Solid State Synthesis and Characterization of Tin-Based Low-Dimensional Materials

2002 ◽  
Vol 755 ◽  
Author(s):  
Tolulope O. Salami ◽  
Scott R. J. Oliver
Keyword(s):  
Variable Temperature ◽  
Layered Compounds ◽  
Layered Compound ◽  
X Ray Diffraction ◽  
Group 14 ◽  
Potential Applications ◽  
Low Dimensional ◽  
2D And 3D ◽  
Extended Materials

ABSTRACTWe report the synthetic conditions, physical properties and potential applications of late group 14 metal (Sn) 0D, 1D, 2D and 3D extended materials. The structures are primarily neutral chain and anionic layered compounds. The latter are charge-balanced by ammonium cations, as in and BING-7 [Sn(C2O4)F-] [NH4+] and BING-8 [Sn(PO4H)F-] [NH4+]. The neutral layered compound and chain compounds BING-1 [Na4Sn4(C2O4)F6], BING-2 [KSn(C2O4)F] and BING-4 [Sn(C2O4)(C5H5N)] have also been synthesized solvothermally. Thermogravimetric analysis (TGA) under nitrogen and in-situ variable temperature X-ray diffraction show that the materials decompose in the 200°C to 300°C range to more stable phases. Nuclear magnetic resonance (NMR) was used to monitor the ion-exchange properties of some of the materials. The intercalation properties of these materials are still being investigated.

W-Doped VO2 (M) with Tunable Phase Transition Temperature

2013 ◽  
Vol 320 ◽  
pp. 483-487 ◽  
Author(s):  
Ming Li ◽  
Deng Bing Li ◽  
Jing Pan ◽  
Guang Hai Li
Keyword(s):  
Electron Microscopy ◽  
Phase Transition ◽  
Transition Temperature ◽  
Phase Transition Temperature ◽  
Variable Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Infrared Transmittance ◽  
Transmission Electron ◽  
Potential Applications

W-doped VO2 (B) nanoneedles were successfully synthesized by solgel combing with hydrothermal treatment, in which the polyethylene glycol (PEG) was used as both surfactant and reducing. The metastable VO2 (B) was completely transformed to thermochromic VO2 (M) after annealing at high purity N2 atmosphere. The DSC results exhibit a strong crystallographic transition, and the phase transition temperature of VO2 (M) can be reduced to about 38 °C by W-doping. Field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HR-TEM) were used to characterize the morphology and crystalline structure of the samples. The variable-temperature infrared transmittance spectra of VO2 (M) demonstrate their potential applications in energy saving field.

Molecular motions of a tetraphenylethylene-derived AIEgen directly monitored through in situ variable temperature single crystal X-ray diffraction

CrystEngComm ◽  
2021 ◽  
Author(s):  
Wei Meng ◽  
Lin Du ◽  
Lin Sun ◽  
Lian Zhou ◽  
Xiaopeng Xuan ◽  
...  
Keyword(s):  
Single Crystal ◽  
Phenyl Ring ◽  
Functional Group ◽  
Variable Temperature ◽  
Molecular Motions ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
X Ray ◽  
Conformation Changes

One organic functional group was introduced to distinguish the four phenyl ring of tetraphenylethylene, and the In situ temperature-dependent crystal structures were determined to exhibit the conformation changes of tert-butyl...

scholarly journals High-temperature in situ crystallographic observation of reversible gas sorption in impermeable organic cages

2015 ◽  
Vol 112 (46) ◽  
pp. 14156-14161 ◽  
Author(s):  
Seung Bin Baek ◽  
Dohyun Moon ◽  
Robert Graf ◽  
Woo Jong Cho ◽  
Sung Woo Park ◽  
...  
Keyword(s):  
Single Crystal ◽  
High Temperatures ◽  
Direct Detection ◽  
Variable Temperature ◽  
Magic Angle Spinning ◽  
Magic Angle ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dynamic Motion

Crystallographic observation of adsorbed gas molecules is a highly difficult task due to their rapid motion. Here, we report the in situ single-crystal and synchrotron powder X-ray observations of reversible CO2 sorption processes in an apparently nonporous organic crystal under varying pressures at high temperatures. The host material is formed by hydrogen bond network between 1,3,5-tris-(4-carboxyphenyl)benzene (H3BTB) and N,N-dimethylformamide (DMF) and by π–π stacking between the H3BTB moieties. The material can be viewed as a well-ordered array of cages, which are tight packed with each other so that the cages are inaccessible from outside. Thus, the host is practically nonporous. Despite the absence of permanent pathways connecting the empty cages, they are permeable to CO2 at high temperatures due to thermally activated molecular gating, and the weakly confined CO2 molecules in the cages allow direct detection by in situ single-crystal X-ray diffraction at 323 K. Variable-temperature in situ synchrotron powder X-ray diffraction studies also show that the CO2 sorption is reversible and driven by temperature increase. Solid-state magic angle spinning NMR defines the interactions of CO2 with the organic framework and dynamic motion of CO2 in cages. The reversible sorption is attributed to the dynamic motion of the DMF molecules combined with the axial motions/angular fluctuations of CO2 (a series of transient opening/closing of compartments enabling CO2 molecule passage), as revealed from NMR and simulations. This temperature-driven transient molecular gating can store gaseous molecules in ordered arrays toward unique collective properties and release them for ready use.

Synthesis of Ultra-Thin Superhydrophilic Titanium Oxide Film and its Effects on the Capillary of Microchannels

2010 ◽  
Author(s):  
Min Zhang ◽  
Bo Zhang ◽  
Tianhong Cui
Keyword(s):  
Titanium Oxide ◽  
Sol Gel ◽  
Nitrogen Atmosphere ◽  
Tio2 Films ◽  
Titanium Tetraisopropoxide ◽  
X Ray Diffraction ◽  
Before And After ◽  
Potential Applications ◽  
Temperature Surface

Ultra-thin superhydrophilic titanium oxide films were fabricated on silicon microchannels by an in situ reaction sol-gel method using titanium tetraisopropoxide as a starting material.. By changing the concentration of water in ethanol and reaction time, the thickness of synthesized TiO2 films can be controlled from around 10 nm to 80 nm. The contact angle of as-synthesized TiO2 films on flat silicon is around 20° and can be further decreased to zero by calcination at 700 °C in nitrogen atmosphere. X-ray diffraction spectra show the microstructure of the TiO2 films changed gradually from amorphous to anatase with the increase of calcination temperature. Surface morphology of the film before and after calcination also shows that a smoother coating with crystal structure was obtained by heat treatment. The flow velocity in the TiO2 coated channel reached around 0.03 m/s, almost ten times of that in PDDA/PSS coated channel and 4 times of that in SiO2 coated one. The ultra-thin superhydrophilic TiO2 films fabricated by this method show the ability to strongly increase the wettability of microchannels without affecting the morphology of the sidewall of the channels, indicating potential applications to biomolecule analysis and surface tension driven microfluidic systems.

scholarly journals Study of the textural properties of some layered double hydroxides

2013 ◽  
Vol 21 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Cornelia-Magda Puscasu ◽  
Carmen Gherasim ◽  
Dragos Mardare ◽  
Gabriela Carja
Keyword(s):  
Layered Double Hydroxides ◽  
Structural Characteristics ◽  
Chemical Species ◽  
Textural Properties ◽  
Layered Compounds ◽  
Layered Compound ◽  
X Ray Diffraction ◽  
Anionic Clays ◽  
Interlayer Region ◽  
Double Hydroxides

Abstract Layered double hydroxides (LDHs) are one of the nano ordered layered compounds. The importance of layered compound is based on their ability to retain chemical species with electrical charges compatible to those of the layers. They may be used in areas such as catalysis, industry, medicine, environmental protection, construction etc. Layered double hydroxides are anionic clays comprising positively charged layers with anions and water molecules intercalated in the interlayer region. The aim of this work was to obtain Cu and/or Ni substituted layered double hydroxides with different micromorphology characteristics. The obtained results pointed out that the relationship between LDHs composition and their textural properties can be controlled. The layered double hydroxides samples were fabricated by using direct coprecipitation method. Field Emission Scanning Electron Microscope (FE-SEM) and X-Ray Diffraction (XRD) analyses were used to study the textural characteristics and the structural characteristics of the samples.

Tautomeric polymorphism of the neuroactive inhibitor kynurenic acid

2019 ◽  
Vol 75 (6) ◽  
pp. 793-805
Author(s):  
Dorota Pogoda ◽  
Jan Janczak ◽  
Sylwia Pawlak ◽  
Michael Zaworotko ◽  
Veneta Videnova-Adrabinska
Keyword(s):  
Solid State ◽  
Kynurenic Acid ◽  
Variable Temperature ◽  
Neurological Diseases ◽  
Crystal Form ◽  
Phase Behaviour ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray

Kynurenic acid (KYN; systematic name: 4-hydroxyquinoline-2-carboxylic acid, C10H7NO3) displays a therapeutic effect in the treatment of some neurological diseases and is used as a broad-spectrum neuroprotective agent. However, it is understudied with respect to its solid-state chemistry and only one crystal form (α-KYN·H2O) has been reported up to now. Therefore, an attempt to synthesize alternative solid-state forms of KYN was undertaken and six new species were obtained: five solvates and one salt. One of them is a new polymorph, β-KYN·H2O, of the already known KYN monohydrate. All crystal species were further studied by single-crystal and powder X-ray diffraction, thermal and spectroscopic methods. In addition to the above methods, differential scanning calorimetry (DSC), in-situ variable-temperature powder X-ray diffraction and Raman microscopy were applied to characterize the phase behaviour of the new forms. All the compounds display a zwitterionic form of KYN and two different enol–keto tautomers are observed depending on the crystallization solvent used.

Synthesis and Molecular Structures of 2-Trimethylsilyl-, 2-Trimethylgermyl-, and 2-Trimethylstannyl-pyridines

1999 ◽  
Vol 54 (1) ◽  
pp. 13-17 ◽  
Author(s):  
Frank Riedmiller ◽  
Alexander Jockisch ◽  
Hubert Schmidbaur
Keyword(s):  
Quantum Chemical ◽  
Crystal And Molecular Structure ◽  
Variable Temperature ◽  
Intrinsic Property ◽  
Molecular Structures ◽  
Grignard Reaction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nitrogen Heteroatom

5-Methyl-2-trimethylsilyl-pyridine (1) has recently been prepared via the “in situ” Grignard reaction of 1-bromo-5-methyl-pyridine with magnesium and trimethylchlorosilane in refluxing tetrahydrofuran (thf) and structurally characterized. 2-Trimethylgermyl- (2) and 2- trimethylstannyl-pyridine (3) were now obtained from 2-bromo-pyridine through metallation (with n-BuLi) and treatment of the intermediates with Me3GeBr and Me3SnCl, respectively, in diethylether/ thf at -70°C. The crystal and molecular structure of compound 2 has been determined by low temperature (in situ) single crystal X-ray diffraction methods. There is a significant bending of the Me3Ge substituent towards the nitrogen heteroatom [Ge-C-N = 114.7(2)°]. This phenomenon is known from previous studies of the silicon analogue 1 to be not due to intramolecular (peripheral) Si/Ge←N coordination, but to be rather an intrinsic property of the heteroarene skeleton, as also confirmed by quantum-chemical calculations. Furthermore, there is no evidence for intermolecular coordination in the crystals. Such interactions could also be ruled out for the solution state of 2 and 3 through variable temperature multinuclear NMR investigations.

scholarly journals In situ variable-temperature single crystal X-ray diffraction studies of the single-crystal-to-single-crystal dehydration and rehydration of a mixed-ligand 2D zinc metal–organic framework using trimesate and 4,4′-bipyridine-N,N′-dioxide as ligands

CrystEngComm ◽  
2015 ◽  
Vol 17 (46) ◽  
pp. 8946-8956 ◽  
Author(s):  
Tayyibah Tahier ◽  
Clive L. Oliver
Keyword(s):  
Single Crystal ◽  
Variable Temperature ◽  
Metal Organic Framework ◽  
Mixed Ligand ◽  
Water Molecules ◽  
X Ray Diffraction ◽  
Metal Organic ◽  
Reversible Loss ◽  
Coordinated Water

A mixed-ligand 2D MOF based on ZnSO4, trimesate and 4,4′-bipyridine-N,N′-dioxide shows reversible loss of uncoordinated and coordinated water molecules.

scholarly journals Intercalates of Bi2Se3 Studied in Situ by Time-Resolved Powder X-ray Diffraction and Neutron Diffraction

2020 ◽  
Author(s):  
Machteld Kamminga ◽  
Simon J. Cassidy ◽  
Partha P. Jana ◽  
Nicola D. Kelly ◽  
Simon J. Clarke
Keyword(s):  
Neutron Diffraction ◽  
Layered Compound ◽  
Bismuth Selenide ◽  
X Ray Diffraction ◽  
Layered Semiconductor ◽  
Time Resolved ◽  
Lithium Amide ◽  
X Ray

<div>Intercalation of lithium and ammonia into the layered semiconductor Bi2Se3 proceeds via a</div><div>hyperextended (by > 60 %) ammonia-rich intercalate, to eventually produce a layered compound</div><div>with lithium amide intercalated between the bismuth selenide layers which offer scope for further</div><div>chemical manipulation.</div>

Endohedral group-14-element clusters TM@E9 (TM = Co, Ni, Cu; E = Ge, Sn, Pb) and their low-dimensional nanostructures: A first-principles study

2021 ◽  
Author(s):  
Xintian Zhao ◽  
Gerui Pei ◽  
Song Xu ◽  
Chuncai Kong ◽  
Zhimao Yang ◽  
...  
Keyword(s):  
Transition Metal ◽  
First Principles ◽  
Group 14 ◽  
First Principles Study ◽  
Group 14 Elements ◽  
Potential Applications ◽  
Low Dimensional

The endohedral group-14-based clusters with the encapsulation of transition metal, which are termed as [TM@Em]n- (TM = transition metal, E = group-14 elements), have lots of potential applications and have...

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