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1

Proces samo-dysproporcjowania enancjomerów podczas chromatografii kolumnowej

Wzorek Alicja, Kwiatkowska Magdalena, Urbaniak Mariusz, Gawdzik Barbara

Wiadomości Chemiczne

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2023

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[Z] 77, 5-6

425--448

EN

The review is devoted to self-disproportionation of enantiomers (SDE) phenomenon which has been observed for many different classes of chiral organic compounds. The SDE phenomenon occurs when the fractionation of an enantioenriched sample due the application of a physicochemical process under achiral conditions results in the variation of the proportion of the enantiomers present across the fractions, though the overall composition in terms of the sample ee remains unchanged. The SDE process can be considered in terms of separating the excess enantiomer from the racemate. The basic terminology related to SDE was described. The formation of the SDE under chromatographic conditions is the result of an association process occurring in a solution of a chiral, non-racemic compound. Information on preferred interactions leading to homo-/heterochiral supramolecules can be provided by quantum chemical calculations, NMR spectroscopy and comparison of crystal structures of the racemic and enantiomeric crystals. Several examples of the chromatographic experiments with different classes of compounds were given in two purposes 1) to highlight the possibility of application SDE during column chromatography as the method for enantiopurification of the chiral, non-racemic compounds; 2) to demonstrate that a standard workup (chromatographic purification, evaporation) can alter the stereochemical outcome of asymmetric reactions.

2

Koloidy w życiu codziennym

Kurek Tomasz, Kuryśko Kacper

Analit

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2023

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Nr 13

6--11

PL

Koloidy, czyli układy złożone z małych cząsteczek rozproszonych w medium, są obecne w wielu aspektach naszego codziennego życia. Jednym z najczęstszych zastosowań koloidów jest żywność. Wiele produktów spożywczych, takich jak mleko, ser i lody, to koloidy. Obecność koloidów w tych produktach może wpływać na ich teksturę, konsystencję i smak. Ponadto są one również stosowane w produkcji wielu produktów kosmetycznych i środków higieny osobistej, w tym balsamów, szamponów i past do zębów. Koloidy mogą pomóc w stabilizacji tych produktów, zapobiegając ich rozdzieleniu i zapewniając jednorodność [1]. Koloidy odgrywają również istotną rolę w miejscach o których większość z nas nie zdaje sobie sprawy, a które mają znaczny wpływ na nasze życie. Na przykład aerozole, w tym dezodoranty czy też leki w postaci sprayu, są koloidami. Układy tego typu nie są jednak tylko sztucznym tworem człowieka. Występują one również naturalnie, w postaci mgły dymu lub chmur. Dzięki koloidom możemy potwierdzić istnienie atomów, a także cieszyć się pięknym błękitnym niebem [2]. Podsumowując, koloidy są wszechobecne w naszym codziennym życiu i mają szeroki zakres zastosowań. Ich obecność znacząco wpływa nie tylko na właściwości i działanie różnych produktów, ale również na cały otaczający nas świat.

EN

Colloids, which are complex systems of small molecules dispersed in a medium, are present in many aspects of our daily lives. One of the most common applications of colloids is in food. Many food products, such as milk, cheese and ice cream, are colloidal suspensions. The presence of colloids in these products can affect their texture, consistency and taste. In addition, they are also used in the production of many cosmetic and personal care products, including lotions, shampoos and toothpastes. Colloids can help stabilize these products, preventing separation and ensuring homogeneity. [1] Colloids also play an important role in areas that most of us are unaware of, but which have a significant impact on our lives. For example, aerosols, including deodorants or drug sprays, are colloids. However, systems of this type are not just an artificial creation of man. They also occur naturally, in the form of smoke mist or clouds. Thanks to colloids, we can confirm the existence of atoms, and enjoy the beautiful blue sky. [2] In summary, colloids are ubiquitous in our daily lives and have a wide range of applications. Their presence significantly affects not only the properties and performance of various products, but also the entire world around us.

3

Intermolecular interactions for two chosen anthracene derivatives

Kania Sylwester, Kuliński Janusz, Kościelniak-Mucha Barbara, Słoma Piotr, Wojciechowski Krzysztof

Scientific Bulletin. Physics / Lodz University of Technology

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2021

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Vol. 42

5--12

EN

The nature of intermolecular interactions for anthrone and anthraquinone differs due to the symmetry of substitution of the central benzene ring, i.e. anthrone substituted with only one keto group and anthraquinone substituted with two keto groups. In order to interpret the interactions among the molecules, the interaction energies between molecules in crystals were calculated using DFT B3LYP calculations. The results reveal the consistency between calculated “lattice energies” and theirs terms and thermodynamical properties as density, boiling point and melting point of examined compounds.

PL

Przeprowadzono obliczenia oddziaływań międzycząsteczkowych wykorzystując program CrystalExplorer17 z wykorzystaniem pakietu oprogramowania Gaussian09. Obliczenia DFT wykazały zgodność pomiędzy uzyskanymi wartościami energii „sieci krystalicznej” badanych związków i jej składowych z osobna a wybranymi do analizy doświadczanymi właściwościami termodynamicznymi jak gęstość materiału, temperatura wrzenia i temperatura topnienia badanych związków. Badania wykazały inny charakter oddziaływań zachodzących podczas procesu topnienia i podczas procesu wrzenia. Proces topnienia związany jest z całkowitą energią sieci. Temperatura wrzenia związana jest z zerwaniem odziaływań pomiędzy pojedynczymi cząsteczkami. Decydujące jest tu zerwanie oddziaływania dipolowego i dyspersyjnego.

4

Badania rozkładu gęstości elektronowej w kryształach, czyli jak zobaczyć szczegóły struktury elektronowej cząsteczek

Kubicki M.

Wiadomości Chemiczne

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2014

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[Z] 68, 5-6

403--427

EN

X-ray structural analysis might be regarded as a method of visualizing molecules as they appear in the crystals. The model, which is conventionally and universally used in this method, the Independent Atom Model (IAM) assumes that the electron density distribution, which scatters the X-rays is built of the spherically-symmetrical, neutral atoms. This model is responsible for the unprecedented success of X-ray structural analysis, which reflects in about one million crystal structures (i.e. the sets coordinates of the atoms constituting the molecules) deposited in the various databanks (cf. Fig. 1), and in the speed and accuracy which the method has reached. In principle, in few hours one can get the complete information about the crystal structure. But this success is accompanied by negligence of the scientific virtue hidden beyond the IAM. In fact, it was known from the very beginning of the X-ray diffraction studies by von Laue and Braggs, that some fine details of the electron density distribution should be available. The technological advance (four-circle diffractometers, powerful X-ray sources, fast computers etc.) caused that in 1960’s the time was ripe for the development of the experimental studies of details of electron density distribution in the crystals, beyond the IAM. The early experiments by Coppens and co-workers proved that this information – about the electron density transferred to the covalent bonds, lone pairs, even intermolecular interactions – can actually be obtained and analyzed (Fig. 2). The need for the model which could be used in the least-squares procedure led to the formulation of so-called pseudoatom models, including the most popular till now, Hansen-Coppens model (eq. 2) in which the aspherical part is described in terms of real spherical harmonics. In this paper, the basics of the electron density studies is described in some detail, including the step-by-step description of a typical procedure from the experiment to the final steps of refinement. An example of the analysis of the high-resolution structure of 1,2-dimethyl-4-nitro-5-morpholine-imidazole hydrate is used to show an application of this method in studying the intermolecular interactions, including weak C-H···O and C-H···N hydrogen bonds. It is shown that the multipolar model is able to deliver more informations than the promolecular model with spherically symmetrical electron distributions.

5

Właściwości adhezyjne powierzchni

Krawczyk-Kłys I., Jaruga I.

Technologia i Jakość Wyrobów

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2014

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R. 59

28--35

PL

Zjawisko adhezji dotyczy oddziaływań powierzchniowych i spotykamy się z nim wszędzie tam, gdzie dochodzi do łączenia się ze sobą powierzchniowych warstw ciał fizycznych lub faz. Z makroskopowego punktu widzenia czystą adhezję definiuje się jako odwracalny termodynamiczny proces, który zachodzi w warstwie łączonych materiałów. Granica między adhezją i zjawiskami powierzchniowymi zachodzącymi pod wpływem tworzenia się wiązań chemicznych jest bardzo płynna. Trudno jednoznacznie rozróżnić "czystą adhezję" od adhezji na skutek tworzenia się słabych wiązań wodorowych, które są jednocześnie rodzajem wiązań chemicznych i oddziaływaniami międzycząsteczkowymi.

EN

The phenomenon of adhesion concerns the interaction of surface and we could meet it wherever it comes to connecting with each other the surface layers of physical bodies or phases. From a macroscopic point of view of clear adhesion is defined as a reversible thermodynamic process that takes place in the layer of the joined materials. The boundary between the adhesion and surface phenomena occurring under the influence of the formation of chemical bonds is very fluid. It is difficult to distinguish between a "pure adhesion" of adhesion due to formation of weak hydrogen bonds, which are also the type of chemical bonds and intermolecular interactions.

6

Magnetic interactions in frozen solutions of ironporphyrins

Dziedzic-Kocurek K., Okła D., Stanek J.

Nukleonika

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2013

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Vol. 58, No. 1

83-86

EN

The powder samples of meso-tetraphenyloporphyrin iron(III) chloride and ferriprotoporphyrin IX chloride and their frozen in solutions N,N-dimethylformamide were studied by Mössbauer spectroscopy. The variation of the outer ligands of the porphyrin rings modifies their magnetic properties but the major influence on the magnetic relaxation process exerts the intermolecular magnetic interactions, which are eliminated in dilute solutions.

7

Elektrooptyczny efekt Kerra w chemii

Prezhdo O., Olan K., Zubkowa W., Preżdo W.

Wiadomości Chemiczne

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2011

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[Z] 65, 1-2

1-31

EN

The electro-optical Kerr effect finds wide application in conformational analysis of molecules and molecular aggregates [1–5], particularly in cases where the standard X-ray and NMR techniques cannot be used. For instance, NMR allows to establish conformations of linear and cyclic unsaturated organic compounds. However, it is less effective in an analysis of molecular complexes, particularly of those that have several rotational symmetry axes. In such cases a combination of techniques based on molecular dipole moments, electro-optical Kerr effect, optical Kerr effect, IR spectroscopy, and Rayleigh scattering can be applied [6]. The foundations of conformational analysis of molecular complexes using several complementary physical approaches are developed in Ref. [7]. The electro-optical methods are particularly useful for an investigation of intramolecular interactions [8–18]. The strength, direction and other details of intramolecular interactions can be determined by analyzing the deviations of the experimental molar Kerr constant (mK) from its value calculated according to the tensor-additive scheme that operates with polarizability tensors of molecular cores and functional groups [19, 20]. For instance, using this approach it has been shown that weakening of conjugation in an electron donor-acceptor chain can lead to flattening of the molecular structure [21]. The Kerr constant is also very sensitive to intermolecular interactions [22–29]. In order to assess quantitatively an extent of the solvent effect on the mK values, both molecular and continuum models of solution structure have been used [30, 31]. The mK values are greatly affected by the mutual orientation of solvent and solute molecules, which interact by dispersive, inductive and dipole-dipole forces [32]. Hydrogen and donor-acceptor bonding have an even stronger influence on the mK values [33]. The equimolar mixtures approach developed in Ref. [34] allows to determine the molar Kerr constant (mK), dipole moment (m), equilibrium constant (K) and, ultimately, structure of a molecular complex based on measurements of the Kerr constant (B), dielectric permittivity (e), density (d) and refractive index (n) of a series of dilute solutions of the complex. Future trends in the development of the electro-optical methods in chemistry are discussed. Theories that relate the electric-optic proprieties of molecules with their reactivity are particularly important. Such theories should be able to predict the changes in the polarizabilities and dipole moments of bonds, molecules and molecular aggregates during the course of chemical reactions.

8

Ammonium nitrate phase state stabilization with small amounts of some organic compounds

Golovina N., Nechiporenko G., Nemtsev G., Zyuzin I., Manelis G. B., Lempert D.

Central European Journal of Energetic Materials

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2009

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Vol. 6, nr 1

45-56

EN

The investigation considers phase stabilization of ammonium nitrate for considerable extension of its application area including new generation of gas-generating compositions for airbag inflators. It was shown that alloys of ammonium nitrate with small amounts (2-10%) of some organic compounds can have no phase transitions or at least have only one instead of three ones in initial ammonium nitrate. The mostly effective as stabilizers are the compounds that have rather close crystallographic parameters. A strong donor-acceptor interaction between nitrate-anion and organic molecules are found. Using quantum-chemical calculations, X-ray analysis, X-ray phase analysis, UV- and IR-spectroscopy it was found a new ammonium nitrate phase state in its alloy with some organic additives. This state is stable in temperature range between -50 and +100 C.

9

An Experimental Test for the Approximation of NMR Solvent Effects by Continuum Models. 19F Gas-to-Solution Shifts of SF6 and CF4

Jackowski K., Wilczek M.

Polish Journal of Chemistry

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2006

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Vol. 80, nr 7

1169-1175

EN

19F gas-to-solution shifts were measured for two solute molecules (SF6, CF4) and 39 organic solvents. A correlation between the results for SF6 and CF4 is satisfactory and proves that solvent effects of both the solute molecules can be described in the same way. The present 19F shifts of SF6 are also compared with some previous gas-to-solution shifts observed for 129Xe gas and 33S in SF6. It is shown that intermolecular interactions change the shifts of external atoms (19F and 129Xe) in slightly different way than it is observed for the central atom of 33S in a SF6 molecule.

10

Influence of Intermolecular Interactions on Nuclear Magnetic Shielding Constans of OCS

Jackowski K., Les A., Makulski W., Wozniak K.

Polish Journal of Chemistry

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2002

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Vol. 76 / nr 4

575-580

EN

The gauge-included atomic orbital (GIAO) method has been applied within the coupled Hartree-Fock (CHF) approximation to compute 13C, 17Oand 33SNMRchemical shifts for solid OCS. Increasing clusters of OCS molecules taken out of crystal lattice have been used in an additive approximation to estimate the effect of intermolecular interactions on shielding of the carbon, oxygen and sulphur nuclei. There is a very good agreement achieved for NMR chemical shifts between the results of calculations and experimental measurements obtained for 13C and also some discrepancies for 17Oand 33S nuclei, probably due to deficiency of ab-initio calculations (lack of electron correlation). The results reveal that the 33S NMR signal of OCS is strongly dependent on intermolecular interactions.

11

QSAR Studies on Bioorganic and Pharmacological Effects of the Antidepressants

Pietrzycki W.

Polish Journal of Chemistry

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2000

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Vol. 74, nr 1

89-108

EN

Quantitantive Structure-Activity relationship (QSAR) studies on 19 most important antidepressants were performed using the PM3 quantum chemical parameters. The ground state population analysis was performed for all the antidepressants (Antds).

12

Aqueous Basicity and Proton Affinity of Zwitterionic W-(N-Methylpiperidine)-alkanocarboxylates and W-(N-Piperidine)-alkanocarboxylic Acids

Barczyński P., Dega-Szafran Z., Dulewicz E., Petryna M., Szafran M.

Polish Journal of Chemistry

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2000

|

Vol. 74, nr 8

1149-1161

EN

Semiempirical geometry optimizations were performed for gaseous betaines. Four conformers were characterized and their PA values estimated. The PA values fulfilled the linear correlation with the aqueous pK values estimated in ref.1.

13

Effects of intermolecular interactions on the 1H, 13C and 14N NMR chemical shifts of N,N-Dimethylformamide dissolved in monosubstituted benzenes

Jackowski K., Makulski W., Trenkner-Olejniczak Z.

Bulletin of the Polish Academy of Sciences. Chemistry

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2000

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Vol. 48, No. 1

81-89

EN

1 H,13 C and 14 N NMR chemical shifts have been used to monitor the dilution process of JV,7V-dimethylformamide (DMF) in monosubstituted benzenes. Both the proton and carbon chemical shifts of non-equivalent methyl groups in DMF are spectacularly influenced by ASIS (Aromatic Solvent Induced Shift) effects at the low concentration of a solute. On the other hand, the destruction of DMF liquid structure itself is better seen when the 13C chemical shift of a carbonyl carbon and the 14N shift are verified. A good correlation between the latter NMR chemical shifts has been found. It is shown on the basis of GIAO-CHF model calculations that the destruction of solute dipole-dipole dimers may be responsible for the increase of carbonyl carbon and nitrogen shielding constants of DMF in solvents.

14

Second virial coefficients for atom-molecule complexes from ab initio SAPT potentials

Moszynski R., Korona T., Heijmen T.G.A., Wormer P.E.S., Avoird A. van der, Schramm B.

Polish Journal of Chemistry

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1998

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Vol. 72, nr 7S

1479-1496

EN

Ab initio potentials, calculated by symmetry-adapted perturbation theory, are applied to compute second virial ciefficients (including first order quantum corrections) for He-CO, Ne-CO, Ar-H2, He-C2H2, and Ar-CH4 mixtures over a wide range of temperatures. The experimental methods are briefly outlined and the errors in the procedure to obtain mixed virial coefficients from the experimental data are discussed. Very good agreement with the majority of the available experimental data is observed for all systems except Ar-CH4 where calculated virial coefficients are slightly too high in comparison with measured data. Possible reasons for discrepancies between theory and experiment at very low temperature are discussed.

15

Matrix isolation and DFT quantum mechanical studies of vibrational spectra of uracil and its methylated derivatives

Szczepaniak K., Person W.B., Leszczynski J., Kwiatkowski J. S.

Polish Journal of Chemistry

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1998

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Vol. 72, nr 2

402-420

EN

The infrared spectra of uracil and its derivatives in the carbonyl region are strikingly complex, and extremely sensitive to substitution, particularly at ring nitrogen. In this work the infrared spectra of uracil, 1,3-di-deuterouracil, 1-methyluracil, 3-methyluracil and 1,3-dimethyluracil are studied experimentally by low temperature (12 K) matrix isolation infrared spectroscopic techniques, and theoretically by DFT/B3LYP/6-31G(d,p) quantum mechanical methods. Particular attention is focused on the carbonyl region and on the mechanical coupling of the C2=O and C4=O stretching vibrations with each other, with the N1H and N3H bending motions, and with other motions. It is shown that this coupling plays a crucial role in determining the frequencies and intersities of the normal modes that determine the spectral patterns in the infrared spectrum in the carbonyl region. The extreme sensitivity of the frequencies, intersities and spectral pattern in the carbonyl region to isotopic substitution and methylation (and to the intermolecular interactions, particularly hydrogen bonding) is attributed, to a large extent, to changes in this coupling. The DFT calculation appear to give quite accurate values for the force constants and allow separation of simple mass effects and chemical substituent effects on the coupling. Fermi resonance in the carbonyl region is an important factor contributing to the observed complexity of this spectral region. Examination of this effect making use of the visualization of normal modes of vibration provides rules for when it may be expected to be important.

16

Isoelectronic dimers [(XH3)2, (YH2)2, (ZH)2, and (Rg)2] in the groups of the periodic system: ab initio quantum chemical calculations

Hobza P., Burda J.V., Zahradnik R.

Polish Journal of Chemistry

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1998

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Vol. 72, nr 7S

1497-1504

EN

The (ZH)2, (YH2)2, (XH3)2 and (Rg)2 dimers [Z=F-At; Y=O.Po; X=N, Bi; Rg=rare gas] were studied ab initio using the CCSD(T) and MP2 procedures. Average relativistic effective potentials were used for all the halogens, while Stuttgart effective core potentials were used for the remaining non-hydrogen atoms. All the (HX)2 structure are H-bonded. All the stabilization energies mutually approach when passing down the group of the periodic system.

17

Intermolecular effects in GIAO-CHF calculations of NMR chemical shifts

Jackowski K.

Bulletin of the Polish Academy of Sciences. Chemistry

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1998

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Vol. 46, No. 1

91-103

EN

Gauge-invariant atomic orbital (GIAO) calculations are applied for the in- vestigation of intermolecular interactions. Some modest examples show that the (GIAO) method allows for the useful estimation of NMR gas to liquid shifts and nuclear shielding tensors for molecules in the solid state. All the theoretical results can be easily verified by the NMR measurements.