A model study on the photochemical isomerization of cyclic silenes

2015 ◽  
Vol 17 (7) ◽  
pp. 5039-5042 ◽  
Author(s):  
Ming-Der Su

The photomigration reaction mechanism for a five-membered-ring silene 1 was theoretically studied using the CAS/6-311G(d) and MP2-CAS/6-311++G(3df,3pd) methods. The model computations conclude that the conical intersection mechanism plays an important role in such a photochemical reaction. That is, the conical intersection mechanism is a one-step process that has no barrier.

2020 ◽  
Vol 22 (36) ◽  
pp. 20265-20283
Author(s):  
Camille A. Farfan ◽  
Daniel B. Turner

Conical intersection topography plays an essential role in excited-state photochemistry. Here, topography is modified systematically to quantify its effects on photochemical reaction rates, reactant recovery, and photoproduct yield.


2020 ◽  
Vol 39 (1) ◽  
pp. 107-116
Author(s):  
Hongyang Wang ◽  
Kai Dong ◽  
Rong Zhu

AbstractThe reaction mechanism models of dechlorination and [Zn] reclaiming in the roasting steelmaking zincrich dust process are studied. The dust collected from a steelwork contains 63.8% zinc and 3.18% chlorine (mass percent), of which, almost all zinc elements exist in ZnO and ZnCl2 forms, and all the chlorine elements are stored in ZnCl2. When the dust is roasted at above 732∘C in an air atmosphere, the ZnCl2 in the steelmaking zinc-rich dust is volatilized into steam and then oxidized into ZnO. Finding the position where the chemical reaction occurs is the key to determining the reaction mechanisms of dechlorination and [Zn] reclaiming. In this study, two groups of thermal experiments are designed and executed for roasting in different atmosphere environments and at different roasting temperatures. Based on the experiment results, the mechanism model is discussed and built, and the reaction of dechlorination and [Zn] reclaiming is shown to be a multi-step process. Because O2 from the air cannot transmit into the dust particle interior or dust bed effectively, the chemical reaction of [Zn] reclaiming occurs in the external gas environment outside of the dust, where the [Zn] recalcining reaction should be limited by the dynamics of new nucleation of ZnO solids.


Nanoscale ◽  
2021 ◽  
Author(s):  
Wipakorn Jevasuwan ◽  
Naoki Fukata

Vertical Al-catalyzed SiNW arrays with shaped surfaces were synthesized by a one-step process and NW-based solar cells were demonstrated with optimized NW surface defects through surface modification and length reduction.


2017 ◽  
Vol 101 (4) ◽  
pp. 1780-1789 ◽  
Author(s):  
Giuliana Taglieri ◽  
Valeria Daniele ◽  
Claudia Mondelli

1984 ◽  
Vol 62 (1) ◽  
pp. 74-76 ◽  
Author(s):  
R. A. Burt ◽  
Y. Chiang ◽  
A. J. Kresge ◽  
S. Szilagyi

The acid-catalyzed hydrolysis of the nine-membered ring cyclic vinyl ether, oxacyclonon-2,8-diene, occurs with a normal isotope effect, [Formula: see text], which indicates that this reaction proceeds by the conventional vinyl ether hydrolysis mechanism involving rate-determining proton transfer to carbon. The specific rate of this reaction, [Formula: see text], may then be used to show that there is no significant ring-size effect on the rate of hydrolysis of a vinyl ether group in a nine-membered ring. The previously noted unusually great reactivity of the vinyl ether group in 9-methoxyoxacyclonon-2-ene, for which an unorthodox reaction mechanism has been claimed, must therefore be due to some other cause.


2007 ◽  
Vol 561-565 ◽  
pp. 1197-1199
Author(s):  
Hideo Kohno ◽  
Seiji Takeda

This paper describes our recent achievements in fabricating various kinds of nanowires of silicon-based materials including beta iron-silicide, silicon carbide, and silicon germanium. Some of them can be grown directly at one-step process, while the others can be fabricated using nanowire templates. We discuss their structures, growth mechanisms, and properties based on electron microscopy observations.


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