a water soluble, bronsted acid, 5-sulfosalicylic acid as an efficient organocatalyst was used for the synthesis of physiologically active 2-substituted benzimidazole derivatives from o-phenylenediamine and aromatic aldehydes in ethanol at reflux condition. cost-effectiveness, use of non-hazardous solvents, metal free and commercially available catalyst, single-step, environmentally friendly gre...

The interactions between liquid targets and plasmas provided by a d.c. point-to-plane corona device operated under p = 1 atm. are considered in terms of both Bronsted and Lewis acid-base reactions. The treatments of aqueous solutions by the chargeless species of air or NH3 plasmas increase the Bronsted acidity of the target, and for an air plasma, the pH decrease is a linear function of the qua...

according to the bronsted definition, any compound which has a hydrogen atom is an acid, since itmay be lost as a proton. a thermodynamical cycle is proposed to calculate absolute pka values forbronsted acids in aqueous solution. the equilibrium of dissociation of a bronsted acid depends onthe interaction of the acid and its conjugate base with solvent molecules. there fore the pka valuedepends...

The bell-shaped pH rate profile for the reaction of tetrahydrofolic acid with formaldehyde to form 5, lo-methylene tetrahydrofolic acid has been shown to result from a change in rate-determining step with changing acidity. In alkaline solution, the rate-determining step is the acid-catalyzed dehydration of hydroxymethyl tetrahydrofolic acid and its conjugate base. This step is subject to genera...

A family 3 beta-glucosidase (EC 3.2.1.21) from Flavobacterium meningosepticum has been cloned and overexpressed. The mechanistic action of the enzyme was probed by NMR spectroscopy and kinetic investigations, including substrate reactivity, secondary kinetic isotope effects and inhibition studies. The stereochemistry of enzymic hydrolysis was identified as occurring with the retention of an ano...

Heterogeneous catalysis and their application in industrial-scale organic synthesis of fine chemicals are greatly facilitated by catalysis and further on by catalyst recovery and recycles to fits most “principles of green chemistry. In acid media, terpenoids generally undergoes various transformations. The terpenoid transformations include various liquid Bronsted and Lewis Acids, Acid clays, He...

The interaction between methanol and the Heulandite-type zeolite has been unveiled to give an atomic scale detail regarding catalytic activity of this for conversion. study was carried out by first principle molecular dynamics get insight into structure electronic behaviour inside at different temperatures. studied when location proton Bronsted acid sites varied both possible direct less with m...

In this study, three raw Brazilian clays from Joao Pessoa, Paraiba State (Aco AP, AVL and Verde Lodo) were characterized before after purification acid activation. Several instrumental techniques used, the classified as dioctahedral smectites with different compositions, where sample had highest content of montmorillonite. addition, analyses showed modification in clay mineral mainly due to rem...

Glucose is one of the primary derivative products from lignocellulosic biomass, which abundantly available. has excellent potential to be converted into valuable compounds such as ethanol, sorbitol, gluconic acid, and levulinic acid (LA). Levulinic an exceptionally promising green platform chemical. It comprises two functional groups, ketone carboxylate, acting highly reactive electrophiles for...