Chemical stability of CVD source materials for high-Tc superconducting films

1992 ◽  
Vol 7 (6) ◽  
pp. 1336-1340 ◽  
Author(s):  
Takuya Hashimoto ◽  
Hideomi Koinuma ◽  
Masaaki Nakabayashi ◽  
Tadashi Shiraishi ◽  
Youichi Suemune ◽  
...  
Keyword(s):  
Chemical Stability ◽  
Room Temperature ◽  
Chemical Vapor ◽  
Superconducting Films ◽  
Adsorbed Species ◽  
High Tc ◽  
H Nmr ◽  
The Stability ◽  
Source Materials ◽  
C Nmr

The stability of chemical vapor deposition (CVD) source materials for high-Tc superconducting films was examined by 1H-NMR (nuclear magnetic resonance), 13C-NMR, IR (infrared) absorption, and TG-DTA (thermogravimetry and differential thermal analysis) measurements. Highly purified Ca(DPM)2 (DPM: dipyvaloylmethane: (CH3)3CCOCHCOC(CH3)3) and Sr(DPM)2, utilizing recrystallization and sublimation, easily decomposed at room temperature and changed their thermal properties when they were handled and stored in air or even in an Ar atmosphere without removing adsorbed species such as water. The stability increased by removing a trace of adsorbed species and storing in an Ar atmosphere at −30 °C. Bi(C6H5)3 and Y(DPM)3 showed higher chemical stability than Ca(DPM)2 and Sr(DPM)2.

Stability and decarbonylation of 1,3-dialkyl-2-formylimidazolium perchlorate in solution

2013 ◽  
Vol 91 (6) ◽  
pp. 442-447 ◽  
Author(s):  
Hong-Xing Xin ◽  
Qi Liu ◽  
Hong Yan ◽  
Xiu-Qing Song
Keyword(s):  
Nmr Spectra ◽  
Room Temperature ◽  
X Ray ◽  
H Nmr ◽  
Protic Solvents ◽  
The Stability ◽  
C Nmr

The stability of 1,3-dialkyl-2-formylimidazolium perchlorate 1 in solution was studied in detail and found to be related to its structure and the solvent character and temperature. 1 was stable in common solvents at room temperature and unstable in protic solvents under reflux. In protic solvents, such as H2O, MeOH, EtOH, and AcOH, 1 decarbonylated into 1,3-dialkylimidazole perchlorates 2, which was confirmed by 1H NMR, 13C NMR, HRMS, and X-ray spectroscopy. The decarbonylation of 1 was proposed to occur via its hemiacetal formed by the addition of solvents based on the tracking NMR spectra of 1 in deuterated reagents.

scholarly journals New Method for Nucleophilic Substitution on Hexachlorocyclotriphosphazene by Allylamine Using an Algerian Proton Exchanged Montmorillonite Clay (Maghnite-H+) as a Green Solid Catalyst

2016 ◽  
Vol 11 (2) ◽  
pp. 151 ◽  
Author(s):  
Lahouaria Medjdoub ◽  
Belbachir Mohammed
Keyword(s):  
Nucleophilic Substitution ◽  
Room Temperature ◽  
Montmorillonite Clay ◽  
New Method ◽  
Solid Catalyst ◽  
H Nmr ◽  
Flight Mass Spectrometry ◽  
Crystalline Product ◽  
First Time ◽  
C Nmr

<p>Nucleophilic substitution on hexachlorocyclotriphosphazene (HCCTP) with allylamine in order to give hexa(allylamino)cyclotriphosphazene (HACTP)  is performed for the first time under mild conditions by using diethylether as solvent to replace benzene which is very toxic. The reaction time is reduced to half and also performed at room temperature but especially in the presence of an eco-catalyst called Maghnite-H<sup>+</sup>. This catalyst has a significant role in the industrial scale. In fact, the use of Maghnite is preferred for its many advantages: a very low purchase price compared to other catalysts, the easy removal of the reaction mixture. Then, Maghnite-H<sup>+</sup> is became an excellent catalyst for many chemical reactions. The structure of HACTP synthesized in the presence of Maghnite-H<sup>+</sup> to 5% by weight is confirmed by <sup>1</sup>H-NMR, <sup>13</sup>C-NMR, <sup>31</sup>P-NMR (Nuclear magnetic resonance) and FTIR (Fourier Transform Infrared spectroscopy). MALDI-TOF (Matrix-Assisted Laser Desorption/Ionisation-time-of-flight mass spectrometry) is used to establish the molecular weight of HACTP which is 471 g/mol. DSC (Differential Scanning Calorimetery) and TGA (Thermogravimetric Analysis) show that HACTP is a crystalline product with a melting point of 88 °C. It is reactive after melting but is degraded from 230 °C. Copyright © 2016 BCREC GROUP. All rights reserved</p><p><em>Received: 28<sup>th</sup> September 2015; Revised: 5<sup>th</sup> December 2015; Accepted: 4<sup>th</sup> January 2016</em></p><p><strong>How to Cite</strong>: Medjdoub, L., Mohammed, B. (2016). New Method for Nucleophilic Substitution on Hexachlorocyclotriphosphazene by Allylamine Using an Algerian Proton Exchanged Montmorillonite Clay (Maghnite-H+) as a Green Solid Catalyst. <em>Bulletin of Chemical Reaction Engineering &amp; Catalysis</em>, 11 (2): 151-160 (doi:10.9767/bcrec.11.2.541.151-160)</p><p><strong>Permalink/DOI:</strong> http://dx.doi.org/10.9767/bcrec.11.2.541.151-160</p>

Metall-π-Komplexe yon Benzolderivaten, XIII Bis(methylthio-η-beiizol)chrom(0) Darstellung und Einsatz als zweizähniger Chelatligand/ Metal-π Complexes of Benzene Derivatives, XIII Bis(methylthio-η-benzene)chromium(0) Preparation and Function as a Bidentate Chelating Ligand

1981 ◽  
Vol 36 (1) ◽  
pp. 94-101 ◽  
Author(s):  
Helmut Burdorf ◽  
Christoph Eischenbroich
Keyword(s):  
Nmr Spectra ◽  
Room Temperature ◽  
Radical Cations ◽  
Esr Spectra ◽  
Benzene Derivatives ◽  
Consecutive Reaction ◽  
H Nmr ◽  
Chelating Ligand ◽  
And Function ◽  
C Nmr

Abstract The thioanisole-π-complexes (methylthio-η-benzene)-(η-benzene)-chromium (2) and bis(methylthio-η-benzene)chromium (3) have been prepared via lithiation of bis(η-benzene)-chromium and consecutive reaction with dimethyldisulfide. 1H NMR and 13C NMR spectra of 2 and 3 as well as ESR-spectra of the corresponding radical cations 2.+ and 3.+ were recorded and analyzed. In contrast to C(η-arene)-Si and C(η-arene)-P bonds, C(y-arene)-S bonds are stable to solvolysis. With (norbornadiene)tetracarbonylmolybdenum, 3 readily forms [bis(methylthio-η-benzene)chromium]tetracarbonylmolybdenum (6) wherein 3 functions as a chelating ligand. 1H and 13C NMR evidence suggests, that at room temperature 6 undergoes rapid conformational interconversions.

scholarly journals Synthesis and Spectroscopic Characterization of Some New Axially Ligated Indium(III) Macrocyclic Complexes and Their Biological Activities

2014 ◽  
Vol 2014 ◽  
pp. 1-7
Author(s):  
Gauri D. Bajju ◽  
Altaf Ahmed ◽  
Deepmala Gupta ◽  
Ashu Kapahi ◽  
Gita Devi
Keyword(s):  
Biological Activities ◽  
Spectroscopic Characterization ◽  
Axial Ligand ◽  
Free Base ◽  
H Nmr ◽  
Pyramidal Geometry ◽  
The Stability ◽  
Square Pyramidal Geometry ◽  
C Nmr

The synthesis and spectroscopic characterization of new axially ligated indium(III) porphyrin complexes were reported. Chloroindium(III) porphyrin (TPPIn-Cl) was obtained in good yield by treating the corresponding free base with indium trichloride. The action of the different phenols on chloroderivatives (TPPIn-Cl) led to the corresponding phenolato complexes (TPPIn-X). These derivatives were characterized on the basis of mass spectrometry,1H-NMR, IR, and UV-visible data. The separation and isolation of these derivatives have been achieved through chromatography. The spectral properties of free base porphyrin and its corresponding metallated and axially ligated indium(III) porphyrin compounds were compared with each other. A detailed analysis of UV-Vis,1H-NMR, and IR suggested the transformation from free base porphyrin to indium(III) porphyrin. Besides,13C-NMR and fluorescence spectra were also reported and interpreted. The stability of these derivatives has also been studied through thermogravimetry. The complexes were also screened for anticancerous activities. Among all the complexes, 4-MePhO-InTPP shows highest anticancerous activity. The title complexe, TPPIn-X (where X = different phenolates), represents a five-coordinate indium(III) porphyrin complex in a square-pyramidal geometry with the phenolate anion as the axial ligand.

scholarly journals Synthesis and properties of novel ammonium-based room-temperature gemini ionic liquids

RSC Advances ◽  
2018 ◽  
Vol 8 (46) ◽  
pp. 26255-26265 ◽  
Author(s):  
Xuzhao Yang ◽  
Yun Fang
Keyword(s):  
Ionic Liquids ◽  
Room Temperature ◽  
H Nmr ◽  
C Nmr

Ammonium-based asymmetrical gemini ionic liquids, 1-trimethylammonium-3-(pyridinium)propane bisdicyanamide and 1-trimethylammonium-3-(1-methylpiperidinium)propane bisdicyanamide were respectively synthesized and characterized by 1H NMR and 13C NMR.

NMR Complexation Study of Several Oxyethylated Calix[4]arenes with Lithium, Sodium and Potassium Ions

1996 ◽  
Vol 61 (12) ◽  
pp. 1783-1797 ◽  
Author(s):  
Jaroslav Havlíček ◽  
Marcela Tkadlecová ◽  
Michaela Vyhnánková ◽  
Evgueni Pinkhassik ◽  
Ivan Stibor
Keyword(s):  
Sodium Cation ◽  
H Nmr ◽  
Nmr Data ◽  
Constant Determination ◽  
Close Proximity ◽  
Dinitro Derivative ◽  
The Stability ◽  
Upper Rim ◽  
Sodium And Potassium ◽  
C Nmr

The influence of calix[4]arene upper rim substitution on the complexation with Li+, Na+, K+ was studied by 1H NMR spectroscopy. Calix[4]arenes 1-4 namely 25,26,27,28-tetrakis(3-oxapentyloxy)calix[4]arene (1), its 5,17-diamino (2) and 5,17-dinitro derivative (3) as well as 25,26,27,28-tetrakis(3,6,9-trioxadecyloxy)calix[4]arene (4) having four monoalkyloligoethylene glycol chains on the lower rim have been studied. No complexation has been observed for Li+. Two electron-donating NH2 groups on the calixarene upper rim (compound 2) improve the complexation ability for Na+ and K+ compared with parent calixarene 1. The electron-withdrawing nitro groups in 3 have the opposite influence. It seems that the complexation of alkali metal ions studied is not significantly influenced by the increasing number of donor atoms (from eight in 1 to sixteen in 4) available for complexation on the lower rim. The position of sodium cation in 1 . Na+ and 4. Na+ is supposed to be in close proximity of phenolic oxygens based on 1H and 13C NMR data. The error analysis is given for the stability constant determination from NMR data.

1,4-Bis(p-pentazolylphenyl)butan, 1-p-Azidophenyl-4-p-pentazolylphenyl- butan und 1,4-Bis(p-azidophenyl)butan / 1,4-Bis(p-pentazolylphenyl)butane, 1-p-Azidophenyl-4-p-pentazolylphenyl-butane and 1,4-Bis(p-azidophenyl)butane

2004 ◽  
Vol 59 (6) ◽  
pp. 716-720 ◽  
Author(s):  
Frank Biesemeier ◽  
Klaus Harms ◽  
Ulrich Müller
Keyword(s):  
Low Temperature ◽  
Sodium Azide ◽  
Rate Constants ◽  
Nmr Spectra ◽  
Room Temperature ◽  
Fine Powder ◽  
Space Group ◽  
H Nmr ◽  
Diazonium Ions ◽  
C Nmr

1,4-Bis(p-pentazolylphenyl)butane (1), 1-p-azidophenyl-4-p-pentazolylphenyl-butane (2) and 1,4-bis(p-azidophenyl)butane (3) were obtained by the reaction of 1,4-diphenylbutane-4’,4”- bis(diazonium) ions with sodium azide in methanol at −50 °C. In the 1H and 13C NMR spectra the three compounds can be distinguished unequivocally. At −50 °C a mixture with a composition 1:2:3 of 10:30:60 was obtained. By recrystallization first from dichloromethane/methanol and then from dichloromethane/petroleum ether the pentazole components were enriched to a composition ratio of 21:62:17. The rate constants of the decompositions 1→2 and 2→3 at 0 °C were determined from the variation of the 1H NMR intensities. At room temperature all of the material is converted to 3. 3 crystallizes in two monoclinic modifications. At −70 °C a modification 3-LT having space group P21/c (a = 950.8, b = 1192.6, c = 701.3 pm, β = 92.55°, Z = 2; R = 0.075) was obtained. The modification crystallizing at room temperature (3-HT) has space group I2/a (a = 1514.5, b = 498.1, c = 2027.9 pm, β = 92.73°, Z = 4; R = 0.040). Whereas both modifications consist of nearly identical molecules, their packings are quite different. When the low temperature modification is warmed to room temperature, its crystals jump like flees and are disrupted to a fine powder.

Syntheses, crystal structures and phosphorescence properties of cyclometalated iridium(III) bis(pyridylbenzaldehyde) complexes with dithiolate ligands

2017 ◽  
Vol 72 (12) ◽  
pp. 941-946 ◽  
Author(s):  
Xue-Mei Wang ◽  
Jia-Yan Qiang ◽  
Ai-Quan Jia ◽  
Bihai Tong ◽  
Qian-Feng Zhang
Keyword(s):  
Crystal Structures ◽  
Emission Spectra ◽  
Transition Metal Ions ◽  
X Ray ◽  
X Ray Crystallography ◽  
H Nmr ◽  
Water Solvent ◽  
The Stability ◽  
C Nmr ◽  
Composition Of Complexes

AbstractThe synthesis of three neutral bis-cyclometalated iridium(III) complexes [Ir(pba)2(S^S)] (pbaH=4-(2-pyridyl)benzaldehyde; S^S=Et2NCS2− (1), iPrOCS2− (2), (nPrO)2PS2− (3)) from [{Ir(μ-Cl)(pba)2}2] and the corresponding sodium or potassium dithiolates in methanol-dichloromethane is described. The composition of complexes 1–3 is discussed on the basis of 1H NMR, 13C NMR, IR, and mass spectroscopy, and the crystal structures of 1 and 3 were determined by X-ray crystallography. The absorption and emission spectra show that the [Ir(pba)2(S^S)] complexes may be effective candidates as green-emitting phosphorescent materials. The stability of the three cyclometalated iridium(III) complexes towards different transition metal ions was also investigated in acetonitrile-water solvent.

scholarly journals A novel hyperbranched polyester based on 2,2-bis(hydro xylmethyl)butyric acid: synthesis and characterization

e-Polymers ◽  
2007 ◽  
Vol 7 (1) ◽  
Author(s):  
Michelina Soccio ◽  
Lara Finelli ◽  
Nadia Lotti ◽  
Paola Marchese ◽  
Valentina Siracusa ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Butyric Acid ◽  
Room Temperature ◽  
Cyanuric Acid ◽  
Acid Synthesis ◽  
Hyperbranched Polyester ◽  
Degree Of Branching ◽  
Good Thermal Stability ◽  
H Nmr ◽  
C Nmr

AbstractA novel hyperbranched polyester was synthesized in bulk from 2,2- bis(hydroxymethyl)butyric acid and two different core molecules (1,1,1-tris- (hydroxylmethyl)propane and 1,3,5-tris(2-hydroxyethyl)cyanuric acid), using ptoluensolfonic acid, scandium trifluoromethanesulfonate, titanium tetrabutoxide and dibutyltin oxide as catalysts and varied reaction temperature and time. At room temperature the samples obtained appeared as glassy, slightly yellow solids, with Mn (calculated by 1H-NMR spectra) in the range 500 - 2000. The degree of branching of the polyesters was determined by 13C-NMR spectroscopy and was found in the range 0.32 - 0.53. The introduction of the monomer in various steps seems to influence slightly the degree of branching, but has no effect on the molecular weight of these polymers. The polyesters exhibited a good thermal stability, as revealed by TGA technique, and the glass transition temperature, determined by DSC, was found to depend on the molecular weight and the kind of catalyst employed.

scholarly journals Synthesis, characterization, biological screening and determination of stability constants of N,N′-Bis[1-(4-chlorophenyl)ethylidene]ethane-1,2-diamine

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Muhammad Aslam ◽  
Asad Gulzar ◽  
Rashad Mehmood ◽  
Zahra Noreen ◽  
Ghania Asad ◽  
...  
Keyword(s):  
Stability Constants ◽  
Brine Shrimp ◽  
Octahedral Geometry ◽  
Biological Screening ◽  
H Nmr ◽  
Biological Potential ◽  
Elemental Analyses ◽  
The Stability ◽  
C Nmr

AbstractA Schiff base ligand, N,N′-bis[1-(4-chlorophenyl)ethylidene]ethane-1,2-diamine (SBL), was synthesized by condensation of 4-chloroacetophenone with ethylenediamine in methanol in the presence of H2SO4 as catalyst. The structure of SBL was elucidated by spectroscopic (1H-NMR, 13C-NMR, IR and MS) and elemental analyses, and also confirmed by XRD. The SBL was used to prepare metal complexes 1-2 with Pb+2 and Cd+2, respectively. The structures of the complexes were elucidated by IR, MS and elemental analyses. On the basis of electronic spectra and magnetic moment data, octahedral geometry was proposed for the synthesized complexes 1-2. The conductivity data showed the non-electrolytic nature of the complexes 1-2. The SBL and complexes 1-2 were subjected to measure their biological potential against Staphylococcus aureus, Bacillus subtilis and Escherichia coli bacteria. SBL showed non-significant anti-bacterial potential whereas complexes showed moderate potential as compared to standard impinium. In the toxicity with brine shrimp larvae, complexes showed more toxic effect than the SBL. In the experiments to determine the stability constants of SBL with CuCl2, Cu(OAc)2, CoCl2 and Co(NO3)2; SBL showed highest stability constants with Cu(OAc)2 which is 1.550 × 107 at 1:1 (L:M) and second highest with Co(NO3)2 which is 6.861 × 106 at 3:2 (L:M).

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