Studies on structure and acid–base properties of high silica MFI-type zeolite modified with methylamine

Two new compounds from the formazan series, viz. 1,3-diphenyl-5-(1H-tetrazol-2-yl)formazan and 1,3-diphenyl-5-(2H-1,2,4-triazol-3-yl)formazan, were prepared, and the dissociation constants and molar absorptivities of all of their acid-base species were determined spectrophotometrically employing the SPEKTFOT computer program.

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Acid-base properties of metals and glasses of Na2O.P2O5-xB2O3 system

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19842355 ◽

1984 ◽

Vol 49 (10) ◽

pp. 2355-2362 ◽

Cited By ~ 2

Author(s):

Juraj Leško ◽

Marie Dorušková ◽

Jan Tržil

Keyword(s):

Boron Oxide ◽

A Priori ◽

Optical Basicity ◽

Galvanic Cell ◽

Acid Base ◽

Tetrahedral Configuration ◽

Relative Basicity ◽

Base Theory ◽

Base Properties

Boron oxide in the Na2O.P2O5-x B2O3 system behaves as a Lux base. Its addition to Na2O.P2O5 brings about transformation of a Co(II) indicator from octahedral to tetrahedral configuration, increase in the optical basicity ΛPb(II), increase in the relative basicity of the melt as determined by means of a galvanic cell, and depolymerization reactions releasing PO43- ions. In the Na2O-B2O3 system free of P2O5, boron oxide behaves as a Lux acid. The amphoretic nature of B2O3 is explained in terms of Lux's acid-base theory extended in analogy with the protolysis theory. The theoretical optical basicity values do not indicate the amphoretic behaviour of B2O3 because in this approach boron oxide is a priori regarded as more acidic than Na2O.P2O5.

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Acid-base properties and supramolecular structure ofN-[(hydroxymethyl)triazolyl]triflamides: DFT, ab initio, and FTIR study

Journal of Physical Organic Chemistry ◽

10.1002/poc.3623 ◽

2016 ◽

Vol 30 (5) ◽

pp. e3623 ◽

Cited By ~ 1

Author(s):

Bagrat A. Shainyan ◽

Nina N. Chipanina ◽

Larisa P. Oznobikhina ◽

Vladimir I. Meshcheryakov

Keyword(s):

Ab Initio ◽

Supramolecular Structure ◽

Acid Base ◽

Ftir Study ◽

Base Properties

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Estimation of pKa* in the first excited singlet state. A physical chemistry experiment that explores acid-base properties in the excited state

Journal of Chemical Education ◽

10.1021/ed069p247 ◽

1992 ◽

Vol 69 (3) ◽

pp. 247 ◽

Cited By ~ 35

Author(s):

B. Marciniak ◽

H. Kozubek ◽

S. Paszyc

Keyword(s):

Physical Chemistry ◽

Excited State ◽

Singlet State ◽

Excited Singlet State ◽

Excited Singlet ◽

Acid Base ◽

Chemistry Experiment ◽

Base Properties

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Gas Permeation Properties of High-Silica CHA-Type Zeolite Membrane

Membranes ◽

10.3390/membranes11040249 ◽

2021 ◽

Vol 11 (4) ◽

pp. 249

Author(s):

Yasuhisa Hasegawa ◽

Chie Abe ◽

Mayumi Natsui ◽

Ayumi Ikeda

Keyword(s):

Molecular Size ◽

Gas Permeation ◽

Zeolite Membrane ◽

Type Zeolite ◽

High Silica ◽

Separation Of Co2 ◽

Α Al2o3 ◽

Separation Performances ◽

Molecular Sieving ◽

Permeation Properties

The polycrystalline CHA-type zeolite layer with Si/Al = 18 was formed on the porous α-Al2O3 tube in this study, and the gas permeation properties were determined using single-component H2, CO2, N2, CH4, n-C4H10, and SF6 at 303–473 K. The membrane showed permeation behavior, wherein the permeance reduced with the molecular size, attributed to the effect of molecular sieving. The separation performances were also determined using the equimolar mixtures of N2–SF6, CO2–N2, and CO2–CH4. As a result, the N2/SF6 and CO2/CH4 selectivities were as high as 710 and 240, respectively. However, the CO2/N2 selectivity was only 25. These results propose that the high-silica CHA-type zeolite membrane is suitable for the separation of CO2 from CH4 by the effect of molecular sieving.

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