Sodium cation complexation behavior of the heteroaromatic sidechains of histidine and tryptophan

2002 ◽  
pp. 1810-1811 ◽  
Author(s):  
Jiaxin Hu ◽  
Leonard J. Barbour ◽  
Riccardo Ferdani ◽  
George W. Gokel
Keyword(s):  
Sodium Cation ◽  
Cation Complexation

ChemInform Abstract: DYNAMICS OF SODIUM CATION COMPLEXATION BY CARBON- AND NITROGEN-PIVOT LARIAT ETHERS

1983 ◽  
Vol 14 (1) ◽  
Author(s):  
A. KAIFER ◽  
H. D. DURST ◽  
L. ECHEGOYEN ◽  
D. M. DISHONG ◽  
R. A. SCHULTZ ◽  
...  
Keyword(s):  
Sodium Cation ◽  
Lariat Ethers ◽  
Cation Complexation ◽  
Carbon And Nitrogen

Dynamics of sodium cation complexation by carbon- and nitrogen-pivot lariat ethers

1982 ◽  
Vol 47 (16) ◽  
pp. 3195-3197 ◽  
Author(s):  
Angel Kaifer ◽  
H. Dupont Durst ◽  
Luis Echegoyen ◽  
Dennis M. Dishong ◽  
Rose Ann Schultz ◽  
...  
Keyword(s):  
Sodium Cation ◽  
Lariat Ethers ◽  
Cation Complexation ◽  
Carbon And Nitrogen

scholarly journals The Role of Triazole and Glucose Moieties in Alkali Metal Cation Complexation by Lower-Rim Tertiary-Amide Calix[4]arene Derivatives

Molecules ◽  
2022 ◽  
Vol 27 (2) ◽  
pp. 470
Author(s):  
Josip Požar ◽  
Marija Cvetnić ◽  
Andrea Usenik ◽  
Nikola Cindro ◽  
Gordan Horvat ◽  
...  
Keyword(s):  
Alkali Metal ◽  
Alkali Metal Cation ◽  
Sodium Cation ◽  
Cation Binding ◽  
Medium Effect ◽  
Cation Complexation ◽  
Tertiary Amide ◽  
Dissolution Enthalpies ◽  
Metal Cation Complexation

The binding of alkali metal cations with two tertiary-amide lower-rim calix[4]arenes was studied in methanol, N,N-dimethylformamide, and acetonitrile in order to explore the role of triazole and glucose functionalities in the coordination reactions. The standard thermodynamic complexation parameters were determined microcalorimetrically and spectrophotometrically. On the basis of receptor dissolution enthalpies and the literature data, the enthalpies for transfer of reactants and products between the solvents were calculated. The solvent inclusion within a calixarene hydrophobic basket was explored by means of 1H NMR spectroscopy. Classical molecular dynamics of the calixarene ligands and their complexes were carried out as well. The affinity of receptors for cations in methanol and N,N-dimethylformamide was quite similar, irrespective of whether they contained glucose subunits or not. This indicated that sugar moieties did not participate or influence the cation binding. All studied reactions were enthalpically controlled. The peak affinity of receptors for sodium cation was noticed in all complexation media. The complex stabilities were the highest in acetonitrile, followed by methanol and N,N-dimethylformamide. The solubilities of receptors were greatly affected by the presence of sugar subunits. The medium effect on the affinities of calixarene derivatives towards cations was thoroughly discussed regarding the structural properties and solvation abilities of the investigated solvents.

Flame Photometry Characterization Procedure for Sodium Content in Brazilian Bentonites for Nanotechnology Applications

2019 ◽  
Vol 12 (2) ◽  
pp. 122-129
Author(s):  
Hellen S. Santos ◽  
Karine L. Buarque da Silva ◽  
Ariel E. Zanini ◽  
Danilo S. Coelho ◽  
Marcelo Embiruçu ◽  
...  
Keyword(s):  
Control Process ◽  
Sodium Concentration ◽  
High Water ◽  
Sodium Content ◽  
Industrial Applications ◽  
Exchange Capacity ◽  
Sodium Cation ◽  
Flame Photometry ◽  
Logarithmic Scale ◽  
Average Value

Background: Brazilian bentonites have a low sodium concentration in their interlayer structure. This is a problem with most of the industrial applications that demand the characteristics of sodium bentonites. Objective: As a solution for this limitation, sodium carbonate is added to in natura clays, promoting ion exchange between other interlayer cations with sodium. Methods: A process was used based on the principle of Stokes’ Law (BR Patent 10 2013 016298). For this, we used four glass columns in series, in which a high water flow was considered to obtain purified clays. It was proposed as a simple, fast and economical method for sodium determination that was developed and applied in bentonites by flame photometry. The equipment calibration was performed with a NaCl standard solution in concentrations between 80 and 110 ppm. The bentonites in the suspension were separated by means of centrifugation, being thus analyzed by a flame photometer. Results: The samples were prepared according to the manufacturer’s specifications to contain detectable amounts of sodium by means of flame photometry. A resulting linear relationship between the average value readings versus sodium standard content solution (both in ppm) was obtained by the logarithmic scale, as expected. Conclusion: The procedure allowed to define a method that could be used in the sodification control process, thus making it possible to differentiate the sodium cation content in terms of the value of cation exchange capacity (CEC) from bentonite. X-ray analysis of in natura and the sodified clays showed nanostructural differences related to interlayer distance.

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