The synthesis: Structure relationship in the ZnO-Cr2O3 system

In this work the development of the spinel phase in the ZnO-Cr2O3 system was discussed from the viewpoint of the synthesis-structure relationship. The nanostructure evolution in particles obtained either via solution-based (spray pyrolysis) or solid-state (mechanical activation) synthesis procedures were investigated by XRD analysis. A detailed structural analysis of the spinel phase lattice parameters, average primary crystallite sizes and micro strains were performed in accordance with a procedure based on the Koalariet-Xfit program. Due to the importance of spinel-phase cat ion distribution for chemical and physical properties, a study of the site occupation factors, i.e. changes in the stoichiometric, of ZnCr2O4 spinals was undertaken. The calculation based on atomistic methods for the description of both perfect and defect spinel ZnCr2O4 crystal lattices has been applied and the presence of individual structural defects was determined.

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Building solids inside nano-space: from confined amorphous through confined solvate to confined ‘metastable’ polymorph

Physical Chemistry Chemical Physics ◽

10.1039/c5cp03880d ◽

2015 ◽

Vol 17 (38) ◽

pp. 24761-24773 ◽

Cited By ~ 15

Author(s):

K. P. Nartowski ◽

J. Tedder ◽

D. E. Braun ◽

L. Fábián ◽

Y. Z. Khimyak

Keyword(s):

Solid State ◽

Structural Analysis ◽

Mesoporous Silicas ◽

Detailed Structural Analysis ◽

Pharmaceutical Molecules

The detailed structural analysis and the control of solid state transformations of encapsulated pharmaceutical molecules inside the pores of mesoporous silicas are demonstrated.

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A bis-Au(III) [28]hexaphyrin triphenylphosphine adduct

Journal of Porphyrins and Phthalocyanines ◽

10.1142/s1088424616500097 ◽

2016 ◽

Vol 20 (08n11) ◽

pp. 997-1001 ◽

Cited By ~ 3

Author(s):

Koji Naoda ◽

Atsuhiro Osuka

Keyword(s):

Solid State ◽

Structural Analysis ◽

Trifluoroacetic Acid ◽

X Ray Diffraction ◽

Nmr Spectrum ◽

X Ray ◽

H Nmr ◽

Detailed Structural Analysis ◽

Nir Absorption ◽

Plausible Mechanism

Triphenylphosphine was added regioselectively at the C(3) position of bis-Au(III) complex of [26]hexaphyrin 5 in the presence of trifluoroacetic acid to produce [28]hexaphyrin triphenylphosphine adduct 6 in 62% yield, which has been fully characterized by NMR, UV-vis/NIR absorption, and MS spectroscopies, and X-ray diffraction analysis. The rigid planar structure forces 6 to take Hückel antiaromaticity, which has been supported by its 1H NMR spectrum. Curiously, the detailed structural analysis elucidated that the triphenylphosphine moiety exists as a phosphorane form in the solid state. A plausible mechanism via a double protonated 5 is proposed, which can explain the observed regioselectivity.

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Taking Advantage of Ortho- and Peri-Substitution to Design Original 9-Membered P,O,Si-Heterocycles

10.26434/chemrxiv.14302520.v1 ◽

2021 ◽

Author(s):

Thomas Delouche ◽

Elsa Caytan ◽

Cassandre Quinton ◽

Thierry Roisnel ◽

Marie Cordier ◽

...

Keyword(s):

Solid State ◽

Structural Analysis ◽

Synthetic Method ◽

Phosphine Oxides ◽

X Ray ◽

Detailed Structural Analysis

A family of 9 cyclic phosphine-disiloxane featuring peri-substituted naphthyl(Nap)/acenaphthyl(Ace) scaffolds have been prepared and fully characterized including X-ray structure, which allows a detailed structural analysis. This straightforward synthesis takes advantage of both ortho- and peri-substitution of Nap/Ace-substituted phosphine oxides. The synthetic method allows diversifying the polyaromatic platform (Nap and Ace) as well as the Si substituents (Me and Ph). Despite a strong steric congestion, the P-atom remains reactive toward oxidation or coordination. In particular, Au(I) complex could be prepared. All the compounds display absorption/luminescence in the UV-Vis range. Surprisingly, the P-trivalent derivatives display unexpected luminescence in the green in solid-state.

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Taking Advantage of Ortho- and Peri-Substitution to Design Original 9-Membered P,O,Si-Heterocycles

10.26434/chemrxiv.14302520 ◽

2021 ◽

Author(s):

Thomas Delouche ◽

Elsa Caytan ◽

Cassandre Quinton ◽

Thierry Roisnel ◽

Marie Cordier ◽

...

Keyword(s):

Solid State ◽

Structural Analysis ◽

Synthetic Method ◽

Phosphine Oxides ◽

X Ray ◽

Detailed Structural Analysis

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Adsorptive and Photocatalytic Properties of Green Synthesized ZnO and ZnO/NiFe2O4 Nanocomposites for Tannery Wastewater Treatment

Nigerian Journal of Technological Development ◽

10.4314/njtd.v17i4.10 ◽

2021 ◽

Vol 17 (4) ◽

pp. 312-322

Author(s):

J.O. Tijani ◽

U.A. Aminu ◽

M.T. Bankole ◽

M.M. Ndamitso ◽

A.S. Abdulkareem

Keyword(s):

Electron Microscope ◽

High Resolution ◽

Spinel Phase ◽

Oxygen Demand ◽

Xrd Analysis ◽

Catalytic Performance ◽

Tannery Wastewater ◽

Bet Analysis ◽

Crystallite Sizes ◽

Analytical Tools

This study investigated adsorptive and catalytic behaviour of ZnO and ZnO/NiFe2O4 nanocomposites for the removal and degradation of organic pollutants in tannery wastewater. ZnO and ZnO/NiFe2O4 nanomaterials were synthesized via a green method using Zn, Fe and Ni salts precursor and leaves extract of Anacardium occidentale (linn.). Subsequently, the synthesized samples were characterized by different analytical tools. The adsorptive and catalytic performance of the prepared nanomaterial were assessed using reduction in Chemical Oxygen Demand (COD), Biochemical Oxygen Demand (BOD) and Total Organic Carbon (TOC) in tannery wastewater as indicator parameters. High Resolution Scanning Electron Microscope (HRSEM), High Resolution Transmission Electron Microscope (HRTEM), and X-Ray Diffraction (XRD) analysis of ZnO and ZnO/NiFe2O4 confirmed the formation of hexagonal wurtzite nanoparticle and cubic spinel phase with an average crystallite sizes in the range of 13- 28 nm and 30.44 – 42.53 nm respectively. XRD analysis confirmed no change in the polymorph of ZnO upon the addition NiFe2O4. XPS spectrum showed the existence of the elements in the following oxidation state (+2) for Zn, (+1, +2) for Ni and (+2 and +3) for Fe. BET analysis revealed order of the specific surface area of ZnO/NiFe2O4 (44.61 m2/g) > NiFe2O4 (40.39 m2/g) > ZnO (8.91 m2 /g). The adsorptive and photocatalytic results revealed that 3% ZnO/NiFe2O4 exhibits higher efficiency compared to ZnO and NiFe2O4 nanoparticles alone and in the order of 3% ZnO/NiFe2O4 > NiFe2O4 > ZnO. The study revealed that the prepared nanomaterial behaved better as photocatalyst than as nanoadsorbent. Keywords: Adsorption, photocatalytic technology; ZnO; ZnO/NiFe2O4, tannery wastewater

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Structural Analysis of Slag and Cement Materials by Solid-state NMR

Concrete Journal ◽

10.3151/coj.56.5_454 ◽

2018 ◽

Vol 56 (5) ◽

pp. 454-459

Author(s):

T. Takahashi ◽

T. Ohkubo ◽

K. Kanehashi

Keyword(s):

Solid State ◽

Structural Analysis ◽

Solid State Nmr

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Chemical Modification of Combusted Coal Gangue for U(VI) Adsorption: Towards a Waste Control by Waste Strategy

Sustainability ◽

10.3390/su13158421 ◽

2021 ◽

Vol 13 (15) ◽

pp. 8421

Author(s):

Yuan Gao ◽

Jiandong Huang ◽

Meng Li ◽

Zhongran Dai ◽

Rongli Jiang ◽

...

Keyword(s):

Structural Analysis ◽

High Efficiency ◽

Low Cost ◽

Chemical Activation ◽

Cost Effective ◽

Coal Gangue ◽

Order Kinetic ◽

Practical Applications ◽

Detailed Structural Analysis ◽

Alkaline Conditions

Uranium mining waste causes serious radiation-related health and environmental problems. This has encouraged efforts toward U(VI) removal with low cost and high efficiency. Typical uranium adsorbents, such as polymers, geopolymers, zeolites, and MOFs, and their associated high costs limit their practical applications. In this regard, this work found that the natural combusted coal gangue (CCG) could be a potential precursor of cheap sorbents to eliminate U(VI). The removal efficiency was modulated by chemical activation under acid and alkaline conditions, obtaining HCG (CCG activated with HCl) and KCG (CCG activated with KOH), respectively. The detailed structural analysis uncovered that those natural mineral substances, including quartz and kaolinite, were the main components in CCG and HCG. One of the key findings was that kalsilite formed in KCG under a mild synthetic condition can conspicuous enhance the affinity towards U(VI). The best equilibrium adsorption capacity with KCG was observed to be 140 mg/g under pH 6 within 120 min, following a pseudo-second-order kinetic model. To understand the improved adsorption performance, an adsorption mechanism was proposed by evaluating the pH of uranyl solutions, adsorbent dosage, as well as contact time. Combining with the structural analysis, this revealed that the uranyl adsorption process was mainly governed by chemisorption. This study gave rise to a utilization approach for CCG to obtain cost-effective adsorbents and paved a novel way towards eliminating uranium by a waste control by waste strategy.

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Oligosilanylated Silocanes

Molecules ◽

10.3390/molecules26010244 ◽

2021 ◽

Vol 26 (1) ◽

pp. 244

Author(s):

Mohammad Aghazadeh Meshgi ◽

Alexander Pöcheim ◽

Judith Baumgartner ◽

Viatcheslav V. Jouikov ◽

Christoph Marschner

Keyword(s):

Cyclic Voltammetry ◽

Solid State ◽

Xrd Analysis ◽

29Si Nmr ◽

Single Crystal Xrd ◽

Substitution Pattern ◽

Silyl Group ◽

Steric Factors ◽

Single Crystal Xrd Analysis ◽

29Si Nmr Spectroscopy

A number of mono- and dioligosilanylated silocanes were prepared. Compounds included silocanes with 1-methyl-1-tris(trimethylsilyl)silyl, 1,1-bis[tris(trimethylsilyl)silyl], and 1,1-bis[tris(trimethylsilyl)germyl] substitution pattern as well as two examples where the silocane silicon atom is part of a cyclosilane or oxacyclosilane ring. The mono-tris(trimethylsilyl)silylated compound could be converted to the respective silocanylbis(trimethylsilyl)silanides by reaction with KOtBu and in similar reactions the cyclosilanes were transformed to oligosilane-1,3-diides. However, the reaction of the 1,1-bis[tris(trimethylsilyl)silylated] silocane with two equivalents of KOtBu leads to the replacement of one tris(trimethylsilyl)silyl unit with a tert-butoxy substituent followed by silanide formation via KOtBu attack at one of the SiMe3 units of remaining tris(trimethylsilyl)silyl group. For none of the silylated silocanes, signs of hypercoordinative interaction between the nitrogen and silicon silocane atoms were detected either in the solid state. by single crystal XRD analysis, nor in solution by 29Si-NMR spectroscopy. This was further confirmed by cyclic voltammetry and a DFT study, which demonstrated that the N-Si distance in silocanes is not only dependent on the energy of a potential N-Si interaction, but also on steric factors and through-space interactions of the neighboring groups at Si and N, imposing the orientation of the pz(N) orbital relative to the N-Si-X axis.

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