Analysis of spectral indications of ammonium ions and their connection with the proton-donor ability of oxide systems

1992 ◽  
Vol 56 (4) ◽  
pp. 356-359 ◽  
Author(s):  
A. A. Davydov ◽  
T. A. Gordymova
Keyword(s):  
Proton Donor ◽  
Ammonium Ions ◽  
Oxide Systems ◽  
Donor Ability

scholarly journals The impact of orally administered gadolinium orthovanadate GdVO4:Eu3+ nanoparticles on the state of phospholipid bilayer of erythrocytes

2020 ◽  
Vol 45 (4) ◽  
pp. 389-395
Author(s):  
Anton Tkachenko ◽  
Anatolii Onishchenko ◽  
Vladimir Klochkov ◽  
Nataliya Kavok ◽  
Oksana Nakonechna ◽  
...  
Keyword(s):  
Fluorescent Probes ◽  
Lipid Membranes ◽  
Chemical Properties ◽  
Proton Donor ◽  
The State ◽  
Phospholipid Bilayer ◽  
Erythrocyte Membranes ◽  
Control Group ◽  
Donor Ability ◽  
The Impact

AbstractObjectivesTo assess the state of phospholipid bilayer of red blood cells (RBCs) in rats orally exposed to gadolinium orthovanadate GdVO4:Eu3+ nanoparticles (VNPs) during two weeks using fluorescent probes − ortho-hydroxy derivatives of 2,5-diaryl-1,3-oxazole.MethodsSteady-state fluorescence spectroscopy: a study by the environment-sensitive fluorescent probes − 2-(2′-OH-phenyl)-5-phenyl-1,3-oxazole (probe O1O) and 2-(2′-OH-phenyl)-phenanthro[9,10]-1,3-oxazole (probe PH7).ResultsNo significant changes are detected in the spectra of the fluorescent probes bound to the RBCs from the rats orally exposed to nanoparticles in comparison with the corresponding spectra of the probes bound to the cells from the control group of animals. This indicates that, in case of the rats orally exposed to nanoparticles, no noticeable changes in physico-chemical properties (i.e., in the polarity and the proton-donor ability) are observed in the lipid membranes of RBCs in the region, where the probes locate.ConclusionsNo changes in the physical and chemical properties of the erythrocyte membranes are detected in the region from glycerol backbones of phospholipids to the center of the phospholipid bilayer in the rats orally exposed to VNPs during 2 weeks.

A Potentiometric Study on Proton-Transfer Equilibria and Cationic Conjugation in Pyridine N-Oxide Systems in Acetone and Methanol

1996 ◽  
Vol 49 (9) ◽  
pp. 931 ◽  
Author(s):  
L Chmurzynski ◽  
E Kaczmarczyk ◽  
M Nesterowicz ◽  
G Wawrzyniak ◽  
Z Warnke
Keyword(s):  
Proton Transfer ◽  
Equilibrium Constants ◽  
Proton Donor ◽  
Heterocyclic Amines ◽  
Transfer Reactions ◽  
Oxide Systems ◽  
Experimental Systems ◽  
Proton Transfer Reactions ◽  
Potentiometric Titration Method

The potentiometric titration method has been used to study the equilibria of cationic in sytems formed by substituted pyridine N-oxides in the polar, non-aqueous solvents acetone and methanol. For comparison, the systems with trimethylamine N-oxide as a representative of aliphatic amine N-oxides and pyridine representing parent heterocyclic amines were also studied. The cationic heteroconjugation constants, i.e. the equilibrium constants for conjugation reactions between free and protonated N-bases leading to the formation of unsymmetric BHB'+ cations, were determined in experimental systems with and without proton transfer. It was found that there were significant differences in the values of the cationic heteroconjugation constants determined in these two acid-base systems. The proton-transfer reactions limit and even preclude the determination of the cationic heteroconjugation constants. On this basis it was concluded that the heteroconjugation constants should be determined in systems without proton transfer. In such systems, in the amphiprotic solvent methanol, cationic heteroconjugation was ascertained in all substituted pyridine N-oxide systems, the values of heteroconjugation constants being relatively low (logarithms of their values of the order of 2-2.5), and only negligible in systems involving trimethylamine N-oxide. A more pronounced tendency towards cationic heteroconjugation of the [OHO]+ type was observed in the aprotic protophobic acetone, where heteroconjugation constants were determined for all amine N-oxide systems studied including those containing protonated trimethylamine N-oxide as a proton donor. However, the values of the cationic heteroconjugation constants were found to be, in methanol likewise, relatively low (log KBHB'+ of the order of 2-3). On the contrary, a greater extent of cationic heteroconjugation equilibria was observed in methanol than in acetone in the case of systems containing pyridine, i.e. [NHO]+ type bridges formed by amine N-oxides and heterocyclic amines. In methanol the heteroconjugation constants turned out to be determinable for all such systems studied (logarithms of the equilibrium constants being of the same order as for N-oxide systems), whereas in acetone the hetero constants were indeterminable for all systems.

IR-spectroscopic evaluation of proton-donor ability of HCl, HBr, HI acids and HSO3CF3, HClO4, HGeCl3, HAlCl4 superacids

1983 ◽  
Vol 32 (3) ◽  
pp. 636-637
Author(s):  
V. B. Kazanskii ◽  
O. M. Nefedov ◽  
A. A. Pankov ◽  
V. Yu. Borovkov ◽  
S. P. Kolesnikov ◽  
...  
Keyword(s):  
Proton Donor ◽  
Donor Ability ◽  
Ir Spectroscopic

scholarly journals The inhibition of the proton donor ability of bicarbonate promotes the electrochemical conversion of CO2 in bicarbonate solutions

2021 ◽  
Vol 48 ◽  
pp. 101521
Author(s):  
Oriol Gutiérrez-Sánchez ◽  
Nick Daems ◽  
Willem Offermans ◽  
Yuvraj Y. Birdja ◽  
Metin Bulut ◽  
...  
Keyword(s):  
Proton Donor ◽  
Electrochemical Conversion ◽  
Donor Ability ◽  
Bicarbonate Solutions

Structure and proton-donor ability of N-(1-trifluoromethylsulfonylamino-2,2,2-trichloroethyl)-acrylamide

2009 ◽  
Vol 79 (6) ◽  
pp. 1146-1151 ◽  
Author(s):  
L. P. Oznobikhina ◽  
N. N. Chipanina ◽  
B. A. Shainyan ◽  
T. N. Aksamentova ◽  
E. V. Kondrashov ◽  
...  
Keyword(s):  
Proton Donor ◽  
Donor Ability

scholarly journals Acidity of HOCN, HSCN, HNCO, HNCS: A treatment from the viewpoint of ab initio approach

2005 ◽  
Vol 70 (10) ◽  
pp. 1183-1192 ◽  
Author(s):  
Alexei Pankratov ◽  
Sergei Khmelev
Keyword(s):  
Electronic Structure ◽  
Ab Initio ◽  
Thermodynamic Stability ◽  
Electronic Structures ◽  
Proton Donor ◽  
Electronic Correlation ◽  
Medium Effects ◽  
General Sequence ◽  
Donor Ability ◽  
Ab Initio Approach

The electronic structures of the molecules HOCN, HSCN, HNCO, HNCS and the anions OCN -, SCN - have been investigated ab initio at the RHF/6-31G(d) RHF/6-31G(d,p), MP2/6-31G(d)//RHF/6-31G(d) and MP2/6-31G(d,p)//RHF/6-31G(d,p) theory levels. The thermodynamic stability of the HNCO and HNCS molecules was shown to be higher than that of the HOCH and HSCN molecules, respectively. The following series of the alteration of the protolytes strength HSCN > HOCH HNCS > HNCO, HOCN > HNCO, HSCN > HNCS was substantiated. The computations taking into account the electronic correlation (MP2/6-31G(d)//RHF/6-31G(d) and MP2/6-31G(d,p)//RHF/6-31G(d,p)) reflect the general sequence of change in the pro- ton-donor properties: HSCN > HOCN > HNCS > HNCO, coinciding with the order of descending hydrophobicity of the compounds. The comparative proton-donor ability of the above acids in aqueous solutions is determined basically from the electronic structure and size of their molecules and anions OCN -, SCN -, but not on medium effects.

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