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1.
The solid–liquid equilibria of the ternary system H 2O–Fe(NO 3) 3–Co(NO 3) 2 were studied by using a synthetic method based on conductivity measurements. Two isotherms were established at 0 and 15 °C, and the stable solid phases which appear are the iron nitrate nonahydrate (Fe(NO3)3·9H2O), the iron nitrate hexahydrate (Fe(NO3)3·6H2O), the cobalt nitrate hexahydrate (Co(NO3)2·6H2O) and the cobalt nitrate trihydrate (Co(NO3)2·3H2O). 相似文献
2.
Thermal decomposition taking place in solid state complex, NiC 2O 4·2H 2O, has been investigated in air by means of TG–DTG/DTA, DSC, XRD. TG–DTG/DTA curves showed that the decomposition proceeds through two well-defined steps with DTA peaks closely corresponding to the weight loss obtained. XRD showed that the final decomposition product of NiC 2O 4·2H 2O was NiO. Kinetics analysis of NiC 2O 4·2H 2O decomposition steps was performed under non-isothermal conditions. The activation energies were calculated through Friedman and Flynn–Wall–Ozawa (FWO) methods, and the most possible kinetic model function has been estimated through the multiple-linear regression method. The activation energies for the two decomposition steps of NiC 2O 4·2H 2O were 171.1 ± 4.2 and 174.4 ± 8.1 kJ/mol, respectively. 相似文献
3.
Thermal events encountered throughout the heat treatment of praseodymium acetate, Pr(CH 3COO) 3·H 2O, were studied in nitrogen and air atmospheres. The samples calcined at the 300–700 °C temperature range were characterized using XRD, IR and N 2 adsorption. Moreover, in situ electrical conductivity was employed to follow up the formation of the different decomposition intermediates. The results indicated that the anhydrous salt decomposes to the final product, PrO 1.833, through the formation of the following intermediates: Pr(OH)(CH 3COO) 2, PrO(CH 3COO) and Pr 2O 2(CO 3). PrO 1.833 formed at 500, 600, and 700 °C possesses a surface area of 17, 16 and 10 m 2/g and crystallites size of 14, 17 and 30 nm, respectively. 相似文献
4.
Hydrated strontium borate, SrB 4O 7·3H 2O, has been synthesized and characterized by XRD, FT-IR, DTA-TG and chemical analysis. The molar enthalpy of solution of SrB 4O 7·3H 2O in 1 mol dm −3 HCl(aq) was measured to be (21.15 ± 0.29) kJ mol −1. With incorporation of the previously determined enthalpies of solution of Sr(OH) 2·8H 2O(s) in [HCl(aq) + H 3BO 3(aq)] and H 3BO 3 in HCl(aq), and the enthalpies of formation of H 2O(l), Sr(OH) 2·8H 2O(s) and H 3BO 3(s), the enthalpy of formation of SrB 4O 7·3H 2O was found to be −(4286.7 ± 3.3) kJ mol −1. 相似文献
5.
Lamellar crystalline calcium phenylphosphonate, as anhydrous Ca(HO 3PC 6H 5) 2 and hydrated Ca(HO 3PC 6H 5) 2·2H 2O compounds, were used as hosts for intercalation of polar n-alkylmonoamine molecules of the general formula CH 3(CH 2) nNH 2 ( n=0–4, 7) in water or 1,2-dichloroethane. An increase in the interlayer distance was observed. The exothermic enthalpic values for intercalation increased with the number of carbon atoms and with increasing concentration of the amines. The intercalation followed by a titration procedure in the solid/liquid interface with Ca(HO 3PC 6H 5) 2·2H 2O and Ca(HO 3PC 6H 5) 2 gave the enthalpy/number of carbons correlations: Δ intH=−(1.74±0.43)–(1.30±0.13) nc and Δ intH=−(4.15±0.15)–(1.07±0.03) nc, for water and 1,2-dichloroethane, respectively. A similar correlation Δ intH=−(4.27±0.80)–(1.85±0.21) nc was obtained in water by using the ampoule breaking procedure for Ca(HO 3PC 6H 5) 2·2H 2O. The increase in exothermic enthalpic values with the increase in n-aliphatic carbon atoms is more pronounced for the anhydrous compound and also when using the ampoule breaking procedure. The Gibbs free energies are negative. Positive entropic values favor intercalation in these systems. 相似文献
6.
The reactions of Zn(NO 3) 2 · 6H 2O and FeSO 4 · 7H 2O with 4-PDS (4-PDS = 4,4′-dipyridyldisulfide) and NH 4SCN in CH 3OH afforded the complexes [Zn(NCS) 2(4-PDS)] n (1) and [Fe(NCS) 2(4-PDS) 2 · 4H 2O] n (2), respectively, while the reaction of CoCl 2 · 6H 2O with 4-PDS in CH 3OH gave the complex {[Co(4-PDS) 2][Cl] 2 · 2CH 3OH} n, (3). These complexes have been characterized by spectroscopic methods and their structures determined by X-ray crystallography. The 4-PDS ligands in 1 are coordinated to the metal centers through the nitrogen atoms to form 1-D zigzag-chains, and the distorted tetrahedral coordination geometry at each zinc center is completed by a pair of N-bonded thiocyanate ligands. Compound 2 has a 1-D channel-chain structure and each octahedral Fe(II) metal center is coordinated by four 4-PDS ligands and two trans N-bonded thiocyanate ligands. Weak SS interactions in complex 1 link the 1-D chains into 2-D molecular sheets. In complex 2, the channel chains are interlinked through SS interactions to form molecular sheets, which interpenetrate through the SS interactions to form 3-D structures with large cavities that are occupied by the water molecules. Compound 3 also has a 1-D channel-chain structure with each square-planar Co(II) metal center coordinated by four 4-PDS ligands. Multiple C–HCl hydrogen bonds and SO interactions in 3 link the 1-D chains into 2-D structures. 相似文献
7.
We reported here four structures of lanthanide–amino acid complexes obtained under near physiological pH conditions and their individual formula can be described as [Tb 2(dl-Cys) 4(H 2O) 8]Cl 2 (1), [Eu 4(μ 3-OH) 4(l-Asp) 2(l-HAsp) 3(H 2O) 7] Cl · 11.5H 2O (2), [Eu 8(l-HVal) 16(H 2O) 32]Cl 24 · 12.5H 2O (3), and [Tb 2(dl-HVal) 4(H 2O) 8]Cl 6 · 2H 2O (4). These complexes showed diverse structures and have shown potential application in DNA detection. We studied the interactions of the complexes with five single-stranded DNA and found different fluorescence enhancement, binding affinity and binding stoichiometry when the complexes are bound to DNA. 相似文献
8.
通过两步法合成铜掺杂的氧化锌纳米棒,通过X射线衍射(XRD)、扫描电子显微镜(FESEM)、透射电子显微镜(TEM)、X射线光电子能谱(XPS)和紫外-可见(UV-Vis)分光光谱等技术对系列样品进行了表征,研究并探索了铜掺杂的氧化锌纳米棒光降解染料罗丹明B(RhB)和气体乙醛的催化活性。通过对多孔Cu掺杂ZnO纳米棒光催化分解乙醛进行了评价。多孔Cu掺杂ZnO纳米棒(CZ-5)光催化剂具有最高的催化分解乙醛的能力,比其它多孔Cu掺杂ZnO纳米棒具有很高的催化活性。多孔Cu掺杂ZnO纳米棒光催化剂在室温下在可见光(435 nm)下照射16 h,5.50×10 -4( φ,体积分数)的乙醛气体完全降解为二氧化碳(CO 2)。多孔铜掺杂的氧化锌纳米棒光催化剂的光催化性能的改善主要归因于铜和氧化锌纳米棒之间的协同作用。这种改进的光催化协同作用归因于Cu掺杂ZnO的可见光吸收的延伸和光生电子空穴对的抗重组。 相似文献
9.
3,6,9-trioxaundecanedioic acid (3,6,9-tddaH 2) reacts with Mn(CH 3CO 2) 2·4H 2O in ethanol to give [Mn(3,6,9-tdda)]·H 2O (1). Recrystallization of 1 from methanol gives crystals of [Mn(3,6,9-tdda) (H 2O) 2]·2H 2O (2). Complex 1 reacts with an ethanolic solution of 1,10-phenanthroline (phen) to give {[Mn(3,6,9-tdda)(phen) 2]·3H 2O·EtOH} n (3). All of the complexes are extremely water soluble. Complexes 2 and 3 were structurally characterised. The manganese(II) ion in 2 is seven coordinate, with an approximately pentagonal bipyramidal O 7 coordination sphere. The axial donors are water molecules and the pentagonal plane is occupied by the diacid, acting as a pentadentate ligand through the three ethereal oxygens and one oxygen atom from each of the carboxylate functions. In complex 3 the manganese(II) ion is six-coordinate, being bound to two bidentate phenanthroline ligands and to the carboxylate oxygen atoms from two symmetry related diacids which are coordinated in a cis fashion. The structure consists of polymeric chains, with diacid ligands bridging the manganese ions. There is π-π stacking of pairs of phenanthroline ligands on adjacent chains, running along both the z and y directions. 相似文献
10.
The optimized structures and proton transfer reactions of 3-methyl-5-hydroxyisoxazole and its water complexes (3-M-5-HIO · (H 2O) n · ( n = 0–3)) were computed at B3LYP and MP2 theoretical level. The results indicates that 3-M-5-HIO has four isomers (Ecis, Etrans, K1 and K2), and the keto tautomer, and K2 is the most stable isomer in the gas phase. Hydrogen bonding between 3-M-5-HIO and the water molecules can dramatically lower the barrier by the concerted transfer mechanism. Ecis · (H 2O) 3 → K1 · (H 2O) 3 and Ecis · (H 2O) 2 → K2 · (H 2O) 2 is found to be very efficient. Comparing with the proton transfer mechanism of 5-HIO shows that the methyl substitution prevents the intramolecular proton transfer. 相似文献
11.
Two novel hydrogen maleato (HL) bridged Cu(II) complexes ∞1[Cu(phen)Cl(HL) 2/2] 1 and ∞1[Cu(phen)(NO 3)(HL) 2/2] 2 were obtained from reactions of 1,10-phenanthroline, maleic acid with CuCl 2·2H 2O and Cu(NO 3) 2·3H 2O, respectively, in CH 3OH/H 2O (1:1 v/v) at pH=2.0 and the crystal structures were determined by single crystal X-ray diffraction methods. Both complexes crystallize isostructurally in the monoclinic space group P2 1/ n with cell dimensions: 1 a=8.639(2) Å, b=15.614(3) Å, c=11.326(2) Å, β=94.67(3)°, Z=4, Dcalc=1.720 g/cm 3 and 2 a=8.544(1) Å, b=15.517(2) Å, c=12.160(1) Å, β=90.84(8)°, Z=4, Dcalc=1.734 g/cm 3. In both complexes, the square pyramidally coordinated Cu atoms are bridged by hydrogen maleato ligands into 1D chains with the coordinating phen ligands parallel on one side. Interdigitation of the chelating phen ligands of two neighbouring chains via π–π stacking interactions forms supramolecular double chains, which are then arranged in the crystal structures according to pseudo 1D close packing patterns. Both complexes exhibit similar paramagnetic behavior obeying Curie–Weiss laws χ m( T−θ)=0.414 cm 3 mol −1 K with the Weiss constants θ=−1.45, −1.0 K for 1 and 2, respectively. 相似文献
12.
Sintering behavior and bioactivity of diopside, CaMgSi 2O 6, prepared by a coprecipitation process were examined for its biomedical applicability. As-prepared powder was synthesized by adding aqueous ammonia to an ethanol solution containing Ca(NO 3) 2·4H 2O, Mg(NO 3) 2·6H 2O, and Si(OC 2H 5) 4 and characterized by means of TG–DTA, XRD, and TG–MS. The dried powder was X-ray amorphous and crystallized into diopside at 845.5 °C. The glass network formation by SiO 4 tetrahedra was almost completed below 800 °C. The bioactivity of the diopside prepared by sintering the compressed powder at 1100 °C for 2 h was evaluated by immersion of the sintered body in a simulated body fluid (SBF) at 36.5 °C. Leaf-like apatite particles were found to be formed on the surface of the sintered body and grew with passage of soaking time. This apatite-forming behavior in the SBF is related to the dissolution of Ca(II) ions from the sintered body in the early stage of immersion. Thus, diopside prepared by the coprecipitation process using the metal alkoxide and the metal salts was found to have an apatite-forming ability. 相似文献
13.
Three new aminodiphosphonates, namely M(phen)(AEDPH 3) 2·4H 2O (M = Zn, (1); Ni, (2)) and Cu(phen)(AEDPH 3) 2·H 2O (4), in addition to the previously reported Co(phen)(AEDPH 3) 2·4H 2O (3), Cu(2,2′-bipy)(H 2O)(HEDPH 2)·2H 2O (5), and Cu(phen)(H 2O)(HEDPH 2)·2H 2O (6) (AEDPH 4 = 1-aminoethylidenediphosphonic acid, HEDPH 4 = 1-hydroxyethylidenediphosphonic acid, phen = 1,10-phenanthroline and 2,2′-bipy = 2,2′-bipyridyl), have been synthesized and characterized. These compounds are all synthesized at the similar condition (80 °C), whereas they illustrate different frameworks. Compounds 1, 2 and 3 are isomorphous, which contain two same chelate and one six-coordinated metal ion, and display a three-dimensional (3D) supramolecular structure through hydrogen bonds and π–π stacking interactions. Compound 4 contains a chelate and a monodentate , while the Cu ion is five-coordinated. The coordination model of Cu 2+ in 4 is similar to that of 5 and 6. Comparing with four aminoethylidenediphosphonates, the difference of their structures is directed to the coordination model of the metal ions, while the three copper(II) diphosphonates illustrate different structures based on the deprotonized degree of the corresponding diphosphonic acids. 相似文献
14.
The infrared spectra of isotopically dilute (matrix-isolated HDO molecules) isostructural compounds M(HCOO) 2·2H 2O (M=Mn,Fe,Co,Ni,Zn,Cu) are presented and discussed in the region of the OD stretching modes. According to the structural data the compounds under study are divided into two groups: in M(HCOO) 2·2H 2O (M=Mn,Ni,Zn) the H 2O(1) molecules form stronger hydrogen bonds as compared to H 2O(2); in M(HCOO) 2·2H 2O (M=Fe,Co,Cu) the H 2O(2) molecules form stronger hydrogen bonds as compared to the H 2O(1) molecules. The influence of the metal–water interactions (synergetic effect) and the unit-cell volumes (repulsion potential of the lattice) on the hydrogen bond strength within the isostructural series is discussed. The wavenumbers of the uncoupled OD stretching modes of the HDO molecules influenced by guest ions (Cu 2+ ions matrix-isolated in M(HCOO) 2·2H 2O and M 2+ ions matrix-isolated in Cu(HCOO) 2·2H 2O) are presented and commented. For example, the analysis of the spectra reveals that when Cu 2+ ions are included in the structure of M(HCOO) 2·2H 2O the hydrogen bonds of the type M–OH 2OCHO–Cu are considerably weaker as compared to those of the same type formed when M 2+ ions are included in the structure of Cu(HCOO) 2·2H 2O if the cations remain unchanged. 相似文献
15.
The syntheses, crystal structures and characterizations of two new divalent metal carboxylate-phosphonates, namely, Zn(H 3L)·2H 2O (1) and Pb(H 3L)(H 2O) 2 (2) (H 5L4-HO 2C–C 6H 4–CH 2N(CH 2PO 3H 2) 2) have been reported. Compound 1 features a 1D column structure in which the Zn(II) ions are tetrahedrally coordinated by four phosphonate oxygen atoms from four phosphonate ligands, and neighboring such 1D building blocks are further interconnected via hydrogen bonds into a 3D network. The carboxylate group of H 3L anion remains non-coordinated. Compound 2 has a 2D layer structure. Pb(II) ion is 7-coordinated by four phosphonate oxygen atoms from four phosphonate ligands and three aqua ligands. The interconnection of Pb(II) ions via bridging H 3L anions results in a 001 layer. The carboxylate group of the H 3L anion also remains non-coordinated and is oriented toward the interlayer space. Solid state luminescent spectrum of compound 1 exhibits a strong broad blue fluorescent emission band at 455 nm under excitation at 365 nm at room temperature. 相似文献
16.
The compound [Zn(H 2O) 4] 2[H 2As 6V 15O 42(H 2O)]·2H 2O (1) has been synthesized and characterized by elemental analysis, IR, ESR, magnetic measurement, third-order nonlinear property study and single crystal X-ray diffraction analysis. The compound 1 crystallizes in trigonal space group R3, a= b=12.0601(17) Å, c=33.970(7) Å, γ=120°, V=4278.8(12) Å 3, Z=3 and R1( wR2)=0.0512 (0.1171). The crystal structure is constructed from [H 2As 6V 15O 42(H 2O)] 4− anions and [Zn(H 2O) 4] 2+ cations linked through hydrogen bonds into a network. The [H 2As 6V 15O 42(H 2O)] 6− cluster consists of 15 VO 5 square pyramids linked by three As 2O 5 handle-like units. 相似文献
17.
The investigation of europium(III) sulphate hydrate and samarium(III) sulphate hydrate was performed by thermal analysis (TG-DTG) and simultaneous infrared evolved gas analysis-Fourier transformed infrared (EGA-FTIR) spectroscopy. The TG, DTG and DTA curves were recorded at the 25–1400 °C in the dynamic air atmosphere by TG/DTA analyser. The infrared evolved gas analysis was obtained on the FTIR spectrometer. Eu 2(SO 4) 3· nH 2O ( n = 3.97) and Sm 2(SO 4) 3· nH 2O ( n = 8.11) were analysed, the dehydration and decomposition steps were investigated and the water content was calculated. The formation of different oxysulphates was studied. The trace rare earth elements in Eu and Sm sulphates were determined by ICP-MS. The concentration of trace Eu, Sm, La, Gd, Y and Ce ranged from 3.9 × 10−6 to 1.5 × 10−4% (m/m). 相似文献
18.
Six mononuclear complexes [M(L 1) 2(H 2O) 4] (M = Co(II), 1a and M = Mn(II), 1b), [Cu(L 1) 2(H 2O) 2] (1c), [Cu(L 1) 2(H 2O)(Py) 2] (1d), [Cu(L 3)(H 2O)Cl] · H 2O (3a) and [Co(Sal)(H 2O)(Py) 3] · 2ClO 4 · H 2O (3b) of phenoxyacetic acid derivatives and Schiff base were determined by single crystal X-ray diffraction. The Co(II) (1a) and Mn(II) (1b) complexes are isomorphous. X-ray crystal structural analyses reveal that these coordination complexes form polymeric structure via formation of different types of hydrogen bonding and π-stacking interactions in solid. Thermal analysis along with the powder X-ray diffraction data of these complexes shows the importance of the coordinated and/or crystal water molecules in stabilizing the MOF structure. Complexes 1a, 1c, 3a show marginal catalytic activity in the oxidation of olefins to epoxides in the presence of i-butyraldehyde and molecular oxygen. 相似文献
19.
TiO 2 nanoparticles and H 2Ti 2O 5·H 2O, Na 2Ti 2O 4(OH) 2 nanotubes were synthesized by solvothermal method and their applications in the degradation of active Brilliant-blue (KN-R) solution were investigated. The experimental results revealed that the synthesized TiO 2 nanoparticles had a good crystallinity and a narrow size distribution (about 4–5 nm); the obtained H 2Ti 2O 5·H 2O, Na 2Ti 2O 4(OH) 2 were tubelike products with an average diameter of 20–30 and 200–300 nm length. The three catalysts we synthesized had some hydroxyl groups and the maximum absorption boundaries of the samples were all red-shifted, which indicated the samples had a promising prospect in photocatalysis. The results of the photocatalytic experiments indicated that the photocatalytic activity of the samples was: TiO2 > H2Ti2O5·H2O > Na2Ti2O4(OH)2, which was in good accordance with the fact of FTIR and UV–vis absorption spectra. The formation mechanism of these nanostructures was also discussed. 相似文献
20.
Chromium doped (CH 3) 2NH 2Al(SO 4) 2·6H 2O (DMAAlS) and (CH 3) 2NH 2Ga(SO 4) 2·6H 2O (DMAGaS) single crystals were grown and investigated using the methods of optical spectroscopy. It was found that the Cr 3+ ions in the two crystals are situated in a strong crystal field in which the 2E state is the lowest. The single narrow R-line associated with the 2E– 4A 2 phosphorescence of Cr 3+ in DMAAlS in a ferroelectric phase indicates an undistorted octahedral site, whereas important distortion of O h symmetry and structural disorder was inferred from spectral data obtained with DMAGaS:Cr 3+ in a low temperature phase. Results of optical investigation are discussed taking into account the structural data. 相似文献
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