scholarly journals BGR MACROHETEROCYCLIC COMPOUNDS OF ASYMMETRIC STRUCTURE WITH THIADIAZOL FRAGMENTS. SYNTHESIS AND PROPERTIES

2020 ◽  
Vol 63 (8) ◽  
pp. 54-59
Author(s):  
Galina R. Berezina ◽  
Margarita N. Medvedeva
Keyword(s):  
Electronic Absorption Spectra ◽  
Bathochromic Shift ◽  
Spectral Characteristics ◽  
Molar Ratio ◽  
Asymmetric Structure ◽  
Systematic Research ◽  
Elemental Analysis Data ◽  
Absorption Bands ◽  
Macroheterocyclic Compounds ◽  
Eluent Acetone

This communication is a continuation of the systematic research of the authors in the field of synthesis and study of the properties of macroheterocyclic compounds. The great potential for structural modification allows us to synthesize macroheterocyclic compounds that differ in composition and the nature of the heteroatoms that make up them and make this class of compounds promising from the point of view of the design for the preparation of substances with valuable practical properties. The interaction of N,N/-bis-(1-imino-2-phenyl-1H-indene-3-iliden)-1,4-phenylenediamine with 2,5-dimiano-1,3,4-thiadiazole and 3,5-diamino-1,2,4-thiadiazole the macroheterocyclic compounds of asymmetric structure were synthesized in the molar ratio of the initial substances. Macroheterocycles are powdered substances with different shades of red color, having melting and crystallization temperatures (investigated in the argon current), soluble in chloroform, DMF, acetone, ethanol. Purification was carried out by column chromatography on aluminum oxide of II degree of activity on Brockman (eluent acetone - chloroform, 1:9 by volume). Identification of synthesis products was performed by thin-layer chromatography on Silufol UV-254 plates (eluent – acetone - chloroform, 1:1 by volume). The obtained compounds were characterized by infrared and electron spectroscopy. The electronic absorption spectra were measured on a Hitachi U-2010 instrument in quartz cuvettes at 20 °C. IR spectra were obtained on the Avatar 360 FT-IR ESP device in KVG. Elemental analysis data were obtained using the CHNS-O Analyzer FlashEA of 1112 Series.  A bathochromic shift of the absorption bands was noted when the compound with 1,3,4-thiadiazole was closed in a cycle. The spectral characteristics indicate that the molecules of the synthesized compounds do not have a flat structure and the absorption is due to individual fragments that are part of the molecules of the synthesized structures.  

scholarly journals SYNTHESIS AND PROPERTIES OF MACROCYCLIC COMPOUNDS WITH FRAGMENT OF METHYLINDANDONE

2018 ◽  
Vol 61 (6) ◽  
pp. 29
Author(s):  
Galina R. Berezina ◽  
Karina A. Nikolaeva
Keyword(s):  
1H Nmr ◽  
Electronic Absorption Spectra ◽  
Internal Standard ◽  
Molar Ratio ◽  
Macrocyclic Compounds ◽  
Single Chain ◽  
Absorption Bands ◽  
Condensation Products ◽  
Macroheterocyclic Compounds ◽  
Eluent Acetone

The present communication is a continuation of the systematic studies of the authors in the field of synthesis and studying the properties of macroheterocyclic compounds, as large as possible structural modifications allow currently to synthesize macroheterocyclic compounds, differing in composition, the nature of their constituent heteroatoms and make this class of compounds promising from the point of view of directed synthesis to obtain materials with valuable practical properties. Condensation products and macroheterocyclic compounds of a symmetrical structure are synthesized by the interaction of diimine 2-methylindandione-1,3 with 2,4-diaminobenzenesulfonic acid and 3,5-diamino-1,2,4-thiadiazole in a molar ratio of 2:1. Condensation products constitute a powdery substance with different shades of red color, soluble in water and organic solvents of different nature. Macroheterocyclic compounds were synthesized with two ways. The first method is cyclization of compounds of structure 2:1 in a symmetric structure, and the second in a molar ratio of the starting materials. A purification was performed by column chromatography on alumina of II degree of activity by Brockmann eluent acetone - chloroform, 1:1 by volume. An identification of the synthesis products was performed by thin-layer chromatography on plates Silufol UV-254 (eluent – acetone - chloroform, 1:1 by volume). The compounds were characterized by data of IR, electronic and 1H NMR spectroscopy. Electronic absorption spectra were measured on instrument Hitachi U-2010 in quartz cuvettes at 20 °C. IR spectra were obtained on the device Avatar 360 FT-IR ESP in KBr. 1H NMR spectra of solutions of samples in acetone – D6 were recorded on device "AMD Brucker 500" with an internal standard of TMS. The data of elemental analysis obtained on the instrument CHNS-O Analyzer FlashEA 1112 Series. A hypsochromic shift of the absorption bands was observed upon closure in a cycle. The widened absorption bands in the visible part of the electron spectrum indicate that the molecules of synthesized compounds have a flat structure and the absorption due to individual fragments, which are part of molecules and single-chain pairing of the synthesized structures.Forcitation:Berezina G.R., Nikolaeva K.A. Synthesis and properties of macrocyclic compounds with fragment of methylindandone. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N 6. P. 29-34

scholarly journals SYNTHESIS AND SPECTRAL CHARACTERISTICS OF PERSPECTIVE NANOSIZED CARBON QUANTUM DOTS FOR ADSORPTION AND CATALYTIC PROCESSES

2020 ◽  
Vol 86 (1) ◽  
pp. 3-11
Author(s):  
Volodymyr Ogenko ◽  
Svitlana Orysyk ◽  
Ljudmila Kharkova ◽  
Oleg Yanko
Keyword(s):  
Quantum Dots ◽  
Bathochromic Shift ◽  
Spectral Characteristics ◽  
Carbon Quantum Dots ◽  
Hypsochromic Shift ◽  
Absorption Bands ◽  
Rhodium Chloride ◽  
Electron Transitions ◽  
Trivalent State ◽  
Adsorption Processes

Processes of interaction between carbon quantum dots (CQDs) and solutions of rhodium, ruthenium and palladium chlorides in the surface layer have been investigated by electron and IR spectroscopy. When rhodium chloride is added to a solution of CQDS, a bathochromic shift of the β- and p-absorption bands (ABs) at 48725 and 41711 cm-1 as well as hypsochromic shift of the α-AB at 28935 cm-1 indicate that rhodium adsorption occurs on the surface of CQDs. The bathochromic shift of the absorption bands at 22400 сm1 together with the hypsochromic shift of ABs corresponding to d-d electron transitions in the metal ions indicates the formation of rhodium with CQDs. When ruthenium and palladium chlorides are added to an aqueous solution of CQDs, the intensive of ABs characterizing the complex anions [RuCl6]3-, [RuCl6]2- or [PdCl4]2- are absent in the UV-Vis spectra. This indicates the passage of adsorption processes of metals on the surface of CQDs.  The present of ABs (at 27055 and 25125 сm-1) indicate the trivalent state of ruthenium ion; the p-ABs bathochromic shift as well as α-ABs hypsochromic shift indicates the probable complex formation of CQDs with Ru3+ ions. The change in the position of the absorption bands of d-d electron transitions (at 25448 сm1) together with the bathochromic shift of p-ABs and hypsochromic shift of α-ABs indicates a change in coordination environment in the palladium ion with the possible formation of Pd → N bond. The IR-spectra data of CQDs showed the presence of a number of characteristic ABs for functionalized CQDs: ν(N–H) at 3260 сm1, (C=O) at 1830, 1840 and 1850 сm1, –С=O(NH) at 1770 сm1, ν(C=N) at 1680 and δ(N–H) at 1640 сm1, which confirms the coordination of metals on the surface of CQDs.

scholarly journals SPECTRAL PROPERTIES OF ZINC AND COBALT MESO-TETRAPHENYLPORPHYRINS IN POLYMER FILMS

2020 ◽  
Vol 63 (10) ◽  
pp. 110-116
Author(s):  
Maria Е. Glazkova ◽  
Maria V. Petrova ◽  
Yuliya S. Rodina ◽  
Sofia S. Rodina ◽  
Тatiana А. Аgeeva
Keyword(s):  
Benzoyl Peroxide ◽  
Polymer Matrix ◽  
Spectral Properties ◽  
Electronic Absorption Spectra ◽  
Bathochromic Shift ◽  
Fluorescent Properties ◽  
Absorption Bands ◽  
Near Ir ◽  
Residual Amount ◽  
First Time

The results of studying the spectral properties of zinc and cobalt meso-tetraphenyl-porphyrins included as the modifiers in polymethylmethacrylate, polystyrene and polyvinylchloride films are presented in this article for the first time. It was established that an inert polymer matrix of polyvinylchloride, block polystyrene and polymethylmethacrylate does not affect the spectral properties of tetrapyrrole macroheterocycles, which are included in it. In this case, insignificant bathochromic shift of the absorption bands of the metal complexes in the modified films is recorded, which is probably due to the presence of intermolecular interaction of the metalloporphyrin with the polymer matrix. The method of polymer producing is important for modification of polystyrene or polymethyl methacrylate films. The ignificant changes are observed in the electronic spectra of metalloporphyrins due to the interaction between the modifier and the residual amount of the radical polymerization initiator (benzoyl peroxide) used in the preparation of polymers. Earlier studies showed that the interaction of benzoyl peroxide with zinc and cobalt meso-tetraphenylporphyrinates in solution leads to the formation of the corresponding metalloisoporphyrinates. In this work, the possibility of such structures formation in a polymer matrix is shown for the first time. In this case, in the electronic absorption spectra of the modified films, as in solutions, bands appear in the near IR region. The fluorescent properties of modified films have been studied. It was shown that in the absence of interaction between the components in the film, metalloporphyrins introduced into the polymer matrix retain their ability to fluorescence.

scholarly journals Spectral and quantum chemical study of tautomeric and ion transformations of 2-(2-(2-hydroxy-5-sulfamoylphenyl)- hydrazono)-3-oxo-N-phenylbutanamide

2019 ◽  
Vol 60 (11) ◽  
pp. 106-113
Author(s):  
Anh Thi Ngoc Vu ◽  
◽  
Mikhail A. Ryabov ◽  
Olga V. Kovalchukova ◽  
Dmitry S. Gusarov ◽  
...  
Keyword(s):  
Absorption Spectra ◽  
Electronic Absorption ◽  
Quantum Chemical ◽  
Electronic Absorption Spectra ◽  
Bathochromic Shift ◽  
Stable Form ◽  
Ionic Form ◽  
Absorption Bands ◽  
Tautomeric Forms ◽  
The Stability

In this paper, using the method DFT/B3LYP of quantum chemical modeling, the stability of tautomeric, conformer, and anionic forms of 2-(2-(2-hydroxy-5-sulfamoylphenyl)hydrazone-3-oxo-N-phenylbutanamide (H2L) was studied and the geometric, electronic structure and bond lengths of molecules in various tautomeric forms were determined. It was shown that the stability of tautomeric molecules H2L as anionic forms was determined by the number of existing intermolecular hydrogen bonds (closing six-membered and five-membered cycles). The most stable tautomeric and conformal forms of an organic molecule and its dianion are proposed. The interatomic distances, angles, charges on atoms, IR and electronic absorption spectra of tautomeric forms of the molecule and dianion (H2L and L2-) were calculated. In this work, we studied the electronic absorption spectra in an aqueous-alcoholic solution and found that in an alkaline medium the molecule transforms into the ionic form with a bathochromic shift of 47 nm, corresponding to the results of the shift of the long-wavelength band electronic absorption spectra upon transition from the hydrazotautomer (form a) to the dianion form (form b’’) at 92 nm obtained by TD-DFT. The calculated results for the distance and angles between atoms are in good agreement with the experimental data of the molecule by X-ray diffraction analysis. It was shown that the IR spectrum of the stable form appears two absorption bands in the region of 1690 and 1655 cm–1, which are attributed to stretching vibrations of carbonyl groups (C=O), bound by a strong intramolecular hydrogen bond and the presence of the NH-hydrazone fragment of the 1H NMR spectrum confirmed the most stable for a neutral molecule is the hydrazone form.

Electronic absorption spectra and structure of hydroxycoumarin derivatives and their ionized forms

1997 ◽  
Vol 75 (4) ◽  
pp. 365-376 ◽  
Author(s):  
Valery F. Traven ◽  
Larisa I. Vorobjeva ◽  
Tatjana A. Chibisova ◽  
Edward Andrew Carberry ◽  
Noelle Jean Beyer
Keyword(s):  
Absorption Spectra ◽  
Electronic Absorption ◽  
Electronic Absorption Spectra ◽  
Bathochromic Shift ◽  
Hydroxyl Group ◽  
Absorption Bands ◽  
Pyrone Ring ◽  
Tautomeric Forms ◽  
Wavelength Absorption ◽  
Carbonyl Function

Electronic absorption spectra of 18 hydroxycoumarin derivatives and their ionized forms have been studied. Close agreement between experimental and the PPP CI calculated electron absorption band energies has been found in most cases. Strong polarization of the carbonyl function of the pyrone ring in the 7-hydroxycoumarin derivatives, H-bonding between the hydroxyl group and neighboring substituent in the ortho-substituted hydroxycoumarins, as well as their tautomeric transformations, have been suggested in the discussion of the electronic absorption spectra of the hydroxycoumarin derivatives. In accord also with calculational results, ionization of the hydroxyl function leads to a bathochromic shift of the longest-wavelength absorption bands in the spectra of 7-hydroxycoumarin derivatives. The ionization has no effect on the electronic absorption of the 4-hydroxycoumarin derivatives. Relative stabilities of the tautomeric forms of hydroxycoumarin derivatives and their ionized forms have also been compared by MNDO calculations. Keywords: hydroxycoumarins, intramolecular H-bonding, ionization, electronic absorption spectra, keto–enol tautomerism.

Ab initio calculations of scytonemin derivatives of relevance to extremophile characterization by Raman spectroscopy

2010 ◽  
Vol 368 (1922) ◽  
pp. 3193-3203 ◽  
Author(s):  
Tereza Varnali ◽  
Howell G. M. Edwards
Keyword(s):  
Ab Initio ◽  
Structural Changes ◽  
Spectral Characteristics ◽  
Special Role ◽  
Absorption Bands ◽  
Parent Molecule ◽  
Detailed Structural Analysis ◽  
Protective Strategy ◽  
Terrestrial Environments ◽  
Martian Regolith

The recognition that scytonemin, the radiation protectant pigment produced by extremophilic cyanobacterial colonies in stressed terrestrial environments, is a key biomarker for extinct or extant life preserved in geological scenarios is critically important for the detection of life signatures by remote analytical instrumentation on planetary surfaces and subsurfaces. The ExoMars mission to seek life signatures on Mars is just one experiment that will rely upon the detection of molecules such as scytonemin in the Martian regolith. Following a detailed structural analysis of the parent scytonemin, we report here for the first time a similar analysis of several of its methoxy derivatives that have recently been extracted from stressed cyanobacteria. Ab initio calculations have been carried out to determine the most stable molecular configurations, and the implications of the structural changes imposed by the methoxy group additions on the spectral characteristics of the parent molecule are discussed. The calculated electronic absorption bands of the derivative molecules reveal that their capability of removing UVA wavelengths is removed while preserving the ability to absorb the shorter wavelength UVB and UVC radiation, in contrast to scytonemin itself. This is indicative of a special role for these molecules in the protective strategy of the cyanobacterial extremophiles.

scholarly journals Modification of Pea Starch and Dextrin Polymers with Isocyanate Functional Groups

Polymers ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 939 ◽  
Author(s):  
Reza Hosseinpourpia ◽  
Arantzazu Echart ◽  
Stergios Adamopoulos ◽  
Nagore Gabilondo ◽  
Arantxa Eceiza
Keyword(s):  
Moisture Sorption ◽  
Analysis Data ◽  
Water Vapor Sorption ◽  
Molar Ratio ◽  
Elemental Analysis Data ◽  
Slight Reduction ◽  
Modified Starch ◽  
13C Nuclear Magnetic Resonance ◽  
High Molar Ratio ◽  
Pea Starch

Pea starch and dextrin polymers were modified through the unequal reactivity of isocyanate groups in isophorone diisocyanate (IPDI) monomer. The presence of both urethane and isocyanate functionalities in starch and dextrin after modification were confirmed by Fourier transform infrared spectroscopy (FTIR) and 13C nuclear magnetic resonance (13C NMR). The degree of substitution (DS) was calculated using elemental analysis data and showed higher DS values in modified dextrin than modified starch. The onsets of thermal degradation and temperatures at maximum mass losses were improved after modification of both starch and dextrin polymers compared to unmodified ones. Glass transition temperatures (Tg) of modified starch and dextrin were lower than unmodified control ones, and this was more pronounced in modified dextrin at a high molar ratio. Dynamic water vapor sorption of starch and dextrin polymers indicated a slight reduction in moisture sorption of modified starch, but considerably lower moisture sorption in modified dextrin as compared to that of unmodified ones.

scholarly journals Improving anti-infrared radiation and heat insulation by potassium hexatitanate whisker-doped Al 2 O 3 –SiO 2 composite xerogel

2018 ◽  
Vol 5 (12) ◽  
pp. 180787
Author(s):  
Liang Furong ◽  
Liu Weijun ◽  
Han Xiuxiu ◽  
Zhang Boru ◽  
Zhang Shuhua
Keyword(s):  
Thermal Conductivity ◽  
Infrared Radiation ◽  
Near Infrared ◽  
Raw Materials ◽  
Sol Gel ◽  
Spectral Characteristics ◽  
Molar Ratio ◽  
Thermal Insulating ◽  
Infrared Spectral ◽  
Potassium Hexatitanate

Taking potassium hexatitanate whisker (PTW) modified by silane coupling agent KH550, aluminium nitrate inorganic salt and tetraethyl orthosilicate and deionized water, respectively, as infrared sunscreen, aluminium source and raw materials forming the network structure of a composite xerogel, a series of structurally intact PTW-doped Al 2 O 3 –SiO 2 composite xerogel thermal-insulating materials were prepared by the sol–gel method and dried under atmospheric pressure. The infrared spectral characteristics, infrared radiation transmittance, microstructures, morphology and thermal conductivity of different composite materials prepared have been determined by a Fourier transform infrared spectrometer, UV–visible–near-infrared spectrophotometer, X-ray diffractometer, scanning electron microscope and thermal conductivity tester. The results exhibit that when the Al to Si molar ratio is 1 : 9, the composite material with 5 wt% modified PTW shows the best infrared radiation blocking performance and the lowest thermal conductivity (0.0604 W m −1 K −1 ).

Chlorine Solutions in Molten Alkali Chlorides

2007 ◽  
Vol 62 (3-4) ◽  
pp. 205-212 ◽  
Author(s):  
Artem Kolobov ◽  
Vladimir Khokhlov ◽  
Alexei Potapov ◽  
Victor Kochedykov
Keyword(s):  
Absorption Band ◽  
Molten Salt ◽  
Electronic Absorption ◽  
Absorption Maximum ◽  
Electronic Absorption Spectra ◽  
Absorption Bands ◽  
Short Waves ◽  
Wide Absorption Band ◽  
Alkali Chlorides ◽  
Saturated Solutions

Electronic absorption spectra of gaseous chlorine and their saturated solutions in molten alkali chlorides were studied in wide ranges of temperature and wavelength. It was found that gaseous chlorine has a wide absorption band between 20 000 and 43 500 cm−1. There is a tendency to both widening of the band and shifting of the absorption maximum to the short-waves region with rising temperature.The absorption bands of saturated solutions of chlorine in all molten alkali chlorides show a maximum in the neighborhood of 30 000 cm−1. A good correlation was found between the optical density of molten salt-Cl2 systems and the solubility of chlorine.

Dihydronaphthalenone Carboxylates - Spectral Characteristics and Structure

1997 ◽  
Vol 52 (5) ◽  
pp. 457-461 ◽  
Author(s):  
Sn. Bakalova ◽  
A. Georgieva ◽  
P. Nikolov ◽  
E. Stanoeva
Keyword(s):  
Ir Spectra ◽  
Quantum Chemical Calculations ◽  
Electronic Spectra ◽  
Quantum Chemical ◽  
Substituent Effect ◽  
Methyl Esters ◽  
Spectral Characteristics ◽  
Absorption Bands ◽  
Tautomeric Forms ◽  
Luminescence Characteristics

Abstract The absorption and luminescence characteristics of a group of newly synthesized methyl esters of 2-alkyl (p-substituted-aryl) -aminomethylene-3,4-dihydro-1(2 H)-naphthalenone-4-carboxylic acids have been investigated. The studied compounds may exist in three tautomeric forms. On the basis of comparison of their electronic spectra to those of similar substances, the observed substituent effect on the position of the UV-VIS absorption bands, the IR spectra and the results of PPP-SCF-CI quantum-chemical calculations it is concluded that the keto tautomer predominates in solution.

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