High-pressure methods as a tool in organometallic syntheses: facilitation of oxidative addition to platinum(II)

1996 ◽  
Vol 74 (11) ◽  
pp. 1998-2001 ◽  
Author(s):  
Andrew R.L. Skauge ◽  
Richard D. Shalders ◽  
Thomas W. Swaddle
Keyword(s):  
High Pressure ◽  
Pressure Dependence ◽  
Pressure Range ◽  
Oxidative Addition ◽  
Activation Process ◽  
Batch Reactors ◽  
Oxidative Additions ◽  
Solvation Of Ions ◽  
Alkyl Iodides ◽  
Kinetics Of

High-pressure (2 GPa) batch reactors now commercially available may offer substantial accelerations of organometallic syntheses, without resort to heating, when the activation process is multicentered or involves the generation and solvation of ions. As an example of the latter class of reactions, the kinetics of the oxidative additions of methyl and ethyl iodides (RI) to dimethyl(2,2′-bipyridine)platinum(II) in acetone have been studied over the pressure range 0–200 MPa. The volumes of activation ΔV1≠, if assumed to be constant over this range, are −11.7 ± 0.3 and −9.7 ± 0.7 cm3 mol−1, respectively, implying an acceleration of ca. 3000-fold for a batch synthesis of this sort at 2 GPa. However, a possible slight pressure dependence of ΔV1≠ may reduce this acceleration to ca. 1 000-fold. The ΔV1≠ data and the 500-fold retardation on going from R = Me to R = Et are consistent with an SN2 attack of Pt11 on the α-carbon in the alkyl iodides, forming I− and [RMe2Pt(bpy)]+. Key words: volumes of activation, high pressure, oxidative addition, platinum(II), organometallic syntheses.

scholarly journals Depolarization Ratios of Methane Raman Bands as a Function of Pressure

Molecules ◽  
2020 ◽  
Vol 25 (8) ◽  
pp. 1951
Author(s):  
Dmitry Petrov
Keyword(s):  
Raman Spectroscopy ◽  
High Pressure ◽  
Natural Gas ◽  
Raman Spectra ◽  
Pressure Dependence ◽  
Pressure Range ◽  
Gas Composition ◽  
Depolarization Ratio ◽  
Depolarization Ratios

In this work, we measured the intensities of Q-branches of the ν1, ν2 and ν3 bands in the polarized and depolarized methane Raman spectra in the pressure range of 1–60 atm. It was established that the pressure dependence of depolarization ratios of the ν2 and ν3 bands are negligible. In turn, the depolarization ratio of the ν1 band increases with increasing pressure and reaches approximately 0.0045 at 60 atm. These data are more precise than previously published ones because ν1 band intensities were determined taking into account the contribution of overlapping lines of ν3 band. The presented data will be useful in calculating the methane polarizabilities at high pressure, as well as in calculating methane Raman spectra for measuring the natural gas composition using Raman spectroscopy.

scholarly journals Novel structural phases and the properties of LaX (X = P, As) under high pressure: first-principles study

RSC Advances ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 3058-3070
Author(s):  
Yu Zhou ◽  
Lan-Ting Shi ◽  
A-Kun Liang ◽  
Zhao-Yi Zeng ◽  
Xiang-Rong Chen ◽  
...  
Keyword(s):  
Phase Transition ◽  
High Pressure ◽  
Thermodynamic Properties ◽  
First Principles ◽  
Electronic Structures ◽  
Pressure Range ◽  
Mechanical Stability ◽  
First Principles Study

The structures, phase transition, mechanical stability, electronic structures, and thermodynamic properties of lanthanide phosphates (LaP and LaAs) are studied in the pressure range of 0 to 100 GPa by first principles.

scholarly journals Oxidative additions of alkynyl/vinyl iodides to gold and gold-catalyzed vinylation reactions triggered by the MeDalphos Ligand

2021 ◽  
Author(s):  
Jessica Rodriguez ◽  
Alexis Tabey ◽  
Sonia Ladeira ◽  
Didier Bourissou
Keyword(s):  
Oxidative Addition ◽  
Oxidative Additions ◽  
Vinyl Iodides

The hemilabile Ad2P(o-C6H4)NMe2 ligand promotes fast, quantitative and irreversible oxidative addition of alkynyl and vinyl iodides to gold. The reaction is general. It works with a broad range of substrates...

Adsorption isotherms and kinetics of carbon dioxide on Chinese dry coal over a wide pressure range

Adsorption ◽  
2015 ◽  
Vol 21 (1-2) ◽  
pp. 53-65 ◽  
Author(s):  
Yongchen Song ◽  
Wanli Xing ◽  
Yi Zhang ◽  
Weiwei Jian ◽  
Zhaoyan Liu ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Adsorption Isotherms ◽  
Pressure Range ◽  
Adsorption Isotherms And Kinetics ◽  
Wide Pressure Range ◽  
Kinetics Of ◽  
Wide Pressure

Measured temperature and pressure dependence of Vp and Vs in compacted, polycrystalline sI methane and sII methane–ethane hydrate

2003 ◽  
Vol 81 (1-2) ◽  
pp. 47-53 ◽  
Author(s):  
M B Helgerud ◽  
W F Waite ◽  
S H Kirby ◽  
A Nur
Keyword(s):  
High Pressure ◽  
Shear Wave ◽  
Pressure Dependence ◽  
Gas Hydrate ◽  
Pressure Vessel ◽  
Wave Speed ◽  
Measured Temperature ◽  
Shear Wave Speed ◽  
Temperature And Pressure ◽  
Fixed End

We report on compressional- and shear-wave-speed measurements made on compacted polycrystalline sI methane and sII methane–ethane hydrate. The gas hydrate samples are synthesized directly in the measurement apparatus by warming granulated ice to 17°C in the presence of a clathrate-forming gas at high pressure (methane for sI, 90.2% methane, 9.8% ethane for sII). Porosity is eliminated after hydrate synthesis by compacting the sample in the synthesis pressure vessel between a hydraulic ram and a fixed end-plug, both containing shear-wave transducers. Wave-speed measurements are made between –20 and 15°C and 0 to 105 MPa applied piston pressure. PACS No.: 61.60Lj

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