scholarly journals Нефелоксетический эффект в нанокристаллах ZnAl-=SUB=-2-=/SUB=-O-=SUB=-4-=/SUB=-:Cr-=SUP=-3+-=/SUP=-, обусловленный их размером

2022 ◽  
Vol 130 (1) ◽  
pp. 130
Author(s):  
Deren P.J ◽  
Watras A. ◽  
Stefanska D.
Keyword(s):  
Size Effect ◽  
Crystallite Size ◽  
Hydrothermal Method ◽  
Spectroscopic Properties ◽  
Unit Cell ◽  
Chromium Ions ◽  
Nephelauxetic Effect ◽  
First Time

ZnAl2O4 nanocrystallites doped with Cr3+ ions with mean sizes ranging from 2 to 16 nm were synthesized by the hydrothermal method. Chromium ions occupy the aluminum positions, which symmetry depends on the crystallite size. The smallest nanocrystals have a much larger unit cell than the bigger ones. The metal to ligand distance increases when the size of the nanocrystals decreases. This causes the nephelauxetic effect, which is for the first time (to our knowledge) observed as a size effect. It was also observed that ZnAl2O4: Cr3+ nanocrystals with size larger than 10 nm possesses the same spectroscopic properties as monocrystal.

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.

Five-coordinate copper(II) complexes: crystal structures, spectroscopic properties and new extended structural pathways of [Cu(chelate)2 X]Y, where chelate = dpyam, phen and bipy; X = pseudohalide ligands

2008 ◽  
Vol 64 (3) ◽  
pp. 318-329 ◽  
Author(s):  
Sujittra Youngme ◽  
Pongthipun Phuengphai ◽  
Chaveng Pakawatchai ◽  
Palangpon Kongsaeree ◽  
Narongsak Chaichit
Keyword(s):  
Crystal Structure ◽  
Size Effect ◽  
Crystal Structures ◽  
Direct Observation ◽  
Spectroscopic Properties ◽  
Modes Of Vibration

The crystal structures of four distortion isomers of the [Cu(chelate)2 X]+ cation, where chelate = 2,2-bipyridine (bipy), 1,10-phenanthroline (phen) and di-2-pyridylamine (dpyam), X = a pseudohalide ligand (NCO, NCS, N3 and C2N3), have been compared by scatterplot analysis with 25 [Cu(chelate)2 X]Y complexes of known crystal structure. The four new complexes [Cu(phen)2NCO]Br (1), [Cu(phen)2N3]BPh4·H2O (2), [Cu(dpyam)2(N3)]NO3·H2O (3) and [Cu(dpyam)2(N3)]ClO4 (4) involve a near regular square-based pyramidal stereochemistry (RSBP). The structures of complexes (1) and (2) are of the rare cases found for the phen analogue. Scatterplots of the 29 cation distortion isomers of the [Cu(chelate)2 X]Y series of complexes suggest that most of the 29 complexes lie on a common structural pathway, involving a mixture of the symmetric, C 2, and the asymmetric, non-C 2, in-plane modes of vibration of the CuN4N′ chromophore. Some datapoints are found to lie on extended routes The resulting structural pathways are consistent with the direct observation of the effect of the modes of vibration on the stereochemistries of the complexes. A comparison of the trends in the 29 datasets suggests a size effect of the phen, bipy and dpyam ligands.

Crystallite size effect of Pd/charcoal catalysts for benzene hydrogenation

1980 ◽  
Vol 13 (3) ◽  
pp. 291-295 ◽  
Author(s):  
A. Benedetti ◽  
G. Cocco ◽  
S. Enzo ◽  
F. Pinna
Keyword(s):  
Size Effect ◽  
Crystallite Size ◽  
Benzene Hydrogenation ◽  
Effect Of Pd

Growth, thermal, and spectroscopic properties of a 2.911 μm Yb,Ho:GdYTaO4 laser crystal

CrystEngComm ◽  
2014 ◽  
Vol 16 (48) ◽  
pp. 11007-11012 ◽  
Author(s):  
Renqin Dou ◽  
Qingli Zhang ◽  
Dunlu Sun ◽  
Jianqiao Luo ◽  
Huajun Yang ◽  
...  
Keyword(s):  
Laser Crystal ◽  
Czochralski Method ◽  
Spectroscopic Properties ◽  
First Time

A promising 2.911 μm Yb,Ho:GdYTaO4 laser crystal was grown successfully by the Czochralski method for the first time.

Synthesis of α-Fluoro-β-lactones and Their Thermal Conversion to 1-Fluoroalkenes

2002 ◽  
Vol 67 (9) ◽  
pp. 1325-1334 ◽  
Author(s):  
Rogelio Ocampo ◽  
William R. Dolbier ◽  
Fabio Zuluaga
Keyword(s):  
Spectroscopic Properties ◽  
Thermal Conversion ◽  
Hydroxy Acids ◽  
Preliminary Results ◽  
First Time

α-Fluoro-β-lactones have been synthesized and isolated for the first time from α-fluoro-β-hydroxy acids by using the couple TsCl/DMAP as lactonization agent. A detailed description of the synthesis and spectroscopic properties of α-fluoro-β-lactones is presented. Preliminary results indicate that thermolysis of these new β-lactones produces 1-fluoroalkenes.

Exploration of K2Ti8O17 as an anode material for potassium-ion batteries

2016 ◽  
Vol 52 (75) ◽  
pp. 11274-11276 ◽  
Author(s):  
Jin Han ◽  
Maowen Xu ◽  
Yubin Niu ◽  
Guan-Nan Li ◽  
Minqiang Wang ◽  
...  
Keyword(s):  
Hydrothermal Method ◽  
Anode Material ◽  
Annealing Treatment ◽  
Potassium Ion ◽  
Subsequent Annealing ◽  
Facile Hydrothermal Method ◽  
First Time

Novel K2Ti8O17 is successfully fabricated via a facile hydrothermal method combined with a subsequent annealing treatment and further evaluated as an anode material for potassium-ion batteries for the first time.

scholarly journals Анизотропия анионной проводимости в монокристаллах суперионного проводника CeF-=SUB=-3-=/SUB=-

2021 ◽  
Vol 63 (9) ◽  
pp. 1376
Author(s):  
Н.И. Сорокин ◽  
В.В. Гребенев ◽  
Д.Н. Каримов
Keyword(s):  
Electrical Conductivity ◽  
Atomic Structure ◽  
Unit Cell ◽  
Conductivity Measurements ◽  
Weak Anisotropy ◽  
Tysonite Structure ◽  
Maximum Value ◽  
Anisotropy Effect ◽  
First Time ◽  
Anionic Conductivity

The anisotropy of anionic conductivity in crystals of a superionic conductor CeF3 with the tysonite structure (sp. gr. P-3с1) has been studied for the first time. The conductivity measurements at temperatures from 300 K to 600 K were carried out along the principal a- and c-axes of trigonal unit cell of the crystal. The maximum value of electrical conductivity is observed along the c-axis. The superionic CeF3 crystals have the weak anisotropy of electrical conductivity equal to σ||c/σ||a = 2.4 and σ||c = 5.6 10–4 S/cm at 500 K. The anisotropy effect of anionic conductivity in individual fluorides with the tysonite structure is discussed in connection with the peculiarities of their atomic structure.

A phthalocyanine–subphthalocyanine heterodinuclear dimer: comparison of spectroscopic properties with those of homodinuclear dimers of constituting units

2014 ◽  
Vol 50 (23) ◽  
pp. 3040-3043 ◽  
Author(s):  
Norio Shibata ◽  
Satoru Mori ◽  
Masamichi Hayashi ◽  
Masashi Umeda ◽  
Etsuko Tokunaga ◽  
...  
Keyword(s):  
Spectroscopic Properties ◽  
X Ray ◽  
X Ray Crystallography ◽  
First Time

A phthalocyanine–subphthalocyanine heterodinuclear dimer has been disclosed for the first time with its unique flat-bowl-shaped structure revealed by X-ray crystallography.

Template-free synthesis of hierarchical γ-Al2O3 nanostructures and their adsorption affinity toward phenol and CO2

RSC Advances ◽  
2015 ◽  
Vol 5 (10) ◽  
pp. 7066-7073 ◽  
Author(s):  
Weiquan Cai ◽  
Yuzhen Hu ◽  
Jiaguo Yu ◽  
Wenguang Wang ◽  
Jiabin Zhou ◽  
...  
Keyword(s):  
Hydrothermal Method ◽  
Adsorption Performance ◽  
Adsorption Affinity ◽  
Template Free ◽  
Enhanced Adsorption ◽  
First Time

Hierarchical γ-Al2O3 nanostructures with tunable morphologies, and enhanced adsorption performance towards phenol and CO2 were synthesized for the first time by a facile template-free hydrothermal method using thiourea as precipitating agent.

scholarly journals Nanorod-assembled NiCo2O4 hollow microspheres assisted by an ionic liquid as advanced electrode materials for supercapacitors

RSC Advances ◽  
2017 ◽  
Vol 7 (18) ◽  
pp. 11123-11128 ◽  
Author(s):  
Yirong Zhu ◽  
Xiaobo Ji ◽  
Ruiming Yin ◽  
Zhongliang Hu ◽  
Xiaoqing Qiu ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Hydrothermal Method ◽  
Electrode Materials ◽  
Hollow Microspheres ◽  
First Time

In this work, nanorod-assembled NiCo2O4 hollow microspheres have been successfully prepared by an ionic liquid-assisted hydrothermal method for the first time.

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