Dielectric evidence for the formation of a clathrate hydrate by sulfuryl chloride

1983 ◽  
Vol 61 (9) ◽  
pp. 2053-2054 ◽  
Author(s):  
S. R. Gough ◽  
J. A. Ripmeester ◽  
D. W. Davidson

A hydrate formed by SO2Cl2 at −20 °C is shown by its low temperature dielectric absorption to be a structure II clathrate hydrate. The activation energy for reorientation of encaged SO2Cl2 molecules is 1.1 kcal mol−1 between 19 and 41 K.

1979 ◽  
Vol 57 (6) ◽  
pp. 635-637 ◽  
Author(s):  
S. K. Garg ◽  
D. W. Davidson ◽  
S. R. Gough ◽  
J. A. Ripmeester

The rigid-lattice nmr line shape of the four-proton system in 1,2-dihaloethanes has been obtained by spectral simulation as a function of dihedral angle [Formula: see text] and used to show that 1,2-dichloroethane is encaged in the structure II hydrate in a gauche configuration with [Formula: see text] Very broad low-temperature dielectric absorption is associated with an average activation energy of 0.87 kcal/mol for guest-molecule reorientation.


1978 ◽  
Vol 56 (15) ◽  
pp. 2025-2028 ◽  
Author(s):  
S. R. Gough

Dielectric relaxation evidence is presented of the encageability of 2-methylpropanal in the structure II clathrate hydrate lattice. The hydrate composition is inferred to be (CH3)2CHCHO 17H2O and, for the 2-methylpropanal/THF mixed hydrate studied in detail, the activation energy for aldehyde reorientation is shown to be 2.0 kcal/mol. The results suggest that the guest–host interactions may be somewhat different for the two guest species.


2019 ◽  
Author(s):  
Raghu Nath Dhital ◽  
keigo nomura ◽  
Yoshinori Sato ◽  
Setsiri Haesuwannakij ◽  
Masahiro Ehara ◽  
...  

Carbon-Fluorine (C-F) bonds are considered the most inert organic functionality and their selective transformation under mild conditions remains challenging. Herein, we report a highly active Pt-Pd nanoalloy as a robust catalyst for the transformation of C-F bonds into C-H bonds at low temperature, a reaction that often required harsh conditions. The alloying of Pt with Pd is crucial to activate C-F bond. The reaction profile kinetics revealed that the major source of hydrogen in the defluorinated product is the alcoholic proton of 2-propanol, and the rate-determining step is the reduction of the metal upon transfer of the <i>beta</i>-H from 2-propanol. DFT calculations elucidated that the key step is the selective oxidative addition of the O-H bond of 2-propanol to a Pd center prior to C-F bond activation at a Pt site, which crucially reduces the activation energy of the C-F bond. Therefore, both Pt and Pd work independently but synergistically to promote the overall reaction


2021 ◽  
Vol 904 ◽  
pp. 363-368
Author(s):  
Xiao Yan Zhou ◽  
Bang Sheng Yin

The 3 at% Al doped ZnO thin films were deposited on p-Si substrate with a native SiO2 layer by spray pyrolysis method. Low temperature conduction behaviors were studied by analysis of impedance spectroscopy and low temperature ac conductivity. The results of impedance spectroscopy showed that the grain boundaries contributed to the resistivity of Al doped ZnO/SiO2/p-Si heterojunction. The calculated activation energy was 0.073 eV for grain boundaries. The equivalent circuit to demonstrate the electrical properties of Al doped ZnO/SiO2/p-Si heterojunction was a series connection of two parallel combination circuits of a resistor and a universal capacitor. Low temperature ac conductivity measurements indicated that the conductivity increased with temperature. Low temperature conductivity mechanism was electron conductivity, and the activation energy was 0.086 eV.


2002 ◽  
Vol 744 ◽  
Author(s):  
Takahide Sugiyama ◽  
Masayasu Ishiko ◽  
Shigeki Kanazawa ◽  
Yutaka Tokuda

ABSTRACTMetastable defects are discovered in hydrogen-implanted n-type silicon. Hydrogen implantation was performed with the energy of 80 keV to a dose of 2×10 cm- at 109 K. After implantation, the sample temperature was raised to room temperature. DLTS measurements were carried out in the temperature range 80–290 K for fabricated diodes. When the sample is reverse-biased at 10V for 10 min at room temperature and then is cooled down to 80 K, three new peaks labeled EM1, EM2 and EM3 appear around 150, 190 and 240 K, respectively. The introduction of metastable defects is found to be characteristic of low temperature implantation. We have evaluated properties of EM1 in detail. EM1 with thermal emission activation energy of 0.29 eV has a peak in concentration around the depth of 0.64 μ m, which corresponds to the projected range of 80 keV hydrogen. EM1 is regenerated with the reverse bias applied around 270 K and is removed with the zero bias around 220 K.


2017 ◽  
Vol 19 (26) ◽  
pp. 17349-17355 ◽  
Author(s):  
Bing Ai ◽  
Chao Liu ◽  
Zhao Deng ◽  
Jing Wang ◽  
Jianjun Han ◽  
...  

Size dependence of exciton activation energy, electron–phonon coupling strength, and thermal expansion of the bandgap of CsPbBr3 QDs were studied.


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