scholarly journals Tetrathiafulvalene: A Gate to the Mechanochemical Mechanisms of Electron Transfer Reactions

Crystals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 482
Author(s):  
Richard Chen ◽  
Mehmet Kerem Gokus ◽  
Silvina Pagola
Keyword(s):  
Mechanochemical Synthesis ◽  
Amorphous Material ◽  
In Situ Monitoring ◽  
Ex Situ ◽  
Mechanochemical Reaction ◽  
Charge Transfer Complexes ◽  
Spectroscopic Techniques ◽  
Diffusion Controlled ◽  
Mechanochemical Reactions

This report describes aspects of our previous studies of the mechanochemical synthesis of charge transfer complexes of the electron donor tetrathiafulvalene, which are relevant to the use of laboratory X-ray powder diffraction for ex situ monitoring of mechanochemical reactions toward investigating their mechanisms. In particular, the reaction of tetrathiafulvalene and chloranil was studied under neat mechanochemical conditions and liquid-assisted grinding with diethyl ether (1 μL/mg). The product in both cases is the green tetrathiafulvalene chloranil polymorph and the mechanism of the redox reaction is presumably the same. However, while the kinetic profile of the neat mechanochemical synthesis was fitted with a second-order rate law, that of the overall faster liquid-assisted grinding reaction was fitted with the Ginstling-Brounshtein 3D diffusion-controlled model. Hence, the diffusional processes and mass transfer bringing the reactants together and separating them from products must be different. Diffraction measurements sensitive to crystalline phases and amorphous material, combined with in situ monitoring by spectroscopic techniques, will ultimately afford a better understanding of mechanochemical reaction mechanisms, a hot topic in mechanochemistry.

scholarly journals In situ monitoring of mechanochemical synthesis of calcium urea phosphate fertilizer cocrystal reveals highly effective water-based autocatalysis

2020 ◽  
Vol 11 (9) ◽  
pp. 2350-2355 ◽  
Author(s):  
Patrick A. Julien ◽  
Luzia S. Germann ◽  
Hatem M. Titi ◽  
Martin Etter ◽  
Robert E. Dinnebier ◽  
...  
Keyword(s):  
Mechanochemical Synthesis ◽  
Phosphate Fertilizer ◽  
In Situ Monitoring ◽  
Mechanochemical Reaction ◽  
Quantitative Investigation ◽  
Urea Phosphate ◽  
Water Based ◽  
Highly Effective ◽  
Effective Water

Using the mechanosynthesis of the fertilizer cocrystal calcium urea phosphate as a model, we provide a quantitative investigation of chemical autocatalysis in a mechanochemical reaction.

scholarly journals Real-Time in Situ Monitoring of Particle and Structure Evolution in Mechanochemical Synthesis of UiO-66 Metal-Organic Framework

2019 ◽  
Author(s):  
Luzia S. Germann ◽  
Athanassios D. Katsenis ◽  
Igor Huskić ◽  
Patrick A. Julien ◽  
Krunoslav Uzarevic ◽  
...  
Keyword(s):  
Metal Organic Framework ◽  
Model System ◽  
In Situ Monitoring ◽  
Mechanochemical Reaction ◽  
Structure Evolution ◽  
X Ray ◽  
Framework Model ◽  
Metal Organic ◽  
Organic Framework

Manuscript about monitoring the mechanochemical reaction of a metal-organic framework model system by in situ X-ray powder diffraction<br>

scholarly journals Real-Time in Situ Monitoring of Particle and Structure Evolution in Mechanochemical Synthesis of UiO-66 Metal-Organic Framework

2019 ◽  
Author(s):  
Luzia S. Germann ◽  
Athanassios D. Katsenis ◽  
Igor Huskić ◽  
Patrick A. Julien ◽  
Krunoslav Uzarevic ◽  
...  
Keyword(s):  
Metal Organic Framework ◽  
Model System ◽  
In Situ Monitoring ◽  
Mechanochemical Reaction ◽  
Structure Evolution ◽  
X Ray ◽  
Framework Model ◽  
Metal Organic ◽  
Organic Framework

Manuscript about monitoring the mechanochemical reaction of a metal-organic framework model system by in situ X-ray powder diffraction<br>

scholarly journals Synthesis, characterization and in situ monitoring of the mechanochemical reaction process of two manganese(II)-phosphonates with N-containing ligands

2018 ◽  
Vol 53 (19) ◽  
pp. 13390-13399 ◽  
Author(s):  
Irina Akhmetova ◽  
Konstantin Schutjajew ◽  
Manuel Wilke ◽  
Ana Buzanich ◽  
Klaus Rademann ◽  
...  
Keyword(s):  
In Situ Monitoring ◽  
Reaction Process ◽  
Mechanochemical Reaction

Applications of Synchrotron Surface X-Ray Scattering Studies of Electrochemical Interfaces

MRS Bulletin ◽  
1999 ◽  
Vol 24 (1) ◽  
pp. 36-40 ◽  
Author(s):  
Hoydoo You ◽  
Zoltán Nagy
Keyword(s):  
Surface Science ◽  
Region Of Interest ◽  
Atomic Layer ◽  
Living Environment ◽  
Ex Situ ◽  
Spectroscopic Techniques ◽  
Engineering Research ◽  
Significant Intensity ◽  
Electrochemical Interfaces

Aqueous-solution/solid interfaces are ubiquitous in modern manufacturing environments as well as in our living environment, and studies of such interfaces are an active area of science and engineering research. An important area is the study of liquid/solid interfaces under active electrochemical control, which has many immediate technological implications, for example, corrosion/passivation of metals and energy storage in batteries and ultracapacitors. The central phenomenon of electrochemistry is the charge transfer at the interface, and the region of interest is usually wider than a single atomic layer, ranging from a monolayer to thousands of angstroms, extending into both phases.Despite the technological and environmental importance of liquid/solid interfaces, the atomic level understanding of such interfaces had been very much hampered by the absence of nondestructive, in situ experimental techniques. The situation has changed somewhat in recent decades with the development of the largely ex situ ultrahigh vacuum (UHV) surface science, modern spectroscopic techniques, and modern surface microscopy.However in situ experiments of electrochemical interfaces are difficult, stemming from the special nature of these interfaces. These are so-called buried interfaces in which the solid electrode surface is covered by a relatively thick liquid layer. For this reason, the probe we use in the structural investigation must satisfy simultaneously two conditions: (1) the technique must be surface/interface sensitive, and (2) absorption of the probe in the liquid phase must be sufficiently small for penetration to and from the interface of interest without significant intensity loss.

scholarly journals In-situ monitoring and ex-situ elasticity mapping of laser induced metal melting pool using ultrasound: Numerical and experimental approaches

2021 ◽  
Vol 71 ◽  
pp. 178-186
Author(s):  
Teng Yang ◽  
Yuqi Jin ◽  
Brian Squires ◽  
Tae-Youl Choi ◽  
Narendra B. Dahotre ◽  
...  
Keyword(s):  
In Situ Monitoring ◽  
Ex Situ ◽  
Melting Pool ◽  
Experimental Approaches ◽  
Metal Melting

In situ HREM of interface interactions

1993 ◽  
Vol 51 ◽  
pp. 830-831
Author(s):  
Robert Sinclair ◽  
Toyohiko J. Konno
Keyword(s):  
Amorphous Material ◽  
Equilibrium Phase ◽  
High Resolution Electron Microscopy ◽  
Atomic Scale ◽  
Orientation Relationships ◽  
Interface Reactions ◽  
Diffusion Controlled ◽  
Resolution Electron

We have applied in situ high-resolution electron microscopy (HREM) to the study of interface reactions, particularly in metal-semiconductor systems. There is contrasting behavior whether or not the manufactured interface undergoes a chemical reaction. The in situ technique allows determination of the reaction mechanisms on an atomic scale.Reactive interfaces are characterized by systems in which new chemical compounds are formed (e.g., silicides for metal-silicon interfaces, metal gallides and arsenides for GaAs, etc.). We found that the equilibrium phase formation is often preceded by a solid-state amorphization reaction. In situ observations allow very precise measurement of the reaction rate in a sufficient temperature range to confirm that this process is diffusion controlled. Crystallization of the amorphous material can be followed as well as the development of any crystallographic orientation relationships. A ledge growth mechanism can easily be distinguished from a random process.It might be expected that non-reactive interfaces are stable upon heating.

In Situ Monitoring of Mechanochemical Synthesis of Calcium Urea Phosphate Fertilizer Cocrystal Reveals Water-Based Autocatalysis

2019 ◽  
Author(s):  
Patrick Julien ◽  
Luzia S. Germann ◽  
Hatem M. Titi ◽  
Martin Etter ◽  
Robert E. Dinnebier ◽  
...  
Keyword(s):  
Direct Evidence ◽  
Phosphate Fertilizer ◽  
In Situ Monitoring ◽  
Mechanochemical Reaction ◽  
X Ray Diffraction ◽  
In Situ Raman Spectroscopy ◽  
X Ray ◽  
In Situ Raman ◽  
In Situ Investigation

Using the mechanosynthesis of the calcium phosphate and urea fertilizer cocrystal as a model, we provide the first in situ investigation of autocatalysis in a mechanochemical reaction. The application of in situ Raman spectroscopy and synchrotron X-ray diffraction provided the first direct evidence of a mechanochemical system in which a reaction product (water) mediates the rate of transformation and underpins positive feedback kinetics.

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