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1
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Molecular Correlations in Liquid mono- and Dlichloroalkanes

100%
Bochyński Z., Drozdowski H.
Acta Physica Polonica A
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1996
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vol. 89
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issue 4
547-554
EN
This paper reports results of the X-ray diffraction structural studies of a series of liquid monochloroalkanes (chlorohexane, chlorooctane, chlorodecane, chlorododecane) and dichloroalkanes (1, 6-dichlorohexane, 1, 8-dichlorooctane, 1, 10-dichlorodecane, 1, 12-dichlorododecane) performed at 20 and 40°C. From the X-ray diffraction patterns, obtained using Mo K_{α} radiation of the wavelength λ = 0.7107 Å, the mean angular distributions of intensities were determined. Then, the functions of radial distributions of electron density were numerically found using Fourier analysis. The mean structural parameters of the studied liquids (the inter- and intramolecular distances, the radii of coordination spheres, the coordination numbers) and the local arrangement of their molecules were established. The intermolecular arrangements in the studied liquid mono- and dichloroalkanes were found to be similar. Correlations were found between certain physical and chemical properties of the studied compounds and the spatial arrangement of their molecules.
2
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X-ray Diffraction Studies of Liquid Methylcyclohexane C_6H_{11}-CH_3 Structure at 293 K

100%
Drozdowski H., Nowakowski K.
Acta Physica Polonica A
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2008
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vol. 114
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issue 2
383-389
EN
The structure of methylcyclohexane C_6H_{11}-CH_3 at 293 K was investigated using the X-ray diffraction method. An angular distribution of X-ray radiation scattered in liquid methylcyclohexane was measured. The observable range of scattering angles was 6°≤2Θ≤120°. Monochromatic radiation Mo K_αenabled determination of the scattered intensity between S_{min}=0.92 Å^{-1} and S_{max}=15.313 Å^{-1}. The differential radial distribution function of electron density was calculated. The mean structural parameters of liquid methylcyclohexane (inter- and intramolecular distances, radii of coordination spheres, and packing coefficient) were determined and discussed. The most probable binary radial correlation of molecules in liquid methylcyclohexane was proposed. The approach proposed in this paper gives a good description of intermolecular interactions in liquids and is a useful X-ray method for their analysis. The paper presents the structure and molecular correlations in liquid methylcyclohexane determined for the first time by the X-ray diffraction method. The study of methylcyclohexane is a continuation of our studies of cyclohexane derivatives cyclohexylamine and 2-methylcyclohexane. The aim of the study was to establish a relation between the cis and trans isomers and the conformation of the cyclohexane derivatives in the liquid phase.
3
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X-ray Analysis of Intermolecular Interactions in Liquid 2-chloronaphthalene at 353 K

100%
Drozdowski H.
Acta Physica Polonica A
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2003
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vol. 104
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issue 5
441-458
EN
The aim of the study was to examine the structure of liquid 2-chloronaphthalene C_{10}H_7-Cl at 353 K by the X-ray diffraction method. Monochromatic radiation Mo K_α,λ= 0.71069Å was used to determine the scattered radiation intensity between S_{min}=4πsinθ_{min}/λ=0.430Å^{-1} and S_{max}= 4π sinθ_{max}/λ=14.311Å^{-1}. The curves of reduced intensity were analysed by the reduction method of Blum and Narten. Experimental distribution of X-ray scattered intensity was compared with theoretical results predicted for a proposed model of 2-chloronaphthalene molecule. The differential radial distribution function 4π r^2Σ_{j,k}^n K_j[ρ_k(r)-ρ_0] was calculated and some intra- and intermolecular distances in liquid 2-chloronaphthalene were determined. X-ray structural analysis was applied to determine the packing coefficient of 2-chloronaphthalene molecules at 353 K. The intermolecular distance Cl ··· Cl' was also determined as 7.90±0.15Å. A simple model of short-range arrangement of the molecules was proposed, which seems to be valid for other weakly polar monosubstituted naphthalene derivatives in the liquid phase.
4
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X-ray Analysis of Liquid 1-Methylnaphthalene Structure at 293 K

100%
Drozdowski H.
Acta Physica Polonica A
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2000
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vol. 98
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issue 6
691-703
EN
The paper reports results of the X-ray diffraction structural studies of liquid 1-methylnaphthalene, C_{10}H_{7}-CH_{3} at 293 K, using Mo K_{α} radiation of the wavelength λ=0.71069 A. The interpretation of the results was carried out using the reduction method of Blum and Narten. Experimental distribution of X-ray scattered intensity was compared with theoretical results predicted for a proposed model of 1-methylnaphthalene molecule. The electron-density radial-distribution function was calculated and some intra- and intermolecular distances in liquid 1-methylnaphthalene were determined. The structural data obtainable by X-ray analysis for liquid 1-methylnaphthalene are discussed. X-ray structural analysis was applied to determine the packing coefficient of 1-methylnaphthalene molecules. The electron-density radial-distribution function $4πr^{2} ∑^{n}_{j,k}\overline{K}_{j}[ρ_{k}(r) — ρ_{0}]$ was calculated and some intra- and intermolecular distances in liquid 1-methylnaphthalene were determined. The structural data obtainable by X-ray analysis for liquid 1-methylnaphthalene are discussed. X-ray structural analysis was applied to determine the packing coefficient of 1-methylnaphthalene molecules.
5
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Structure and Molecular Correlation of Liquid Alkanes

100%
Bochyński Z., Drozdowsκi H.
Acta Physica Polonica A
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1995
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vol. 88
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issue 6
1089-1096
EN
The paper reports structural investigations of a series of liquid alkanes, from n-C_{6}H_{14} (n-hexane) to n-C_{16}H_{34} (n-hexadecane), differing by two methyl groups (CH_{2})_{2}, n-C_{20}H_{42} (n-eicosane) and n-C_{30}H_{62} (n-triacontane) performed in temperatures from 20°C to 70°C. The average angular distri­bution of intensity was determined by diffraction of monochromatic X-ray radiation Mo K_{α}, λ = 0.7107 Å and the functions of radial distribution of electron density were calculated for the studied compounds. Mean structural parameters including distances between molecules and atoms, coordination numbers as well as correlation parameters were obtained. The suitability of the method for structural studies of n-alkanes with the number of carbon atoms from 6 to 30 is discussed.
6
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Positron Annihilation in and Compressibility of Water-Organic Mixtures. The System Water-Acetamide

63%
Jerie K., Baranowski A., Gliński J., Orzechowski K.
Acta Physica Polonica A
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1996
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vol. 90
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issue 6
1169-1177
EN
The experimental results of positron annihilation experiments in aqueous solutions of acetamide were compared to those of ultrasonic velocity. The system under investigation behaves untypically when changing acetamide concentration. From the point of view of surface tension it interacts with water like normal alcohols, while the positron annihilation and ultrasonic results suggest hydrophilic hydration and lack of hydrophobic interactions.
7
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Positron Annihilation in and Adiabatic Compressibility of Water-Organic Solutions. The System Water-Dimethylsulfoxide

63%
Jerie K., Baranowski A., Rozenfeld B., Jeżowska-Trzebiatowska B., Gliński J.
Acta Physica Polonica A
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1991
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vol. 79
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issue 4
507-515
EN
The results of positron lifetime and ultrasonic velocity measurements in dilute aqueous dimethylsulfoxide (DMSO) solutions show the usual extreme characteristic for polar organic solutes. The results obtained suggest that strong structural changes occur in the system, in the region of low DMSO concentrations. Liquid clathrate hydrates forming in the system are supposed, with unusual stoichiometry and untypical geometry of the hydrates.
8
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Structure of Aqueous Solutions of Acetonitrile Investigated by Acoustic and Positron Annihilation Measurements

63%
Jerie K., Baranowski A., Koziol S., Gliński J., Burakowski A.
Acta Physica Polonica A
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2005
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vol. 107
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issue 5
826-831
EN
We report the results of acoustic and positron annihilation measurements in aqueous solutions of acetonitrile (CH_3CN). Hydrophobicity of the solute is discussed, as well as the possibility of describing the title system in terms of hydrophobic solvation. The concept of Levay et al. of calculating the "ideal positronium lifetimes is applied, basing on the mean volume of cavities (holes) in liquid structure available for positronium pseudoatom. The same calculations performed using the Tao model of annihilation yield very different results. It can be concluded that either acetonitrile forms with water clathrate-like hydrates of untypical architecture, or it is too weak hydrophobic agent to form clathrate-like hydrates at all. The former interpretation seems to be more probable.
9
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Structure of Carbon Tetrachloride + t-Butanol Mixtures from Positron Annihilation and Ultrasonic Velocity Measurements

63%
Jerie K., Baranowski A., Gliński J.
Acta Physica Polonica A
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1993
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vol. 83
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issue 3
313-320
EN
The densities of and sound velocities in t-butyl alcohol solutions in CCl_{4} were determined in temperature range 25 to 45°C. From these data the adiabatic compressibility coefficients of the solutions were calculated, as well as excess densities and compressibilities. The positron annihilation spectrum for this system in room temperature was measured. The results plotted against alcohol concentration suggest that the structural processes occurring in this system are caused by dimerization of the solute molecules.
10
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Structure of Aqueous Solutions of Tetramethylammonium Chloride Investigated by Positron Annihilation and Ultrasonic Methods

63%
Jákli G., Jerie K., Baranowski A., Gliński J.
Acta Physica Polonica A
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1998
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vol. 93
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issue 4
649-658
EN
The structure of aqueous solutions of tetramethylammonium chloride was investigated using sound velocity and positron annihilation methods. The results are different than those obtained earlier for systems where hydrophobic hydration occurs, although some evidences for formation of clathrate-like hydrates in liquid phase were observed. The results are interpreted, among others, in terms of competition of different hydrates of tetraalkylammonium cations, hydration of chloride anions, and formation of ionic pairs.
11
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Structure of Cyclohexane + t-Butanol Mixtures from Positron Annihilation and Ultrasonic Velocity Measurements

63%
Jerie K., Baranowski A., Gliński J.
Acta Physica Polonica A
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1993
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vol. 83
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issue 3
321-326
EN
The densities of and sound velocities in t-butyl alcohol solutions in cyclohexane were determined in the temperature range 25 to 45°C. From these data adiabatic compressibility coefficients of the solutions were calculated, as well as excess densities and compressibilities. The positron annihilation spectra of the solutions were measured at room temperature. The results plotted against alcohol concentration show structural processes, which can be attributed to dimerization of the solute molecules.
12
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Positron Annihilation in and Adiabatic Compressibility of Ethylene Glycol Aqueous Solutions

63%
Baranowski A., Jerie K., Gliński J., Orzechowski K.
Acta Physica Polonica A
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1995
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vol. 88
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issue 1
59-66
EN
The positron annihilation lifetime and ultrasonic velocity in aqueous ethylene glycol solutions were measured. A comparison between the concen­tration and temperature dependences of the above parameters suggests that there is a competition of hydrophobic (interstitial) and hydrophylic (substi­tutional) hydration.
13
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Positron Annihilation in and Compressibility of Water-Organic Solutions. The System Water-Pyridine

63%
Jerie K., Baranowski A., Gliński J., Jeżowska-Trzebiatowska B.
Acta Physica Polonica A
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1992
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vol. 82
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issue 3
471-479
EN
The results of positron lifetime and ultrasonic velocity measurements in dilute aqueous pyridine (PYR) solutions show unusual changes in ultrasonic, annihilation data in function of pyridine concentration. The results obtained suggest that strong structural changes occur in the system, in the region of low pyridine concentrations. Liquid clathrate hydrates forming in the system are supposed with unusual stoichiometry and untypical geometry. They are supposed to be very short-living and/or unstable.
14
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Structure of Aqueous Solutions of 1,2- and 1,3-Propanediol Investigated by Positron Annihilation and Ultrasonic Methods

63%
Jerie K., Baranowski A., Gliński J., Orzechowski K.
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vol. 95
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issue 4
562-567
EN
The structure of aqueous solutions of 1,2-propanediol and 1,3-propane-diol was investigated using adiabatic compressibility measurements and positron annihilation methods. The experimental results are different than those obtained earlier for systems where hydrophobic hydration dominates. There are some evidences for increased rigidity of the water network, which can arise from the formation of hydrogen bonds between diols and water.
15
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Hydrophobic-Like Solvation in Non-Aqueous Solutions: Positron Annihilation in and Compressibility of Tert-butanol and Tetramethylurea in Ethylene Glycol

63%
Jerie K., Baranowski A., Gliński J., Przybylski J.
Acta Physica Polonica A
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2001
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vol. 99
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issue 3-4
385-392
EN
The pioneer experimental results of positron annihilation experiments in non-aqueous solutions of tetramethylurea and tert-butanol were compared to those of ultrasonic velocity. For tert-butanol, the positron annihilation results exclude existence of hydrophobic-like interactions and formation of weak, labile crystalline-like solvates in solution. For tetramethylurea solute the changes of annihilation parameters with concentration are minor and only limited conclusions can be drawn on this system, while they are stronger for tert-butanol solute. However, all the above is consistent with an assumption that the more hydrophobic solute (tert-butanol) should affect the original glycol structure stronger than that interacting with glycol via hydrogen bondings only. On the other hand, the ultrasonic data for the systems tested, although very precise, hardly confirm formation of any specific structure. It is possible, however, that the solvates do not differ in their compressibility from the pure liquids, and/or are formed only in very small amounts. Thus, usefulness of the positron annihilation method in investigation of liquid structure was proven.
16
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Structure of Aqueous Solutions of 1,2-, 1,3- and 1,4-Butanediol Investigated by Positron Annihilation and Ultrasonic Methods

63%
Jerie K., Baranowski A., Gliński J., Orzechowski K., Przybylski J.
Acta Physica Polonica A
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2001
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vol. 99
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issue 3-4
393-398
EN
The structure of aqueous solutions of 1,2-, 1,3- and 1,4-butanediol was investigated using adiabatic compressibility measurements and positron annihilation methods. In the case of 1,2-butanediol the experimental results are very similar to those obtained earlier for systems where hydrophobic hydration dominates. In other cases there are evidences for increased rigidity of the water network, which arises from formation of hydrogen bonds between diols and water. Usefulness of both the methods applied in investigating the structure of liquid solutions was proved.
17
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Positron Annihilation in and Compressibility of Water-Organic Mixtures. The System Water-Formamide

63%
Jerie K., Baranowski A., Gliński J., Orzechowski K.
Acta Physica Polonica A
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1994
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vol. 85
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issue 3
563-569
EN
The experimental results of positron annihilation experiments in aqueous solutions of formamide were compared to those of ultrasonic velocity. The systems under investigation behave untypically while changing formamide concentration. The results are explained in terms of hydrophilic hydration and lack of hydrophobic interactions.
18
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Dielectric Study of Dipolar Association in Dihalogenobenzenes

51%
Dutkiewicz M.
Acta Physica Polonica A
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1992
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vol. 82
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issue 3
443-449
EN
The nonlinear dielectric effect (NDE) has been studied in o-bromochlorobenzene and m-bromochlorobenzene, and their solutions in benzene. On the basis of NDE results and the values of electric permittivity ε, density d, and refractive index n obtained in this work, the molar polarizabilities: linear ⟨μ^{2}⟩ and nonlinear ⟨μ^{4}⟩ were calculated. Assuming dipolar association of the investigated dihalogenobenzenes molecules to be restricted to dimerization, the Gibbs energy ΔG^{0}_{dim} of the dimerization process as a function of the Onsager field factor f(ε) is determined, which allowed us to draw a conclusion on the structure of associates.
19
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Investigation of Sol-Gel Glasses Doped with Lanthanide Ions by Spectroscopic, Acoustic, and Positron Annihilation Methods

38%
Jerie K., Baranowski A., Legendziewicz J., Guzik M., Burakowski A., Gliński J.
Acta Physica Polonica A
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2006
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vol. 110
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issue 5
583-591
EN
The results of optical spectroscopic (UV-Vis, absorption, and emission), acoustic (sound velocity of precursor solutions, the solvation numbers of ions in these solutions), and positron annihilation of glasses are presented and discussed for silica glasses obtained by the alcoholic sol-gel technique, doped with selected lanthanides and with some addition of ethylene glycol. The aim of these investigations was the determination of the local structure of glass close to lanthanide ions and its influence on the optical properties of the material. The results show that the existence of alcohol-glycol solvates in glasses decrease the number of empty voids in its structure as well as the size of the remaining ones. One can suppose that this is caused by cooperative interactions of glycol molecules with the network of hydrogen bonds of the glass.
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