Crystal structure of a new organic dihydrogenomonophosphate (C6H8N3O)2(H2PO4)2

Chemical preparation, X-ray single-crystal, thermal behavior, and IR spectroscopy investigations are given for a new organic cation dihydrogenomonophosphate (C₆H₈N₃O)₂(H₂PO₄)₂ (denoted IAHP) in the solid state. This compound crystallizes in the orthorhombic space group P2₁2₁2₁. The unit cell dimensions are: a = 7.422(3) Å, b = 12.568(5) Å, c = 20.059(8) Å with V = 1871.1(13) Å³ and Z = 4. The structure has been solved using direct method and refined to a reliability R factor of 0.029. The atomic arrangement can be described as inorganic layers of H₂PO₄⁻ anions between which are located the organic groups (C₆H₈N₃O)⁺ through multiple hydrogen bonds.     

A zinc phosphate, [NH3(CH2)3NH3][Zn4(PO4)2(HPO4)2], possessing alternate inorganic and organic layers

A new zinc phosphate of the formula, [NH₃(CH₂)₃NH₃][Zn₄(PO₄)₂(HPO₄)₂], has been synthesized hydrothermally starting from a zinc amine complex. It crystallizes in the monoclinic space group C2/c; a=17.279(1), b=5.193(1), c=20.115(1) Å, β=92.6(1)°; V=1803.1(2) ų; Z=4; D_calc=2.05 g cm⁻³; μ (MoKα)=5.62 mm⁻¹. The final R, and wR₂=0.037, 0.093 obtained for 136 observed data [I>2σ(I)]. The structure consists of macroanionic sheets of interconnected ZnO₄ and PO₄ tetrahedra in the ab plane. The sheets are held together by hydrogen bond interactions with the organic structure-directing amine, forming alternate inorganic–organic layers in this material. Hydrogen bond interactions between the inorganic layers, via the terminal –OH group, leads to the formation of pseudo one-dimensional channels.     

Synthesis of Macroscopic Zr（C6H5PO3）2 Tubes

A new method of infiltration-diffusion is used to synthesize macroscopic α-Zr（C6H5PO3）2 （α-ZrBP） tube. Compared to the routine method, no HF was used and a fiberlike product with several millimeters in length was obtained. SEM （scanning electronic microscopy） result indicates that these fibers are tubes. The wall of the tubes is composed of the flake of α-ZrBP overlapped with each other. As we know, it is the first report on the synthesis of millimeter-scale supramolecular assembly of α-ZrBP.     

Synthesis and crystal structures of a new (2,3-(CH3)2C6H3NH3)H2XO4 (X=P,As)

The aim of encapsulation of 2,3-dimethylanilinium cation in (H₂XO₄)_n polymeric anion chains is to build acentric frameworks that are efficient for non-linear optical (NLO) applications. The synthesis and structures of two new inorganic–organic NLO crystals with general formula (2,3-(CH₃)₂C₆H₃NH₃)H₂XO₄ (X=P, As) are reported. The magnitude of their second harmonic generations (SHG) responses was found to be between the KDP and urea. They crystallize with monoclinic unit-cells and are isotopic. We have determined the structure of phosphoric salt. The following unit-cell parameters were found: a=8.866(3) Å, b=5.909(6) Å, c=10.644(5) Å, β=112.44(1)°, V=515.5(5) Å³ and D_X=1.412 g cm⁻³. The space group is P2₁ with Z=2. The structure was refined with R=0.041 (R_w=0.057) for 1652 reflections with I≥3σ(I). It exhibits infinite (H₂PO₄)_nⁿ⁻ chains. The organic groups (2,3-(CH₃)₂C₆H₃NH₃)⁺ are anchored between adjacent polyanions through multiple hydrogen bonds. Chemical preparation, crystal structure, calorimetric and spectroscopic investigation are described.     

Preparation and stability of nanocrystalline (C6H5C2H4NH3)2PbI4-doped PMMA films

Preparation and stability of nanocrystalline (C₆H₅C₂H₄NH₃)₂PbI₄-doped PMMA films were investigated. By using spin-coating and subsequent annealing technique, nanometer-sized (C₆H₅C₂H₄NH₃)₂PbI₄ precipitates were successfully formed into a PMMA matrix. These films showed clear exciton absorption and free exciton emission at room temperature. Comparing with (C₆H₅C₂H₄NH₃)₂PbI₄ film, marked improvement of thermal- and photo-stability was observed for nanocrystalline (C₆H₅C₂H₄NH₃)₂PbI₄-doped PMMA films. The thermal-stability of these films correlates with the decomposition of the organic part. As for photo-stability, photo-irradiation induced oxidation is one of the possible reasons for the degradation of the films.     

Complexes of Np(VI) with Cyclobutanecarboxylic Acid Anions and Single-Charged Cations in the Outer Sphere: [NH4][NpO2(cbc)3], [C(NH2)3][NpO2(cbc)3], and [N(CH3)4][NpO2(cbc)3]

Radiochemistry - Three new Np(VI) complexes with cyclobutanecarboxylic acid anions and single-charged outer-sphere anions: ammonium, [NH4][NpO2(cbc)3] (I), guanidinium, [C(NH2)3][NpO2(cbc)3] (II),...     

有机/无机杂化钙钛矿(C4H9NH3)2ZnCl4的制备与表征

合成了新型的有机/无机杂化钙钛矿（C4H9NH3）2ZnCl4,采用元素分析、红外光谱和X射线衍射对其结构进行了表征,结果表明这种材料具有规则的层状结构,有序性高,热分析结果表明（C4H9NH3）2ZnCl4在170℃的高温处存在一个固-固相转变。     

Preparation and optical properties of nanocrystalline (C6H5C2H4NH3)2PbI4-doped PMMA films

Nanocrystalline (RNH3)2PbI4-doped PMMA films were successfully fabricated on glass substrates by the spin-coating technique and subsequent annealing. X-ray diffraction spectra revealed that the (RNH3)2PbI4 crystals dispersed as nanometre-sized crystals in the PMMA matrix. These films showed a strong exciton absorption band with narrow bandwidth, even at room temperature. The exciton absorption observed here could be attributed to the 6s to 6p transition of Pb2+. The stability of the (RNH3)2PbI4 crystal was improved by doping these crystals into a PMMA matrix. © 1998 Chapman & Hall     

Nucleation studies in supersaturated aqueous solutions of (NH4)H2PO4 doped with (NH4)2C2O4·H2O

Induction periods were measured for various supersaturated aqueous solutions of ammonium dihydrogen orthophosphate doped with ammounium oxalate monohydrate by the direct vision method. Various critical nucleation parameters were calculated based on classical theory for homogeneous crystal nucleation and the results reported and discussed. The critical nucleation parameters increased with increase in doping concentration.     

Synthesis, structure, and properties of [Be(H2O)4][UO2(CH3COO)3]2

Crystals of previously unknown compound [Be(H₂O)₄][UO₂(CH₃COO)₃]₂ were prepared and studied by X-ray diffraction analysis. The compound crystallizes in the tetragonal system, unit cell parameters (at 100 K): a = 10.3647(3), c = 23.4127(8) Å, V = 2515.16(13) ų, space group I4₁/a, Z = 4, R = 0.0194. The structure consists of mononuclear complexes [Be(H₂O)₄]²⁺ and [UO₂(CH₃COO)₃]^? linked with each other by electrostatic interactions and hydrogen bonds formed by water molecules and O atoms of acetate anions. The compound was also studied by methods of thermal analysis and IR spectroscopy.     

Viscosity of [bmim][PF6] and [bmim][BF4] at High Pressure

The viscosities of 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim] [PF₆]) and 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF₄]) were measured by using a rolling-ball viscometer. The experimental temperatures were from 293.15 to 353.15 K, and the pressures were from 0.1 to 20.0 MPa.Paper presented at the Seventh Asian Thermophysical Properties Conference, August 23–28, 2004, Hefei and Huangshan, Anhui, P. R. China.     

A new three-dimensional open-framework iron(III) phosphate, [C2N2H10][Fe2(HPO4)4]

A new open-framework iron(III) phosphate, I, [C₂N₂H₁₀][Fe₂(HPO₄)₄] has been hydrothermally synthesized in the presence of ethylenediamine (en). The structure is built up from the vertex linkages between the FeO₆ octahedra and the PO₄ tetrahedra, strictly alternating, forming the three-dimensional architecture. The linkages between the FeO₆ and PO₄ polyhedra gives rise to ladder-like edge-shared chains, which are connected variously forming two types of channels. The di-protonated en molecules occupy these channels. Crystal data for I, [C₂N₂H₁₀][Fe₂P₄O₁₆]: a=9.341(1), b=8.892(1), c=9.480(1) Å, β=117.6(1)°, V=698.1(1) ų, space group P2/n (No. 13), Z=2, M=557.7, D_calc=2.65 g cm⁻³, MoKα (λ=0.71073 Å), R₁=0.03, wR₂=0.08 and S=1.10. Magnetic susceptibility studies indicate a predominantly antiferromagnetic interaction with T_N=30 K.     

离子液体[BMIM][BF_4]中CdS纳米棒的合成与表征

以室温离子液体1-甲基-3-丁基咪唑四氟硼酸盐为介质制备了CdS纳米棒,采用X射线衍射和透射电镜对样品进行了结构表征。结果表明所制备CdS纳米棒具有六方相结构,直径为30nm左右,长度为300nm左右。离子液体和长链烷胺的双重作用促使了CdS一维棒状结构的形成。离子液体同时起到了修饰剂和导向剂的作用。     

Growth imperfections in NH4H2PO4-KH2PO4 mixed crystals by X-ray topographic analysis

X-ray topographs of ammonium dihydrogen phosphate (ADP)—potassium dihydrogen phosphate (KDP) mixed crystals with various compositions were taken by the Lang transmission method. Growth imperfections such as growth bands, misorientations, lattice deformations at the boundary between two growth sectors and inclusions etc., present in the crystals were analysed. Dislocations were identified by using the g.b criterion.     

Synthesis,Crystal Structure,and Spectral Characteristics of the Np(V) Complex with Triphenylphosphine Oxide [NpO2(PO(C6H5)3)4]ClO4

Single crystals of [NpO₂(PO(C₆H₅)₃)₄]ClO₄ were grown and the structure of this compound was studied (CAD4 diffractometer, MoK ; triclinic unit cell: a = 9.140(2), b = 13.528(3), c = 13.918(3) Å, = 97.14(3)°, = 108.17(3)°, = 91.75(3)°, space group P-1, Z = 1, V = 1618.0 ų, d _{c a l c} = 1.521 g cm^-3; R ₁ = 0.0245 for 5342 observed reflections with F ₀ > 4(F ₀), wR ₂ = 0.0677 for 5601 unique reflections, 419 refined parameters). [NpO₂(PO(C₆H₅)₃)₄]ClO₄ consists of complex cations [NpO₂(PO(C₆H₅)₃)₄]⁺ and disordered ClO_4- anions. The Np(V) atom has tetragonal-bipyramidal oxygen surrounding with coordination number (CN) 6. The NpO₂ group is linear, the O = Np = O bond angle is 180.0°, and the Np = O bond length is 1.797(2) Å. The equatorial coordination plane of the bipyramid is formed by oxygen atoms of four triphenylphosphine oxide (TPPO) molecules. The Np-O_eq bond lengths vary from 2.434(2) to 2.442(2) Å (average 2.438 Å). The O_eq-Np-O_eq bond angle is close to the right angle (88.98°). The average bond lengths in TPPO ligands are P-O 1.498, P-C 1.798, and C-C 1.376 Å; the average bond angles are O-P-O 111.12°, C-P-C 107.78°, P-C-C 120.2, and C-C-C 120.0°. The electronic absorption spectra (Shimadzu UV-3100, 900-1050 nm) and IR spectra (Specord-M80, 400-4000 cm^{- 1}) of crystalline [NpO₂(PO(C₆H₅)₃)₄] were measured in an NaCl matrix. The absence of the main characteristic absorption band of the NpO₂ ⁺ dioxocation (980 nm) in the electronic absorption spectrum suggests centrosymmetrical equatorial surrounding of the Np(V) atom. The narrow absorption band ta_{a s}(NpO₂ ⁺) in the IR spectra in the region of 860 cm^-1 suggests the absence of cation-cation interaction, and its position is consistent with a short Np-O bond length in neptunyl(V) groups.