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1

Właściwości optyczne refrakcyjne wybranych olejków roślinnych

Andriyevsky B., Andriyevska L., Piecuch T., Kowalczyk A.

Rocznik Ochrona Środowiska

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2016

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Tom 18, cz. 1

597--608

PL

Współczynnik załamania n optycznie przezroczystego materiału jest ważną jego charakterystyką, która zależy od elektronowej struktury cząsteczek odpowiedniej substancji. W przypadku olejków roślinnych, zawierających stosunkowo słabo oddziałujące cząsteczki, są jednak własności, które zależą w znacznym stopniu od oddziaływania międzycząsteczkowego. Do takich własności można odnieść krzepnięcie i parowanie olejków. Ostatnie zjawisko wpływa prawdopodobnie w dużym stopniu na natężenie zapachu każdego olejku, który jest ważny w odpowiednich zastosowaniach praktycznych. W związku z tym wyniki badań zależności temperaturowych gęstości r(T) i współczynnika załamania n(T) olejków roślinnych mogą być pomocne w oszacowaniu stopnia oddziaływania międzycząsteczkowego i odpowiednich możliwości ewentualnych zastosowań praktycznych. W niniejszej pracy przedstawiono wyniki badań zależności temperaturowych w zakresie 20-60°C współczynnika załamania nD(T) i gęstości r(T) trzech olejków roślinnych: z pomarańczy, cytryny i grejpfruta. Do pomiarów bezwzględnego współczynnika załamania nD olejków na długości fali świetlnej lD = 589 nm wykorzystano standardowy refraktometr Abbe. Gęstość olejków ρ w temperaturze pokojowej była otrzymana poprzez mierzenie masy m określonej objętości V olejku i następujące obliczenie według wzoru definiującego ρ = m/V. Pomiary zależności temperaturowych współczynnika załamania n(T) i objętości olejków V(T) o określonej masie m wykonano przy pomocy 6-litrowego wodnego termostatu przepływowego typu “PolyScience model 912”. Otrzymane zależności wykorzystano do obliczenia charakterystycznych wielkości refrakcji właściwej i oddziaływania międzycząsteczkowego w olejkach według modelu pola efektywnego zaproponowanego we wcześniejszych pracach autorów (Andriyevsky, B., et al. 2009, Andriyevsky, B., et al. 2010). Na bazie przeprowadzonych badań densymetrycznych i refraktometrycznych olejków roślinnych z pomarańczy, cytryny i grejpfruta w zakresie temperatur 20-60°C sformułowano następujące wnioski.- Zależności temperaturowe gęstości ρ(T) i podatności elektrycznej cD(T) trzech olejków aproksymują się zadowalająco wielomianem pierwszego rzędu, ρ(T)=a+bT, z ujemnymi wartościami współczynników b.-Właściwości optyczne refrakcyjne olejków cytrynowego i grejpfrutowego są zbliżone w porównaniu do właściwości olejku pomarańczy.- Wiązania międzycząsteczkowe w olejkach z cytryny i grejpfruta mogą być słabsze niż w olejku z pomarańczy.

EN

Refractive index n of an optically transparent material is an important its parameter, which depends on the electronic structure of the corresponding substance. In the case of plant oils, consisting of the relatively weak interacting particles, there are properties that however depend greatly on the intermolecular interaction. These properties are the oils coagulation and vaporization. The last phenomenon influences probably greatly the odor intensity of each oil, which can be significant for certain applications. Therefore, results of the temperature dependences of density p(T) and refractive index n(T) of plant oils can be helpful for estimation of the degree of intermolecular interaction and corresponding possibilities of practical applications of oils. In the present paper, the results of study of the temperature dependences of refractive index nD(T) and density p(T) in the range of 20-60 degrees C have been presented for three plant oils obtained from orange, lemon and grapefruit. For measurements of the absolute refractive index nD of oils at the wavelength lambda(D) = 589 nm a standard Abbe refractometer was used. The oil's density p at ambient temperature was obtained by the measurement of the corresponding mass m and volume V, p = m/V. Measurements of the temperature dependences of refractive index n(T) and volume V(T) of the known mass of oil m were performed using the 6-liters water thermostat "PolyScience model 912". The dependences obtained have been used for calculation of the characteristic values of specific refraction and intermolecular interaction of the oils according to the model of the effective electric field proposed in the former publications of the authors (Andriyevsky, B., et al. 2009, Andriyevsky, B., et al. 2010). The following conclusions have been formulated on the basis of investigations of the orange, lemon and grapefruit plant oils done in the temperature range of 20-60 degrees C. 1. The temperature dependences of density p(T) and electric susceptibility X-D(T) are fitted satisfactorily by the first order polynomial, p(T) = a + bT, with negative coefficients b. 2. Refractive properties of the lemon and grapefruit oils are close in comparison to the analogous values for the orange oil. 3. Intermolecular bonds in the lemon and grapefruit oils can be weaker in comparison to the orange oil.

2

Comparative Study of Experimental and Theoretical Ultrasonic Velocities in Binary Mixtures of Cyclohexanone with Aliphatic Esters at Different Temperatures

Divakar P. P., Samatha K.

International Letters of Chemistry, Physics and Astronomy

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2015

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Vol. 42

13--24

EN

Ultrasonic velocity evaluated by various theoretical relations viz., Nomoto, Free Length Theory (FLT), Van deal and Vangeel ideal mixing relation (IMR), Impedance Dependence Relation (IDR), and Junjie in three binary liquid mixtures of cyclohexanone as a common component with aliphatic esters (isopropyl acetate, isobutyl acetate and isoamyl acetate) at 303, 308, 313 and 318K over the entire composition range. An attempt has been made to compare the merits of the relations and the relative applicability of these theories to the present systems have been checked and discussed. The results are explained in terms of intermolecular interactions occurring in these binary systems. The deviation in the variation of U2exp / U2 imx from unity has also been evaluated for explaining the non-ideality in the mixtures.

3

Intermolecular Interactions between TNAZ and H2O: a DFT Study

Oftadeh M., Selahvarzi S., Keshavarz M. H.

Central European Journal of Energetic Materials

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2013

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Vol. 10, no. 2

289--300

EN

All of the possible TNAZ/H2O complexes (1, 2 and 3), as well as the uncomplexed form, were fully optimized with the density functional method. Complex 3 was the most stable, with the largest corrected intermolecular interaction energy. Charge redistribution mainly occurs on the adjacent N–O...H atoms of the submolecules. Strong hydrogen bonds predominantly contribute to the interaction energies. It is energetically and thermodynamically unfavourable for TNAZ to bind with H2O and to form any stable complexes at room temperature.

4

Propedeutyka kierunkowych oddziaływań miedzycząsteczkowych. Wiązania wodorowe, oddziaływania asocjacji warstwowej i wiązania halogenowe

Kruszyński R.

Zeszyty Naukowe. Chemia / Politechnika Łódzka

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2011

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Z. 50

5-47

EN

The review presents the typical bonding intermolecular interactions: hydrogen bonds, halogen bonds and stacking interactions. The first part describes the specific types of intermolecular interactions, including their definitions, energy and selected properties. The second part deals with the application of quantum-mechanical methods to study of intermolecular interactions, especially the appliance of the natural bond orbitals method, and usage of ab intio calculations for solving of structural problems appearing during the above mentioned studies. All above referred interactions have been presented in orbital terms. The third part describes the novel employment of graph theory to characterise the motifs formed by intermolecular interactions in the solid state.

5

Zastosowanie spektroskopii jądrowego rezonansu magnetycznego w badaniach oddziaływań międzycząsteczkowych ligandów organicznych i biocząsteczek

Bocian W., Kozerski L.

Wiadomości Chemiczne

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2005

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[Z] 59, 1-2

3--22

EN

The title problem is reviewed in the three main areas of general interest to chemists, biochemists and biologists, i.e. mutual interactions of small molecules, ligand to biomolecule binding and interactions of biomolecules. Physical phenomena, specific and nonspecific, such as hydrogen bonding, self association, hydrophobic interactions, etc., are shown as being defined by NMR spectral parameters in solution and solid state. Diversity of hydrogen bonding encountered in nature is exemplified by the interaction of acetic acid with Watson-Crick vs Hoogsteen faces of adenosine, studied by DNMR in organic solvent at low temperatures. The complementarity of solid state NMR to solution studies of defining the nature of hydrogen bonding is presented in the case of genistein interaction with nitrogen bases. Application of a title method is presented for searching the geometry of complexes formed of organic ligands and biological molecules. General protocol for searching the geometry of complex is presented for the case of topotecan (TPT) interaction with duplex octamer and nicked decamer duplexes of DNA. Interaction of biomolecules is presented for the case of duplex octamer DNMR study showing effects of base pairing and stacking on the b 'H values and insulin aggregation as studied by Pulse Field Gradient NMR spectroscopy leading to relating the radius of molecular aggregate with the diffusion constants. In conclusion it is stated that various NMR techniques in solid and liquid state, coupled with X-ray and MS, constitute modern tool of structural biology in pursue of disclosing functions of biomolecules expressed by their interactions.

6

Niekonwencjonalne wiązania wodorowe. [Część] 2. Natura przesunięcia do wyższych częstości

Jabłoński M.

Wiadomości Chemiczne

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2004

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[Z] 58, 11-12

791--814

EN

The conventional hydrogen bonds, X-HźźźY, are believed to arise due to the attractive interaction between the polarized proton donor (X-H) bond and the region of high electron density Y. This leads to the elongation of the X-H bond and the concomitant decrease of its stretching frequency (red shift). This effect can be further reinforced by electron density transfer from the proton acceptor (Y) to the proton donor molecule. The direction of this transfer is primarily to the ?* antibonding orbital of the X-H bond and consequently causes its weakening. The X-H bond in the X-HźźźY system undergoes elongation and its stretching frequency is lowered. The red shift of the X-H stretching frequency is seen as the most important manifestation of the hydrogen bonding. In some cases, however, the complexation may lead to its shortening with the concomitant stretching frequency shift to higher values (blue shift). For this kind of interaction the three main features of the classical hydrogen bond (elongation of X-H, red shift, and IR intensity increase) are all in opposite direction and for this reason this new type of bonding (interaction) is commonly referred to as the improper, blue-shifting H-bond. In Part II of this review different theories, which attempt to explain the origin of the blue shift, are discussed. Particular attention is given to the role of electrostatic interactions and charge transfer between interacting molecules. According to recently proposed models it is believed that the blue shift is mostly caused by the electrostatic interaction and is possibly enhanced by some intermolecular charge transfer from the proton acceptor molecule to remote parts of the proton donor. This is followed by the reorganization of the electron density distribution and structural changes in the whole proton donor molecule [12, 13]. Some other ideas and theories, which expose the role of the balance between electrostatic attraction and Pauli repulsion, are also discussed. Within these models there are no fundamental differences in the bonding characteristics of the red-shifting and blue-shifting H-bonded complexes; the blue shift is seen rather as an accidental result of the balance between different contributions to the interaction energy [6, 23].

7

Numerical calculations of the energy of dispersion interaction between particles of crude-oil emulsion in water. Part II

Staroń W., Mielnik J., Gurgul H.

Zeszyty Naukowe. Acta Physica / Uniwersytet Szczeciński

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2003

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Nr 13

47--78

PL

Jest to druga część obliczeń energii oddziaływania między cząsteczkami emulsji substancji ropopochodnych przy skokowej zmianie stałej Hamakera: 0,4; 0,5 i 0,6 x 1020J, rozmiarów cząsteczek od 0,5 do 10 μm o odległości od 1 μm do 10 μm.

8

Computation of transport and equilibrium properties of molecular systems with quantum mechanical calculation of interaction potentials

Arefiev K. M., Shevkunov S. V.

International Journal of Applied Mechanics and Engineering

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2002

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Vol. 7, no 4

1095-1123

EN

The computation of transport coefficients in gases on the basis of molecular theory requires the determination of interaction potentials. As a rule, the dependencies of interaction energy on the distances between the molecules extracted from experimental data on different measurable characteristics are used. At the same time, direct calculation of interaction potentials on the basis of approximate solution of Schroedinger equation is possible for a number of relatively simple in their electron structure, but important for applications systems. Mixtures of the vapors of the atoms of metals with noble gases represent a typical example of such systems. In this paper, a comparison between experimental and calculated diffusion coefficients of the vapors of metals in the first and the second groups of Periodic Table dissolved in noble gases is presented. A sufficient for practical needs convergence of numerical results is demonstrated. The interaction potentials obtained can be used in the calculations of other transport coefficients, such as viscosity and thermal conductivity, in the mixtures of the vapors of metals with gases. Along with the traditional approach based on Schroedinger formalism, modern alternative methods of quantum mechanics and quantum statistics are presented. One example is the Path Integral Monte Carlo method based on Feynman representation of quantum mechanics. This formalism makes it possible to solve quantum statistical problems for thermally excited electron states and in this way to simulate numerically equilibrium properties of dense non-ideal plasma. Exchange and all correlation effects can be described in this formalism in an explicit way. Another modern approach aimed at stochastic simulations of electron quantum states is the so-called Diffusion Method, representing a solution of Schroedinger equation in imaginary time. Applications of stochastic methods in the problems of thermodynamics and plasma physics are presented. The perspectives and possible directions of development of new methods in the statistical description of condensed matter is briefly discussed.

9

Numerical calculations of the energy of dispersion interaction between particles of crude-oil emulsion in water [part I]

Staroń W., Mielnik J., Gurgul H.

Zeszyty Naukowe. Acta Physica / Uniwersytet Szczeciński

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2001

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Nr 12

45-77

PL

Jest to pierwsza część obliczeń energii oddziaływania między cząsteczkami emulsji substancji ropopochodnych przy skokowej stałej Hamakera: 0,1; 0,2 i 0,3 x 10(20)J, rozmiarów cząsteczek od 0,5 do 10 um o odległości od 1 um do 10 um.

10

The influence of the O-H stretch and O...O distance on the many-body interactions in the cyclic water trimer

Rak J., Szczęśniak M.M., Chałasiński G., Cybulski S.M.

Polish Journal of Chemistry

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1998

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Vol. 72, nr 7S

1505-1523

EN

The effects of the O-H stretch and changes in the O...O distance upon the one-, two- and three-body interaction energy components were studied in a cyclic water trimer. Calculations were carried out using supermolecular Moller-Plesset perturbation (S-MPPT) theory in conjunction with perturbation theory of intermolecular forces, also known as intermolecular Moller-Plesset theory (I-MPPT). The dependence of the one-body relaxation as well as electrostatic, induction, exchange and dispersion terms upon changes in the intramolecular O-H bond length and upon the intermolecular O...O distance were studied to identify the terms which have the strongest influence on the structural parameters of the trimer. We found that the one-body terms must be evaluated at a high level of theory (MP4) with an elaborate basis set. The two-body perturbation energies appear to be reliably reproduced through the second order (MP2), and the three-body terms are reliable already at the self consistent field (SCF) level of theory. The two-body and three-body terms vary approximately linearly with the OH stretch of proton-donors.