The acidity and its effects on reactivity of Keggin-type heteropolycompounds were examined by catalytic probe reactions, microcalorimetry of ammonia sorption, and density functional quantum chemical calculations. Phosphotungstic, phosphomolybdic, silicotungstic, and silicomolybdic acids were used as model compounds. The specific rates of double-bond isomerization of both 1-butene and cis-2-bute...

Synthesis of 3,1,5-benzoxadiazepines from the condensation of o-phenylenediamine (o-PDA) and acyl chlorides in the presence of a catalytic amount of various heteropolyacids (HPAs) is reported.

An efficient and improved procedure for the synthesis of 1,4-diazepine and 1,5-benzodiazepine derivatives via the reaction of ketimine intermediates with aldehydes in the presence of Keggin-type heteropolyacids (HPAs) was developed. High yields and short reaction times were obtained for both electron-releasing and electron-withdrawing substituted 1,4-diazepine  and 1,5-benzodiazepines derivatives.

A family of polyoxometalates with the composition [H2V3M17O62](6-) features a Dawson-like architecture containing two tetrahedral {VVO4} templates rather than main group hetero-anions ({PO4} or {SO4} etc.) typically associated with classical heteropolyacids, situated within a mixed-metal {MVI17VIVO54} cage and these clusters were first discovered using mass spectrometry.

Basic characteristics of heteropolyacids as green catalysts are overviewed, focusing on the various reaction fields in which the heteropolyacid catalysts function as acid and oxidation catalysts, and then two industrial processes which were made very green by the use of heteropolyacid catalysts in liquid biphase systems are described. In this context an interesting new reaction field formed at ...

The antiviral activity of Keggin heteropolyacids (HPAs) against the human influenza A/California/07/09 (H1N1) pdm09 virus is studied in MDCK cell culture. Transmission electron microscopy reveals new features destruction viral particles by HPAs. A proton-anion model that considers main biochemical processes leading to enveloped viruses: depletion membrane cholesterol HPA anions, acidification M...

12-molybdophosphoric acid (pmo12) was encaged into hmor zeolite by “ship in a bottle”method in aqueous phase which is strongly retained and not easily leached from the host channels.the solid was characterized by xrd prior to using it for the electrode preparation. this compoundwas incorporated with a carbon paste electrode for cyclic voltammetric measurements. pmo12immobilized on the support u...

The composition, structural evolution and the related property variations of mixed cesium/ammonium acidic salts of heteropolyacids were investigated in detail by tracking and analyzing the initial precipitates, evaporation residues and the calcined products in their preparation process. Results show that V cannot completely enter the heteropolyanions in the initial precipitates when the Cs+ add...