Ca(H2PO4)2-H3PO4-K2SO4体系中石膏晶型及形貌调控

为将Ca(H₂PO₄)₂制备KH₂PO₄过程中的石膏资源化利用,以H₃PO₄与CaCO₃反应制备Ca(H₂PO₄)₂溶液,并与K₂SO₄溶液反应,进行Ca(H₂PO₄)₂-H₃PO₄-K₂SO₄体系中石膏晶型和形貌调控研究。结果表明:通过改变反应时间、反应温度、SO^2-₄过量系数和CaO含量等参数可对Ca(H₂PO₄)₂-H₃PO₄-K₂SO₄体系中石膏晶型和形貌进行调控,制得短柱状α-CaSO₄·0.5H₂O。体系在温度高于95 ℃和CaO含量为3.0%~5.0%(质量分数,下同)时形成α-CaSO₄·0.5H₂O,在CaO含量为5.5%主要形成CaSO₄·2H₂O;反应时间长于20 min和SO^2-₄过量系数大于1.4将形成K₂SO₄(CaSO₄)₅·H₂O,导致石膏晶体表面缺陷增加。本实验条件下,适宜反应条件为:反应时间10 min、反应温度95 ℃、SO^2-₄过量系数1.2和CaO含量5.0%,此条件下可制得长度42~70 μm、直径13~24 μm的短柱状α-CaSO₄·0.5H₂O,其抗折和抗压强度分别可达5.61 MPa和33.74 MPa,滤液中钾收率和脱钙率分别可达94.23%和83.80%。     

NH4H2PO4晶体反铁电相的对称性及序参量

在反铁电晶体NH4H2PO4(ADP)顺电反铁电相变中,对称性所属点群也随之发生相应的改变.通过对实验结果的分析,我们认为NH4H2PO4(ADP)晶体反铁电相对称性所属点群为P2(C2).选用轴矢量R作为序参量来描述NH4H2PO4(ADP)晶体反铁电相变中对称性的变化,应用居里原理,恰能得到NH4H2PO4(ADP)晶体反铁电相的正确对称性所属点群P2(C2).     

Crystal structure of N-benzylmethylammonium dihydrogen-monophosphate monohydrate, [C6H5CH2NH2CH3]H2PO4·H2O

The salt N-benzylmethylammonium dihydrogenmonophosphate monohydrate is monoclinic with the following unit cell dimensions: a = 6.356(1)Å, b = 8.385(7)Å, c = 11.472(5)Å, = 104.32(1)°, space group P2₁ with Z = 2. The structure consists of infinite parallel two-dimensional [110] planes built of mutually connected ions and water molecules by strong O–H···O and N–H···O hydrogen bonding. There are no contacts other than normal van der Waals interactions between the layers.     

层状结构钒磷酸盐(H2 NC4 H8 NH2)0.5[(VO)(PO4)]的水热合成及热稳定性

采用新配方水热合成了层状结构钒磷酸盐(H2 NC4 H8 NH2)0.5[(VO)(PO4)],用ICP、TG-DTA、单晶XRD和动态XRD对合成物进行了表征.结果表明,该化合物有机模板的开始分解温度,在空气气氛中为343℃,在氮气气氛中为376℃.有机模板的分解逃逸导致了结构的破坏.随着温度的升高结构发生重组,约760 ℃时形成(VO)2P2O7;温度继续升高,(VO)2P2O7进一步氧化,形成钒磷氧化物新物相.与结构相似化合物(H3 NCH2 CH2 NH3)[(VO)(PO4)]的热稳定性比较表明,有机模板的热稳定性及其与无机骨架结合的牢固性影响化合物的热行为.     

Synthesis and structure determination of a new layered zincophosphate: [H2N2C6H16]0.5[Zn2(PO4)(HPO4)(H2O)]·H2O

The synthesis and crystal structure of a new microporous zincophosphate are described. [H₂N₂C₆H₁₆]_0.5[Zn₂(PO₄)(HPO₄)(H₂O)]·H₂O crystallizes in the triclinic space group P1¯ with a = 8.822(4), b = 9.236(4), c = 8.451(3) Å, = 67.19(3), = 91.32(3), = 111.10(3)°, V = 586.7(4) ų and Z = 2. This new material consists of infinite two-dimensional anionic layers alternated with planes containing organic diprotonated templates, N, N, N, N-tetramethylethylenediamine [H₂N₂C₆H₁₆]²⁺ molecules. The framework structure is built up of ZnO₄, ZnO₃OH₂, PO₄, and PO₃OH tetrahedra, linked through oxygen vertices. The presence of terminal OH₂ and OH groups, leads to an open structure containing four- and eight-rings. The organic molecules are interconnected to the framework through hydrogen bonds.     

HPO42-与H2PO4-在水热法制备CeO2纳米颗粒过程中的影响

以Ce(NO3)3·6H2O、Na5P3O10和Na3PO4·12H2O为原料,用水热法在180℃反应60h分别制备了CeO2纳米八面体和纳米棒,且对Na5P3O10与Na3PO4 · 12H2O系统同时调节pH =2时180℃反应12 h制备了纳米棒.通过XRD、FE-SEM、TEM等方法对CeO2纳米棒和纳米八面体进行了测试和分析.结果表明,对于Na5P3O10与Na3PO4·12H2O系统,初始时CeO2八面体与纳米棒共存,但随着水热时间的延长,Na5 P3O10系统中CeO2八面体成为主要产物,而在Na3PO4·12H2O系统中CeO2纳米棒成为主要产物.Na5P3O10水解产生的HPO42-是CeO2纳米八面体形成的主要原因,而Na3PO4·12H2O水解产生的H2PO4-是纳米棒形成的主要原因.     

Hydrothermal synthesis and X-ray structure: A reduced titanic molybdenum(V) phosphate (NH3CH2CH2NH2)5Na [Ti2Mo12O30(PO4)(HPO4)4(H2PO4)3]⋅6H2O

A novel titanic molybdenum(V) phosphate (NH₃CH₂CH₂NH₂)₅Na [Ti₂Mo₁₂O₃₀(PO₄) (HPO₄)₄(H₂PO₄)₃]6H₂O crystallizes in the triclinic space group P1 with a = 12.057(3) Å, b = 14.668(2) Å, c = 21.2680(10) Å, = 80.840(10)°, = 82.960(10)°, = 76.65(2)°, and D _c = 2.707 g cm^–3 for Z = 2, Refinement based on 12,037 observed reflections led to R = 0.0609. The result of single crystal x-ray diffraction revealed the presence of a tunnel and two crystallographically independent clusters in the solid state structure. The plane layers in its solid-state structure are interconnected in-sheet (axial) through multipoint hydrogen bonding between the ethylenediamine nitrogen atoms and the cluster oxygen atoms.     

孔道结构铁磷酸盐(C4H12N2)2[Fe6(HPO4)2(PO4)6(H2O)2]·H2O的水热合成及热变化过程研究

在与前人不同的条件下水热合成了孔道结构铁磷酸盐(C4H12N2)2[Fe6(HPO4)2(PO4)6(H2O)2]·H2O.用ICP、有机元素分析仪、TG-DTA、变温XRD、变温FT-IR等分析技术对其成份、物相和热变化过程进行了系统研究.结果表明,室温-330℃,化合物失去吸附水,有机模板哌嗪开始氧化脱氢;330-380℃,哌嗪环破坏,大部分有机模板和结晶水脱除,化合物结构骨架明显破坏;470℃化合物完全非晶化;650℃形成FePO4和Fe4(P2O7)3新物相.哌嗪起到平衡电荷和支撑结构的作用.哌嗪环破坏并脱除是导致结构破坏的根本原因.     

Compositions of supersaturated solutions for enhanced growth of α-NiSO4 · 6H2O, Me 2Ni(SO4)2 · 6H2O, MeH2PO4 [Me = Li, Na, K, Rb, Cs, NH4], and K(H x D1−x )2PO4 single crystals

The possibility of determining the optimal compositions and temperatures of supersaturated solutions for enhanced growth of single crystals of congruently and incongruently dissolving solid phases from the solubility diagrams of ternary systems is shown, and this approach is justified. The NiSO₄-H₂SO₄-H₂O, Me ₂SO₄-NiSO₄-H₂O, and Me ₂O-P₂O₅-H₂O(D₂O) systems have been used to determine the optimal compositions and temperatures of supersaturated solutions for growth of α-NiSO₄ · 6H₂O, Me ₂Ni(SO₄)₂ · 6H₂O, MeH₂PO₄ [Me = Li, Na, K, Rb, Cs, NH₄], and K (H _x D_1?x )₂PO₄ (D is deuterium) single crystals.     

Database Survey of Single-and-Half Phosphorus–Oxygen Bonds in Salts with the C2PO2 Segment: Crystal Structure of [NH2C5H4NH][(C6H5)2P(O)(O)]⋅2H2O

Crystallography Reports - For structures with a C2PO2 skeleton, a comparison of “single-and-half” phosphorus–oxygen bonds with single and double phosphorus–oxygen bonds is...     

孔道结构铁磷酸盐（C4H12N2）2[Fe6（HPO4）2（PO4）6（H2O）2]·H2O的水热合成及热变化过程研究

在与前人不同的条件下水热合成了孔道结构铁磷酸盐（C4H12N2）2[Fe6（HPO4）2（PO4）6（H2O）2]·H2O。用ICP、有机元素分析仪、TG-DTA、变温XRD、变温FT-IR等分析技术对其成份、物相和热变化过程进行了系统研究。结果表明,室温～330℃,化合物失去吸附水,有机模板哌嗪开始氧化脱氢;330～380℃,哌嗪环破坏,大部分有机模板和结晶水脱除,化合物结构骨架明显破坏;470℃化合物完全非晶化;650℃形成FePO4和Fe4（P2O7）3新物相。哌嗪起到平衡电荷和支撑结构的作用。哌嗪环破坏并脱除是导致结构破坏的根本原因。     

Crystal Packing of Potentially Mesomorphic Azobenezene Derivatives R1–C6H4–N=N–C6H4–R2 (R1, R2 = CH3COO,C2H5O; CH2=C(CH3)COO,C2H5; C6H13COO,C2H5O)

Crystallography Reports - The structure and thermal properties of azobenzene derivatives R1–C6H4–N=N–C6H4–R2, where R1/R2 = CH3COO/C2H5O (I), CH2=C(CH3)COO/C2H5 (II), or...     

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.     

Local structure around phosphorus and silicon in the CaO–SiO2–PO2.5 system

The local structure of phosphorus and silicon in the molten CaO–SiO₂–PO_2.5 slag system was investigated by magic angle spinning nuclear magnetic resonance (MAS-NMR). The ³¹P MAS-NMR spectra revealed that phosphorus was present primarily as the monophosphate complex ion PO₄^3?, with a small amount of diphosphate ion also present. Their relative ratio to total phosphorus was independent of the phosphate concentration of the sample. In the case of the ²⁹Si MAS-NMR, the mean number of the non-bridging oxygen atoms associated with tetrahedrally coordinated silicon decreased as the phosphate concentration increased at a fixed CaO/SiO₂ ratio. This indicates that the nonbridging oxygen atoms around the silicon were replaced by bridging oxygen atoms around the phosphorus as the phosphate concentration in the samples increased.To elucidate the basicity dependence of the structure of slag, the relationship between the structure and optical basicity was also investigated. The relative ratio of Qⁿ (Qⁿ means the silicon atoms tetrahedrally bonded with “n” number of bridging oxygen atoms) strongly depends on the optical basicity. These optical basicity dependencies of the structures of phosphorus and silicon can be explained clearly by the basicity equalization concept (Duffy and Ingram, 1976) [12].     

尖晶石LiMn2O4表面包覆TiO2与LiTi2(PO4)3及其性质研究

采用湿化学法对LiMn2O4进行TiO2及LiTi2 (PO4)3表面包覆.采用X射线衍射仪、扫描电镜、恒电流充放电等技术对合成产物进行物相、形貌和电化学分析.结果表明:TiO2及LiTi2(PO4)3包覆LiMn2O4与未包覆LiMn2O4具有相似的X射线衍射结果.室温和55℃以0.5C倍率充放电循环20次后,TiO2包覆LiMn2O4的容量保持率分别为98.2;和95.3;,LiTi2(PO4)3包覆LiMn2O4的容量保持率分别为99.1;和96.8;,高于未包覆LiMn2O4的94.6;和92.2;.表面包覆LiTi2(PO4)3后LiMn2O4的锂离子扩散系数变化不大,但包覆TiO2后的锂离子扩散系数略有下降.     

Production of Complex Hydrosulphates in the K3H(SO4)2–Rb3H(SO4)2 Series: Part I

Crystallography Reports - The phase equilibria in the K3H(SO4)2–Rb3H(SO4)2–H2O cross section have been investigated under isothermal conditions at 25°C. The concentration limits of...     

层状结构钒磷酸盐(pipzH2)2[(VO)3(HPO4)2(PO4)2]·H2O的水热合成及热稳定性研究

水热合成了钒磷酸盐体系中少有的结构中具有多面体共棱连接的层状孔道结构化合物(pipzH2)2[(VO)3(HPO4)2(PO4)2]·H2O的纯相.用ICP、单晶XRD、TG-DTA、粉晶XRD和SEM对产物进行了表征.结果表明,化合物在空气中开始失重的温度为274 ℃,随着温度的升高,化合物中有机分子分解,同时伴随着重结晶过程,但晶体的外观形貌保持不变直至有机部分分解殆尽.相变过程分析和与模板相同的(pipzH2)0.5[(VO)(PO4)]的热稳定性对比研究表明,有机模板的稳定性及分解过程不但影响化合物的热稳定性和热变化过程,还影响原晶体微形貌的保持;无机骨架结合的牢固程度在很大程度上影响化合物的热稳定性.     

Crystal structures of acid ethylenediaminetetraacetates [Cd(H2 Edta)(H2O)] · 2H2O and [Mn(H2O)4][Mn(HEdta)(H2O)]2 · 4H2O

The crystal structures of [Cd(H₂ Edta)(H₂O)] · 2H₂O (I) and [Mn(H₂O)₄][Mn(HEdta)(H₂O)]₂ · 4H₂O (II) are studied by X-ray diffraction [R ₁ = 0.0209 (0.0272), wR ₂ = 0.0571 (0.0730) for 2551 (4025) reflections with I > 2σ(I) in I (II), respectively]. Structure I contains mononuclear [Cd(H₂ Edta)(H₂O)] complexes with the C ₂ symmetry, and structure II contains centrosymmetric trinuclear [Mn(H₂O)₄][Mn(HEdta)(H₂O)]₂ complexes. In I and II, the protonated ligands are hexadentate (2N + 4O), and the water molecule increases the coordination number of the metal atom to seven. The acid protons participate in short intermolecular hydrogen bonds, which are symmetric in II and asymmetric in I.     

Diphosphine ligand substitution in H4Ru4(CO)12: X-ray diffraction structures and reactivity studies of the cluster compounds H4Ru4(CO)10(P–P) [where P–P–(Z)–Ph2PCH–CHPPh2, bpcd]

The tetraruthenium cluster H₄Ru₄(CO)₁₂ (1) has been studied for its reactivity with the unsaturated diphosphine ligands (Z)–Ph₂PCH–CHPPh₂ and 4,5-bis(diphenylphosphino)-4-cyclopenten-1,3-dione (bpcd) under thermal, near-UV photolysis, and Me₃NO-assisted activation. All three cluster activation methods promote loss of CO and furnish the anticipated substitution products H₄Ru₄(CO)₁₀[(Z)–Ph₂PCH–CHPPh₂] (2) and H₄Ru₄(CO)₁₀(bpcd) (3) that possess a chelating diphosphine ligand. Clusters 2 and 3 have been characterized in solution by IR and NMR spectroscopies, and these data are discussed with respect to the crystallographically determined structure for both new cluster compounds. The ³¹P NMR spectral data and the solid-state structures confirm the presence of a chelating diphosphine ligand in clusters 2 and 3. Cluster 2 crystallizes in the monoclinic space P2₁/c, a=11.768(6) ?, b=18.521(9) ?, c=20.48(1) ?, β=102.291(8)°, V=4361(4) A³, Z=4, and d _calc=1.726 Mg/m³; R=0.0225, R _w=0.0491 for 6798 reflections with I > 2σ(I). The four bridging hydrides were located in H₄Ru₄(CO)₁₀[(Z)–Ph₂PCH–CHPPh₂] and their adopted positions are discussed relative to the solution ¹H NMR spectrum. H₄Ru₄(CO)₁₀(bpcd) crystallizes in the orthorhombic space Pbca, a=19.072(3) ?, b=20.169(3) ?, c=22.774(3) ?, V=8760(2) A³, Z=8, and d _calc=1.870 Mg/m³; R=0.0428, R _w=0.0896 for 10296 reflections with I > 2σ(I). Sealed NMR tubes containing clusters 2 and 3 were found to be exceeding stable towards near-UV light and temperatures up to ca. 125 °C. The surprisingly robust behavior of 2 and 3 is contrasted with the related cluster Ru₃(CO)₁₀(bpcd) that undergoes fragmentation to the donor-acceptor compound Ru₂(CO)₆(bpcd) and the phosphido-bridged compound Ru₂(CO)₆(μ–PPh₂)[μ–C–C(PPh₂)C(O)CH₂C(O)] under mild conditions. The electrochemical properties of each substituted cluster have been investigated by cyclic voltammetry, and our findings are discussed with respect to the reported electrochemical data on the parent cluster H₄Ru₄(CO)₁₂.