On the role of the alkali cations on methanol thiolation

The electronegativity effect of the alkali cations on the formation of methanethiol by reaction of methanol and H2S was studied with K+, Rb+, and Cs+ supported on γ-Al2O3.

Dispersion of Titanium Oxide Nanoparticles in Aqueous Solution with Anionic Stabilizer via Ultrasonic Wave

This paper aims to reveal the effects of odium hexametaphosphate (SHMP) and polyacrylic acid (PAA) on dispersion of TiO2 (P25) nanopowder in de-ionic water through ultrasonic horn. We characterized TiO2 suspension by transmission electron microscopy (TEM), dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR), zeta potential, and surface contact angle instruments. As shown in the results, particularly, it were noticed that (1) the SHMP has better dispersion than PAA due to electronegativity effect, resulting in that the average particle size of the dispersed titanium dioxide in de-ionic water was roughly 92 nm, and (2) the zeta potential of TiO2 suspension with SHMP can be achieved by 54 mV at pH value of 7.7, causing stronger electrostatic repulsion in the suspension solution, compared with PAA.

The theory of chemical shifts in nuclear magnetic resonance II. Interpretation of proton shifts

The interpretation of proton chemical shifts is discussed in terms of the magnetic field due to the types of electronic current discussed in part I. It is shown that local paramagnetic circulations on neighbouring atoms may have a considerable effect on the resonance frequency. The anomalous position of the acetylenic proton can be ascribed to this effect. For the series of molecules CH 4 , NH 3 , H 2 O, HF, calculations show that there is an effect of paramagnetic currents around the central atom which increases along the series and which operates in the opposite direction to the electronegativity effect. It is suggested that the comparatively small change in the proton frequency along this series is due to cancellation of these terms.