Solid acid catalysts of MgO–Al2O3 mixed oxides containing B4O72−, HPO42−, Mo7O246−, MoO42−, WO42−, and SO42− were synthesized by anion exchange with Cl− located in the space between anionic layers hydrotalcite, followed heat treatment at 773 K. The distance hydroxide was expanded intercalation oxyanions larger than Cl−. interlayer confirmed IR spectroscopy. Acid sites generated on obtained elec...

The mechanism of proton exchange in a metal-ligand enzyme active site mimic (compound 1) is described through amide hydrogen-deuterium exchange kinetics. The type and ratio of cationic guest to host in solution affect the rate of isotope exchange, suggesting that the rate of exchange is driven by a host whose cavity is occupied by water. Rate constants for acid-, base-, and water-mediated proto...

Gas gland cells of the European eel (Anguilla anguilla) were cultured on collagen-coated coverslips, and intracellular pH was measured using the pH-sensitive fluorescent probe 2',7'-bis-(2-carboxypropyl)-5-(6)-carboxyfluorescein (BCPCF). The contributions of various proton-translocating mechanisms to homeostasis of intracellular pH (pHi) were assessed by adding specific inhibitors of the variou...

The acid-activated proton channel formed by the influenza M2 protein is important for the life cycle of the virus. A single histidine, His37, in the M2 transmembrane domain (M2TM) is responsible for pH activation and proton selectivity of the channel. Recent studies suggested three models for how His37 mediates proton transport: a shuttle mechanism involving His37 protonation and deprotonation,...

ZSM-5 zeolites are highly silicate materials that have significant application in catalytic processes petrochemistry, especially due to their high selectivity. Most reactions the petrochemical industry acid-catalyzed. The acidic properties of zeolite depend on number acid centers, i.e. presence hydrogen ions, and therefore, this paper possibility reducing sodium content pores with modulus (SiO2...

In glacial acetic acid, phthalanilic acid and its monosubstituents are known to be converted to the corresponding phthalimides in relatively good yields. In this study, we computationally investigated the experimentally proposed two-step (addition-elimination or cyclization-dehydration) mechanism at the second-order Møller-Plesset perturbation (MP2) level of theory for the unsubstituted phthala...

[Zn(H2O)4][Zn2Sn3Se9(MeNH2)] has an open polar framework based on supertetrahedral clusters with a unique double connectivity mode and exhibits a strong second harmonic generation response, excellent acid stability and proton exchange capacity.

(13)C NMR monitored the dynamics of exchange from specific hydrogens of hepatic [2-(13)C]glutamate and [3-(13)C]aspartate with deuterons from intracellular heavy water providing information on alpha-ketoglutarate/glutamate exchange and subcellular compartmentation. Mouse livers were perfused with [3-(13)C]alanine in buffer containing or not 50% (2)H(2)O for increasing periods of time (1 min < t...

Two types of inorganic/organic hybrids comprising Brønsted acid-base ionic groups have been prepared and studied for proton exchange membranes (PEM) applications. The hybrid membranes have a highly cross-linked silicon-oxygen backbone and trifluoromethanesulfonimide (HTFSI) doped organic amine groups. The Si-O backbone provides the membranes thermal/chemical/mechanical properties and the HTFSI-...

The preparation of fairly strained carbocyclic ring systems by intramolecular 5-exo-trig ring closure has been well documented, and the absence of proton transfers that would compromise such cyclizations is a hallmark of this chemistry. In an effort to explore the limitations of this approach to more highly strained systems, the preparation of a stellane (tricyclo[3.3.0.0(3,7)]octane) framework...