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1.
The speed of sound (u), density (ρ), and viscosity (η) of 2,4-dihydroxyacetophenone isonicotinoylhydrazone (DHAIH) have been measured in N,N-dimethyl formamide and dimethyl sulfoxide at equidistance temperatures 298.15, 303.15, 308.15, and 313.15 K. These data were used to calculate some important ultrasonic and thermodynamic parameters such as apparent molar volume (V ? s st ), apparent molar compressibility (K ?), partial molar volume (V ? 0 ) and partial molar compressibility (K ? 0 ), were estimated by using the values of (V ? 0 ) and (K ?), at infinite dilution. Partial molar expansion at infinite dilution, (? E 0 ) has also been calculated from temperature dependence of partial molar volume V ? 0 . The viscosity data have been analyzed using the Jones–Dole equation, and the viscosity, B coefficients are calculated. The activation free energy has been calculated from B coefficients and partial molar volume data. The results have been discussed in the term of solute–solvent interaction occurring in solutions and it was found that DHAIH acts as a structure maker in present systems.  相似文献   

2.
The densities, viscosities and refractive indices of N,N /-ethylene-bis(salicylideneiminato)-diaquochromium(III) chloride, [Cr(salen)(H2O)2]Cl, in aqueous dimethylsulfoxide (DMSO) with different mass fractions (w 2 = 0.20, 0.40, 0.60, 0.80 and 1.00) of DMSO were determined at 298.15, 308.15 and 318.15 K under atmospheric pressure. From measured densities, viscosities and refractive indices the apparent molar volumes (V φ ), standard partial molar volume (V φ 0 ), the slope (S V * ), standard isobaric partial molar expansibility (φ E 0 ) and its temperature dependence (?φ E 0 /?T) p , the viscosity B-coefficient, its temperature dependence (?B/?T), solvation number (S n ) and apparent molar refractivity (R D φ ), etc., were calculated and discussed on the basis of ion–ion and ion–solvent interactions. These results revealed that the solutions are characterized by ion–solvent interactions rather than by ion–ion interactions and the complex behaves as a long range structure maker. Thermodynamics of viscous flow was discussed in terms of transition state theory.  相似文献   

3.
Apparent molar volumes, apparent molar adiabatic compressibilities and viscosity B-coefficients for metformin hydrochloride in aqueous d-glucose solutions were determined from solution densities, sound velocities and viscosities measured at T = (298.15–318.15) K and at pressure p = 101 kPa as a function of the metformin hydrochloride concentrations. The standard partial molar volumes (\( \phi_{V}^{0} \)) and slopes (\( S_{V}^{*} \)) obtained from the Masson equation were interpreted in terms of solute–solvent and solute–solute interactions, respectively. Solution viscosities were analyzed using the Jones–Dole equation and the viscosity A and B coefficients discussed in terms of solute–solute and solute–solvent interactions, respectively. Adiabatic compressibility (\( \beta_{s} \)) and apparent molar adiabatic compressibility (\( \phi_{\kappa }^{{}} \)), limiting apparent molar adiabatic compressibility (\( \phi_{\kappa }^{0} \)) and experimental slopes (\( S_{\kappa }^{*} \)) were determined from sound velocity data. The standard volume of transfer (\( \Delta_{t} \phi_{V}^{0} \)), viscosity B-coefficients of transfer (\( \Delta_{t} B \)) and limiting apparent molar adiabatic compressibility of transfer (\( \Delta_{t} \phi_{\kappa }^{0} \)) of metformin hydrochloride from water to aqueous glucose solutions were derived to understand various interactions in the ternary solutions. The activation parameters of viscous flow for the studied solutions were calculated using transition state theory. Hepler’s coefficient \( (d\phi /dT)_{p} \) indicated the structure making ability of metformin hydrochloride in the ternary solutions.  相似文献   

4.
Densities, viscosities, and refractive indices of aqueous solutions of hydroxylamine hydrochloride containing 0.05, 0.10, and 0.15 mol/dm3 NaCl, KCl, and NH4Cl were measured at different concentrations of hydroxylamine hydrochloride at 30°C. Viscosity coefficients A and B representing ion-ion and ion-solvent interactions were determined from Jones-Dole equation. Experimental properties and viscosity coefficients have been interpreted in terms of ion-ion and ion-solvent interactions. Ion-solvent interactions were found to be dominating over the ion-ion interactions in studied systems.  相似文献   

5.
Structural parameters and IR spectra of the (1A1//C4v)-PcLuCl, (2B2//C4v)-PcYbCl, and (8A2//C4v)-PcGdCl molecules, (2A2//C4v)-Pc+LuCl, (3B1//C4v)-Pc+YbCl, and (9A1//C4v)-Pc+GdCl cations, (1Ag//D2h)-PcLuCl2LuPc dimer, and PcLuCl···PcLuCl coaxial molecular pair have been simulated using the DFT (U) PBE0/SDD method. The PcLnCl (Ln = Lu, Yb, Gd) molecules have exhibited the equilibrium Ln–N bond length of 222, 223, and 230 pm, the Ln–Cl bond length of 245, 246, and 253 pm, the dipole moment of 4.73, 4.57, and 4.84 D directed from Cl to Ln, and ionization potential of 6.6 eV. β-Decay (1A1//C4v)-Pc177LuCl → (1A1//C4v)-(Pc177mHfCl)+ occurs with no significant change of the charge on the metal atom.  相似文献   

6.
The apparent molar volumes (V ϕ) and viscosity B-coefficients of sodium molybdate and sodium tungstate in aqueous binary mixtures of acetonitrile were determined from solution density and viscosity measurements at 298.15, 308.15 and 318.15 K and various electrolyte concentrations. The experimental density and viscosity data were evaluated by the Masson and Jones-Dole equations, respectively, and the parameters derived were interpreted in terms of ion-solvent and ion-ion interactions. The activation parameters of viscous flow were also determined and discussed using transition state theory. The article is published in the original.  相似文献   

7.
Densities of acefylline piperazine (AP) in aqueous, aqueous methanol, and aqueous ethylene glycol (10% v/v) systems are determined in the concentration range 0.04-0.14±0.001 mol/dm3 at different temperatures (298.15-318.15 K) with the interval of 5 K. The apparent molar volume (φv), the partial molar volume \((\phi_v^0)\), and the ion-ion interaction parameter (Sv) are calculated using the Masson equation. Partial molar expansibilities \((\phi_E^0)\), which indicate the presence or absence of the caging or packing effect, are also evaluated and discussed. The results are interpreted in terms of solute-solvent and solute-solute interactions of AP in aqueous, aqueous methanol, and aqueous ethylene glycol systems. The structure-breaking and structure-making properties of AP are inferred by the sign of Hepler′s criterion \((\partial^2\phi_v^0/\partial{T}^2)_p\), i.e. the second derivative of the partial molar volume with respect to the temperature at the constant pressure.  相似文献   

8.
Phase formation in the A1 + x Al x Ti2 ? x P3O12 (A = Li, Na, K, Rb, or Cs; 0 ≤ x ≤ 2.0) and B0.5(l + x)Al x Ti2 ? x P3O12 (B = Mg, Ca, Sr, or Ba; 0 ≤ x ≤ 2.0) systems was studied using X-ray powder diffraction, electron probe microanalysis, and IR spectroscopy. The following double and triple orthophosphates were found to exist: A1 + x Al x Ti2 ? x (PO4)3 with A = Li (0 ≤ x ≤ 0.3), Na (0 ≤ x ≤ 1.0), K (x = 0, 1.0, or 2.0), Rb (x = 0, 1.0, or 2.0), or Cs (0 ≤ x ≤ 1.0) and B0.5(l + x)Al x Ti2 ? x (PO4)3 with B = Mg and Ba (x = 0), Ca and Sr (0 ≤ x ≤ 0.2). These orthophosphates crystallize in the structure types of kosnarite, langbeinite, cesium titanium arsenate, potassium aluminum phosphate, or rubidium aluminum phosphate. Their crystal parameters were calculated. For CsTi2(PO4)3 (x = 0), Rietveld refinement was carried out: space group Ia \(\bar 3\) d, Z = 32, a = 19.909(5) Å, V = 7892(1) Å3. This compound has a framework structure. The framework is built of TiO6 octahedra and PO4 tetrahedra; eight- and 12-coordinated Cs+ cations populate interstices.  相似文献   

9.
An approximate analytical solution of the Schrödinger equation is obtained to represent the rotational–vibrational (ro-vibrating) motion of a diatomic molecule. The ro-vibrating energy states arise from a systematical solution of the Schrödinger equation for an empirical potential (EP) V ±(r) = D e {1 ? (?/δ)[coth (ηr)]±1/1 ? (?/δ)}2 are determined by means of a mathematical method so-called the Nikiforov–Uvarov (NU). The effect of the potential parameters on the ro-vibrating energy states is discussed in several values of the vibrational and rotational quantum numbers. Moreover, the validity of the method is tested with previous models called the semiclassical (SC) procedure and the quantum mechanical (QM) method. The obtained results are applied to the molecules H2 and Ar2.  相似文献   

10.
Oxepin and azepin are heterocyclic compounds with a seven-membered ring, which are present in the main skeleton of many anti-depressive drugs. Planar configuration instability due to the pseudo Jahn-Teller effect (PJTE) in oxepin, azepin and six their halogen substituted derivatives were investigated as an original PJTE study. Optimization and the following frequency calculations in these two series illuminated that all of these eight compounds were unstable in high-symmetry planar (with C 2v symmetry) configuration and their structures were puckered to lower C s symmetry stable geometry. Moreover, the vibronic coupling interaction between 1 A 1 ground and the first 1 B 1 excited states via (1 A 1 + 1 A 1 + 1 B 1) ? b 1 and (1 A 1 + 1 B 1 + 1 A 1 ) ? b 1 PJTE problems were the reasons for the symmetry breaking phenomenon and non-planarity of the seven-member ring in those series. Finally, numerical fitting of the adiabatic potential energy surface (APES) cross-sections along the b 1 puckering coordination was employed to estimate the vibronic coupling constants of PJTE problems for all the considered compounds.  相似文献   

11.
The crystal structure of a new bismuth aluminoborate Bi0.96Al2.37(B4O10)O is studied by single-crystal X-ray diffraction. The Bi0.96Al2.37(B4O10)O single crystals are hexagonal (space group \(P\bar 6\) 2m). The unit cell parameters are as follows: a = b = 4.587(4) Å, c = 2.253(9) Å, α = β = 90°, γ = 120°, V = 168.60 Å3, Z = 1.  相似文献   

12.
Volumetric, viscometric and speed of sound studies of binary mixtures of tert-butyl acetate with fluorobenzene, chlorobenzene and bromobenzene have been made over the entire range of composition, at (298.15 and 308.15) K and at atmospheric pressure (p?=?0.089 MPa). From the experimental values of density, viscosity, and speed of sound, the excess molar volumes VE, deviations in viscosity ?η and deviation in isentropic compressibility ΔK S have been calculated. The VE and ΔK S values are negative while the ?η the values are positive over the entire composition range for the binary mixtures. The derived parameters have been fitted with the Redlich–Kister polynomial equation. The interaction parameters of McAllister model are used to correlate the experimental values of density, viscosity and speed of sound.  相似文献   

13.
The crystal structures of compounds from the series [M(NH3)5Cl](NO3)2, (M = Ir, Rh, Ru) were described. The compounds crystallized in the tetragonal crystal system, space group I4, Z = 2. Crystal data for [Ir(NH3)5Cl](NO3)2 (I): a = 7.6061(1) Å, b = 7.6061(1) Å, c = 10.4039(2) Å, V = 601.894(16) Å3, ρcalc = 2.410 g/cm3, R = 0.0087; [Rh(NH3)5Cl](NO3)2 (II): a = 7.5858(5) Å, b = 7.5858(5) Å, c = 10.41357(7) Å, V = 599.24(7) Å3, ρcalc = 1.926 g/cm3, R = 0.0255; [Ru(NH3)5Cl](NO3)2 (III): a = 7.5811(6) Å, b = 7.5811(6) Å, c = 10.5352(14) Å, V = 605.49(11) Å3, ρcalc = 1.896 g/cm3, R = 0.0266. The compounds were defined by IR spectroscopy and XRPA and thermal analyses.  相似文献   

14.
Heteroligand complexes [Co2(HMTA)(iso-Bu2PS2)4] (I) (μeff = 4.67 μB) and [Cd2(HMTA)(iso-Bu2PS2)4] (II) have been synthesized. Single crystals of compounds I and II have been obtained. The crystals are monoclinic: a = 32.622(2) Å, b = 9.4891(6) Å, c = 21.7570(13) Å, β = 125.774(1)o, V = 5464.3(6) Å,3, Z = 4, ρcalcd = 1.331 g/cm3 for I; a = 34.6092(7) Å, b = 9.5595(2) Å, c = 22.3473(5) Å, β = 127.144(1)o, V = 5893.5(2) Å, Z = 4, ρcalcd = 1.355 g/cm3 for II; space group for both complexes C2/c. Structures I and II are based on discrete binuclear molecules. The coordination polyhedra of the Co and Cd atoms are distorted tetragonal pyramids NS4, with the bases formed by four S atoms of two bidentate chelating ligand iso-Bu2PS 2 ? and the axial vertices occupied by N atoms of bidentate bridging HMTA ligand. The character of interaction of the molecules in structures I and II is considered.  相似文献   

15.
The topological types of suprapolyhedral clusters composed of i-B12 icosahedra have been modeled. The models of icosahedral supraclusters have been used in analysis of the crystal structures of boron and borides (the TOPOS program package). To identify nanocluster precursors in crystal structures, there have been used special algorithms for partitioning structural graphs into disjoint substructures and constructing a basis 3D network of the structure as a graph with the nodes corresponding to the positions of the centroids of the cluster precursors. The cluster self-assembly have been modeled for 25 types of icosahedral framework structures of boron—B12-hR 12, (B12)2(B2)2-oP 28, (B12)4B2-P50, B196-tP 196, and B333-hR 333; binary borides—(B12)O2-hR 14, (B12)P2-hR 14, and (B12)(CBC)-hR 15; templated metal borides—Na2(B12)2B6-oI 64, Mg2(B12)B2-oI 68, Tb(B12)(B4)-mI 60, Al4(B12)4B8-oC 88, (B12)4(Si4)4-oI 64, (B12)4B2Be4-tP 58, Ti2(B12)4B2-tP 52, Sc12B180-tP 192, Cu4Sc12B180-tP 192, Si1.5Sc9B178-tP 216, Mg28B360-oP 388, Al28B352-oP 384, Si28B352-oP 306, Y24(B156)8(B39)8-cF1944, Sc10B315-hR339, and Li24B315-hR336. The symmetry and topology code of the crystal structure self-assembly from nanocluster precursors in the form of primary chain → microlayer → microframework has been completely restored. Frequency analysis of various topological and symmetry pathways for the formation and evolution of cluster precursors makes it possible to elucidate crystal-formation trends in inorganic systems at the microscopic level.  相似文献   

16.
UV absorption spectroscopy, electrical conductivity and density experiments have been used to investigate the interactions of some small biomolecules (amino acids/dipeptides) with an active pharmaceutical ingredient in ionic liquid form (API-IL), benzalkonium salicylate (BaSal), in aqueous solution. A number of useful parameters, such as critical micellar concentration (cmc), aggregation number (Nagg) and limiting molar conductivity (Λ0) of BaSal, standard partial molar volumes (\(V_{2,\phi }^{ \circ }\)), corresponding volumes of transfer from water to aqueous BaSal solutions (ΔtrVo), standard partial molar expansibilities (\(E_{\phi }^{ \circ }\)), hydration number (nH) of small biomolecules, as well as the binding constants (Kb) for small biomolecule–BaSal complexes have been evaluated. The dependence of the properties on concentration, temperature and alkyl chain length of amino acids/dipeptides is examined. The results are used to identify the solute–solvent physicochemical interactions occurring in the studied systems.  相似文献   

17.
Two coordination polymers, {[Cd(L1)2(L2)] · 0.25H2O} n (I) and {[Cd(L1)(L3)H2O] · 2H2O} n (II) (L1 = 2-pyrimidineamidoxime, L2 = 4-sulfobenzoate dianion and L3 = 5-sulfosalicylate dianion), has been synthesized and structurally characterized by single-crystal X-ray diffraction (CIF files CCDC nos. 1565646 (I) and 1565728 (II)). Complex I crystallizes in monoclinic space group P21/n with a = 10.1462(3), b = 16.0152(5), c = 14.0349(5) Å, β = 93.267(3)°, V = 2276.87(13) Å3, C68H66N32O29S4Cd4, M = 2373.36, ρcalcd = 1.731 g/cm3, μ(MoKα) = 1.109 mm?1, F(000) = 1186, GOOF = 0.806, Z = 1, the final R1 = 0.0287 and wR2 = 0.0733 for I > 2σ(I). Complex II crystallizes in monoclinic space group P21 with a = 6.882(2), b = 17.138(2), c = 7.883(2) Å, β = 103.83(3)°, V = 902.8(4) Å3, C12H16N4O10SCd, M = 520.75, ρcalcd = 1.916 g/cm3, μ(MoKα) = 1.388 mm?1, F(000) = 520, GOOF = 1.047, Z = 2, the final R1 = 0.0739 and wR2 = 0.2041 for I > 2σ(I). Crystal structural analysis reveals that complex I possesses the corrugated 1D chain structure extending along the \([\bar 101]\) direction. However, complex II displays a 2D coordination network lying on the ab crystal plane, which can be simplified as a binodal 3-connected 63 topological network by considering Cd2+ ions and L3 ligands as 3-connected nodes. Their photoluminescent and thermal properties were also investigated.  相似文献   

18.
The quantum mechanics of a diatomic molecule in a noncentral potential of the type V (r) = V θ (θ)/r 2 + V r (r) are investigated analytically. The θ-dependent part of the relevant potential is suggested for the first time as a novel angle-dependent (NAD) potential \({V_{\theta}(\theta)=\frac{\hbar^2}{2\mu}\left(\frac{\gamma +\beta \sin^2\theta +\alpha \sin^4 \theta}{\sin^2\theta \cos^2\theta}\right)}\) and the radial part is selected as the Coulomb potential or the harmonic oscillator potential, i.e., V r (r) =  ? H/r or V r (r) = Kr 2, respectively. Exact solutions are obtained in the Schrödinger picture by means of a mathematical method named the Nikiforov–Uvarov (NU). The effect of the angle-dependent part on the solution of the radial part is discussed in several values of the NAD potential’s parameters as well as different values of usual quantum numbers.  相似文献   

19.
A DFT method with the B3LYP functional and the 6-311++G(d,p) diffuse basis set is used to predict geometries, relative stabilities, electronic structures, and the bonding of closo- and nido-GamBnmH n 2? , GemBnmH n m?2 , and AsmBnmH n 2 m?2 (n = 10, 12 and m = 1, 2) Clusters are obtained by replacing BH with isolobal GaH, GeH+, and AsH2+ fragments, keeping the same skeleton electron pairs (SEP). Based on the polyhedral skeletal electron pairs theory (PSEPT), closo and nido structures are predicted and can be of significant interest for experimentalists working in the field of heteroboranes. Different cluster stabilities are studied according to Gimarc′s and Williams′ rules, where our calculations show that the monosubstituted clusters deviate from these rules, giving rise to open structures. As2B8H n 2+ as 10-vertex structures lead to nido-type clusters, however, GemBnmH n m?2 (n = 10, 12 and m = 1, 2) give rise to closo isomers with close energies. All optimized structures exhibit large HOMO–LUMO gaps suggesting a good kinetic stability, thus predicting their isolation and characterization.  相似文献   

20.
Reaction of tridentate Schiff bases with nickel and cadmium salts in methanol afforded two new mononuclear complexes, [Ni(L1)2] (I) and [Cd(L2)2] (II), where L1 and L2 are the anions of 2-bromo-4-chloro-6-[(3-dimethylaminopropylimino)methyl]phenol (HL1) and 2-bromo-4-chloro-6-[(3-morpholin-4-ylpropylimino)methyl]phenol (HL2), respectively. The complexes were characterized by singlecrystal X-ray diffraction (CIF files CCDC nos. 1428653 (I) and 1428654 for (II)), FT-IR, and elemental analysis. Complex I crystallizes in the monoclinic space group P2 1/c, with a = 8.8216(8), b = 14.0424(8), c = 11.8687(12) Å, β = 111.238(2)°, V = 1370.4(2) Å3, Z = 2. Complex II crystallizes in the monoclinic space group P2 1/n, with a = 9.6774(4), b = 15.8970(6), c = 20.3144(7) Å, β = 90.408(2)°, V = 3125.1(2) Å3, Z = 4. The metal atoms in the complexes are coordinated by two tridentate Schiff base ligands, forming octahedral coordination. The free Schiff bases and the complexes were assayed for antibacterial activities. Both complexes are more active against the bacteria than the free Schiff bases. Complex II has the MIC value of 0.39 μg mL–1 against Bacillus subtilis.  相似文献   

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