Structural Effect on the Stability of (Pyridine)2Cu+Complexes in the Gas Phase:  Nature of the Bond between Copper(I) Ion and Neutral Molecules

2007 ◽  
Vol 111 (27) ◽  
pp. 5988-5994 ◽  
Author(s):  
Soe Than ◽  
Hideaki Maeda ◽  
Maki Irie ◽  
Shuhei Itoh ◽  
Kiyoshi Kikukawa ◽  
...  
Keyword(s):  
Gas Phase ◽  
Structural Effect ◽  
The Stability

The influence of the chlorine-hydrogen ratio in the gas phase on the stability of the {113} faces of silicon in Si-H-Cl CVD

1990 ◽  
Vol 102 (1-2) ◽  
pp. 233-244 ◽  
Author(s):  
J.G.E. Gardeniers ◽  
M.M.W. Mooren ◽  
M.H.J.M. De Croon ◽  
L.J. Giling
Keyword(s):  
Gas Phase ◽  
The Stability

scholarly journals Catalytic Performance of Nitrogen-Doped Activated Carbon Supported Pd Catalyst for Hydrodechlorination of 2,4-Dichlorophenol or Chloropentafluoroethane

Molecules ◽  
2019 ◽  
Vol 24 (4) ◽  
pp. 674 ◽  
Author(s):  
Haodong Tang ◽  
Bin Xu ◽  
Meng Xiang ◽  
Xinxin Chen ◽  
Yao Wang ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Liquid Phase ◽  
Gas Phase ◽  
Nitrogen Doping ◽  
Catalyst Surface ◽  
Catalytic Performance ◽  
Atomic Ratio ◽  
Pd Catalyst ◽  
Nitrogen Doped ◽  
The Stability

Nitrogen-doped activated carbon (N-AC) obtained through the thermal treatment of a mixture of HNO3-pretreated activated carbon (AC) and urea under N2 atmosphere at 600 °C was used as the carrier of Pd catalyst for both liquid-phase hydrodechlorination of 2,4-dichlorophenol (2,4-DCP) and gas-phase hydrodechlorination of chloropentafluoroethane (R-115). The effects of nitrogen doping on the dispersion and stability of Pd, atomic ratio of Pd/Pd2+ on the surface of the catalyzer, the catalyst’s hydrodechlorination activity, as well as the stability of N species in two different reaction systems were investigated. Our results suggest that, despite no improvement in the dispersion of Pd, nitrogen doping may significantly raise the atomic ratio of Pd/Pd2+ on the catalyst surface, with a value of 1.2 on Pd/AC but 2.2 on Pd/N-AC. Three types of N species, namely graphitic, pyridinic, and pyrrolic nitrogen, were observed on the surface of Pd/N-AC, and graphitic nitrogen was stable in both liquid-phase hydrodechlorination of 2,4-DCP and gas-phase hydrodechlorination of R-115, with pyridinic and pyrrolic nitrogen being unstable during gas-phase hydrodechlorination of R-115. As a result, the average size of Pd nanocrystals on Pd/N-AC was almost kept unchanged after liquid-phase hydrodechlorination of 2,4-DCP, whereas crystal growth of Pd was clearly observed on Pd/N-AC after gas-phase hydrodechlorination of R-115. The activity test revealed that Pd/N-AC exhibited a much better performance than Pd/AC in liquid-phase hydrodechlorination of 2,4-DCP, probably due to the enhanced stability of Pd exposed to the environment resulting from nitrogen doping as suggested by the higher atomic ratio of Pd/Pd2+ on the catalyst surface. In the gas-phase hydrodechlorination of R-115, however, a more rapid deactivation phenomenon occurred on Pd/N-AC than on Pd/AC despite a higher activity initially observed on Pd/N-AC, hinting that the stability of pyridinic and pyrrolic nitrogen plays an important role in the determination of catalytic performance of Pd/N-AC.

The Stability of Gold Iodides in the Gas Phase and the Solid State

2001 ◽  
Vol 7 (14) ◽  
pp. 3167-3173 ◽  
Author(s):  
Tilo Söhnel ◽  
Reuben Brown ◽  
Lars Kloo ◽  
Peter Schwerdtfeger
Keyword(s):  
Solid State ◽  
Gas Phase ◽  
The Stability

Exploring halide anion affinities to native cyclodextrins by mass spectrometry and molecular modelling

2017 ◽  
Vol 24 (3) ◽  
pp. 269-278 ◽  
Author(s):  
Chongsheng Xu ◽  
Nan He ◽  
Zhenhua Li ◽  
Yanqiu Chu ◽  
Chuan-Fan Ding
Keyword(s):  
Gas Phase ◽  
Density Functional ◽  
Binding Constants ◽  
Density Functional Theory Calculations ◽  
Collision Induced Dissociation ◽  
Binding Affinities ◽  
Cyclodextrin Complex ◽  
Halide Anion ◽  
Mass Frame ◽  
The Stability

The binding affinities of cyclodextrins complexation with chlorine (Cl−), bromine (Br−) and iodine (I−), were measured by mass spectrometric titrimetry, and the fitting of the binding constants was based on the concentration measurement of the cyclodextrin equilibrium. The binding constants (lg Ka) for α-, β- or γ-cyclodextrin with Cl− were 3.99, 4.03 and 4.11, respectively. The gas-phase binding affinity of halide anions for native cyclodextrins was probed by collision-induced dissociation. In collision-induced dissociation, the centre-of-mass frame energy results revealed that in the gas phase, for the same type of cyclodextrin, the stability of the complexes decreased in order: Cl > Br > I, and for the same halide anion, the binding stability of the complex with α-, β- or γ-cyclodextrin decreased in the order: γ-cyclodextrin >β-cyclodextrin > α-cyclodextrin. The density functional theory calculations showed that halide anion binding on the primary face had a lower energy than the secondary face and hydrogen bonding was the main driving force for complex formation. The higher stability of the γ-cyclodextrin complex with the Cl anion can be attributed to the higher charge density of the Cl anion and better flexibility of γ-cyclodextrin.

Gas-Phase Acidities of Cycloheptatrienes: Effects of Alkyl Groups on the Stability of Carbanions

2002 ◽  
Vol 8 (5) ◽  
pp. 359-366 ◽  
Author(s):  
Masaaki Mishima ◽  
Tomomi Kinoshita ◽  
Yoshitaka Hattori ◽  
Ken'ichi Takeuchi
Keyword(s):  
Mass Spectrometry ◽  
Fourier Transform ◽  
Gas Phase ◽  
Cyclotron Resonance ◽  
Ion Cyclotron Resonance ◽  
Charge Delocalization ◽  
Alkyl Groups ◽  
Respective Parent ◽  
The Stability ◽  
Ft Icr

The gas-phase acidities of 7-alkyl substituted cycloheptatrienes have been determined by Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry using a proton-transfer equilibrium method, Δ G0acid (kJ mol−1): methyl 1520.0, ethyl 1516.7, n-propyl acid 1513.3, i-propyl 1512.1, n-butyl 1510.4. The effect of alkyl groups on the acidity of cycloheptatriene is linearly correlated with the polarizability parameters ( σα) of substituents, giving a ρα of–55.3 (kJ σ−1α unit). The magnitude of pa is half of that for RCH3 and is significantly larger than that for the fluorene series. These results suggest that the extent of the charge-delocalization in a carbanion plays an important role in determining the susceptibility of the stability of the carbanion to substituent polarizability effects. In addition, comparison of ρ values of acidities of a series of elemental hydrides shows that the numerical value of ρα decreases in the order, C > O ≈ N > S, and that the change of ρα is related to the stability of the respective parent anions (R = H) rather than the atomic electronegativity at the deprotonation center.

scholarly journals Spectroscopic observation of two-center three-electron bonded (hemi-bonded) structures of (H2S)n+ clusters in the gas phase

2017 ◽  
Vol 8 (4) ◽  
pp. 2667-2670 ◽  
Author(s):  
Dandan Wang ◽  
Asuka Fujii
Keyword(s):  
Infrared Spectroscopy ◽  
Ab Initio ◽  
Gas Phase ◽  
Spectroscopic Observation ◽  
The Stability

The presence of a two-center three-electron (2c–3e) bonded (hemi-bonded) ion core in the (H2S)n+ cluster is revealed by infrared spectroscopy combined with ab initio calculations. The stability of the hemi-bonded ion core to solvation is also proved.

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