scholarly journals Novel Non-Metal Cation (NMC) Pentaborate Salts of Some Amino Acids

Molecules ◽  
2019 ◽  
Vol 24 (15) ◽  
pp. 2790 ◽  
Author(s):  
Ümit Sızır ◽  
Ömer Yurdakul ◽  
Dursun Ali Köse ◽  
Fatih Akkurt
Keyword(s):  
Thermal Analysis ◽  
Amino Acids ◽  
Hydrogen Storage ◽  
Metal Cation ◽  
Degradation Products ◽  
Analysis Data ◽  
X Ray ◽  
Ft Ir ◽  
11B Nmr

Non-metal cation (NMC) pentaborate structures, in which some amino acids (valine, leucine, isoleucine, and threonine) were used as cations, were synthesized. The structural characterization of molecules was carried out by elemental analysis, FT-IR, mass, 11B-NMR, and thermal analysis (TGA/DTA) methods. The hydrogen storage capacity of molecules was also calculated by taking experimental results into consideration. The FT-IR spectra support the similarity of structures. The characteristic peaks attributable to pentaborate rings and amino acids were observed. When thermal analysis data were examined, it was observed that pentaborate salts gave similar degradation steps and degradation products. As a final degradation product of all thermal analysis experiments, a glassy form of B2O3 was observed. The valine pentaborate is the most thermally stable. Also, the amounts of hydrate water outside the coordination sphere of the compounds were determined by thermal analysis curves. The peaks of boric acid, triborate, and pentaborate structures were obtained in ppm with the 11B-NMR results of synthesized pentaborate compounds. With powder X-ray spectroscopy, all structures were found to be crystalline but not suitable for single-crystal X-ray analysis. The molecular cavities of the compounds detected by BET were found to be 3.286, 1.873, 2.309, and 1.860 g/cm3, respectively. A low number of molecular cavities can be interpreted in several existing hydrogen bonds in structures. The hydrogen storage capacities of the molecules were found to be in the range of 0.04 to 0.07% by mass.

Preparation and Characterization of Fibri-Form Silica from Short Chrysotile Fibers by Mix-Roasting

2014 ◽  
Vol 809-810 ◽  
pp. 313-318
Author(s):  
Peng Cheng Song ◽  
Tong Jiang Peng ◽  
Hong Juan Sun ◽  
Yu Cao Yu
Keyword(s):  
Electron Microscopy ◽  
Thermal Analysis ◽  
Scanning Electron Microscopy ◽  
Fluorescence Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Fibrous Morphology ◽  
Ft Ir ◽  
Scanning Electron

Fibri-form silica was extracted from short chrysotile fibers by mix-roasting with ammonium bisulfate. The fibri-form silica were characterized by X-ray fluorescence analysis (XRF), X-ray diffraction (XRD), thermogravimetry and differential thermal analysis (TG-DTA), scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FT-IR) and N2 adsorption isotherms. The results show that the fibri-form silica with disordered crystalline structure, but also in fibrous morphology. The surface area and pore volume of fibri-form silica are 181.66 m2/ g and 0.44 cc/ g, respectively. The structure of fibri-form silica is stable, no phase transformed from 50 to 1200 oC.

Thermal Behaviour of Candesartan Active substance and in pharmaceutical compounds

2017 ◽  
Vol 68 (8) ◽  
pp. 1895-1902
Author(s):  
Ioana Cristina Tita ◽  
Eleonora Marian ◽  
Bogdan Tita ◽  
Claudia Crina Toma ◽  
Laura Vicas
Keyword(s):  
Thermal Behaviour ◽  
Active Substance ◽  
Pharmaceutical Research ◽  
Pharmaceutical Product ◽  
Nitrogen Atmosphere ◽  
Pure Substance ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Ft Ir

Thermal analysis is one of the most frequently used instrumental techniques in the pharmaceutical research, for the thermal characterization of different materials from solids to semi-solids, which are of pharmaceutical relevance. In this paper, simultaneous thermogravimetry/derivative thermogravimetry (TG/DTG) and differential scanning calorimetry (DSC) were used for characterization of the thermal behaviour of candesartan cilexetil � active substance (C-AS) under dynamic nitrogen atmosphere and nonisothermal conditions, in comparison with pharmaceutical product containing the corresponding active substance. It was observed that the commercial samples showed a different thermal profile than the standard sample, caused by the presence of excipients in the pharmaceutical product and to possible interaction of these with the active substance. The Fourier transformed infrared spectroscopy (FT-IR) and X-ray powder diffraction (XRPD) were used as complementary techniques adequately implement and assist in interpretation of the thermal results. The main conclusion of this comparative study was that the TG/DTG and DSC curves, together with the FT-IR spectra, respectively X-ray difractograms constitute believe data for the discrimination between the pure substance and pharmaceutical forms.

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.

One Step Synthesis and Characterization of Zirconia-Graphene Composites

2012 ◽  
Vol 600 ◽  
pp. 174-177 ◽  
Author(s):  
Jian Fei Xia ◽  
Zong Hua Wang ◽  
Yan Zhi Xia ◽  
Fei Fei Zhang ◽  
Fu Qiang Zhu ◽  
...  
Keyword(s):  
Synthesis And Characterization ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
X Ray ◽  
Graphene Composite ◽  
Transmission Electron ◽  
One Step ◽  
Ft Ir ◽  
Xrd Techniques

Zirconia-graphene composite (ZrO2-G) has been successfully synthesized via decomposition of ZrOCl2•6H2O in a water-isopropanol system with dispersed graphene oxide (GO) utilizing Na2S as a precursor could enable the occurrence of the deposition of Zr4+ and the deoxygenation of GO at the same time. Transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) techniques were used to characterize the samples. It was found that graphene were fully coated with ZrO2, and the ZrO2 existing in tetragonal phase, which resulted in the formation of two-dimensional composite.

Microwave-assisted solvent-free synthesis and spectral and structural characterization of cyclotriphosphazene hexakis(o-tolylamide)

2018 ◽  
Vol 73 (12) ◽  
pp. 999-1003 ◽  
Author(s):  
Mohammad Hakimi ◽  
Homeyra Rezaei ◽  
Keyvan Moeini ◽  
Heidar Raissi ◽  
Vaclav Eigner ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Microwave Irradiation ◽  
Stacking Interactions ◽  
X Ray Diffraction ◽  
Aromatic Rings ◽  
X Ray ◽  
Microwave Assisted ◽  
Ft Ir ◽  
Solvent Free Synthesis

AbstractA new cyclotriphosphazene, 2,2,4,4,6,6-hexakis (o-tolylamono)-1,3,5,2λ5,4λ5,6λ5-triazatriphosphinine (MPAP), was prepared using microwave irradiation and identified by elemental analysis, FT-IR, Raman, 31P NMR spectroscopy, and single-crystal X-ray diffraction. In the crystal, in addition to hydrogen bonds, the network is further stabilized by inter- and intramolecular π–π stacking interactions between aromatic rings.

scholarly journals Hydrogenative Cyclization of Levulinic Acid to γ-Valerolactone with Methanol and Ni-Fe Bimetallic Catalysts

Catalysts ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1096
Author(s):  
Ligang Luo ◽  
Xiao Han ◽  
Qin Zeng
Keyword(s):  
Photoelectron Spectroscopy ◽  
Levulinic Acid ◽  
Hydrogen Donor ◽  
Effect Of Temperature ◽  
X Ray ◽  
Transmission Electron ◽  
Ft Ir ◽  
Temperature Programmed

A series of Ni-Fe/SBA-15 catalysts was prepared and tested for the catalytic hydrogenation of levulinic acid to γ-valerolactone, adopting methanol as the only hydrogen donor, and investigating the synergism between Fe and Ni, both supported on SBA-15, towards this reaction. The characterization of the synthesized catalysts was carried out by XRD (X-ray powder diffraction), TEM (transmission electron microscopy), H2-TPD (hydrogen temperature-programmed desorption), XPS (X-ray photoelectron spectroscopy), and in situ FT-IR (Fourier transform–infrared spectroscopy) techniques. H2-TPD and XPS results have shown that electron transfer occurs from Fe to Ni, which is helpful both for the activation of the C=O bond and for the dissociative activation of H2 molecules, also in agreement with the results of the in situ FT-IR spectroscopy. The effect of temperature and reaction time on γ-valerolactone production was also investigated, identifying the best reaction conditions at 200 °C and 180 min, allowing for the complete conversion of levulinic acid and the complete selectivity to γ-valerolactone. Moreover, methanol was identified as an efficient hydrogen donor, if used in combination with the Ni-Fe/SBA-15 catalyst. The obtained results are promising, especially if compared with those obtained with the traditional and more expensive molecular hydrogen and noble-based catalysts.

The Characterization of Bovine Bone-Derived Hydroxyapatite Isolated Using Novel Non-Hazardous Method

2020 ◽  
Vol 45 ◽  
pp. 49-56
Author(s):  
Aniek Setiya Budiatin ◽  
Samirah ◽  
Maria Apriliani Gani ◽  
Wenny Putri Nilamsari ◽  
Chrismawan Ardianto ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Extraction Method ◽  
Bovine Bone ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ft Ir ◽  
Novel Method ◽  
Scanning Electron

Bovine bone is a considerable source for the production of hydroxyapatite. The recent study reported a novel method to extract hydroxyapatite from bovine bone without producing hazardous residue. The bovine bones were cut and boiled in the opened chamber followed by boiling in pressurized tank. The bones were then soaked into 95% ethanol. Calcination was then conducted in 800°C, 900°C and 1,000°C, for 2 hours. The result was then grinded and sieved. The powder then was characterized using Fourier transform infrared (FT-IR), Scanning electron microscopy (SEM) and X-ray diffraction analysis (XRD) to measure the purity of hydroxyapatite. It is concluded that the hydroxyapatite derived from this process showed 100% purity, resulting 35.34 ± 0.39% w/w from the wet bone weight and 72.3% w/w from the dried weight. The present extraction method has been proven to yield high amount of pure hydroxyapatite as well as reducing the use of hazardous reagent.

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.

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