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 INVESTIGATIONS OF COBALT PORPHYRINATES INTERACTION WITH RADICAL POLYMERIZATION INITIATORS

2019 ◽  
Vol 62 (5) ◽  
pp. 91-96
Author(s):  
Maria Е. Glazkova ◽  
Тatiana А. Аgeeva ◽  
Yuliya S. Rodina ◽  
Oscar I. Koifman
Keyword(s):  
Benzoyl Peroxide ◽  
Radical Polymerization ◽  
Electronic Absorption Spectra ◽  
Visible Region ◽  
Soret Band ◽  
Absorption Bands ◽  
Reaction Rate Constants ◽  
Near Ir ◽  
Cobalt Porphyrins ◽  
First Time

The article presents the results of the kinetics study of the cobalt porphyrins interaction with radical polymerization initiators – benzoyl peroxide and lauryl peroxide – in solution by the spectrophotometric method. From disparate literature data, it is known that some metalloporphyrins can interact with benzoyl peroxide to form the tautomers of porphyrins – isoporphyrins. These compounds have a number of specific properties, for example, it can be catalysts of various processes. Perhaps the isoporphyrins formation is the reason for high activity of the initiating systems “cobalt porphyrin – benzoyl peroxide” in the polymerization of vinyl monomers. Cobalt(II)complexes of tetraphenylporphyrin, tetra-para-methoxyphenylporphyrin, 5,15-bis(4´-tert-butylphenyl)-3,7,13,17-tetramethyl-2,8,12,18-tetra-p-butylporphyrin were selected as the objects of this study. The influence of the porphyrin ligand structure on the formation of cobalt isoporphyrins was estimated. The interaction of cobalt (II) tetraphenylporphyrin and cobalt (II) tetra-para-methoxyphenylporphyrin with peroxides showed changes in the electronic absorption spectra of metalloporphyrins: deformation of the Soret band, reduction of the absorption band in the visible region, and the appearance of absorption bands in the near IR region. These changes are characteristic for metalloisoporphyrins. Data on the interaction of cobalt porphyrins with lauryl peroxide were obtained for the first time. The formation of isoporphyrins is possible with the different ratio of concentrations of reagents: with a lack of peroxide, with equimolar ratio, and also with a significant (100-fold) excess of peroxide. When 5,15-bis (4´-tert-butylphenyl)-3,7,13,17-tetramethyl-2,8,12,18-tetra-p-butylporphyrinate cobalt (II) reacted with peroxides, no isoporphyrinates were observed. The article presents the effective reaction rate constants of the cobalt isoporphyrinates formation at 25 °C. It is shown that the structure of both cobalt porphyrinates and organic peroxides affects the possibility and rate of isoporphyrins formation.

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 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.

Unusual solvent dependent electronic absorption spectral properties of nickel(II) and copper(II) perhaloporphyrins

2004 ◽  
Vol 08 (12) ◽  
pp. 1343-1355 ◽  
Author(s):  
Muniappan Sankar ◽  
Chellaiah Arunkumar ◽  
Puttaiah Bhyrappa
Keyword(s):  
Electronic Absorption ◽  
Spectral Properties ◽  
Metal Ion ◽  
Electronic Absorption Spectra ◽  
Divalent Metal ◽  
Spectral Features ◽  
Wavelength Band ◽  
Absorption Bands ◽  
The Core ◽  
Porphyrin Macrocycle

Electronic absorption spectra of divalent metal ( Ni (II) and Cu (II)) complexes of 2,3,7,8,12,13,17,18-octa(bromo/chloro)-5,10,15,20-tetraphenylporphyrins (MOXTPP; X = Br , Cl ) were examined in various solvents. M (II) perhaloporphyrins exhibited dramatic shifts in their optical absorption spectral features relative to the corresponding metallotetraphenylporphyrins, MTPPs. Copper(II) perhaloporphyrins show significant red-shifts of the absorption bands in coordinating solvents relative to that observed for nickel(II) perhaloporphyrins. The large red-shift of the electronic absorption bands and the gain in intensity of the longest wavelength band (Q(0,0)), of Cu (II) perhaloporphyrins in certain coordinating solvents is comparable to that found in meso-tetraphenylporphinatozinc(II), ZnTPP. The solvent dependent spectral features of M (II) perhaloporphyrins are attributed to a coordinative interaction of the solvent with the core metal ion induced by the electron deficient porphyrin macrocycle.

Synthesis of Galactomannan Sulfate-Citrate

2022 ◽  
Vol 1049 ◽  
pp. 218-223
Author(s):  
Aleksandr S. Kazachenko ◽  
Yuriy N. Malyar ◽  
Anna S. Kazachenko
Keyword(s):  
Biological Activity ◽  
Ftir Spectroscopy ◽  
X Ray Diffraction ◽  
Absorption Bands ◽  
X Ray ◽  
Mixed Ester ◽  
First Time ◽  
Derivatives Of

Sulfated derivatives of polysaccharides have anticoagulant, hypolipedimic and other biological activity. In this work, a complex mixed ester of galactomannan, its sulfate-citrate, was obtained for the first time. The introduction of citrate and sulfate groups was proved by FTIR spectroscopy by the appearance of corresponding absorption bands. It was shown by X-ray diffraction that the introduction of the citrate group leads to the amorphization of the galactomannan structure.

Investigating structure-fluorescence properties of imidazole fused tetraphenylethylene AIEgens: Reversible mechanofluorochromism and polymer matrix controlled fluorescence tuning

CrystEngComm ◽  
2021 ◽  
Author(s):  
Palaniyappan Nagarasu ◽  
Anu Kundu ◽  
Vijay Thiruvenkatam ◽  
Raghavaiah Pallepogu ◽  
Philip Philip Anthony ◽  
...  
Keyword(s):  
Solid State ◽  
Polymer Matrix ◽  
Fluorescence Properties ◽  
Stimuli Responsive ◽  
Fluorescent Properties ◽  
Imidazole Derivatives

A series of stimuli-responsive AIEgens of tetraphenylethyelene (TPE) fused Imidazole derivatives (1-7) were synthesized and explored their substituents controlled fluorescent properties in the solid state. The structure of the synthesized...

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.

On the Radiation Stability of BaSO4 Pigment Modified with SiO2 Nanoparticles and Applied for Spacecraft Thermal Control Coatings

2018 ◽  
Vol 386 ◽  
pp. 277-282 ◽  
Author(s):  
Mikhail M. Mikhailov ◽  
Vitaly V. Neshchimenko ◽  
Semyon A. Yuryev ◽  
Anatoly V. Grigorevsky ◽  
Alexey A. Lovitskiy ◽  
...  
Keyword(s):  
Thermal Control ◽  
Radiation Stability ◽  
Maximum Effect ◽  
Nanoparticle Concentration ◽  
Absorption Bands ◽  
Near Ir ◽  
Uv Visible ◽  
Thermal Control Coatings ◽  
Spacecraft Thermal Control ◽  
High Temperature Modification

The authors investigated the effect of a high-temperature modification with SiO2 nanoparticles on the optical properties and radiation stability of BaSO4 powders. The modification leads to insignificant alteration in the reflecting capacity within the UV, visible, and near-IR spectral regions. Appending SiO2 nanoparticles with a concentration of up to 10 wt.% results in the increasing radiation stability of BaSO4 powders. The maximum effect was obtained due to the decreasing intensity of the absorption bands at 270-280, 375-395, 440-460, 500-600, 700, and 950 nm at a nanoparticle concentration of 3 wt.%.

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