scholarly journals Fluorine-Substituted Arylphosphine for an NHC-Ni(I) System, Air-Stable in a Solid State but Catalytically Active in Solution

Molecules ◽  
2019 ◽  
Vol 24 (18) ◽  
pp. 3222 ◽  
Author(s):  
Matsubara ◽  
Fujii ◽  
Hosokawa ◽  
Inatomi ◽  
Yamada ◽  
...  
Keyword(s):  
Solid State ◽  
High Catalytic Activity ◽  
X Ray Diffraction ◽  
Aryl Bromides ◽  
Solid State Stability ◽  
Catalytically Active ◽  
Triphenylphosphine Complex ◽  
Oxidation In Air ◽  
Monovalent Nickel ◽  
First Time

Monovalent NHC-nickel complexes bearing triarylphosphine, in which fluorine is incorporated onto the aryl groups, have been synthesized. Tris(3,5-di(trifluoromethyl)-phenyl)phosphine efficiently gave a monovalent nickel bromide complex, whose structure was determined by X-ray diffraction analysis for the first time. In the solid state, the Ni(I) complex was less susceptible to oxidation in air than the triphenylphosphine complex, indicating greatly improved solid-state stability. In contrast, the Ni(I) complex in solution can easily liberate the phosphine, high catalytic activity toward the Kumada–Tamao–Corriu coupling of aryl bromides.

Niobium-bearing arsenides and germanides from elemental mixtures not involving niobium: a new twist to an old problem in solid-state synthesis

2018 ◽  
Vol 74 (5) ◽  
pp. 623-627 ◽  
Author(s):  
Sviatoslav Baranets ◽  
Hua He ◽  
Svilen Bobev
Keyword(s):  
High Temperature ◽  
Solid State ◽  
Diffraction Data ◽  
Alkaline Earth ◽  
Alkaline Earth Metals ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Temperature Reactions ◽  
First Time ◽  
Synthetic Work

Three isostructural transition-metal arsenides and germanides, namely niobium nickel arsenide, Nb0.92(1)NiAs, niobium cobalt arsenide, NbCoAs, and niobium nickel germanide, NbNiGe, were obtained as inadvertent side products of high-temperature reactions in sealed niobium containers. In addition to reporting for the very first time the structures of the title compounds, refined from single-crystal X-ray diffraction data, this article also serves as a reminder that niobium containers may not be suitable for the synthesis of ternary arsenides and germanides by traditional high-temperature reactions. Synthetic work involving alkali or alkaline-earth metals, transition or early post-transition metals, and elements from groups 14 or 15 under such conditions may yield Nb-containing products, which at times could be the major products of such reactions.

Sodium Alanate Dehydrogenation Properties Enhanced by MnTiO3 Nanoparticles

2020 ◽  
Vol 15 (2) ◽  
pp. 197-203
Author(s):  
Yujie Sun ◽  
Xia Yang ◽  
Yue Huang ◽  
Jianquan Li ◽  
Xinghua Cen ◽  
...  
Keyword(s):  
Solid State ◽  
Hydrogen Desorption ◽  
Test Results ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sodium Alanate ◽  
State Ceramic ◽  
Solid State Ceramic Route ◽  
Ceramic Route ◽  
First Time

In this study, we investigated the influence of MnTiO3 nanoparticles additive on hydrogen released performance of NaAlH4 for the first time. The MnTiO3 nanoparticles were successfully synthesized using conventional solid-state ceramic route. It was found that the hydrogen released performance of NaAlH4 can be significantly improved by the addition of MnTiO3 nanoparticles. Meantime, the composite of NaAlH4 doped 5 wt% MnTiO3 possessed excellent dehydrogenation properties, the onset dehydrogenation temperature was only 70.6 °C, reduced by about 105 °C in comparison with the pristine NaAlH4, and approximately 5.01 wt% of hydrogen could be released from composite with temperature heated to 220 °C. The isothermal dehydrogenation test results indicated that the amount of hydrogen released by NaAlH4-5 wt% MnTiO3 composite could reach 4.4 wt% under 200 °C within 25 min. According to the analysis of X-ray diffraction, the presence of MnTiO3 nanoparticles did not alter the overall dehydrogenation pathway of NaAlH4, and the Al3 Ti phases formed after dehydrogenation, which enhanced hydrogen desorption performances of NaAlH4 .

scholarly journals Aluminates with Fluorinated Schiff Bases: Influence of the Alkali Metal–Fluorine Interactions in Structure Stabilization

Molecules ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3108
Author(s):  
Francisco M. García-Valle ◽  
Vanessa Tabernero ◽  
Tomás Cuenca ◽  
Jesús Cano ◽  
Marta E. G. Mosquera
Keyword(s):  
Solid State ◽  
Alkali Metal ◽  
Schiff Bases ◽  
X Ray Diffraction ◽  
Metal Compounds ◽  
Stabilization Effect ◽  
Alkali Metal Compounds ◽  
Structure Stabilization ◽  
First Time ◽  
Electron Withdrawing Substituents

New heterometallic aluminium-alkali metal compounds have been prepared using Schiff bases with electron withdrawing substituents as ligands. The synthesis of these new species was achieved via the reaction of AlMe3 with the freshly prepared alkali-metallated ligand. The derivatives formed were characterized by NMR in solution and by single crystal X-ray diffraction in the solid state. Aluminate derivatives with lithium and sodium were prepared and a clear influence of the alkali metal in the final outcome is observed. The presence of a Na···F interaction in the solid state has a stabilization effect and the species [NaAlMe3L]2 can de isolated for the first time, which was not possible when using Schiff bases without electron withdrawing substituents as ligands.

scholarly journals A Simple Approach to Achieve Organic Radicals with Unusual Solid-State Emission and Extraordinary Stability

2020 ◽  
Author(s):  
Xueqian ZHAO ◽  
zheng zhao ◽  
Junyi Gong ◽  
Chao Ma, ◽  
Parvej Alam ◽  
...  
Keyword(s):  
Solid State ◽  
Ion Pairs ◽  
Red Light ◽  
Simple Approach ◽  
Ambient Conditions ◽  
X Ray Diffraction ◽  
Photo Induced Electron Transfer ◽  
One Year ◽  
Computational Analyses ◽  
First Time

Herein, we report a simple approach to generate stable<br>luminescent radicals in the presence of gentle UV irradiation. The newly generated radical<br>species are capable of emitting unusual red light with a maximum fluorescence quantum<br>efficiency of 4.6% at ambient conditions in the solid state. Additionally, the luminescent<br>radicals show extraordinary stability with more than one-year life-span at ambient conditions.<br>X-ray diffraction study combined with photophysical and computational analyses reveal that<br>the unique molecular symmetry breaking in the crystalline state lead to the unusual formation<br>and stabilization of radical ion pairs via the photo-induced electron transfer (PET) process. Such<br>results represent the first time to achieve stable emissive radicals in the solid state at ambient<br>conditions via in-situ PET process. <br>

scholarly journals A Simple Approach to Achieve Organic Radicals with Unusual Solid-State Emission and Extraordinary Stability

2020 ◽  
Author(s):  
Xueqian ZHAO ◽  
zheng zhao ◽  
Junyi Gong ◽  
Chao Ma, ◽  
Parvej Alam ◽  
...  
Keyword(s):  
Solid State ◽  
Ion Pairs ◽  
Red Light ◽  
Simple Approach ◽  
Ambient Conditions ◽  
X Ray Diffraction ◽  
Photo Induced Electron Transfer ◽  
One Year ◽  
Computational Analyses ◽  
First Time

Herein, we report a simple approach to generate stable<br>luminescent radicals in the presence of gentle UV irradiation. The newly generated radical<br>species are capable of emitting unusual red light with a maximum fluorescence quantum<br>efficiency of 4.6% at ambient conditions in the solid state. Additionally, the luminescent<br>radicals show extraordinary stability with more than one-year life-span at ambient conditions.<br>X-ray diffraction study combined with photophysical and computational analyses reveal that<br>the unique molecular symmetry breaking in the crystalline state lead to the unusual formation<br>and stabilization of radical ion pairs via the photo-induced electron transfer (PET) process. Such<br>results represent the first time to achieve stable emissive radicals in the solid state at ambient<br>conditions via in-situ PET process. <br>

The Collagenic Molecular Structural Unit of Solid State Complexes

1971 ◽  
Vol 29 ◽  
pp. 478-479
Author(s):  
Kenneth M. Richter ◽  
John A. Schilling
Keyword(s):  
Molecular Weight ◽  
Solid State ◽  
Structural Unit ◽  
X Ray Diffraction ◽  
X Ray ◽  
Naoh Treatment

The structural unit of solid state collagen complexes has been reported by Porter and Vanamee via EM and by Cowan, North and Randall via x-ray diffraction to be an ellipsoidal unit of 210-270 A. length by 50-100 A. diameter. It subsequently was independently demonstrated by us in dog tendon, dermis, and induced complexes. Its detailed morphologic, dimensional and molecular weight (MW) aspects have now been determined. It is pear-shaped in long profile with m diameters of 57 and 108 A. and m length of 263 A. (Fig. 1, tendon, KMnO4 fixation, Na-tungstate; Fig. 2a, schematic of unit in long, C, and x-sectional profiles of its thin, xB, and bulbous, xA portions; Fig. 2b, tendon essentially unmodified by ether and 0.4 N NaOH treatment, Na-tungstate). The unit consists of a uniquely coild cable, c, of ṁ 22.9 A. diameter and length of 2580-3316 A. The cable consists of three 2nd-strands, s, each of m 10.6 A.

TEM studies of solid-state reactions in sputter-deposited Nb/Al multilayer thin films

1996 ◽  
Vol 54 ◽  
pp. 1020-1021
Author(s):  
F. Ma ◽  
S. Vivekanand ◽  
K. Barmak ◽  
C. Michaelsen
Keyword(s):  
Thin Films ◽  
Solid State ◽  
Stoichiometric Composition ◽  
Analytical Electron Microscopy ◽  
Grain Structure ◽  
Solid State Reactions ◽  
Multilayer Thin Films ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sputter Deposited

Solid state reactions in sputter-deposited Nb/Al multilayer thin films have been studied by transmission and analytical electron microscopy (TEM/AEM), differential scanning calorimetry (DSC) and X-ray diffraction (XRD). The Nb/Al multilayer thin films for TEM studies were sputter-deposited on (1102)sapphire substrates. The periodicity of the films is in the range 10-500 nm. The overall composition of the films are 1/3, 2/1, and 3/1 Nb/Al, corresponding to the stoichiometric composition of the three intermetallic phases in this system.Figure 1 is a TEM micrograph of an as-deposited film with periodicity A = dA1 + dNb = 72 nm, where d's are layer thicknesses. The polycrystalline nature of the Al and Nb layers with their columnar grain structure is evident in the figure. Both Nb and Al layers exhibit crystallographic texture, with the electron diffraction pattern for this film showing stronger diffraction spots in the direction normal to the multilayer. The X-ray diffraction patterns of all films are dominated by the Al(l 11) and Nb(l 10) peaks and show a merging of these two peaks with decreasing periodicity.

Fabrication and study the effect of the laser on the properties of the compound Tl2-xHgxBa2-ySryCa2Cu3O10+δ superconductor

2018 ◽  
pp. 168
Author(s):  
A. Kareem Dahash Ali ◽  
Nihad Ali Shafeek
Keyword(s):  
Transition Temperature ◽  
Solid State ◽  
Hydrostatic Pressure ◽  
Electrical Properties ◽  
Co2 Laser ◽  
Temperature Shift ◽  
Unit Cell ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structural And Electrical Properties

This study included the fabrication of    compound (Tl2-xHgxBa2-ySryCa2Cu3O10+δ) in a manner solid state and under hydrostatic pressure ( 8 ton/cm2) and temperature annealing(850°C), and determine the effect of the laser on the structural and electrical properties elements in the compound, and various concentrations of x where (x= 0.1,0.2,0.3 ). Observed by testing the XRD The best ratio of compensation for x is 0.2 as the value of a = b = 5.3899 (A °), c = 36.21 (A °) show that the installation of four-wheel-based type and that the best temperature shift is TC= 142 K  .When you shine a CO2 laser on the models in order to recognize the effect of the laser on these models showed the study of X-ray diffraction of these samples when preparing models with different concentrations of the values ​​of x, the best ratio of compensation is 0.2 which showed an increase in the values ​​of the dimensions of the unit cell a=b = 5.3929 (A °), c = 36.238 (A°). And the best transition temperature after shedding laser is TC=144 K. 

New Copper Compounds with Antiplatelet Aggregation Activity

2019 ◽  
Vol 15 (8) ◽  
pp. 850-862
Author(s):  
Mirthala Flores-García ◽  
Juan Manuel Fernández-G. ◽  
Cristina Busqueta-Griera ◽  
Elizabeth Gómez ◽  
Simón Hernández-Ortega ◽  
...  
Keyword(s):  
Schiff Base ◽  
Solid State ◽  
Thrombotic Event ◽  
X Ray Diffraction ◽  
Nmr Studies ◽  
Schiff Base Ligands ◽  
X Ray ◽  
Antiplatelet Aggregation ◽  
Aggregation Activity ◽  
L1 And L2

Background: Ischemic heart disease, cerebrovascular accident, and venous thromboembolism have the presence of a thrombotic event in common and represent the most common causes of death within the population. Objective: Since Schiff base copper(II) complexes are able to interact with polyphosphates (PolyP), a procoagulant and potentially prothrombotic platelet agent, we investigated the antiplatelet aggregating properties of two novel tridentate Schiff base ligands and their corresponding copper( II) complexes. Methods: The Schiff base ligands (L1) and (L2), as well as their corresponding copper(II) complexes (C1) and (C2), were synthesized and characterized by chemical analysis, X-ray diffraction, mass spectrometry, and UV-Visible, IR and far IR spectroscopy. In addition, EPR studies were carried out for (C1) and (C2), while (L1) and (L2) were further analyzed by 1H and 13C NMR. Tests for antiplatelet aggregation activities of all of the four compounds were conducted. Results: X-ray diffraction studies show that (L1) and (L2) exist in the enol-imine tautomeric form with a strong intramolecular hydrogen bond. NMR studies show that both ligands are found as enol-imine tautomers in CDCl3 solution. In the solid state, the geometry around the copper(II) ion in both (C1) and (C2) is square planar. EPR spectra suggest that the geometry of the complexes is similar to that observed in the solid state by X-ray crystallography. Compound (C2) exhibited the strongest antiplatelet aggregation activity. Conclusion: Schiff base copper(II) complexes, which are attracting increasing interest, could represent a new approach to treat thrombosis by blocking the activity of PolyP with a potential anticoagulant activity and, most importantly, demonstrating no adverse bleeding events.

scholarly journals Quartz Crystallite Size and Moganite Content as Indicators of the Mineralogical Maturity of the Carboniferous Chert: The Case of Cherts from Eastern Asturias (Spain)

Minerals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 611
Author(s):  
Celia Marcos ◽  
María de Uribe-Zorita ◽  
Pedro Álvarez-Lloret ◽  
Alaa Adawy ◽  
Patricia Fernández ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Crystallite Size ◽  
Archaeological Sites ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Infrared And Raman Spectroscopy ◽  
First Time ◽  
Geological Formations

Chert samples from different coastal and inland outcrops in the Eastern Asturias (Spain) were mineralogically investigated for the first time for archaeological purposes. X-ray diffraction, X-ray fluorescence, transmission electron microscopy, infrared and Raman spectroscopy and total organic carbon techniques were used. The low content of moganite, since its detection by X-ray diffraction is practically imperceptible, and the crystallite size (over 1000 Å) of the quartz in these cherts would be indicative of its maturity and could potentially be used for dating chert-tools recovered from archaeological sites. Also, this information can constitute essential data to differentiate the cherts and compare them with those used in archaeological tools. However, neither composition nor crystallite size would allow distinguishing between coastal and inland chert outcrops belonging to the same geological formations.

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