scholarly journals Synthesis, Crystal Structures, and Spectroscopic Characterization of Bis-aldehyde Monomers and Their Electrically Conductive Pristine Polyazomethines

Polymers ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1498 ◽  
Author(s):  
Abdul Hafeez ◽  
Zareen Akhter ◽  
John F. Gallagher ◽  
Nawazish Ali Khan ◽  
Asghari Gul ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Spectroscopic Characterization ◽  
Spectroscopic Techniques ◽  
Conductivity Measurements ◽  
X Ray Diffraction ◽  
Electrically Conductive ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Ft Ir

Bis-aldehyde monomers 4-(4′-formyl-phenoxy)benzaldehyde (3a), 3-methoxy-4-(4′-formyl-phenoxy)benzaldehyde (3b), and 3-ethoxy-4-(4′-formyl-phenoxy)benzaldehyde (3c) were synthesized by etherification of 4-fluorobenzaldehyde (1) with 4-hydroxybenzaldehyde (2a), 3-methoxy-4-hydroxybenzaldehyde (2b), and 3-ethoxy-4-hydroxybenzaldehyde (2c), respectively. Each monomer was polymerized with p-phenylenediamine and 4,4′-diaminodiphenyl ether to yield six poly(azomethine)s. Single crystal X-ray diffraction structures of 3b and 3c were determined. The structural characterization of the monomers and poly(azomethine)s was performed by FT-IR and NMR spectroscopic techniques and elemental analysis. Physicochemical properties of polymers were investigated by powder X-ray diffraction, thermogravimetric analysis (TGA), viscometry, UV–vis, spectroscopy and photoluminescence. These polymers were subjected to electrical conductivity measurements by the four-probe method, and their conductivities were found to be in the range 4.0 × 10−5 to 6.4 × 10−5 Scm−1, which was significantly higher than the values reported so far.

scholarly journals Studies on the growth and characterization of L-cysteine hydrogen fluoride single crystal

2019 ◽  
Vol 37 (3) ◽  
pp. 304-309
Author(s):  
Azeezaa Varsha Mohammed ◽  
Suresh Sagadevan
Keyword(s):  
Single Crystal ◽  
Hydrogen Fluoride ◽  
Grown Crystal ◽  
Optical Band Gap ◽  
Second Harmonic ◽  
X Ray Diffraction ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Ft Ir

AbstractL-cysteine hydrogen fluoride (LCHF) single crystals were grown from aqueous solution. Single crystal X-ray diffraction, FT-IR, UV-Vis-NIR, and TG-DTA were used to test the grown crystals. The specimen dielectric and mechanical behaviors were also studied. Powder X-ray diffraction of the grown crystal was recorded and indexed. The optical properties of the LCHF crystal were determined using UV-Vis spectroscopy. It was found that the optical band gap of LCHF was 4.8 eV. The crystal functional groups were identified using FT-IR. Second harmonic generation (SHG) efficiency of the LCHF was three times higher than that of KDP. The dielectric constant, dielectric loss and AC conductivity were measured at different frequencies and temperatures.

scholarly journals Experimental techniques for the characterization of carbon nanoparticles – a brief overview

2014 ◽  
Vol 5 ◽  
pp. 1760-1766 ◽  
Author(s):  
Wojciech Kempiński ◽  
Szymon Łoś ◽  
Mateusz Kempiński ◽  
Damian Markowski
Keyword(s):  
Electrical Conductivity ◽  
Raman Spectroscopy ◽  
Carbon Nanoparticles ◽  
Carrier Transport ◽  
Structural Changes ◽  
Conductivity Measurements ◽  
X Ray Diffraction ◽  
Paramagnetic Resonance ◽  
X Ray

The review of four experimental methods: X-ray diffraction, Raman spectroscopy, electron paramagnetic resonance and four-point electrical conductivity measurements is presented to characterize carbon nanoparticles. Two types of carbon nanoparticle systems are discussed: one comprising the powder of individual carbon nanoparticles and the second as a structurally interconnected nanoparticle matrix in the form of a fiber. X-ray diffraction and Raman spectroscopy reveal the atomic structure of the carbon nanoparticles and allow for observation of the changes in the quasi-graphitic ordering induced by ultrasonic irradiation and with the so-called quasi-high pressure effect under adsorption conditions. Structural changes have strong influence on the electronic properties, especially the localization of charge carriers within the nanoparticles, which can be observed with the EPR technique. This in turn can be well-correlated with the four-point electrical conductivity measurements which directly show the character of the charge carrier transport within the examined structures.

Molecular and X-ray Spectroscopies for Noninvasive Characterization of Mayan Green Stones from Bonampak, Chiapas

2019 ◽  
Vol 73 (9) ◽  
pp. 1074-1086
Author(s):  
Valentina Aguilar-Melo ◽  
Alejandro Mitrani ◽  
Edgar Casanova-Gonzalez ◽  
Mayra D. Manrique-Ortega ◽  
Griselda Pérez-Ireta ◽  
...  
Keyword(s):  
Archaeological Site ◽  
Molecular Techniques ◽  
Spectroscopic Techniques ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ft Ir ◽  
Noninvasive Characterization ◽  
A Minor

A burial and a rich offering were found under Room 2 in the Murals Building, Bonampak, a Mayan archaeological site situated in Chiapas, Mexico. This burial may be related with the creation of the famous mural paintings. A rich set of jewelry made of green stones was among the different objects found. Green stones have great importance in Mesoamerican cultures, those composed of jadeite being the most appreciated. To characterize the green stones, different spectroscopic techniques were used in a complementary way: Raman and infrared spectroscopies (FT-IR) were used for global mineralogical analysis, while X-ray diffraction (XRD) and X-ray fluorescence (XRF) were applied simultaneously in situ on the artifacts that were not successfully identified by these molecular techniques. In addition, XRF was used to contrasts the elemental information from pieces composed of pyroxenes that may be related to the raw sources of jade in Guatemala. The main minerals identified within the beads and earrings were jadeite with omphacite and jadeite with albite; to a minor extent, quartz, and serpentine. In this paper, the main features of the molecular and X-ray techniques are compared in order to determine the advantages and limitations of these spectroscopies for mineral identification. With this combination of techniques, it was possible to undertake a suitable characterization of the analyzed objects. This paper focuses on the XRD–XRF combined analysis for in situ noninvasive characterization.

scholarly journals Novel Functionalized Cellulose Derivatives Fabricated with Cu Nanoparticle: Synthesis, Characterization and Degradation of Organic Pollutants

2021 ◽  
Author(s):  
Faiza Lughmani ◽  
Farzana Nazir ◽  
Shahid Ali Khan ◽  
Mudassir Iqbal
Keyword(s):  
Copper Ions ◽  
Nanoparticle Synthesis ◽  
Cellulose Derivatives ◽  
Oxidized Cellulose ◽  
X Ray Diffraction ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Ft Ir ◽  
Supporting Material

Abstract In this study, microcrystalline cellulose (MCC) was modified to oxidized cellulose (OC), 6-deoxycellulose hydrazide and 6-deoxycellulose(N,N-diethyl)amine (MCC-Hyd and MCC-DEM) derivatives and employed as supporting material for the synthesis of copper nanoparticles (NPs). Copper ions from aqueous solution were adsorbed and then reduced to zero valent copper (ZVC) NPs using sodium borohydride on films of prepared derivatives. The characterization of prepared derivatives and Cu NPs embedded films was performed using Fourier Transform Infrared Spectroscopy (FT-IR), Elemental analysis, X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and Nuclear Magnetic Resonance (NMR) spectroscopy. Ultraviolet/Visible (UV-VIS) spectroscopy was performed for the degradation studies of 4-nitrophenol (4-NP) and various azo dyes viz. Congo Red (CR), Methylene Blue (MB), and Methyl orange (MO). Results revealed that all the films showed degradation only in the presence of ZVC NPs. Oxidized cellulose, MCC-Hyd and MCC-DEM showed excellent degradation efficiencies (> 85%) in all the cases. Our findings revealed that MCC derivatives could be efficient and renewable candidates for removal of water pollutants in future.

scholarly journals Spectroscopic Characterization of Eoholocene Bones Found in a Cave in Northeast Brazil

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
P. V. Oliveira ◽  
M. S. S. Viana ◽  
O. A. Barros ◽  
P. T. C. Freire ◽  
F. I. Bezerra ◽  
...  
Keyword(s):  
National Park ◽  
Animal Species ◽  
Spectroscopic Characterization ◽  
Spectroscopic Techniques ◽  
X Ray Diffraction ◽  
Future Studies ◽  
X Ray ◽  
Inorganic Chemical ◽  
Supply Information

The preservation of fossils depends on several interactions of organic and inorganic chemical processes. The hard parts, which are more suitable for fossilization, might record valuable information of biogenic processes, while the taphonomic characteristics supply information on postmortem chemical transformation. Here, X-ray fluorescence, X-ray diffraction, and infrared spectroscopy analyses were carried out in Early Eoholocene fragments of bones collected from the subsurface at Gruta do Urso Fóssil, Ubajara National Park, northeast of Ceará State in Brazil. It is suggested a lower degree of decomposition, a preservation of the original mineral composition, along with some incidence of encrustation, and the occurrence of different animal species are analyzed. These preliminary data serve as a basis for future studies involving fossil biota from the deposits of Gruta do Urso Fóssil using spectroscopic techniques.

Structural and IR-spectroscopic characterization of pyridinium acesulfamate, a monoclinic twin

2018 ◽  
Vol 73 (11) ◽  
pp. 753-758
Author(s):  
Enrique J. Baran ◽  
Oscar E. Piro ◽  
Gustavo A. Echeverría ◽  
Beatriz S. Parajón-Costa
Keyword(s):  
Crystal Structure ◽  
Spectroscopic Characterization ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
X Ray ◽  
Pyridinium Cation ◽  
Ft Ir ◽  
The Fourier Transform ◽  
Ir Spectroscopic

AbstractThe crystal structure of pyridinium 6-methyl-1,2,3,-oxathiazine-4(3H)-one-2,2-dioxide [(C5NH6)(C4H4NO4S)], for short, pyH(ace), was determined by X-ray diffraction methods. It crystallizes as a twin in the monoclinic space group P21/c with a=6.9878(9), b=7.2211(7), c=21.740(2) Å, β=91.67(1)° and Z=4 molecules per unit cell. The structure was determined employing 1599 reflections with I>2σ(I) from one of the twin domains and refined employing 2092 reflections from both crystal domains to an agreement R1 factor of 0.0466. Besides electrostatic attractions, intermolecular pyH···O=C(ace) hydrogen bonds stabilize the acesulfamate anion and the pyridinium cation into planar discrete units parallel to the (100) crystal plane. The units form stacks of alternating ace− and pyH+ ions along the a axis that favors inter-ring π–π interactions. The Fourier transform-infrared (FT-IR) spectrum of the compound was recorded and is briefly discussed. Some comparisons with related pyridinium saccharinate salts are also made.

scholarly journals The Reduction of Pyridine by K12Si17 to the 4,4′-Bipyridine Radical Anion [C10H8N2]-•: Crystal Structure and Spectroscopic Characterization of [K([2.2.2]crypt)][C10H8N2]

2014 ◽  
Vol 69 (11-12) ◽  
pp. 1119-1123 ◽  
Author(s):  
Christian B. Benda ◽  
Thomas F. Fässler
Keyword(s):  
Crystal Structure ◽  
Radical Anion ◽  
Spectroscopic Characterization ◽  
X Ray Diffraction ◽  
Compound K ◽  
Zintl Phase ◽  
X Ray ◽  
Vis Spectroscopy ◽  
C Nmr

Abstract From an anhydrous pyridine extract of the binary Zintl phase K12Si17 in the presence of the cation sequestering agent [2.2.2]crypt (4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8.8.8]hexacosane) crystals of the compound [K([2.2.2]crypt)][C10H8N2] have been isolated which contains the 4,4′- bipyridine radical monoanion. This compound was fully characterized by X-ray diffraction, 1H, 13C NMR, EPR, IR and UV=Vis spectroscopy

scholarly journals Synthesis and Characterization of Zinc Peroxide Nanoparticles for the Photodegradation of Nitrobenzene Assisted by UV-Light

Catalysts ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1041
Author(s):  
Jesús Isaías De León Ramírez ◽  
Víctor Alfredo Reyes Villegas ◽  
Sergio Pérez Sicairos ◽  
Esteban Hernández Guevara ◽  
Mirna Del Carmen Brito Perea ◽  
...  
Keyword(s):  
Uv Light ◽  
Sol Gel ◽  
Gas Chromatography Mass Spectrometry ◽  
X Ray Diffraction ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Ft Ir ◽  
Zinc Peroxide ◽  
Uv Lamps

The contamination of both soil and water by nitrobenzene (NB) is a problem that has been studied, where several reactive agents have been developed for the degradation of this compound as well as different methods. Nanoparticles with semiconductive properties have been studied for organic compounds photodegradation due to their assistance in optimizing the degradation processes. Two of the most promising photocatalysts are ZnO and TiO2 because of their optimal results. In the present work the performance of the zinc peroxide (ZnO2) nanoparticles was evaluated. ZnO2 nanoparticles were synthesized from zinc acetate and hydrogen peroxide using the Sol-Gel method under ultrasound assistance. The characterization was carried out by UV–Vis spectroscopy, infrared Fourier transform total reflectance (ATR-FT-IR) spectroscopy, Raman spectroscopy, X-ray diffraction (XRD), Zeta potential, dynamic light scattering (DLS), field emission scanning electron microscopy (FE-SEM), and Energy Dispersive X-ray spectroscopy (EDX). The experiments for the degradation of NB were carried out in a photoreactor with UV lamps of 254 nm at 25 °C, using a solution of nitrobenzene with the nanoparticles. The best conditions for NB photodegradation were 30 ppm (ZnO2) and 15 ppm (NB) at pH 2, reaching up to 90% degradation in 2 h. The intermediates formed during the photodegradation of NB were identified by gas chromatography mass spectrometry.

scholarly journals Synthesis and characterization of four N-acylhydrazones as potential O,N,O donors for Cu2+: An experimental and theoretical study

2021 ◽  
Vol 26 (2) ◽  
Author(s):  
Dorian Polo-Cerón ◽  
María Mercedes Hincapié-Otero ◽  
Andrey Joaqui-Joaqui
Keyword(s):  
Organic Molecules ◽  
2D Nmr ◽  
Spectroscopic Techniques ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ft Ir ◽  
Multistep Procedure ◽  
Good Agreement ◽  
Ft Ir Spectroscopy

N-acylhydrazones 2-(4-chlorophenyl)-N0 -(2-hydroxybenzylidene)acetohydrazide, N0 -(2-hydroxybenzylidene)-2-(4-methoxyphenyl)acetohydrazide, 2-(4-chlorophenyl)-N0 -(2,4-dihydroxybenzylidene)-acetohydrazide, and N0 -(2,4-dihydroxybenzylidene)-2-(4-methoxyphenyl)acetohydrazide were successfully synthesized by a multistep procedure. The obtained organic molecules were characterized by spectroscopic techniques (FT-IR, 1D and 2D NMR, UV-Vis) and mass spectrometry. The structure of 2-(4-chlorophenyl)-N0 -(2-hydroxybenzylidene)acetohydrazide was also confirmed by X-ray diffraction. Ab initio computational simulations of the ligand spectra were in good agreement with experimental data and validated the hypothesis about the existence of a conformational mixture of each ligand in solution. Finally, the complexation potential of the synthesized ligands to Cu2+ was assessed by continuous variation experiments and FT-IR spectroscopy.

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