Quantum chemical calculations show that thiourea-S,S-dioxides like 2 are Lewis acid-base adducts of the respective diamino carbenes with SO2 (CS bond energies < 20 kcal·mol1). They possess long CS bonds and a pyramidal sulfur atom and are thus structurally distinct from sulfur ylides or ...
This marked difference is due to SO3 being a much stronger Lewis acid (pF(-) value of 7.83) than SO2 (pF(-) value of 3.99), thus forming a stronger S-N bond with the Lewis base N-3(-). The geometry of the free gaseous SO2N3- anion was calculated at the RHF, MP2, B3LYP, ...
Addition of pyridine to the sulfene C atom affords adducts better described as Lewis acid/base adducts between carbene pyridine ylides and SO2 rather than as pyridinium sulfinate zwitterions. Again, scipcm calculations predict tighter binding in polar solvents. In the series of sulfene-pyridine ...
NHCs carrying negative charge are believed to dominate the interaction with acid gas, while the positively charged parts (cations) are often considered as charge balancing agents only5,14,15,16. However, recent studies of the cation effects on the interactions between Lewis base and CO2 have ...
Lewis acid/base catalyzed [2+2]-cycloaddition of sulfenes and aldehydes: a versatile entry to chiral sulfonyl and sulfinyl derivatives. -sulfones, -sulfonic acids, -sulfinic acids, -sultines, and -sultones or a single stereocenter, such as in -branched alkyl or allyl sulfonic acids... ...
Meanwhile, CeO2 had certain Lewis basicity. In other words, CeO2 as the active component would decrease the surface acidity of Ce-Al-Ox catalyst to a certain extent, and the NH3-TPD results followed the Tanabe rule. The weak acid desorption peak temperature and medium acid desorption peak ...
The water and the steep chemicals (generally 2000-2500 ppm SO2 and 0.5-2% lactic acid (usually produced during steeping by lactobacillus bacteria)) diffuse into the corn kernel through the base end of the tip cap, move through the cross and tube cells of the pericarp to the kernel crown ...
In the temperature range 450–600 °C, the catalytic activity of alumina was practically unaffected by pretreatment with an organic base, such as quinoline, which normally blocks the Lewis acid sites. Elemental sulfur activates the alumina surface during the catalyst break-in period....
The stability of the FeG-Gas interactions is dominated by Lewis-acid-base interactions, and its strength is sorted as SO> CO > HS > CO. The adsorption stability is also retained at room temperature (300 K). Due to the strong interaction of SO, CO, and HS, FeG could catalyze or ...
where CRO2 CRO2 is the absorbed CO2 or SO2 concentration in the nanofluids or deionized water (mol/m3), M is HCl molarity (mol/lit), and V is the volume of absorbent used in the column, (equal to 100 mL), in all experiments. V1 and V2 are the volumes (mL) of standard acid so...