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1.
The (pρT) of methanol, ethylbenzene and (methanol + benzene) and (methanol + ethylbenzene) at temperatures between (290 and 500) K and pressures in the range (0.1 to 60) MPa have been measured with a magnetic suspension densimeter with an uncertainty of ±0.1%. Our measurements with methanol deviate from the literature values by less than 0.2%. The (pρT) measurements were fitted with experimental uncertainties by an empirical equation. The temperature and mole fraction dependence of the coefficients of the equation of state are presented.  相似文献   

2.
Total vapour pressures, measured at the temperature 313.15 K, are reported for the ternary mixture (N,N-dimethylacetamide + methanol + water), and for binary constituents (N,N-dimethylacetamide + methanol) and (N,N-dimethylacetamide + water). The present results are compared with previously obtained data for binary mixtures (amide + water) and (amide + methanol), where amide=N-methylformamide, N,N-dimethylformamide, N-methyl-acetamide, 2-pyrrolidinone and N-methylpyrrolidinone. Moreover, it was found that excess Gibbs free energy of mixing for binary mixtures varies roughly linearly with the molar volume of amide.  相似文献   

3.
New compounds of the type M2(H2F3)(HF2)2(AF6) with M = Ca, A = As and M = Sr, A = As, P) were isolated. Ca2(H2F3)(HF2)2(AsF6) was prepared from Ca(AsF6)2 with repeated additions of neutral anhydrous hydrogen fluoride (aHF). It crystallizes in a space group P4322 with a = 714.67(10) pm, c = 1754.8(3) pm, V = 0.8963(2) nm3 and Z = 4. Sr2(H2F3)(HF2)2(AsF6) was prepared at room temperature by dissolving SrF2 in aHF acidified with AsF5 in mole ratio SrF2:AsF5 = 2:1. It crystallizes in a space group P4322 with a = 746.00(12) pm, c = 1805.1(5) pm, V = 1.0046(4) nm3 and Z = 4. Sr2(H2F3)(HF2)2(PF6) was prepared from Sr(XeF2)n(PF6)2 in neutral aHF. It crystallizes in a space group P4122 with a = 737.0(3) pm, c = 1793.7(14) pm, V = 0.9744(9) nm3 and Z = 4. The compounds M2(H2F3)(HF2)2(AF6) gradually lose HF at room temperature in a dynamic vacuum or during being powdered for recording IR spectra or X-ray powder ray diffraction patterns. All compounds are isotypical with coordination of nine fluorine atoms around a metal center forming a distorted Archimedian antiprism with one face capped. This is the first example of the compounds in which H2F3 and HF2 anions simultaneously bridge metal centers forming close packed three-dimensional network of polymeric compounds with low solubility in aHF. The HF2 anions are asymmetric with usual F?F distances of 227.3-228.5 pm. Vibrational frequency (ν1) of HF2 is close to that in NaHF2. The anion H2F3 exhibits unusually small F?F?F angle of 95.1°-97.6° most probably as a consequence of close packed structure.  相似文献   

4.
(Liquid + liquid) equilibrium (LLE) data for the {water + acetic acid + dibasic esters mixture (dimethyl adipate + dimethyl glutarate + dimethyl succinate)} system have been determined experimentally at T = (298.2, 308.2, and 318.2) K. Complete phase diagrams were obtained by determining solubility curve and tie-line data. The reliability of the experimental tie-line data was confirmed by using the Othmer-Tobias correlation. The UNIFAC model was used to predict the phase equilibrium in the system using the interaction parameters determined from experimental data between CH2, CH3COO, CH3, COOH, and H2O functional groups. Distribution coefficients and separation factors were compared with previous studies.  相似文献   

5.
Ph2SiCl2 and PhMeSiCl2 react with Li2E (E = S, Se, Te) under formation of trimeric diorganosilicon chalcogenides (PhRSiE)3 (R = Ph: 1a-3a, R = Me: cis/trans-4a (E = S), cis/trans-5a (E = Se)). In case of E = S, Se dimeric four-membered ring compounds (PhRSiE)2 (R = Ph: 1b-2b, R = Me: cis/trans-4b (E = S), cis/trans-5b (E = Se)) have been observed as by-products. 1a-5b have been characterized by multinuclear NMR spectroscopy (1H, 13C, 29Si, 77Se, 125Te). Four- and six-membered ring compounds differ significantly in 29Si and 77Se chemical shifts as well as in the value of 1JSiSe.The molecular structures of 2a, 3a and trans-5a reported in this paper are the first examples of compounds with unfused six-membered rings Si3E3 (E = Se, Te). The Si3E3 rings adopt twisted boat conformations. The crystal structure of 3a reveals an intermolecular Te-Te contact of 3.858 Å which yields a dimerization in the solid state.  相似文献   

6.
(Liquid + liquid) equilibrium (LLE) data for (water + propionic acid + cyclohexanone) were measured under atmospheric pressure and at T = (293.2, 298.2 and 303.2) K. Phase diagrams were obtained by determining solubility and tie-line data. The LLE data of the ternary systems were predicted by UNIFAC method. Distribution coefficients and separation factors were evaluated over the immiscibility regions.  相似文献   

7.
The series of cis/trans-trifluoromethylselenato complexes [Pt(SeCF3)2 − xClx(PPh3)2] (x = 0, 1) was identified by NMR spectroscopic methods. While in acetonitrile solution spectra are dominated by the resonances of the cis derivatives, those of pure cis-[Pt(SeCF3)2(PPh3)2] indicate cis-trans-isomerisation in CH2Cl2 solution. In contrast, exchange reactions of cis-[PtCl2(PPh3)2] and [NMe4]TeCF3 only gave evidence for cis isomers. Molecular structures of cis- and trans-[Pt(SeCF3)2(PPh3)2] and cis-[Pt(TeCF3)2(PPh3)2] are discussed in comparison with related compounds.  相似文献   

8.
(Liquid + liquid) equilibrium (LLE) data of the solubility (binodal) curves and tie-line end composition were examined for mixtures of {water (1) + propionic acid (2) + octanol or nonanol or decanol or dodecanol (3)} at T = 298.15 K and 101.3 ± 0.7 kPa. The reliability of the experimental tie-line data was confirmed by using the Othmer-Tobias correlation. The LLE data of the ternary systems were predicted by UNIFAC method. Distribution coefficients and separation factors were evaluated for the immiscibility region.  相似文献   

9.
Electrochemical deposition of PbTe from 50 mM Pb(NO3)2 + 1 mM TeO2 + 0.1 M HNO3 solution onto n-Si(1 0 0) wafers was studied using cyclic voltammetry (CV), chronoamperometry, ex situ SEM, XRD and EDX. Electrochemical behavior of n-Si(1 0 0) electrode in electrolytes 50 mM Pb(NO3)2 + 0.1 M HNO3 and 1 mM TeO2 + 0.1 M HNO3 was also studied. No underpotential deposition (UPD) of Pb and Te onto n-Si was observed in the investigated systems indicating weak Pb–Si and Te–Si interactions. Deposition of Pb and Te on n-Si occurred with overvoltage via 3D island growth. Electrosynthesis of PbTe (NaCl-like structure, a = 0.650 nm) takes place due to codeposition of Pb and Te at potentials E > EPb2+/Pb0 (lead UPD onto tellurium). Cathodic deposition of PbTe onto n-Si(1 0 0) is irreversible – there is no anodic current in the CV curve. Oxidation of PbTe on n-Si is observed only under illumination, when photoelectrons and photoholes are generated in silicon substrate.  相似文献   

10.
Schiff base N,N′-bis(salicylidene)-p-phenylenediamine (LH2) complexed with Pt(en)Cl2 and Pd(en)Cl2 provided [Pt(en)L]2 · 4PF6 (1) and Pd(Salen) (2) (Salen = N,N′-bis(salicylidene)-ethylenediamine), respectively, which were characterized by their elemental analysis, spectroscopic data and X-ray data. A solid complex obtained by the reaction of hexafluorobenzene (hfb) with the representative complex 1 has been isolated and characterized as 3 (1 · hfb) using UV–Vis, NMR (1H, 13C and 19F) data. A solid complex of hfb with a reported Zn-cyclophane 4 has also been prepared and characterized 5 (4 · hfb) for comparison with complex 3. The association of hfb with 1 and 4 has also been monitored using UV–Vis and luminescence data.  相似文献   

11.
The crystal structure of tricarbonyl-6,6′-dimethylfulvene chromium(0) was determined using X-ray diffraction at room temperature and at 120 K. The title compound crystallizes in the centrosymmetric, monoclinic space group P21/n (no. 14) with one complete molecule in the asymmetric unit. The deviation of the chromium(0) complex from Cs(m) symmetry is negligible in agreement with results derived from density functional calculations using three different methods as well as ab initio calculations (MP2). The 6,6′-dimethylfulvene ligand is bent by 30.9° as a result of the π-η2:π-η2:π-η2 coordination to the Cr(0) metal. In addition, the chromium(0) complex was studied by IR and Raman spectroscopy and selected vibrational data are compared to values derived from DFT calculations.  相似文献   

12.
We describe reactions of [99mTc(H2O)3(CO)3)]+ (1) with Diels-Alder products of cyclopentadiene such as “Thiele’s acid” (HCp-COOH)2 (2) and derivatives thereof in which the corresponding [(Cp-COOH)99mTc(CO)3)] (3) complex did form in water. We propose a metal mediated Diels-Alder reaction mechanism. To show that this reaction was not limited to carboxylate groups, we synthesized conjugates of 2 (HCp-CONHR)2 (4a-c) (4a, R = benzyl amine; 4b, R = Nα-Boc-l-2,3-diaminopropionic acid and 4c, R = glycine). The corresponding 99mTc complexes [(4a)99mTc(CO)3)] 6a, [(4b)99mTc(CO)3)] 6b and [(4c)99mTc(CO)3)] 6c have been prepared along the same route as for Thiele’s acid in aqueous media demonstrating the general applicability of this synthetic strategy. The authenticity of the 99mTc complexes on the no carrier added level have been confirmed by chromatographic comparison with the structurally characterized manganese or rhenium complexes.Studies of the reaction of 1 with Thiele’s acid bound to a solid phase resin demonstrated the formation of [(Cp-COOH)99mTc(CO)3)] 3 in a heterogeneous reaction. This is the first evidence for the formation of no carrier added 99mTc radiopharmaceuticals containing cyclopentadienyl ligands via solid phase syntheses. Macroscopically, the manganese analogue 5a and the rhenium complexes 5b-c have been prepared and characterized by IR, NMR, ESI-MS and X-ray crystallography for 5a (monoclinic, P21/c, a = 9.8696(2) Å, b = 25.8533(4) Å, c = 11.8414(2) Å, β = 98.7322(17)°) in order to unambiguously assign the authenticity of the corresponding 99mTc complexes.  相似文献   

13.
(Liquid + liquid) equilibrium (LLE) data for ternary system {heptane (1) + m-xylene (2) + N-formylmorpholine (3)} have been determined experimentally at temperatures ranging from 298.15 K to 353.15 K. Complete phase diagrams were obtained by determining solubility and tie-line data. Tie-line compositions were correlated by Othmer-Tobias and Bachman methods. The universal quasichemical activity coefficient (UNIQUAC) and The non-random two liquids equation (NRTL) were used to correlate the phase equilibrium in the system using the interaction parameters determined from experimental data. It is found that UNIQUAC and NRTL used for LLE could provide a good correlation. Distribution coefficients, separation factors, and selectivity were evaluated for the immiscibility region.  相似文献   

14.
The novel bis(cyclohexylaminium) cyclohexylaminebis(orotate–N,O)cuprate(II) dihydrate, (C6H15N)2[Cu(C5H2N2O4)2(C6H14N)] · 2H2O, has been prepared and characterized by elemental analysis, magnetic measurements, FT-IR and UV–Vis spectroscopy, thermal analysis and X-ray diffraction. The Cu(II) complex crystallizes in the monoclinic space group P21/c. The copper atom in the five-coordinated (chaH)2[Cu(HOr–N,O)2(cha)] · 2H2O is chelated by a deprotonated pyrimidine nitrogen atom and carboxylate oxygen atom as a bis(bidentate) ligand and the cyclohexylamine ligand completes the square-pyramidal coordination. The thermal decomposition of the complex has been predicted by the help of thermal analysis (TG, DTG and DTA).  相似文献   

15.
Four copper(I) cyanide coordination polymers containing 2-(n-pyridyl)benzimidazole ligands, namely [Cu2(CN)(2-PyBIm)]n (1), [Cu2(CN)2(3-PyHBIm)]n (2), {[Cu3(CN)3(4-PyHBIm)4] · 2H2O}n (3) and [Cu5(CN)3(4-PyBIm)2]n (4), have been synthesized and characterized by X-ray crystallography. Complex 1 is a one-dimension coordination polymer in which 2-(2-pyridyl)benzimidazole is deprotonated and adopts a bridging tridentate coordination mode. Complex 2 has ladder-like structure in which 2-(3-pyridyl)benzimidazole does not deprotonate and acts as a bidentate bridge. Complex 3 displays a saddle-shaped helical chain constructed through μ2-cyanide group and the outstretched neutral 2-(4-pyridyl)benzimidazole monodentate ligand. Complex 4 shows two-dimension layer polymeric structure in which deprotonated 2-(4-pyridyl)benzimidazole acts as a tridentate bridging ligand. The cyanide groups in four complexes all act as bidentate bridging ligands. These complexes are thermal stable and display luminescence in the solid states.  相似文献   

16.
The reaction of 2-functionalized 1-halo-2,n-enynes (n = 7 or 8) with a divalent titanium reagent, Ti(O-i-Pr)4/2i-PrMgCl, proceeded in a domino fashion to afford bicyclic compounds in good yields.  相似文献   

17.
Electrochemical measurements are done on (water + NaBr + K3PO4 + glycine) mixtures at T (298.15 and 308.15) K by using (Na+ glass) and (Br solid-state) ion selective electrodes. The mean ionic activity coefficients of NaBr are determined at five NaBr molalities (0.1, 0.3, 0.5, 0.7, and 1) in the above mixtures. The activity coefficients of glycine are evaluated from mean ionic activity coefficients of sodium bromide. The ratio of mean ionic activity coefficient of NaBr in the (water + NaBr + K3PO4 + glycine) mixtures to the mean ionic activity coefficients of NaBr at the same molalities in the (H2O + NaBr) mixtures are correlated by using a new expression.  相似文献   

18.
Isothermal vapor-liquid equilibrium data at 333.15 K are reported for the ternary systems {di-methyl carbonate (DMC) + ethanol + benzene} and {DMC + ethanol + toluene} as determined with headspace gas chromatography. The experimental ternary vapor-liquid equilibrium (VLE) data were correlated with different activity coefficient models. The excess volume (VE) and deviations in molar refractivity (ΔR) data are reported for the binary systems {DMC + benzene} and {DMC + toluene} and also for the ternary systems {DMC + ethanol + benzene} and {DMC + ethanol + toluene} at 298.15 K. These VE and ΔR data were correlated with the Redlich-Kister equation for binary systems and the Cibulka equation for ternary systems.  相似文献   

19.
20.
The present study experimentally demonstrated clathrate hydrate formation in the systems of (methane + water + each of the three methylcyclohexanone isomers, i.e., 2-methylcyclohexanone, 3-methylcyclohexanone, and 4-methylcyclohexanone) and measured the first data of the quadruple (water rich liquid + hydrate + methylcyclohexanone rich liquid + methane rich vapor) equilibrium pressure and temperature conditions in these systems over the temperatures from T=273 K to T=281 K. In the three systems with methylcyclohexanone, the measured equilibrium pressure at each given temperature is ∼1.3 MPa lower than that in a structure-I hydrate forming (methane + water) system without any methylcyclohexanone, which suggests the formation of structure-H hydrates with methylcyclohexanones as large-molecule guest substances. Among the three systems, 3-methylcyclohexanone provides the highest equilibrium pressure, and 2-methylcyclohexanone, the lowest.  相似文献   

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