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 31 毫秒
1.
The thermal dehydration of mixtures of Ca(H2PO4)2·H2O with silicic acid and glauconite was studied by thermal (under dynamic and quasi-isothermal-quasi-isobaric conditions), X-ray and Chromatographic analyses.It was found that the dehydration of Ca(H2PO4)2·H2O is accelerated in the mixtures. SiO2·nH2O and glauconite react with the intermediates of dehydration of Ca(H2PO4)2·H2O, and silicophosphates and Al, K, Fe-phosphates are formed, respectively. The total degree of polymerization of calcium polyphosphates is lower in the mixtures than in Ca(PO3)2 itself.
Zusammenfassung Mittels röntgenographischer, chromatographischer und thermischer (unter dynamischen und quasi-isothermen-quasi-isobaren Bedingungen) Analyse wurde die thermische Dehydratation eines Gemisches aus Ca(H2PO4)2·H2O, KieselsÄure und Glaukonit untersucht.Es wurde festgestellt, da\ die Dehydratation von Ca(H2PO4)2·H2O im Gemisch beschleunigt ablÄuft. SiO2·nH2O und Glaukonit reagieren mit den Zwischenprodukten der Dehydratation von Ca(H2PO4)2·H2O und formen Silikophosphate und Al,K,Fe-Phosphate. Der totale Polymerisationsgrad von Calciumpolyphosphat ist im Gemisch geringer als in Ca(PO3)2 selbst.
  相似文献   

2.
Synthesis and characterization of new strontium 4-carboxyphenylphosphonates   总被引:1,自引:0,他引:1  
Several new strontium 4-carboxyphenylphosphonates, i.e., two modifications of Sr(HOOCC6H4PO3H)2, SrH(OOCC6H4PO3)·H2O, Sr3(OOCC6H4PO3)2·4H2O and Sr3(OOCC6H4PO3)2·5.7H2O were prepared and characterized by elemental analysis, thermogravimetry, X-ray powder diffraction and infrared spectroscopy. It was found that the compositions of these compounds depend on the acidity of the reaction medium. In addition, the presented compounds are interconvertible in dependence on pH. The position of the acid hydrogen atom in SrH(OOCC6H4PO3)·H2O was determined from the IR spectra of the studied compounds.The structure of the β modification of Sr(HOOCC6H4PO3H)2 was solved from its X-ray powder diffraction pattern using an ab initio method (the FOX program) with subsequent Rietveld refinement in the FULLPROF program. The compound is monoclinic, with the space group P21/c (No. 14), a=49.88(2), b=7.867(2), c=5.602(3) Å, β=128.68(2)°, and Z=4. It has a one-dimensional structure with an inorganic part built of SrO8 distorted tetragonal antiprisms.  相似文献   

3.
Three new copper 4-carboxyphenylphosphonates with formulae Cu(HOOCC6H4PO3)·2H2O, Cu(HOOCC6H4PO3) and Cu3(OOCC6H4PO3)2·3H2O were prepared and characterized by thermogravimetric analysis, X-ray diffraction analysis, energy-dispersive X-ray microanalysis and infrared spectroscopy. The preparation conditions of Cu(HOOCC6H4PO3)·2H2O and Cu3(OOCC6H4PO3)2·3H2O differ in the acidity of the reaction mixture, where Cu(HOOCC6H4PO3) was prepared under hydrothermal conditions. Copper 4-carboxyphenylphosphonate with formula Cu3(OOCC6H4PO3)2·3H2O reacts with 4-carboxyphenylphosphonic acid to form Cu(HOOCC6H4PO3)·2H2O.Cu(HOOCC6H4PO3)·2H2O is orthorhombic, space group Pbcn (no. 60), a=8.234(2) Å, b=9.438(2) Å, c=24.899(5) Å. Cu(HOOCC6H4PO3) crystallizes in the monoclinic space group P21/c (no. 14), a=19.0951(3), b=8.0968(4), c=5.2111(11) Å, β=94.914(6)°, Z=4. Its layered structure is composed of distorted CuO6 octahedra arranged hexagonally in a gibbsite-like manner around two phosphonate groups, which have their carboxyphenyl groups extending into the space above and below the copper–phosphonate layer. Infrared spectra indicate that for both Cu(HOOCC6H4PO3)·2H2O and Cu(HOOCC6H4PO3) the acid hydrogen is present at the carboxyl group and not at the phosphonic group.  相似文献   

4.
Hydrothermal reactions of divalent transition metal salts with imino-bis(methylphosphonic acid), NH(CH2PO3H2)2 (H4L) afforded three new metal phosphonates, namely, Cu[NH(CH2PO3H)2] 1, {Co[NH2(CH2PO3H)(CH2PO3)](H2O)2}·H2O 2 and Mn[NH2(CH2PO3H)(CH2PO3)](H2O) 3. When HO2C(CH2)3N(CH2PO3H2)2 was used as the phosphonate ligand and 4,4′-bipy as the second metal linker, {Cu4[NH(CH2PO3)2]2(4,4′-bipy)(H2O)4}·9H2O 4 with a pillared layered architecture was obtained. The NH(CH2PO3)2 anion resulted from the cleavage of the HO2C(CH2)3-group during the reaction. Although compounds 1-3 have a same M/L ratio (1:1), they exhibit totally different structures.Compound 1 has a linear chain structure, in which each pair of square-pyramidal coordinated copper(II) ions are bridged by two phosphonate oxygen atoms to form a Cu2O2 dimeric unit, and such dimeric units are further interconnected via phosphonate groups to form a [010] chain. Compound 2 has a layered architecture built from CoO6 octahedra bridged by phosphonate ligands. In compound 3, the interconnection of the manganese(II) ions by bridging imino-diphosphonate ligands leads to a 3D network. Compound 4 has a pillar-layered structure, the layers composed of Cu(II) ions bridged by aminodiphosphonate ligands are interconnected by 4,4′-bipy ligands to form channels along c-axis. Several factors that affect the structures of the metal phosphonates formed have also been discussed. Compounds 2 and 3 show predominant antiferromagnetic interactions between magnetic centers.  相似文献   

5.
An interesting series of nine new copper(II) complexes [Cu2L2(OAc)2]·H2O (1), [CuLNCS]·½H2O (2), [CuLNO3]·½H2O (3), [Cu(HL)Cl2]·H2O (4), [Cu2(HL)2(SO4)2]·4H2O (5), [CuLClO4]·½H2O (6), [CuLBr]·2H2O (7), [CuL2]·H2O (8) and [CuLN3]·CH3OH (9) of 2-benzoylpyridine-N(4)-phenyl semicarbazone (HL) have been synthesized and physico-chemically characterized. The tridentate character of the semicarbazone is inferred from IR spectra. Based on the EPR studies, spin Hamiltonian and bonding parameters have been calculated. The g values, calculated for all the complexes in frozen DMF, indicate the presence of the unpaired electron in the dx2-y2 orbital. The structure of the compound, [Cu2L2(OAc)2] (1a) has been resolved using single crystal X-ray diffraction studies. The crystal structure revealed monoclinic space group P21/n. The coordination geometry about the copper(II) in 1a is distorted square pyramidal with one pyridine nitrogen atom, the imino nitrogen, enolate oxygen and acetate oxygen in the basal plane, an acetate oxygen form adjacent moiety occupies the apical position, serving as a bridge to form a centrosymmetric dimeric structure.  相似文献   

6.
Decomposition of mineral sphene, CaTiOSiO4, by H3PO4 is investigated in detail. During the dissolution process, simultaneous calcium leaching and formation of titanium phosphate (TiP) take place. The main product of decomposition is a solid titanium phosphate-silica composite. The XRD, solid-sate NMR, IR, TGA, SEM and BET data were used to identify and characterize the composite as a mixture of crystalline Ti(HPO4)2·H2O and silica. When 80% phosphoric acid is used the decomposition degree is higher than 98% and calcium is completely transferred into the liquid phase. Formation of Ti(HPO4)2·H2O proceeds via formation of meta-stable titanium phosphate phases, Ti(H2PO4)(PO4)·2H2O and Ti(H2PO4)(PO4).The sorption affinities of TiP composites were examined in relation to caesium and strontium ions. A decrease of H3PO4 concentration leads to formation of composites with greater sorption properties. The maximum sorption capacity of TiP is observed when 60% H3PO4 is used in sphene decomposition.The work demonstrates a valuable option within the Ti(HPO4)2·H2O-SiO2 composite synthesis scheme, to use phosphoric acid flows for isolation of CaHPO4·2H2O fertilizer.  相似文献   

7.
The X-ray crystal structures of two ciprofloxacin compounds, viz. [Cu(cfH)2(Cl)2] · 2MeOH · 6H2O (2) and [Cu(cfH)(phen)Cl]BF4 · 4H2O (3) are reported. Complex (2) has a distorted octahedral geometry, whereas for the nitrogen adduct (3) a distorted square–pyramidal geometry is seen. Significant enhancement in the antimycobacterial activity of the copper conjugates correlates with their copper redox couples (Cu2+ /Cu+) probably due to its relevance to intracellular accumulations and subsequent role in generating oxidative stress.  相似文献   

8.
The reaction of copper(II) hydroxocarbonate, mandelic acid (H2MANO) and 2,2′-bipyridine (bpy) or 1,10-phenanthroline (phen) in water affords [Cu(bpy)(μ2-MANO)]2 · 8H2O (1), [Cu(bpy)(MANO)] · 4H2O (2) and the opened tetranuclear hydroxo-bridged copper(II) complexes of formulae [Cu43-OH)22-MANO)2(bpy)4](phglyo)2 · 8H2O (3) (phglyo = phenylglyoxylate) or [Cu43-OH)22-OH)2(OH2)2(phen)4](Bza)2(OH)2 · 5H2O (4) (Bza = benzoate), respectively. The compounds have been characterized by spectroscopic techniques and studied by single-crystal X-ray diffractometry. The formation of 3 and 4 takes place in basic media through dehydrogenation or oxidative dehydrogenation followed by in situ oxidative decarboxylation of mandelic acid to phenylglyoxylate or benzoate, respectively. These results indicate that cooperative catalysis of diimine ancillary ligands and copper(II) is essential.  相似文献   

9.
Amorphous calcium hydroxyapatite was examined by vibrational spectroscopy (Raman and infra-red (IR)) and quantum chemical simulation techniques. The structures and vibrational (IR, Raman and inelastic neutron scattering) spectra of PO43− ion, Ca3(PO4)2, [Ca3(PO4)2]3, Ca5(PO4)3OH, CaHPO4, [CaHPO4]2, Ca3(PO4)2·H2O, Ca3(PO4)2·2H2O and Ca3(PO4)2·3H2O clusters were quantum chemically simulated at ab initio and semiempirical levels of approximation. A complete coordinate analysis of the vibrational spectra was performed. The comparison of the theoretically simulated spectra with the experimental ones allows to identify correctly the phase composition of the amorphous calcium hydroxyapatite and related materials. The shape of the bands in the IR spectra of the hydroxoapatite can be used in order to characterize the structural properties of the material, e.g., the PO43− ion status, the degree of hydrolysis of the material and the presence of hydrolysis products.  相似文献   

10.
Four tetrahydrofuran-2,3,4,5-tetracarboxylato bridged copper(II) coordination polymers with alkali metals, Na2[Cu(H2O)(THFTC)]·5H2O 1, K2[Cu3(H2O)2(THFTC)2]·9H2O 2, Rb2[Cu3(H2O)2(THFTC)2]·6H2O 3 and Cs2[Cu3(H2O)2(THFTC)2]·6H2O 4 (H4THFTC = tetrahydrofuran-2,3,4,5-tetracarboxylic acid) were prepared from reactions of Cu(NO3)2·3H2O, tetrahydrofuran-2,3,4,5-tetracarboxylic acid and alkali hydroxide or carbonate at pH 5.0–6.0 under ambient conditions. Compound 1 features 2D (33·43·54) topological layers generated from six-coordinated Cu2+ cations interlinked by (THFTC)4− anions, and the resulting layers are ecliptically stacked along [1 0 0] direction to form lozenge-shaped and octagonal channels filled with Na+ ions and lattice H2O molecules. In 2–4, both penta- and hexa-coordinated copper(II) ions are bridged by tetracarboxylate anions to form negatively charged 2D layers formulated as 2[Cu(H2O)2L3/2]2− with the corresponding alkali metal cations (K+, Rb+ or Cs+ ions) and hydrogen bonded lattice H2O molecules sandwiched between them. Additionally, the results about i.r. spectroscopic, thermal characterizations and magnetic properties are presented.  相似文献   

11.
A new phosphate compound, Mg2KNa(PO4)2·14H2O, formed in the laboratory by cyanobacteria, has been identified and its crystal structure studied with single-crystal X-ray diffraction and infrared spectroscopy. The crystal is orthorhombic with the space group Pnma and unit-cell parameters a=25.1754(18) Å, b=6.9316(5) Å, c=11.2189(10) Å, V=1957.8(3) Å3. Its structure can be viewed as stacking of three types of layers along the a-axis in a sequence ABCBABCB…, where layer A is composed of Mg1(H2O)6 octahedra and Na(H2O)6 trigonal prisms, layer B of two crystallographically distinct PO43− tetrahedra (designated as P1 and P2), and layer C of Mg2(H2O)6 octahedra and highly irregular K-polyhedra formed by five H2O molecules and one O2− from the P2 tetrahedron. The linkage between layers is principally achieved through hydrogen bonding, except for the K-O5 bond between layers B and C. The structure of Mg2KNa(PO4)2·14H2O has many features similar to those for the struvite analogs of MgK(PO4)·6H2O (Acta Crystallogr. B 35 (1979) 11) or MgNa(PO4)·7H2O (Acta Crystallogr. B 38 (1982) 40) and represents the first struvite-type phosphate compound that contains both K and Na as univalent cations.  相似文献   

12.
Summary The new complexes K2[Ni(H2heo)2]·3H2O, K2[Pd-(H2heo)2], K2[Cu(heo)]·3H2O and [Cu2(heo)·2H2O] {heo = [(CONCH2CH2O)2]4-} were prepared and characterized by chemical analyses, conductivity measurements, thermogravimetry, magnetic susceptibility and i.r. and u.v. spectroscopy.Monomeric square planar structures with MN4 coordination spheres are found for the nickel and palladium complex anions.For copper, two different complexes were identified. In slightly alkaline media, a green insoluble nonelectrolyte [Cu2(heo)·2H2O] was prepared; the two copper(II) centres are bridged by the tetra-deprotonated ligand in a trans-planar configuration with the H2O molecules strongly coordinated to the copper(II). The copper(II) monomer has been prepared in strong alkaline media, this anion also contains the tetra-deprotonated ligand in a planar trans form.  相似文献   

13.
Six new copper(II) complexes, CuLCl·H2O (1), CuL(NO3)·2H2O (2), [Cu(L)2] (3), CuL(SCN)·2H2O (4), CuL(ClO4)·2H2O (5) and (CuL)2(SO4)·4H2O (6), where HL = 1-phenyl-2,3-dimethyl-4-(N-2-hydroxy-4-methoxy-benzaldehyde)-3-pyrazolin-5-one, have been synthesized. The characterization of the newly formed compounds was done by 1H NMR, UV-Vis, IR, ESR spectroscopy, elemental analysis and molar electric conductivity. The crystal structure of 1-phenyl-2,3-dimethyl-4-(N-2-hydroxy-4-methoxy-benzaldehyde)-3-pyrazolin-5-one has been determined by X-ray diffraction studies, as well as the crystal structure of one of its copper(II) complexes, [Cu(L)2] (3). The copper atom is coordinated to two nitrogen and two oxygen atoms of the Schiff base ligand. The in vitro antibacterial activity against Klebsiella pneumoniae ATCC 100131, Staphylococcus aureus var. Oxford 6538, Pseudomonas aeruginosa ATCC 9027 and Escherichia coli ATCC 10536 strains was studied and compared with that of free ligand. The anti-microbial activity was dependent on the microbial species tested and the metal salt anion used.  相似文献   

14.
Thermal analyses of synthetic and natural vivianite (Fe2+)3(PO4)2·8H2O) were determined using a high-resolution thermal analyser coupled to a mass spectrometer.Five dehydration weight loss steps were observed for the natural vivianite at 105, 138, 203, 272 and 437 °C. The first weight loss step involves the reaction (Fe2+)3(PO4)2·8H2O→(Fe2+)3(PO4)2·3H2O+5H2O. The TGA/MS for the synthetic vivianite gave similar results to that of the natural sample. Mass spectrometry shows that water is lost up to 450 °C and after this temperature oxygen is lost. Changes in the structure of vivianite were followed using infrared emission spectroscopy. A model is proposed for the dehydration of vivianite.  相似文献   

15.
The reaction of [Cu(L)](ClO4)2 · H2O (L=1,3,10,12,16,19-hexaazatetracyclo[17,3,1,112.16,04.9]tetracosane) with NaN3 and Na2tp yields mononuclear and dinuclear copper(II) complexes, [Cu(L)(N3)](ClO4) (1) and [Cu(L)(μ-tp)](ClO4) · 2H2O (2). These complexes have been characterized by X-ray crystallography, electronic absorption, cyclic voltammetry and magnetic susceptibility. The crystal structure of (1) shows that the copper(II) ion has a distorted square-pyramidal geometry with the two secondary and two tertiary amines of the macrocycle and one nitrogen atom from the azide group coordinating the axial position. The copper(II) ions in (2) are bridged by the terephthalate anion to form a dinuclear complex, in which each copper(II) ion reveals a distorted square-pyramid with four nitrogen atoms of the macrocycle and the oxygen atom of bridging tp ligand. Cyclic voltammetry of the complexes gives two one-electron waves corresponding to CuII/CuIII and CuII/CuI processes. The magnetic susceptibility measurement for (2) exhibits a weak antiferromagnetic interaction between copper(II) centers with a 2J value of −2.21 cm−1 (H = −2JΣS1 · S2). The electronic spectra and electrochemical behavior of the complexes are significantly affected by the nature of the organic ligands.  相似文献   

16.
Cadmium hydroxyapatite (Cd-Hap) crystals were synthesized by hydrothermal method at 200 °C using the solutions of Cd(NO3)2·4H2O and (NH4)2HPO4. Influences of pH values and reaction time on the crystalline phases and morphology of the products were investigated. In low pH reaction media, Cd5H2(PO4)4·4H2O was formed and a relatively high pH reaction media was necessary to obtain Cd-Hap. Morphology of the Cd-Hap crystals changed from stubby hexagonal prismatic to rod-like in shape with the increase in the pH value. This morphological change was explained by the difference in growth mechanism through intermediate phases, Cd5H2(PO4)4·4H2O in the low pH reaction media and Cd2P2O7·5H2O in the high pH reaction media.  相似文献   

17.
In order to deepen our understanding of the versatile behaviour of adenine (Hade) as ligand, we have synthesized four novel ternary copper(II) complexes having two deazaadenine ligands, namely 4-azabenzimidazole (H4abim) or 7-azaindole (H7azain) as N1,N6-dideazaadenine or N1,N6,N7-trideazaadenine, respectively. The related compounds were studied by thermal, spectral and single crystal X-ray diffraction methods. In [Cu(NBzIDA)(H4abim)]n (1) the recognition between H4abim and the (N-benzyliminodiacetate)-copper(II) chelate only displays the formation of the Cu–N7(purine-like) bond, in contrast to Hade behaviour in [Cu(NBzIDA-like)(Hade)(H2O)]·H2O (Cu–N3(Hade) bond reinforced by N9–H···O(IDA-like) interaction). In [Cu(EIDA)(H7azain)(H2O)] (2, EIDA = N-ethyliminodiacetate ligand), [Cu(NBzIDA)(H7azain)(H2O)] (3) and [Cu(μ2-SO4)(H7azain)2(H2O)2]n (4), H7azain binds Cu(II) centre by the Cu–N3(purine-like) bond, reinforced by a N9–H···O(IDA-like or sulfate) intra-molecular interligand interaction.  相似文献   

18.
Hydrothermal reactions of VOSO4·3H2O, CdAc2·2H2O, NiCl2·6H2O, H3PO4, and H2O yield the first example of trimetallic phosphate materials, [Ni(H2O)4]Cd(VO)(PO4)21. The single-crystal X-ray diffraction shows that its structure consists of Cd/V/O binary metal oxide lamellas decorated by PO4 tetrahedra, which are further pillared by NiO2(H2O)4 octahedra to generate a neutral 3-D framework containing two intercrossing 8-MR channels where the coordinated water molecules protrude into. Thermal and magnetic behaviors of this material were also measured. Crystal data: CdNiVP2O13H8, orthorhombic Ibca (No.73), a=7.1307(2) Å, b=18.6248(3) Å, c=14.8046(2) Å, V=1966.17(7) Å3, Z=8.  相似文献   

19.
The behaviour of thermal dehydrations of isomorphous complexes of calcium copper acetate hexahydrate, CaCu(CH3CO2)4·6H2O and calcium cadmium acetate hexahydrate, CaCd(CH3CO2)4· 6H2O was studied by means of thermal analyses and X-ray structural analysis. The enthalpy changes for the dehydration of CaCu(CH3CO2)4·6H2O and CaCd(CH3CO2)4·6H2O were 315±9.7 and 295±8.0 kJ mol–1, respectively. The DSC curves of the dehydrations indicated that the seemingly simple dehydrations are more complex than they appear at first sight. Apparent activation energies for the dehydrations of CaCu(CH3CO2)4·6H2O and CaCd(CH3CO2)4·6H2O were 85.7±7.4 and 87.9±12.5 kJ mol–1, respectively.The authors wish to express their thanks to Associate Professor Yasuhiko Yukawa of the Niigata University for the analysis of the X-ray-intensity data.  相似文献   

20.
Four copper complexes with similar trinuclear copper units, [Cu6(Bmshp)2(SO4)2(H2O)7]·2H2O (1), [Cu3(Bmshp)(ClO4)2(H2O)4]·5H2O (2), [Cu3(Bmshp)(DMF)4(H2O)2]·H2O·2DMF·2ClO4 (3) and [Cu3(H2Bcshp)(ClO4)2(H2O)4]·3H2O (4) (H4Bmshp = 2,6-bis[(3-methoxysalicylidene)hydrazinocarbonyl]pyridine, H6Bcshp = 2,6-bis[(3-carboxylsalicylidene)hydrazinocarbonyl]pyridine), were synthesized and characterized by elemental analysis, IR and single crystal X-ray diffraction analysis. Due to the different anions, solvents and ligands used in the syntheses, complexes 14 exhibit diverse supramolecular structures constructed from the corresponding trinuclear copper units via H-bonds.  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