Properties of chromatographic columns prepared on the basis of poly(1-trimethylsilyl-1-propyne) modified with organic bases.

This article describes the effect of modification with organic bases such as uracil (U) and polyethyleneimine (PEI) on the adsorption and chromatographic properties of poly(1-trimethylsilyl-1-propyne) (PTMSP) used as a stationary phase (SP) in packed and capillary columns. It was shown that the sorbents prepared on the basis of diatomite Chromosorb P NAW support and successively modified with 9 wt.% PTMSP and 1 wt.

Heterogeneous HO-based selective oxidations over zirconium tungstate α-ZrWO.

Catalytic properties of a crystalline zirconium tungstate, ZrWO, the material known mainly for its isotropic negative coefficient of thermal expansion, have been assessed for the liquid-phase selective oxidation of a range of organic substrates comprising CC, OH, S and other functional groups using aqueous hydrogen peroxide as the green oxidant. Samples of ZrWO were prepared by hydrothermal synthesis and characterised by N adsorption, PXRD, SEM, EDX, FTIR and Raman spectroscopic techniques. Studies by IR spectroscopy of adsorbed probe molecules (CO and CDCl) revealed the presence of Brønsted acidic and basic sites on the surface of ZrWO.

State of Formic Acid Dissolved in Tar According to Infrared Spectroscopy.

Formic acid is considered as a promising hydrogen carrier and can be used as a source of hydrogen in the processing of heavy oil fractions such as tar. The interaction of formic acid with tar was studied by infrared Fourier transform spectroscopy via special technique using a mirror substrate. The infrared (IR) spectra were interpreted considering density functional theory (DFT) calculations.

New DRIFT spectroscopic methodology for acquiring infrared spectra of fiberglass materials.

We report a new approach for infrared spectroscopic analysis of fiberglass materials using a mirror substrate, which allowed the specular reflection from the sample surface to be minimized and detect the light passing through the sample. The application of this technique for platinum-containing fiberglass catalysts made it possible for the first time to identify sulfate compounds formed in glass fibers during the oxidation reaction of sulfur dioxide. The developed technique can be applied for a number of research samples that are difficult to analyze by conventional IR spectroscopic methods.

Catalytic Performance of Zr-Based Metal-Organic Frameworks Zr-abtc and MIP-200 in Selective Oxidations with H O.

The catalytic performance of Zr-abtc and MIP-200 metal-organic frameworks consisting of 8-connected Zr clusters and tetratopic linkers was investigated in H O -based selective oxidations and compared with that of 12-coordinated UiO-66 and UiO-67. Zr-abtc demonstrated advantages in both substrate conversion and product selectivity for epoxidation of electron-deficient C=C bonds in α,β-unsaturated ketones. The significant predominance of 1,2-epoxide in carvone epoxidation, coupled with high sulfone selectivity in thioether oxidation, points to a nucleophilic oxidation mechanism over Zr-abtc.

New Insight into Titanium-Magnesium Ziegler-Natta Catalysts Using Photoluminescence Spectroscopy.

This paper presents the results of study of titanium-magnesium catalysts often used in polymerization processes, by photoluminescence spectroscopy (PL) in combination with diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). The interaction of dibutyl phthalate (DBP) with MgCl was studied at DBP/Mg = 0-1 (mol/mol). The luminescence spectra with excitation at 278 nm and the excitation spectra for main emission bands were recorded.