z = 4. The coordination geometry around the nickel atom is slightly distorted square planar and the conformation of the six-membered ring containing the metal,azomethine nitrogens and three carbon atoms of the connecting 1,3-diaminopropane is a symmetric boat.     

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.     

AlO3-Re2O3(Re=La,Nd,Y,Lu)对无压烧结Si3N4陶瓷显微结构与力学性能的影响

研究了二元助剂Al2O3-Re2O3(Re=La,Nd,Y,Lu)对无压烧结Si3N4陶瓷的相对密度、显微结构及力学性能的影响.结果表明:经1800℃无压烧结后,Si3N4陶瓷试样的相对密度均达到97;以上;以Al2O3-Lu2O3为烧结助剂的Si3N4陶瓷试样具有最高的维氏硬度和抗弯强度,分别为15.2±0.18 GPa和920±5 MPa.