Analysis of the characteristic absorption bands of the stretching vibrations of the lactone carbonyl groups in IR spectra of natural pseudoguaianolides

1990 ◽  
Vol 26 (2) ◽  
pp. 216-217
Author(s):  
�. L. Kristallovich ◽  
I. D. Sham'yanov ◽  
A. Ovezdurdyev ◽  
B. A. Akyev ◽  
M. R. Yagudaev ◽  
...  
Keyword(s):  
Ir Spectra ◽  
Carbonyl Groups ◽  
Absorption Bands ◽  
Characteristic Absorption ◽  
Lactone Carbonyl ◽  
Stretching Vibrations

The absorption bands of the stretching vibrations of the carbonyl groups and the proton-accepting capacity of polyfluorinated ketones and esters

1973 ◽  
Vol 19 (1) ◽  
pp. 926-929 ◽  
Author(s):  
�. M. Marek ◽  
I. P. Kolenko ◽  
A. Ya. Zapevalov ◽  
G. F. Ovchinnikov ◽  
L. A. Perelyaneva
Keyword(s):  
Carbonyl Groups ◽  
Absorption Bands ◽  
Stretching Vibrations

An Infrared Study of Metal Isopropoxide Precursors for SrTiO3

1984 ◽  
Vol 32 ◽  
Author(s):  
R. E. Riman ◽  
D. M. Haaland ◽  
C.J.M. Northrup ◽  
H. K. Bowen ◽  
A. Bleier
Keyword(s):  
Ir Spectra ◽  
Detailed Analysis ◽  
Infrared Spectra ◽  
Spectral Features ◽  
Absorption Bands ◽  
Infrared Study ◽  
Characteristic Absorption ◽  
Local Environments ◽  
Insight Into ◽  
Hydrolysis Reactions

ABSTRACTA Sr/Ti bimetallic isopropoxide complex was synthesized by two methods. The complex served as a precursor to the production of homogeneous SrTiO3 powders via alkoxide hydrolysis. Infrared spectra were obtained for Sr(OPri)2, Ti(OPri)4, and the product of the syntheses. In addition, the IR spectra of the solutions of each of the alkoxides were followed as hydrolysis reactions proceeded. Detailed analysis of the spectral features support the existence of a 1:1 Sr/Ti bimetallic alkoxide. The new Sr/Ti compound exhibits characteristic absorption bands at (1017, 993, 972, 961 cm−1), (844, 838, 827 cm−1) and (620, 596, and 572 −1). A band at 819−1 might also be associated with the new Sr/Ti bimetallic alkoxide. The infrared spectra suggest that the isopropoxide ligands in the bimetallic alkoxide are in at least three separate local environments. This information offers insight into possible structures for the complex.

Photo-Oxidation of an IR Vulcanizate

1981 ◽  
Vol 54 (1) ◽  
pp. 1-14 ◽  
Author(s):  
Shoichiro Yano
Keyword(s):  
Ir Spectra ◽  
Rate Constant ◽  
Wavelength Dependence ◽  
The Other ◽  
Hydroxyl Groups ◽  
Carbonyl Groups ◽  
Absorption Bands ◽  
Photo Oxidation ◽  
Other Hand ◽  
Uv And Ir Spectra

Abstract On irradiation with uv light, changes in uv and ir spectra were observed. In the uv spectrum, a minimum at 290 nm due to sulfur, dibenzothiazyl disulfide, and double bonds in the main chains disappeared initially by the consumption of them; but the minimum reappeared on further irradiation reflecting the formation of carbonyl groups. On the other hand, in the ir spectrum two absorption bands appeared at 1720 cm−1 (due to carbonyl groups) and 3450 cm−1 (due to hydroxyl groups). The latter band faded out suggesting the decomposition of hydroperoxides when the vulcanizate was kept in the dark after irradiation. From the findings of the wavelength dependence of photo-oxidation on uv and ir spectra, it was found that the degradation occurred below about 430 nm. However, investigation of the wavelength dependence of photo-oxidation by the measurement of the crosslink density gave the results that crosslinking reactions occurred below about 340 nm, scissions of C-C and polysulfide crosslinks between 340 and about 400 nm, and scissions of polysulfide crosslinks between 400 and 600 nm. These were confirmed by measurements of the dynamic modulus during irradiation. The relative modulus E′(t)/E′(0) increased on irradiation with light at 253.7 nm in a longer time region reflecting a crosslinking reaction. On the other hand, on irradiation with light above 330 nm, E′(t)/E′(0) decreased with time. Change in E′(t)/E′(0) could be represented by the equation of the first order reaction containing an exponential term and the rate constant was determined. The activation energy was calculated as 18.6 kcal/mole from the temperature dependence of the rate constant and agreed with that for scission of polysulfide crosslinks. The photodegradation of the IR vulcanizate occurred also on irradiation with visible light (> 430 nm), and the modulus decreased.

scholarly journals SYNTHESIS OF A MODIFIED 4-AMINOBENZOIC ACID DERIVATIVE UNDER ULTRASOUND CONDITIONS

2020 ◽  
Vol 2 (440) ◽  
pp. 153-155
Author(s):  
A.Kh. Zhakina ◽  
D.S. Abdrakhmanova
Keyword(s):  
Nmr Spectroscopy ◽  
Maleic Anhydride ◽  
Ir Spectra ◽  
Chemical Reactions ◽  
Biologically Active ◽  
Aminobenzoic Acid ◽  
Absorption Bands ◽  
Synthesis Time ◽  
Propenoic Acid ◽  
Stretching Vibrations

The search for new effective drugs with biologically active properties is one of the urgent problems. Recently, to intensify the process of their synthesis and increase the efficiency of chemical reactions, wave chemistry has been used. Increased interest of researchers is caused by the synthesis of compounds with biologically active properties using the method of ultrasonic treatment (US). It is known that derivatives of p-aminobenzoic acid and their esters are synthetic analogues of natural compounds, and pyrrolidone derivatives have high hypnotic, anticonvulsant, antiarrhythmic activity, which stimulates the synthesis of new biologically active compounds. In a brief report, the possibility of synthesizing ethyl-4-(2,5-dioxo-2,5-dihydro-1H-pyrrolyl) benzoate from 3-[(4-ethoxycarbonyl) phenylcarbamoyl]-2-propenoic acid using ultrasonic activation through a step is considered disclosure of the furan cycle with further cyclization. Ethyl ester p-aminobenzoic acid and maleic anhydride were used as starting reagents. An ultrasound device IL-100-6/2, equipped with a magnetostrictive transducer, with an operating frequency of 22 kHz, with a maximum power of 1200 W and a cylindrical waveguide, was used as a source of ultrasound. The synthesis of 3-[(4-ethoxycarbonyl) phenylcarbamoyl]-2-propenoic acid was carried out by reacting the starting reagents at equimolar ratios and room temperature. The US time was 10 minutes. The reaction proceeds smoothly. Ultrasound has a significant effect on the rate of chemical reactions and can increase the yield of the final product. Under classical conditions, the synthesis time was 180 minutes; using ultrasound, the synthesis time was reduced by 3 times. The product yield was 92%. The structure and composition of the obtained compound was confirmed by IR- and H1 NMR-spectroscopy. In the IR-spectra of the obtained compound, there are absorption bands of the amide group (NHCO) in the region of 3280, 3190 cm-1, absorption bands of the carbonyl group (C=O), characteristic in the region of 1670 cm-1, absorption band (COC) in the region of 1230 cm-1. The resulting compound, 3-[(4-Ethoxycarbonyl) phenylcarbamoyl]-2-propenoic acid, made it possible to study the step of opening the furan ring, with further cyclization. Ethyl 4-(2,5-dioxo-2,5-dihydro-1H-pyrrolyl) benzoate was obtained in 89% yield by azeotropic distillation of water in the presence of toluenesulfonic acid in a DMFA-toluene mixture. The resulting product is a light yellow powder with melting point 114-115°C. The structure and composition of the obtained compound was confirmed by IR-and H1 NMR-spectroscopy. In the IR-spectra of the obtained compound, the stretching vibrations of the НС=СН group manifest themselves in the form of a low-intensity but characteristic signal at 3100-3090 cm-1, stretching vibrations of the С=О group as intense bands in the region of 1700-1680 cm-1 and a weak overtone at 3465-3450 cm-1, stretching vibrations of the COC group in the region of 1245 cm-1. When analyzing the Н1 NMR-spectrum of a compound, ethyl 4-(2,5-dioxo-2,5-dihydro-1Н-pyrrolyl) benzoate, the signals of aromatic four protons Н1- Н2 (4Нaryl, 3JНН 8 Hz) are recorded in the field of weak fields: H1 doublet at 7.51 ppm. and a doublet at 8.05 ppm. Signals of the ethyl fragment: (3H, CH3, 3JHH 8 Hz), appear as a singlet at 1.43 ppm. and (2H, CH2, 3JHH 8 Hz) quadruplet at 4.34 ppm. The protons of the CH group of the imide cycle (2H, CH=CH) appear as a singlet at 7.11 ppm. Keywords: ultrasound, ethyl ether p-aminobenzoic acid, maleic anhydride, cyclization.

Identification of absorption bands corresponding to C-C1 stretching vibrations in the IR spectra of organic compounds

1991 ◽  
Vol 55 (3) ◽  
pp. 863-866
Author(s):  
B. V. Lopatin ◽  
V. G. Vinokurov ◽  
N. B. Lopatina ◽  
V. A. Berdyugin
Keyword(s):  
Ir Spectra ◽  
Organic Compounds ◽  
Absorption Bands ◽  
Stretching Vibrations

scholarly journals Effect of Water Leaching on Photodegraded Scots Pine and Spruce Timbers Monitored by FTIR Spectroscopy

Forests ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 833
Author(s):  
Edina Preklet ◽  
László Tolvaj ◽  
Eszter Visi-Rajczi ◽  
Tamás Hofmann
Keyword(s):  
Ftir Spectroscopy ◽  
Scots Pine ◽  
Uv Irradiation ◽  
Chemical Elements ◽  
Uv Light ◽  
Carbonyl Groups ◽  
Water Leaching ◽  
Absorption Bands ◽  
Chemical Changes ◽  
Absorption Increase

The goal of this research was the systematic study and comparison of the divided individual effects of UV light irradiation and water leaching during artificial weathering. Spruce (Picea abies Karst.) and Scots pine (Pinus sylvestris L.) samples were irradiated by ultraviolet (UV) light. Another sequence of samples was treated with the combination of UV irradiation and water leaching. The total extent of UV treatment was 20 days for both series of samples. Time relation of UV irradiation and water leaching was 2:1. The chemical changes were observed by FTIR spectroscopy. The difference spectrum was used for determination of the chemical changes. Degradation of lignin was greater for the leached samples than for the pure UV treated samples. Scots pine suffered greater lignin degradation than spruce, and produced higher absorption increase on the absorption region of unconjugated carbonyls. The unconjugated carbonyl groups were the most responsive chemical elements to leaching. Spruce was more susceptible to leaching of unconjugated carbonyl groups than Scots pine. Two absorption bands of unconjugated carbonyl groups at 1706 and 1764 cm−1 wavenumbers were produced by photodegradation. The absorption band at 1764 cm−1 was more sensitive to water leaching than the band at 1706 cm−1.

SYNTHESIS AND PROPERTIES OF OLIGODIURETANEDIOLS BASED ON A MIXTURE OF (2,4–2,6) TOLUILENDIISOCYANATE

2021 ◽  
Vol 43 (3) ◽  
pp. 198-203
Author(s):  
S.M. KUZMENKO ◽  
◽  
E.O. SPORYAGIN ◽  
O.M. KUZMENKO ◽  
A.YA. PUZENKO ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Ir Spectra ◽  
Azeotropic Distillation ◽  
Synthesis Temperature ◽  
Side Reactions ◽  
Absorption Bands ◽  
Formation Reaction ◽  
Viscous Liquids ◽  
Urethane Formation ◽  
Product Control

The paper describes the synthesis, the reaction of a mixture of isomers (2,4–2,6) of toluilendiisocyanate with a double molar excess of aliphatic individual or oligomeric diols, a number of previously unknown oligodiuretanediols and their physicochemical constants. It is shown that with an increase in the synthesis temperature from 50 to 70 °C, the reaction time to complete depletion in the mixture of free NCO-groups decreases from 8–9 hours to 3–4 hours. The reaction temperature of 70–2 °С should be considered optimal, because at higher temperatures side reactions of free NCO-groups with already formed urethane ones are possible. Because the presence of even a small amount of moisture in the diols can provoke side effects during the urethane formation reaction, all of the above diols were dried from the adsorbed moisture by azeotropic distillation with toluene before use in the reaction. Since the final products are even at the synthesis temperature (68–70 °C) viscous liquids, and there are difficulties with the homogenization of the reaction mass during synthesis, and when unloading the finished product from the reaction plant, in all cases, the synthesis was performed in solution cyclohexanone by 50 % by weight of the final product. Control of the reaction was performed by changing the % wt. free NCO-groups in time. The reaction was considered complete if the measured % wt. free NCO-groups in the reaction mixture for at least one hour twice showed zero. The isolated oligodiuretanediols range from solid at room temperature to very viscous products, which significantly depends on the molecular weight of the diol used in the reaction (ie the concentration of urethane groups formed). They are homogeneous, transparent compounds that are readily soluble in esters, ethers, aromatic and halide-containing, aprotic solvents, ketones, poorly or completely insoluble in aliphatic saturated hydrocarbons. The structure of the synthesized oligomeric products is confirmed by functional analysis, IR–spectra. In the IR-spectra of each of the synthesized oligodiuretanediols there are no absorption bands in the region of 2270 cm-1, which confirms the complete completion of the reaction of urethane formation according to the scheme. At the same time, the absorption bands in the region of 3450 cm-1, 1720 cm-1, 1540 cm-1 are fixed, which are characteristic of the presence of urethane groups in the structure of the target products. As the chain length of the diol component –R– increases in the target product (which synchronously leads to an increase in molecular weight), the intensity of these absorption bands decreases, which is associated with a decrease in the concentration of formed urethane groups in the structure of oligodiuretanediols. The refractive index also decreases synchronously. Synthesized series of oligodiuretanediols can be used for synthesis on its basis of other classes of oligomers with the simultaneous presence in the structure of urethane groups. The ability of such compounds to be soluble in solvents of different nature has been studied, which provides information for the directions of their further use (varnishes, enamels, primers).

scholarly journals A surface confined yttrium(iii) bis-phthalocyaninato complex: a colourful switch controlled by electrons

2016 ◽  
Vol 7 (8) ◽  
pp. 4940-4944 ◽  
Author(s):  
I. Alcón ◽  
M. Gonidec ◽  
M. R. Ajayakumar ◽  
M. Mas-Torrent ◽  
J. Veciana
Keyword(s):  
Optical Properties ◽  
Absorption Bands ◽  
Electrical And Optical Properties ◽  
Redox States ◽  
Characteristic Absorption ◽  
Double Decker ◽  
Visible Spectra

SAMs of a Y(iii) double-decker complex on ITO have been prepared and their electrical and optical properties explored, exhibiting three accessible stable redox states with characteristic absorption bands in the visible spectra, corresponding to three complementary colors (i.e., green, blue and red).

scholarly journals Synthesis of ZnO and CuO nanoparticles via Sol gel method and Its Characterization by using XRD and FT-IR Analysis

2022 ◽  
Author(s):  
Monika Patel ◽  
Sunita Mishra ◽  
Ruchi Verma ◽  
Deep Shikha
Keyword(s):  
Particle Size ◽  
Zno Nanoparticles ◽  
Sol Gel ◽  
Broad Band ◽  
Zinc Nitrate ◽  
Zno Nanoparticle ◽  
Absorption Bands ◽  
Characteristic Absorption ◽  
Sol Gel Process ◽  
Ft Ir

Abstract Nanotechnology is a completely unique branch of technology that offers with substances in a very small size between (1-100 nm) with various crystal shapes which include spherical nanoparticles, flower shaped, Nano rods, Nano ribbons, and Nano platelets. Metals have ability to produce large number of oxides. These metal oxides play an major role in many areas of chemistry, physics, material science and food science. In this research, Zinc Oxide (ZnO) and Copper (II) oxide nanoparticles were synthesized via sol-gel process using zinc nitrate and copper (II) nitrate as precursor respectively. The characterization of CuO and ZnO nanoparticles was done by using various techniques. X-ray Diffraction (XRD) indicates the crystallinity and crystal size of CuO and ZnO nanoparticle. Fourier transform infrared spectroscopy (FT-IR) was used to get the infrared spectrum of the sample indicating composition of the sample which contains various functional groups. XRD result shows the particle size of CuO at highest peak 29.40140 was 61.25 nm and the particle size of ZnO at highest peak 36.24760 was 21.82 nm. FT-IR spectra peak at 594.56 cm-1 indicated characteristic absorption bands of ZnO nanoparticles and the broad band peak at 3506.9 cm-1 can be attributed to the characteristic absorption of O-H group. The analysis of FT-IR spectrum of CuO shows peaks at 602.09, 678.39, and 730.19cm−1 which refer to the formation of CuO. A broad absorption peak noticed at 3308.2 cm−1 attributed to O–H stretching of the moisture content.

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