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1

Zastosowanie spektroskopii oscylacyjnej w detekcji barwników azowych w opakowaniach do żywności

Kucharska Edyta, Michalski Jacek, Sąsiadek Wojciech, Dymińska Lucyna, Hołubniak Paulina, Hanuza Jerzy

Wiadomości Chemiczne

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2023

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[Z] 77, 7-8

687--718

EN

This work is a continuation of our research on spectroscopic and structural properties and applications of a number of azo-dipyridine and phenyl-azopyridine derivatives. In the previous works, the results of DFT quantum calculations were used to discuss infrared and Raman spectra. The presented study generalizes these results using the literature data on the structure of aromatic azo compounds. Analysis of the spectra and detailed assignment of the observed bands to the specific oscillating modes enables their application to identification of azo dyes widely used in the food industry. The bioactivity of azo dyes means that the safety of their use requires the search for new methods of their detection in food. The paper shows that vibrational spectroscopy is an effective diagnostic method for identifying not only the material from which the plastic foil is made, but also the dye used for its dyeing. In this work, the method was applied to colour plastic foils used as pasta packaging. It has been shown that this foil is made of polypropylene, and azo dyes, such as orange yellow (orange dye), tartrazine (yellow dye), allura red (red dye), brilliant blue (blue dye) and a mixture of yellow and blue dyes (green dye) were used for its dyeing.

2

Study of Crystalline and Thermal Properties of Nanocomposites Based on Polyamide-6 and Modified Montmorillonite

Krasinskyi Volodymyr, Dulebova Ludmila, Gajdoš Ivan, Krasinska Oksana, Jachowicz Tomasz

Advances in Science and Technology. Research Journal

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2023

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Vol. 17, no 6

88--97

EN

The main operational characteristics of polyamide-6-montmorillonite (PA6/MMT) nanocomposites, which determine their fields of application, mainly depend on the crystal structure and crystallinity of the polymer. Therefore, the study of the crystalline behavior of PA6 in such nanocomposites is of considerable scientific and practical importance. In this work, the structure, crystalline, and thermal properties of nanocomposites based on PA6 and modified MMT prepared in a formic acid solution were investigated using the methods of differential scanning calorimetry (DSC) and X-ray Diffraction (XRD). It was established that during the manufacture of PA6/MMT nanocomposites in a solution, the dominant crystal structures are the thermodynamically stable α structures of PA6. The crystallinity degree of PA6 in nanocomposites is about 1.5 times higher than that of the original PA6. It is shown that after additional thermomechanical treatment of nanocomposites on a capillary viscometer at 230°С and a load of 5 kg, the uniformity of the distribution of exfoliated MMT in the polymer matrix increases, as a result of which the crystalline structure of PA6 changes and its glass transition and melting temperatures increase. These changes in the PA6 structure also have a significant impact on the melt flow index and the softening temperature of nanocomposites.

3

Comparison study of crystal and electronic structures for chalcopyrite (CuFeS2) and pyrite (FeS2)

Li Yuqiong, Liu Yingchao, Chen Jianhua, Zhao Cuihua, Cui Weiyong

Physicochemical Problems of Mineral Processing

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2021

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Vol. 57, iss. 1

100--111

EN

Chalcopyrite (CuFeS2) and pyrite (FeS2) are commonly associated with each other, and they both belong to semiconductor minerals. The difference in crystal and electronic structures is an important factor for their flotation separation. Using the density functional method (DFT) combined with Hubbard U correction, their crystal and electronic properties are comparatively studied. The calculated results suggest that the use of antiferromagnetic calculations and Hubbard U correction are very important to the accuracy of the chalcopyrite results. Antiferromagnetic calculations combined with a U value of 2.0 eV on chalcopyrite show a band gap of 0.53 eV, which is very consistent with the experimental results of ~0.5 eV. The density of states (DOS) and Mulliken bond population results indicate that stronger hybridization between Fe 3d and S 3p states in chalcopyrite than in pyrite leads to a stronger covalency of Fe-S bonds in chalcopyrite, causing a reduction in the spin magnetic moment (3.5 μB) from the ideal value. In addition, the greater covalency of bonds in chalcopyrite results in greater hydrophobicity of chalcopyrite than pyrite. The DOS results suggest that S has similar electronic properties in pyrite and chalcopyrite. The oxidation states of Fe and Cu ions in chalcopyrite are discussed based on the coordination field theory according to the calculation results, which confirms an oxidation state of Fe3+Cu1+S2.

4

Borowce jako centra kwasów Lewisa w oddziaływaniach międzycząsteczkowych : porównanie z wiązaniami wodorowymi

Grabowski S. J.

Wiadomości Chemiczne

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2017

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[Z] 71, 7-8

447--471

EN

The triel bonds are analyzed and compared with the hydrogen bond interaction. The triel bonds belong to the class of interactions that are named as the σ-hole and π-hole bonds. The σ-hole bond is an interaction between the σ-hole characterized by the positive electrostatic potential and the electron rich regions such as lone electron pairs, π-electron systems, in other words, centers paying a role of Lewis bases. The σ-holes may be observed for elements of the 14–18 groups of the periodic system and the corresponding interactions with Lewis bases are named; tetrel, pnicogen, chalcogen, halogen and aerogen bonds, respectively. On the other hand, π-holes also characterized by the positive electrostatic potential are observed for centers in planar molecules or planar fragments of molecules in regions above those planes. π-holes may be attributed to triel centers (13th group of the periodic system). The boron and aluminium trihydrides and trihalides are examples of molecules where triels are characterized by π-holes. The mechanism of the triel bond formation is very similar to the mechanism of the formation of the hydrogen bond. It is the Lewis acid – Lewis base interaction where the electron charge transfer from the base unit to the acid one is observed. Next there is outflow of the electron charge from the triel center to the other parts of the Lewis acid unit; in other words the positive charge of the triel center increases as a result of complexation. The triel bonds are often very strong and often they possess characteristics of typical covalent bonds; this is confirmed by the QTAIM (Quantum Theory of Atoms in Molecules) and NBO (Natural Bond Orbital) approaches. For example, for the triel bonds the bond paths between the triel center and the Lewis base center are observed with the bond critical points (BCPs) attributed to those paths. Similarly for the A-H…B hydrogen bonds the H…B bond paths are observed. The parameters of those BCPs often indicate the covalent character of the triel bonds and analogously those characteristics for H-bonds may also indicate the covalent character of the latter interactions. It is very interesting that the triel bonds are observed experimentally in the real systems; for example in crystal structures. The triel center which is trivalent and possesses the trigonal configuration is hypovalent; it means that the octet rule is not obeyed here because of the valence electrons´ deficiency (the triel center possesses six valence electrons in such species). Thus it may interact with one Lewis base ligand reaching rather stable octet and tetrahedral configuration. If the trivalent triel center interacts with two Lewis base ligands thus it may lead to the configuration of the trigonal bipyramid with the hypervalent and pentavalent triel center. These kinds of the triel species occur in crystal structures that are described here.

5

Transformacje strukturalne w kryształach wywołane reakcjami fotochemicznymi

Turowska-Tyrk I., Bąkowicz J.

Wiadomości Chemiczne

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2014

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[Z] 68, 5-6

381--402

EN

Structural changes induced in crystals by photochemical reactions were presented. The changes concern: a) the distances between neighbouring reactant molecules and their mutual orientation in the case of intermolecular reactions, b) the distances and angles between fragments of a molecule for intramolecular reactions, c) the position of molecules in crystals, d) geometry of hydrogen bonds, e) cell constants, and f) the content of product molecules in crystals. For most intramolecular reactions, the distances between reactive atoms are constant for a long time in phototransformation and decrease rapidly at its end (Figs. 3 and 5). In the case of intermolecular reactions, the distances between reactive atoms of reactant molecules decrease linearly along with the phototransformation of crystals (Fig. 7). Additionally, unreacted molecules become, to a certain degree, similar to product molecules in terms of their shape (Figs, 4 and 8). Reactant and product molecules do not assume a fixed place in crystals. Product molecules change their orientation towards that of which is observed in a pure product crystal and reactant molecules gradually move away from the position they took in pure reactant crystals. All this has an influence on the geometry of hydrogen bonds existing in crystals (Fig. 9). The above-mentioned structural transformations find their expression in values of cell constants (Fig. 10). The factors influencing the photoreactivity of molecules in crystals were also described. Knowledge of crystal and molecular structures of partly reacted crystals, determined thanks to X-ray structure analysis which is a branch of crystallography, reveals the behaviour of molecules in crystals in which photochemical reactions proceed and helps to understand a pathway of these reactions.

6

Highly Energetic Salts of 3,6-Bishydrazino-1,2,4,5-tetrazine

Klapötke T. M., Preimesser A., Schedlbauer S., Stierstorfer J.

Central European Journal of Energetic Materials

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2013

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Vol. 10, no. 2

151--170

EN

3,6-Bishydrazino-1,2,4,5-tetrazine was synthesized as described by hydrazinolysis of 3,6-bis-(3,5-dimethylpyrazolyl)-1,2,4,5-tetrazine. Doubly protonated 1:1 and 1:2 salts of the highly energetic anions were synthesized. These are bishydrazinium-tetrazine dichloride dihydrate (1:2) (BHT-2HCl•2H2O) (2), bishydrazinium-tetrazine (5,5´-azotetrazolate) dihydrate (1:1) (BHT-ATz•2H2O) (3), bishydrazinium-tetrazine bis (3,5-dinitrotriazolate) dihydrate (1:2) (BHT(DNT)2•2H2O) (4), bishydrazinium-tetrazine bis (5-nitrotetrazolate) (1:2) (BHT(NT)2) (5), bishydrazinium-tetrazine (5,5´-bistetrazolate) dihydrate (1:1) (BHTBT•2H2O) (6), bishydrazinium-tetrazine bistetrazolylamine (1:1) (BHT-BTA) (7), bishydrazinium-tetrazine bis (3-amino-5-nitrotriazolate) (1:2) (BHT-(ANTA)2) (8) and bishydrazinium-tetrazine 4,4´,5,5´-tetranitro-2,2´-bisimidazolate (1:1) (9). Compounds 2-6 could be characterized by low temperature X-ray diffraction. All of the compounds were suffciently analyzed by 1H and {1H}13C and 14N NMR spectroscopy, elemental analysis (CHN), mass spectroscopy (FAB)) and vibrational spectroscopy (IR and Raman). The detonation parameters of the most promising candidates 5 and 9 in terms of energetic applications were calculated using the EXPLO5 V5.05 computer code. The energies of formation were calculated using CBS-4M electronic enthalpies and the atomization method. Furthermore, since all of the compounds are energetic materials, sensitivity tests towards impact (IS), friction (FS) and electrostatical discharge (ESD) were carried out. In addition their thermal stabilities were determined using a differential scanning calorimeter with a heating rate of 5 °C min-1.

7

Influence of UV irradiation and temperature on polyamides PA6, PA6,6 and polypropylene PP

Brzozowska-Stanuch A., Rabiej S., Sarna E., Maślanka A.

Polish Journal of Applied Chemistry

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2011

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Vol. 55, nr 3-4

115-122

EN

In outdoor applications, all polymer materials weather which causes deterioration of their mechanical properties and has a negative influence on their appearance. In this article, the influence of UV irradiation and high temperature on polyamides PA6, PA6.6 and polypropylene PP and influence of aging parameters on their appearance (the state of surface) and chemical crystal structure have been shown. Microscopic examination of samples has shown that the biggest destruction in the surface of PP occurred in a short time after the beginning of the exposure. The examination of the surface and crystal structure of the materials clearly indicated that during exposure to UV irradiation and temperature degradation in PP materials occurred. Polyamides showed longer reaction time but after some time they also underwent radical changes in their supermolecular structure and they lost their esthetic appearance.

8

Structural Basis for Superiority of N-Methyl-N-(4,6-dimethoxy-1,3,5-triazin-2-yl)morpholinium Tetrafluoroborate as Modular Coupling Reagent. Crystal Structures of N-Methyl-N-(4,6-dimethoxy-1,3,5-tri azin-2-yl)morpholinium and -piperidinium Tetrafluorobor

Olczak A., Błaszczyk M., Główka M. L., Kolesińska B., Kamiński Z. J.

Polish Journal of Chemistry

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2008

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Vol. 82, nr 7

1413-1413

EN

Structural characteristics of tetrafluoroborates of N-methylated N-(4,6- dialkoxy- 1,3,5- triazin-2-yl)-morpholine and -piperidine, as determined by X-ray diffraction study, not only explain their good performance as modular coupling reagents in the peptide synthesis but also their higher stability than appropriate chlorides, which degrade easily through demethylation. Not expected axial orientation of 4,6-dialkoxy-1,3,5-triazinyl substituent at the quaternary N atom of the aliphatic ring observed in the crystal state has been confirmed in a solution by NMR technique. Quarternary triazinyl ammonium salts have been found as excellent modular coupling reagents, particularly in peptide syntheses. Crystal structure determination of N-methyltriazinylmorpholinium and -piperidinium tetrafluoroborates as well as their demethylated products provides a structural reason for the observed reaction. Namely, formation of very stable guanidine system around C(2) atom in 2-morpholine- and 2-piperidine-s-tri azines is controlled thermodynamically, while the difference in stability of chlorides and tetrafluoroborates (being superior) of quarternary N-methyl-N-triazinylmorpholinium (or piperidinium) results from conservative conformation of their cations, which hinders an a cess of large and less nucleophilic tetrafluoroborate an ion than Cl– to the methyl carbon atom.

9

Stabilization ofWVI in Nitride Environment via Acid/Base Reactions, and General Route to Layered Transition Metal Nitrides

Grochala W.

Polish Journal of Chemistry

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2007

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Vol. 81, nr 5-6

613-620

EN

DFT calculations for two hypothetical ternary nitrides of hexavalent tungsten: LaWN3 and La2WN4 (in perovskite and K2NiF4 structures, respectively) show that these compounds should spontaneously form fromWN2 (acid) and LaN (base) reagents, or simply from (WN + 1/2 N2 orW+ N2) and LaN, at ambient or elevated temperature and high N2 pressure to speed up the reactions. This concept may be utilized to stabilize other efemeric nitrides, like these of ReVII, OsVIII, and possibly even of unprecedented IrIX. La2WN4 is example of rare two-dimensional nitride materials. Band structure calculations confirm that LaWN3, La2WN4 and several related compounds should exhibitmetallic conductivity, and they show good prospect for 2Dsuperconductivity via self-doping.

10

Cienkowarstwowe struktury fotowoltaiczne

Olchowik J.

Zeszyty Naukowe Politechniki Rzeszowskiej. Budownictwo i Inżynieria Środowiska

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2006

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z. 40 [229]

363-370

PL

Praca poświęcona jest analizie wytwarzania i wykorzystania cienkowarstwowych struktur współczesnych baterii słonecznych. Zjawisko konwersji energii słonecznej odbywa się zazwyczaj w niewielkiej przypowierzchniowej części. półprzewodnikowych struktur krystalicznych. Zatem dla celów użytecznych wykorzystywana jest zaledwie niewielka część materiału, natomiast znaczna jego część stanowi jedynie podstawę konstrukcyjną ogniwa słonecznego.

EN

This work presents the analysis of thin layer technology of modern solar celIs. The photovoltaic conversion is realized in thin region of crystalIine substrates, near the surface. For practical purposes one uses only smalI amount of semiconductor material, but majority of these materials support mechanically PV celIs structures.

11

Phase and structural transformations in Ti-Ta alloys in wide region of compositions

Dobromyslov A. V., Dolgikh G. V., Dutkiewicz J., Trenogina T. L.

Archives of Metallurgy and Materials

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2006

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Vol. 51, iss. 4

547-550

EN

Optical microscopy, X-ray diffraction, transmission electron microscopy, and hardness measurements were used to study the structure of quenched Ti-Ta alloys containing 1-40 at.% tantalum. Two martensitic phases, Α' and Α'', are formed in quenched Ti-Ta alloys. The type of martensite crystal structure is determined by the composition of the alloy. The Α'-phase is formed in the alloys containing up to 10 at.% tantalum. The orthorhombic Α''-phase was found in the alloys containing 15-30 at.% Ta. The concentration dependence of the lattice parameters of the Α''-phase is given. Omega-phase precipitation were not found in quenched alloys. The alloys of 35-40 at.% Ta consist of metastable Β-phase only upon quenching. The electron diffractions patterns of the Ti-Ta alloys containing from 25 to 35 at.% tantalum exhibit diffuse scattering. It was established that stress-induced {110}Β and {332}Β twinning appeared in metastable Β-phase.

PL

Struktury stopów Ti-Ta zawierających 1-40% at. Ta badano metodami mikroskopii optycznej, dyfrakcji rentgenowskiej i transmisyjnej mikroskopii elektronowej. Dwie fazy martenzytyczne Α' i Α'', zidentyfikowano w tych stopach. Rodzaj struktury martenzytu zależy w pierwszym rzędzie od składu chemicznego. Faza Α' tworzy się w stopach zawierających do 10% at. Ta, a fazę ortorombową Α'' zidentyfikowano w stopach zawierających 15-30% at. Ta. Zmierzono zależność parametru fazy Α od składu chemicznego. Nie zidentyfikowano natomiast fazy ω. Stopy z zakresu 35-40% Ta zawierają po hartowaniu metastabilna faze Β. Dyfrakcje elektronowe wykonane ze stopów zawierających 25-35% Ta wykazują rozmyte refleksy, które jak ustalono wynikają z bliźniakowania na płaszczyznach {110}Β i {332}Β wywołanego naprężeniem w metastabilnej fazie Β.

12

New magnetic structure in TbMn0.33Ge2 compound

Gil A., Szytuła A.

Prace Naukowe. Chemia / Wyższa Szkoła Pedagogiczna w Częstochowie

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2001

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Vol. 5

123--129

EN

A study of the magnetic structure of TbMn0.33Ge2 has been made using a neutron diffractometer of better resolution and new results have been obtained. The paramagnetic neutron diffraction data confirmed the CeNiSi2 - type of crystal structure reported earlier for this compound. The magnetic moments are located on terbium. At 1.5 K Tb magnetic moments have two components: a collinear and sine wave modulated one so the magnetic order at this temperature has a complex character. With increasing temperature, the change of the magnetic structure to the new sine wave modulated one is observed near the Neel temperature TN=28 K.

13

X-ray crystallographic and spectroscopic investigations of copper(II) nitrate-1-allylimidazole complexes

Kurdziel K., Głowiak T.

Polish Journal of Chemistry

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1998

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Vol. 72, nr 9

2181-2188

EN

Copper(II) complexes Cu2L4(NO3)4 (a) and (CuL4(NO3)2 (b), where L is 1-allylimidazole, have been synthesized and characterized by elemental analysis, IR, FTIR, near IR, VIS, magnetic and crystallographic measurements. In centrosymmetric binuclear complex (a) the nitrate anions are linked to the Cu(II) cations through bidentate oxygen atoms. In complexes (b) the Cu(II) cation occupies a symmetry centre and is tetragonalbipyramid coordinated.

14

Reaction of phenyllithium with N-pivaloyl-20-piperidone

Maurin J.K., Czarnocki Z., Burdach A.

Polish Journal of Chemistry

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1998

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Vol. 72, nr 5

940-948

EN

Structural features of the reaction of N-pivaloyl-2-piperidone with phenyllithium were elaborated. Two compounds (4) and (5) were obtained and their structures were established by X-ray analysis. C16H23NO2(4): monoclinic, C2/c, a=37,197(7), b=8.479(2), c=9.988(2) A, beta=96.5(3)degree, Z=8; C22H27NO (5): orthorhombic, P2-12-12-1, a=8.244(2), b=10.305(2), c=22.616(5) A, Z=4.