首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 140 毫秒
1.
Synthesis and Crystal Structure of 2‐Azido‐4,6‐dichloro‐s‐triazine Single crystals of 2‐azido‐4,6‐dichloro‐s‐triazine were obtained from a reaction between cyanuric chloride and sodium azide. The structure of this compound was determined by single crystal X‐ray diffraction. 2‐Azido‐4,6‐dichloro‐s‐triazine crystallizes in the orthorhombic space group Pbca (no. 61), Z = 8, a = 746.48(8) pm, b = 952.6(1) pm, c = 2001.6(2) pm. The crystal structure contains (C3N3)(N3)Cl2 molecules being arranged in a tape‐like fashion, with tapes running along a‐axis direction. The tapes are combined with each other by interlocking azide‐ligands including an angle of approximately 90°. This arrangement leads to the formation of corrugated layers in the crystal structure.  相似文献   

2.
Pale yellow single crystals of [O=C(NPPh3)C(I)=C(NPPh3)‐C(NPPh3)2]+I·1.5 thf ( 1 ·1.5 thf) have been obtained by the reaction of INPPh3 with thallium in thf suspension. They are characterized by IR spectroscopy and by a crystal structure determination. 1 ·1.5 thf crystallizes in the monoclinic space group P21/n, Z = 4, lattice dimensions at ‐83?C: a = 1101.7(1), b = 3449.0(2), c = 2000.4(1) pm, β = 104.88(1)?, R1 = 0.0382. 1 can be understood as a cationic variation of (Z)‐2‐butenale in which all H atoms are substituted by triphenylphosphoraneimine residues and by a iodine atom, respectively.  相似文献   

3.
4.
Rubidium amide‐ammonia(3/2), RbNH2·2/3NH3, was synthesized from Rubidiumhydride, RbH, in liquid ammonia at ?78 °C. The compound crystallizes in the cubic space group I213 with Z = 4, a = 10.0490(12) Å, and V = 1014.77(20) Å as isometric colorless crystals. The crystal structure was solved from single‐crystal X‐ray data. The structure contains a three‐dimensional network of amide anions and ammonia molecules, which are interconnected via hydrogen bonds.  相似文献   

5.
[Mn4Br(CH=CMe2)33‐NPEt3)4] — a 2‐Methyl‐prop‐1‐enyl‐Phosphoraneiminato Complex of Manganese(II) with Heterocubane Structure [Mn4Br(CH=CMe2)33‐NPEt3)4] ( 1 ) has been prepared from [MnBr(μ3‐NPEt3)]4 and BrMg(CH=CMe2) in thf solution and subsequent extraction of the solvent‐free residue with n‐hexane. 1 forms red single crystals from diethylether solution, which are characterized by a crystal structure determination. Space group P1¯, Z = 2, lattice dimensions at —80 °C: a = 1144.7(1), b = 1411.3(2), c = 1521.8(2) pm, α = 91.581(14), β = 90.163(14), γ = 91.947(14)°, R1 = 0.0448. 1 exhibits a Mn4N4 heterocubane core, a terminally coordinated bromine ligand and three Mn—CH=CMe2 groups with M—C bond lengths of 213.8 pm on average.  相似文献   

6.
The crystal structure of the triclinic polymorph of 1‐(4‐hexyloxy‐3‐hydroxyphenyl)ethanone, C14H20O3, differs markedly from that of the orthorhombic polymorph [Manzano et al. (2015). Acta Cryst. C 71 , 1022–1027]. The two molecular structures are alike with respect to their bond lengths and angles, but differ in their spatial arrangement. This gives rise to quite different packing schemes, even if built up by similar chains having the hydroxy–ethanone O—H…O hydrogen‐bond synthon in common. Both phases were found to be related by a first‐order thermally driven phase transformation at 338–340 K, which is discussed in detail. The relative stabilities of both polymorphs are explained on the basis of both the noncovalent interactions operating in each structure and quantum chemical calculations. The polymorphic phase transition has also been studied experimentally by means of differential scanning calorimetry (DSC) experiments, conducted on individual single crystals, Raman spectroscopy and controlled heating under a microscope of individual single crystals, which were further characterized by powder and single‐crystal X‐ray diffraction.  相似文献   

7.
The structure of completely exchanged Mn2+—ß″—Al2O3(Mn0.77Al10.46Mg0.54O17) crystals has been investigated by single—crystal X—ray diffraction methods at room temperature (trigonal, R3¯, Z = 3, a = 560.65(7), c = 3329.3(9) pm). The manganese ions (Mn2+) are found to occupy Beevers‐Ross (56 %) and mid—oxygen positions (44 %) in nearly the same amounts. The crystal composition was confirmed by electron probe microanalyses on various crystals.  相似文献   

8.
Gd3(SeO3)4F: A Fluoride Selenite with μ3‐SeO32– and μ3‐F Capped Gd3 Rings The decomposition of Gd2(SeO4)3 in the presence of LiF in sealed gold ampoules yields single crystals of Gd3(SeO3)4F (hexagonal, P63mc, Z = 2, a = 1044.3(1), b = 694.32(7) pm, Rall = 0.0286). In the crystal structure one SeO32– group and one F ion cap a ring of three Gd atoms. Furthermore, the crystal structure is strongly influenced by the lone pairs of the SeO32– ions.  相似文献   

9.
Single crystals of the high‐temperature modification of zinc catena‐polyphosphate, β‐Zn(PO3)2, were grown from a melt and quenched from 1093 K to room temperature. The structure was solved from single‐crystal X‐ray diffraction data and is built of corrugated (PO3) polyphosphate chains, which extend along the c direction with an eight‐tetrahedra repeat. Slightly distorted [ZnO4] tetrahedra link the polyphos­phate chains into a three‐dimensional network.  相似文献   

10.
Powder material of ?‐Fe2O3 was obtained by thermal decomposition of the clay mineral nontronite and subsequent isolation of the ferric oxide by leaching the silicate phases. Additionally, crystals of ?‐Fe2O3 were grown as precipitates by internal oxidation of a Pd96Fe4 alloy. Analysis of the precipitate crystals by electron diffraction yields an orthorhombic crystal system and space group Pna21 ab initio. X‐ray diffraction data of the powder containing small amounts of Al substituting Fe were refined by the Rietveld method. The refinement yields lattice parameters a = 507.15 pm, b = 873.59 pm and c = 941.78 pm, and atom positions. ?‐Fe2O3 is isostructural with κ‐Al2O3, AlFeO3, and GaFeO3 having an anion stacking sequence /ABAC/, and 1/4 of the cations in tetrahedral co‐ordination. Some strongly distorted FeO6 octahedrons with one large Fe‐O distance, which may be considered as a 5+1 co‐ordination, appear to be characteristic for ?‐Fe2O3. The structure shows elements known from silicates and oxyhydroxides of iron, respectively.  相似文献   

11.
The investigation of CdCl2‐HIO3 system, in aqueous and HNO3 solutions, revealed that anhydrous cadmium iodate presents a marked polymorphism. No less than four new Cd(IO3)2polymorphs have been isolated and characterized, two of which showing second harmonic generation activity. Single crystals of ε‐Cd(IO3)2 are obtained by slowly evaporating, at 60 °C, a saturated solution of γ‐Cd(IO3)2 in 30 % nitric acid. This compound crystallizes in the orthorhombic space group Pca21 [a = 17.581(2), b = 5.495(2), c = 11.163(2) Å]. The basic structural unit can be described as the connection of two cadmium polyhedrons with a short metal – metal distance of 3.88Å. These units are further linked through two other iodate bridges resulting in layers parallel to the (100) plane. The 3D linkage is ensured by short bonds of the fourth iodate group.  相似文献   

12.
Single crystals of the filled Ti2Ni‐type Ti3Zn3Ox η‐phase (cubic, space group Fdm) having {111} facets were obtained by heating Ti, Zn and ZnO with a Bi flux. The lattice parameter of a single crystal prepared at 800°C was 11.4990 (2) Å, which is close to that of Ti3Zn3O∼0.5 (a = 11.502 Å), as reported by Rogl & Nowotny [Monatsh. Chem. (1977), 108 , 1167–1180]. The occupancies of the O1 (16c) and O2 (8a) sites were 1 and 0.071 (12), respectively, and the composition of the crystal was determined to be Ti3Zn3O1.04. A single crystal from the sample prepared at 650°C had the same structure type, with a lattice parameter of 11.5286 (2) Å. However, O atoms were situated at a new 32e site in addition to the original 16c and 8a sites, and the Zn‐atom positions were split in accordance with the new O‐atom site. The chemical formula Ti3Zn3O1.27 determined by X‐ray diffraction occupancy refinement agreed with the chemical composition obtained for the cross section of the single crystal determined with an electron probe microanalyzer.  相似文献   

13.
The crystal and molecular structure of γ‐P4S6 was determined from single‐crystal X‐ray diffraction. It crystallizes monoclinically in the space group P21/m (No. 11) with a = 6.627(3) Å, b = 10.504(7) Å, c = 6.878(3) Å, β = 90.18(4)°, V = 478.8(4) Å3, and Z = 2. The structure consists of cage‐like P4S6 molecules with CS symmetry arranged with the topology of a cubic close packing.  相似文献   

14.
The title compound, C26H23NO2, (Ia) and (Ib), shows polymorphism with crystals obtained from different solvents displaying different crystal structures. However, it is not the geometry of the single mol­ecules nor the hydrogen‐bond pattern that is different in (Ia) and (Ib), but the way in which the hydrogen‐bonded chains, running along the a‐axis direction, are arranged with respect to each other.  相似文献   

15.
Synthesis and Crystal Structure of the First Oxonitridoborate — Sr3[B3O3N3] The cyclotri(oxonitridoborate) Sr3[B3O3N3] was synthesized at 1450 °C as coarsely crystalline colourless crystals by the reaction of SrCO3 with poly(boron amide imide) using a radiofrequency furnace. The structure was solved by single‐crystal X‐ray diffractometry (Sr3[B3O3N3], Z = 4, P21/n, a = 663.16(2), b = 786.06(2), c = 1175.90(3) pm, η = 92.393(1)°, R1= 0.0441, wR2 = 0.1075, 1081 independent reflections, 110 refined parameters). Besides Sr2+ there are hitherto unknown cyclic [B3O3N3]6— ions (B—N 143.7(10) — 149.1(9) pm, B—O 140.5(8) — 141.4(8) pm).  相似文献   

16.
The chain type nitridotantalate LiSr2[TaN3]F was synthesized by reaction of strontium with AlF3, Eu(NH2)2, LiN3 and lithium metal as fluxing agent in weld shut tantalum ampoules. Single crystals were obtained as byproduct from reaction with the ampoule material. The crystal structure (Pbca (no. 61), a = 10.768(2), b = 5.5913(11), c = 15.891(3) Å, Z = 8) was solved on the basis of single‐crystal X‐ray diffraction data. LiSr2[TaN3]F contains infinite chains of vertex sharing TaN4 tetrahedra running along [010]. The structure can be understood as an intercalation of Li+ and F into Sr2TaN3. Lattice energy calculations (MAPLE) and EDX measurements confirmed the electrostatic bonding interactions and the chemical composition.  相似文献   

17.
A photochromic diarylethene, 1,2‐bis(5‐phenyl‐2‐propyl‐3‐thienyl)perfluorocyclopentene ( 1a ), was found to have two polymorphic crystal forms, α‐ and β‐crystals. From X‐ray crystallographic analysis, the space groups of α‐ and β‐crystals were determined to be P21/c and C2/c, respectively. The difference between two crystal forms is ascribed to the orientation of two of four molecules in the unit cell. The thermodynamic phase transition from α‐ to β‐forms occurred via a crystal‐to‐crystal process, as confirmed by differential scanning calorimetry measurements, optical microscopic observations in the reflection mode and under crossed Nicols, and powder X‐ray diffraction measurements. The movement of the molecules in the crystal was evaluated by analyzing the change of face indices before and after the phase transition.  相似文献   

18.
The synthesis and single crystal X‐ray structure determination are reported for the 2,2′ : 6′,2″‐terpyridine (= tpy) adduct of bismuth(III) nitrate. The hydroxide‐bridged dimer [(η2‐NO3)2(tpy)Bi(μ‐OH)2Bi(tpy)(η2‐NO3)2] with nine‐coordinate geometry about Bi was the only isolable product from all crystallization attempts in varying ratios of Bi(NO3) : terpy.; [(η2‐NO3)2(tpy)Bi(μ‐OH)2Bi(tpy) · (η2‐NO3)2] is triclinic, P 1, a = 7.941(8), b = 10.732(9), c = 11.235(9) Å; α = 63.05(1), β = 85.01(1), γ = 79.26(1)°, Z = 1, dimer, R = 0.058 for N0 = 2319.  相似文献   

19.
Tetra(N‐methylimidazole)‐beryllium‐di‐iodide, [Be(Me‐Im)4]I2 ( 1 ), was prepared from beryllium powder and iodine in N‐methylimidazole suspension to give yellow single crystal plates, which were characterized by X‐ray diffraction and IR spectroscopy. Compound 1 crystallizes tetragonally in the space group I 2d with four formula units per unit cell. Lattice dimensions at 100(2) K: a = b = 1784.9(1), c = 696.2(1) pm, R1 = 0.0238. The structure consists of homoleptic dications [Be(Me‐Im)4]2+ with short Be–N distances of 170.3(3) pm and iodide ions with weak interionic C–H ··· I contacts. Experiments to yield crystalline products from reactions of N‐methylimidazole with BeCl2 and (Ph4P)2[Be2Cl6], respectively, in dichloromethane solutions were unsuccessful. However, single crystals of [Be3(μ‐OH)3(Me‐Im)6]Cl3 ( 2 ) were obtained from these solutions in the presence of moisture air. According to X‐ray diffraction studies, two different crystal individuals ( 2a and 2b ) result, depending on the starting materials BeCl2 and (Ph4P)2[Be2Cl6], respectively [ 2a : Space group P21/n, Z = 4; 2b : Space group P , Z = 2]. As a side‐product from the reaction of N‐methylimidazole with (Ph4P)2[Be2Cl6] single crystals of (Ph4P)Cl·CH2Cl2 ( 3 ) were identified crystallographically (P21/n, Z = 4) which are isotypical with the corresponding known bromide (Ph4P)Br·CH2Cl2.  相似文献   

20.
The trinuclear manganese(II) complex [Mn3(ppi)2(μ‐OAc)4(H2O)2]·2MeOH ( 1 ) (Hppi = 2‐pyridylmethyl‐2‐hydroxyphenylimine) is prepared by dissolving two equivalents of Hppi (from the Schiff Base reaction of aminophenol and pyridine‐2‐carboxaldehyde) in acetonitrile and three equivalents of Mn(OAc)2·4H2O in methanol and combining both solutions. The resulting red precipitate was recrystallized to yield red crystals suitable for single crystal X‐ray diffraction. Compound 1 crystallizes in the triclinic space group P1¯ (no. 2), with a = 9.691(2), b = 10.683(2), c = 11.541(2)Å, α = 63.19(3)°, β = 67.47(3)°, γ = 69.11(3)°, V = 960.2(3)Å3, and Z = 1. The binding mode of carboxylate in 1 represents a model for a transition state between symmetric syn, syn, anti‐μ2‐carboxolato‐O‐ and syn, anti‐μ2‐carboxylato‐O, O′‐coordination. Therefore a rare binding mode for the phenomenon of the carboxylate shift is realized. Furthermore the complex is stabilized by a distinctive hydrogen bonding pathway.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号