FT-IR Solution Spectra of Propyl Sulfide, Propyl Sulfoxide, and Propyl Sulfone

1995 ◽  
Vol 49 (12) ◽  
pp. 1772-1775 ◽  
Author(s):  
R. Louis Staggs ◽  
William G. Lyon
Keyword(s):  
Organic Acids ◽  
Ir Spectra ◽  
Stretching Vibration ◽  
Donor Acceptor ◽  
Ft Ir ◽  
Stretching Vibrations ◽  
Acidic Solvents ◽  
Sulfoxide Group

FT-IR spectra were obtained of 0.5% volumetric solutions of propyl sulfide, propyl sulfoxide, and propyl sulfone in hexane, CCl4, CS2, and CHCl3 to assist in the assignment of FT-IR-PAS spectra of propyl sulfoxide sorbed within the structure of several peats and onto cellulose. The C-H stretching bands of all three compounds showed a 10-fold larger solvent sensitivity than did analogous aliphatic bands in a comparable series of n-alkanes in solution. The S=O stretching bands of alkyl sulfoxides are known to be quite sensitive to solvent environments because of donor-acceptor interactions involving the oxygen of the sulfoxide group and the slightly acidic protons of generalized organic acids; the expected decreases in frequency were seen with propyl sulfoxide and acidic solvents like chloroform. The frequencies of asymmetric and symmetric stretching vibrations of the -SO2 group of propyl sulfone both exhibit smaller decreases in Old, than does the sulfoxide S=O stretching vibration.

Synthesis, spectroscopic (FT–IR and UV–Vis), crystallographic and theoretical studies, and a molecular docking simulation of an imatinib-like template

2019 ◽  
Vol 75 (12) ◽  
pp. 1681-1689
Author(s):  
Rodolfo Moreno-Fuquen ◽  
Kevin Arango-Daraviña ◽  
Esteban Garcia ◽  
Juan-C. Tenorio ◽  
Javier Ellena
Keyword(s):  
Crystal Growth ◽  
Hydrogen Bonds ◽  
Docking Simulation ◽  
Myelogenous Leukemia ◽  
Amino Group ◽  
Protein Residues ◽  
Function Analyzer ◽  
Stretching Vibration ◽  
Donor Acceptor ◽  
Ft Ir

The aim of the present study was to report the crystal structure and spectroscopic, electronic, supramolecular and electrostatic properties of a new polymorph of 4-(pyridin-2-yl)pyrimidin-2-amine (C9H8N4). The compound was synthesized under microwave irradiation. The single-crystal X-ray structure analysis revealed an angle of 13.36 (8)° between the planes of the rings, as well as molecules linked by Nsp 2—H...N hydrogen bonds forming dimers along the crystal. The material was analyzed by FT–IR vibrational spectroscopy, while a computational approach was used to elucidate the vibrational frequency couplings. The existence of Nsp 2—H...N hydrogen bonds in the crystal was confirmed spectroscopically by the IR peaks from the N—H stretching vibration shifting to lower wavenumbers in the solid state relative to those in the gas phase. The supramolecular studies confirmed the formation of centrosymmetric R 2 2(8) rings, which correspond to the formation of dimers that stack parallel to the b direction. Other weak C—H...π interactions, essential for crystal growth, were found. The UV–Vis spectroscopic analysis showed a donor–acceptor process, where the amino group acts as a donor and the pyridine and pyrimidine rings act as acceptors. The reactive sites of the molecule were identified and their quantitative values were defined using the electrostatic potential model proposed in the multifunctional wave function analyzer multiwfn. The calculated interaction energies between pairs of molecules were used to visualize the electrostatic terms as the leading factors against the dispersion factors in the crystal-growth process. The docking results showed that the amino group of the pyrimidine moiety was simultaneously anchored by hydrogen-bonding interactions with the Asp427 and His407 protein residues. This compound could be key for the realization of a series of syntheses of molecules that could be used as possible inhibitors of chronic myelogenous leukemia.

FT-IR Spectroscopic Study of 1,5-Pentanedithiol and 1,6-Hexanedithiol Adsorbed on NaA, CaA and NaY Zeolites

2005 ◽  
Vol 60 (8-9) ◽  
pp. 633-636 ◽  
Author(s):  
Nuri Öztürk ◽  
Çağrı Çırak ◽  
Semiha Bahçeli
Keyword(s):  
Infrared Spectroscopy ◽  
Ir Spectra ◽  
Spectroscopic Study ◽  
The Other ◽  
Other Hand ◽  
Liquid Phases ◽  
Stretching Vibration ◽  
Ft Ir ◽  
Ir Spectroscopic ◽  
Nay Zeolites

The adsorption of 1,5-pentanedithiol (1,5-PDT) and 1,6-hexanedithiol (1,6-HDT) in liquid phases on NaA (or 4A-type), CaA (or 5A-type) and NaY zeolites has been studied by using infrared spectroscopy. From the IR spectra it is found that the peak positions of the symmetric as well as the antisymmetric modes of the methylene (CH2) groups are observed at almost the same band values for the title dithiolates adsorbed on the A-type and NaY zeolites. On the other hand, the weak SH stretching vibration, observed for all samples, can be attributed to the sulphure atoms of 1,5-PDT and 1,6-HDT coordinatively adsorbed on cationic sites of the zeolites.

Die Polarisation der σ-Bindungen im Azulen

1972 ◽  
Vol 27 (1) ◽  
pp. 110-128 ◽  
Author(s):  
H. Seydewitz ◽  
E.D. Schmid
Keyword(s):  
Experimental Data ◽  
Ir Spectra ◽  
Linear Function ◽  
Electron Density ◽  
Coupling Constants ◽  
Ir Absorption ◽  
Absorption Intensity ◽  
Bond Lengths ◽  
Stretching Vibration ◽  
Stretching Vibrations

Abstract On the basis of a simple MO-approach a model to interprete the IR-absorption intensity of the aromatic CH-stretching vibration is developed. Accordingly the gradient of the CH-bond moment is a linear function of the ionicity of the CH-bond.Eight azulenes, which were deuterated at various specified positions, were synthetisized and out of their IR-spectra the gradients of the CH-bond moment at all positions of azulene could be determined. From these experimental data it is concluded, that in relation to benzene the electrons of the CH-bonds in azulene are displaced towards the C-atom at positions with high and towards the H-atom at positions with low π-electron density.Such a polarisation of the CH-bonds in azulene is confirmed, although only qualitatively, by the ionicities of the CH-bonds calculated by the CNDO/2-method and is also in accordance with other experimental observations such as bond lengths and angles, C13H-coupling constants, and the frequencies of the CH-stretching vibrations.It is demonstrated that experiment and calculation fail to correlate quantitatively due to in-adequacies inherent in the CNDO/2-method.

FT-IR Spectra Of The C=O And C-H Stretching Vibration Of Lauric Acid

1989 ◽  
Author(s):  
Weng Shifu ◽  
Wu Jinguang ◽  
Xu Guangxian
Keyword(s):  
Ir Spectra ◽  
Lauric Acid ◽  
Stretching Vibration ◽  
Ft Ir

Reflectance FT-IR Microspectroscopy of Fossil Algae Contained in Organic-Rich Shales

1993 ◽  
Vol 47 (3) ◽  
pp. 265-271 ◽  
Author(s):  
Rui Lin ◽  
G. Patrick Ritz
Keyword(s):  
Ir Spectra ◽  
Green Alga ◽  
Botryococcus Braunii ◽  
Aliphatic Chain ◽  
Cross Sectional ◽  
Unicellular Green Alga ◽  
Ft Ir ◽  
Ir Microspectroscopy ◽  
Stretching Vibrations ◽  
Insight Into

A microscope sampling accessory interfaced to a Fourier transform infrared (FT-IR) spectrometer has been employed to characterize the remains of individual microscopic fossil algae and algal colonies contained in organic-rich shales. The microspectrometer is able to measure reflectance IR spectra of samples with cross-sectional areas as small as 20 × 20 microns. The fossil algae studied include the colonial green alga Botryococcus braunii, the unicellular green alga Tasmanites, and an unidentified filamentous alga. It was found that IR spectra of the fossil algae, in common, contain intense aliphatic C-H stretching bands in the 2900-cm−1 region relative to the C=C stretching band at 1600 cm−1. The carboxylic acid C=O stretching band at 1710 cm−1 is moderately intense. The relative intensities of these bands vary among the three different fossil algae. Maximum-likelihood spectral restoration and subsequent curve fitting of the stretching vibrations of the aliphatic C-H bands provide greater insight into the aliphatic structures of fossil algae. The CH2/CH3 intensity ratio can be calculated and used to assess the relative average aliphatic chain length and the degree of branching.

Light- or Dark-Colored, L-DOPA-Based Melanins

2018 ◽  
Author(s):  
Koen Vercruysse ◽  
Margaret M. Whalen
Keyword(s):  
Human Physiology ◽  
Ir Spectra ◽  
Immune Cells ◽  
Chemical Properties ◽  
Chemical Signature ◽  
Ft Ir

<p>This report is a continuation of previous research on the H<sub>2</sub>O<sub>2</sub>-mediated synthesis of melanin-like pigments. We synthesized and characterized L-DOPA-based pigments using air- or H<sub>2</sub>O<sub>2</sub>-mediated<sub> </sub>oxidation. We compared their physic-chemical properties and evaluated their capacity to affect the interleukin release from immune cells. The use of higher concentrations of H<sub>2</sub>O<sub>2</sub> resulted in melanin-like materials with a distinct chemical signature in their FT-IR spectra and a lighter color. All pigments enhanced the interleukin release from immune cells. The possibility that lighter-colored melanins can be generated is discussed in the context of the importance of melanin-based pigmentation in human physiology.</p>

Infrared spectra and substituent effects in 2-(3-, and 4-substituted phenylmethylene)-1,3-cycloheptanediones

1983 ◽  
Vol 48 (2) ◽  
pp. 586-595 ◽  
Author(s):  
Alexander Perjéssy ◽  
Pavol Hrnčiar ◽  
Ján Šraga
Keyword(s):  
Substituent Effects ◽  
Phenyl Group ◽  
Wave Number ◽  
Vibrational Coupling ◽  
Wave Numbers ◽  
Stretching Vibration ◽  
Stretching Vibrations ◽  
The Relationship ◽  
Derivatives Of ◽  
Effect Of Structure

The wave numbers of the fundamental C=O and C=C stretching vibrations, as well as that of the first overtone of C=O stretching vibration of 2-(3-, and 4-substituted phenylmethylene)-1,3-cycloheptanediones and 1,3-cycloheptanedione were measured in tetrachloromethane and chloroform. The spectral data were correlated with σ+ constants of substituents attached to phenyl group and with wave number shifts of the C=O stretching vibration of substituted acetophenones. The slope of the linear dependence ν vs ν+ of the C=C stretching vibration of the ethylenic group was found to be more than two times higher than that of the analogous correlation of the C=O stretching vibration. Positive values of anharmonicity for asymmetric C=O stretching vibration can be considered as an evidence of the vibrational coupling in a cyclic 1,3-dicarbonyl system similarly, as with derivatives of 1,3-indanedione. The relationship between the wave numbers of the symmetric and asymmetric C=O stretching vibrations indicates that the effect of structure upon both vibrations is symmetric. The vibrational coupling in 1,3-cycloheptanediones and the application of Seth-Paul-Van-Duyse equation is discussed in relation to analogous results obtained for other cyclic 1,3-dicarbonyl compounds.

scholarly journals Spectroscopy as a useful tool for the identification of changes with time in post-mortem vitreous humor for forensic toxicology purposes

2021 ◽  
Author(s):  
Anna Wójtowicz ◽  
Agata Mitura ◽  
Renata Wietecha-Posłuszny ◽  
Rafał Kurczab ◽  
Marcin Zawadzki
Keyword(s):  
Ir Spectra ◽  
Forensic Toxicology ◽  
Principal Component ◽  
Hierarchical Cluster ◽  
Vitreous Humor ◽  
Attenuated Total Reflection ◽  
Glass Slides ◽  
Added Benefit ◽  
Ft Ir ◽  
Non Destructive

AbstractVitreous humor (VH) is an alternative biological matrix with a great advantage of longer availability for analysis due to the lack of many enzymes. The use of VH in forensic toxicology may have an added benefit, however, this application requires rapid, simple, non-destructive, and relatively portable analytical analysis methods. These requirements may be met by Fourier transform infrared spectroscopy technique (FT-IR) equipped with attenuated total reflection accessory (ATR). FT-IR spectra of vitreous humor samples, deposited on glass slides, were collected and subsequent chemometric data analysis by means of Hierarchical Cluster Analysis and Principal Component Analysis was conducted. Differences between animal and human VH samples and human VH samples stored for diverse periods of time were detected. A kinetic study of changes in the VH composition up to 2 weeks showed the distinction of FT-IR spectra collected on the 1st and 14th day of storage. In addition, data obtained for the most recent human vitreous humor samples—collected 3 and 2 years before the study, presented successful discrimination of all time points studied. The method introduced was unable to detect mephedrone addition to VH in the concentration of 10 µg/cm3. Graphic abstract

Luminescent Properties of Zn2SiO4:Eu3+,Dy3+ Phosphors via Sol-Gel Process

2012 ◽  
Vol 217-219 ◽  
pp. 733-736
Author(s):  
Xiu Mei Han ◽  
Shu Ai Hao ◽  
Ying Ling Wang ◽  
Gui Fang Sun ◽  
Xi Wei Qi
Keyword(s):  
Thermal Analysis ◽  
Ir Spectra ◽  
Sol Gel ◽  
Luminescent Properties ◽  
Photoluminescence Spectra ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sol Gel Process ◽  
Ft Ir

Zn2SiO4:Eu3+, Dy3+ phosphors have been prepared through the sol-gel process. X-ray diffraction (XRD), thermogravimetric and ddifferential thermal analysis (TG-DTA), FT-IR spectra and photoluminescence spectra were used to characterize the resulting phosphors. The results of XRD indicated that the phosphors crystallized completely at 1000oC. In Zn2SiO4:Eu3+,Dy3+ phosphors, the Eu3+ and Dy3+ show their characteristic red(613nm, 5D0-7F2), blue (481nm, 4F9/2–6H15/2) and yellow (577nm, 4F9/2–6H13/2) emissions.

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