Study of pH-dependent charges of soils by surface acid–base properties

2007 ◽  
Vol 305 (1) ◽  
pp. 94-100 ◽  
Author(s):  
Noémi M. Nagy ◽  
József Kónya
Keyword(s):  
Acid Base ◽  
Ph Dependent ◽  
Base Properties

scholarly journals Self-Structuring in Water of Polyamidoamino Acids with Hydrophobic Side Chains Deriving from Natural α-Amino Acids

Polymers ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1261 ◽  
Author(s):  
Federica Lazzari ◽  
Amedea Manfredi ◽  
Jenny Alongi ◽  
Raniero Mendichi ◽  
Fabio Ganazzoli ◽  
...  
Keyword(s):  
Amino Acids ◽  
Main Chain ◽  
Intramolecular Interactions ◽  
Wavelength Interval ◽  
Acid Base ◽  
Repeat Units ◽  
Inflection Points ◽  
Ph Dependent ◽  
Selective Interactions ◽  
Base Properties

This paper reports on synthesis, acid-base properties and self-structuring in water of chiral polyamidoamino acids (PAACs) obtained by polyaddition of N,N′-methylenebisacrylamide with l-alanine, l-valine and l-leucine (M-l-Ala, M-l-Val, M-l-Leu) with potential for selective interactions with biomolecules. The polymers maintained the acid-base properties of amino acids. In water, the circular dichroism spectra of PAACs revealed pH-dependent structuring in the range 3–11 and in the wavelength interval 200–280 nm. Taking as reference the values at pH 3, the differential molar ellipticities were plotted in the pH interval 3–11. Sigmoidal curves were obtained presenting inflection points at pH 8.1, 6.8 and 7.3 for M-l-Ala, M-l-Val and M-l-Leu, respectively, corresponding to the amine half-ionization. Theoretical modeling showed that PAACs assumed stable folded conformations. Intramolecular interactions led to transoid arrangements of the main chain reminiscent of protein hairpin motif. Oligomers with ten repeat units had simulated gyration radii consistent with the hydrodynamic radii obtained by dynamic light scattering.

Acid-base properties of 1,3-diphenyl-5-(1H-tetrazol-2-yl)formazan and 1,3-diphenyl-5-(2H-1,2,4-triazol-3-yl)formazan

1982 ◽  
Vol 47 (11) ◽  
pp. 2882-2889
Author(s):  
Nadezhda Likhareva ◽  
Ladislav Šůcha ◽  
Miloslav Suchánek
Keyword(s):  
Computer Program ◽  
Dissociation Constants ◽  
Acid Base ◽  
New Compounds ◽  
Base Properties

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.

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

1984 ◽  
Vol 49 (10) ◽  
pp. 2355-2362 ◽  
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.

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

2016 ◽  
Vol 30 (5) ◽  
pp. e3623 ◽  
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

scholarly journals Differentiation of isomeric metabolites of carbamazepine based on acid-base properties; experimental vs theoretical approach

2021 ◽  
pp. 462275
Author(s):  
Paweł Mateusz Nowak ◽  
Mariusz Mitoraj ◽  
Filip Sagan ◽  
Renata Wietecha-Posłuszny
Keyword(s):  
Theoretical Approach ◽  
Acid Base ◽  
Base Properties
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