Extraction and DFT study of complexation of the cesium cation with beauvericin

Abstract  

From extraction experiments in the two-phase water–nitrobenzene system and γ-activity measurements, the stability constant of the beauvericin–Cs⁺ complex species dissolved in nitrobenzene saturated with water was determined. By using quantum–mechanical density functional level of theory (DFT) calculations, the most probable structure of this complex was derived.     

A combined experimental and theoretical study on the complexation of the ammonium ion with benzo-18-crown-6

Abstract  

From extraction experiments in the two-phase water/nitrobenzene system and γ-activity measurements, the stability constant of the benzo-18-crown-6–ammonium complex in nitrobenzene saturated with water was determined. Furthermore, the structure of the resulting complex was derived by means of theoretical calculations at the density functional level.     

On the protonation of dibenzo-18-crown-6

Abstract  

The stability constant of the dibenzo-18-crown-6·H₃O⁺ cationic complex species dissolved in nitrobenzene saturated with water has been determined from extraction experiments in the two-phase water–nitrobenzene system and from γ-activity measurements. Various structures of protonated dibenzo-18-crown-6 are discussed.     

Solvent extraction of silver trifluoromethanesulfonate from water into nitrobenzene in the presence of silver ionophore?IV

Abstract  

From extraction experiments in the two-phase water/nitrobenzene system, the stability constant of the silver ionophore IV (i.e., 5,11,17,23-tetra-tert-butyl-25,27-bis[2-(methylthio)ethoxy]calix[4]arene)–Ag⁺ complex in nitrobenzene saturated with water was determined. Furthermore, the most probable structure of the resulting complex was derived by means of density functional level of theory calculations.     

A combined experimental and theoretical study on the complexation of Li<Superscript>+</Superscript> with valinomycin

Abstract  From extraction experiments in the two-phase water–nitrobenzene system and γ-activity measurements, the stability constant of the valinomycin–lithium complex in nitrobenzene saturated with water was determined. Further, the structure of the resulting complex was indicated by means of the density functional level of theory (DFT) calculations. Graphical abstract        

Experimental and theoretical study of the complexation of the thallium cation with a hexaarylbenzene-based receptor

Abstract  

From extraction experiments in the two-phase water/nitrobenzene system and γ-activity measurements, the stability constant of a hexaarylbenzene-based receptor. Tl⁺ complex species dissolved in nitrobenzene saturated with water was determined. By using the quantum-mechanical density functional level of theory calculations, the most probable structure of this complex was derived.     

On the complexation of the sodium cation with beauvericin: experimental and theoretical study

Abstract  

From extraction experiments in the two-phase water/nitrobenzene system and γ-activity measurements, the stability constant of the beauvericin·Na⁺ complex species dissolved in nitrobenzene saturated with water was determined. By using quantum mechanical density functional level of theory (DFT) calculations, the most probable structure of this complex species was derived.     

A combined extraction and DFT study on the complexation of the silver cation with dibenzo-18-crown-6

Abstract  

Extraction experiments in the two-phase water/nitrobenzene system and γ-activity measurements were used to determine the stability constant of the dibenzo-18-crown-6·Ag⁺ complex species in nitrobenzene saturated with water. Furthermore, the structure of the resulting complex was derived by means of theoretical calculations at the density functional level.     

A combined extraction and DFT study on the complexation of K+ with valinomycin

Abstract  From extraction experiments in the two-phase water–nitrobenzene system and γ-activity measurements, the stability constant of protonated tetraethyl p-tert-butylcalix[4]arene tetraacetate in nitrobenzene saturated with water was determined. By using DFT calculations, the most probable structure of the tetraethyl p-tert-butylcalix[4]arene tetraacetate·H₃O⁺ complex species was derived. Graphical Abstract        

On the protonation of dibenzo-18-crown-6

Abstract  The stability constant of the dibenzo-18-crown-6·H₃O⁺ cationic complex species dissolved in nitrobenzene saturated with water has been determined from extraction experiments in the two-phase water–nitrobenzene system and from γ-activity measurements. Various structures of protonated dibenzo-18-crown-6 are discussed. Graphical abstract        

Experimental evidence, stability, and the most probable structure of protonated p-tert-butylcalix[4]arenetetrakis(N,N-dimethylacetamide)

Abstract  

From extraction experiments and γ-activity measurements, the extraction constant corresponding to the equilibrium H₃O⁺(aq) + 1·Na⁺(nb) \leftrightarrows \leftrightarrows 1·H₃O⁺ (nb) + Na⁺ (aq) taking place in the two-phase water–nitrobenzene system (1 = p-tert-butylcalix[4]arenetetrakis(N,N-dimethylacetamide); aq = aqueous phase, nb = nitrobenzene phase) was evaluated as log K _ex (H₃O⁺, 1·Na⁺) = −0.1 ± 0.1. Further, the stability constant of the 1·H₃O⁺ complex in water-saturated nitrobenzene was calculated for a temperature of 25 °C as log β _nb (1·H₃O⁺) = 10.9 ± 0.2. By using quantum mechanical DFT calculations, the most probable structure of the 1·H₃O⁺ cationic complex species was derived. In this complex, the hydroxonium ion H₃O⁺ is bound partly to one phenoxy oxygen atom and partly to two carbonyl oxygens of 1 by strong hydrogen bonds and obviously by other electrostatic interactions.     

Extraction and DFT study on the complexation of H3O+ ion with tetrakis(2-ethoxyethoxy)-tetra-p-tert-butylcalix[4]arene

Abstract  

Extraction experiments in the two-phase water/nitrobenzene system and γ-activity measurements were used to determine the stability constant of protonated tetrakis(2-ethoxyethoxy)-tetra-p-tert-butylcalix[4]arene in nitrobenzene saturated with water. Density functional theory (DFT) calculations were applied to derive the most probable structure of the tetrakis(2-ethoxyethoxy)-tetra-p-tert-butylcalix[4]arene·H₃O⁺ complex species.     

Stability constants of the Li+, Na+, H3O+, NH4+, Ag+, and K+ complexes of the cone conformer of tetraethyl p-tert-butyltetrathiacalix[4]arene tetraacetate in nitrobenzene saturated with water

Abstract  

From extraction experiments in the two-phase water–nitrobenzene system and γ-activity measurements, the stability constants of the tetraethyl p-tert-butyltetrathiacalix[4]arene tetraacetate (cone)·M⁺ complexes (M⁺ = Li⁺, H₃O⁺, NH₄ ⁺, Ag⁺, or K⁺) were determined in water-saturated nitrobenzene. It was found that these constants increase in the cation order NH₄ ⁺ < K⁺ < H₃O⁺ < Ag⁺ < Li⁺ < Na⁺.     

Extraction and DFT study on the complexation of the cesium cation with a hexaarylbenzene-based receptor

From extraction experiments and γ-activity measurements, the extraction constant corresponding to the equilibrium Cs⁺(aq) + A⁻(aq) + 1(nb) ⇆ 1·Cs⁺(nb) + A⁻ (nb) taking part in the two-phase water–nitrobenzene system (A⁻ = picrate, 1 = hexaarylbenzene-based receptor; aq = aqueous phase, nb = nitrobenzene phase) was evaluated as log K _ex (1·Cs⁺, A⁻) = 2.8 ± 0.1. Further, the stability constant of the hexaarylbenzene-based receptor·Cs⁺ complex (abbrev. 1·Cs⁺) in nitrobenzene saturated with water was calculated for a temperature of 25 °C: log β _nb (1·Cs⁺) = 4.7 ± 0.1. By using quantum mechanical DFT calculations, the most probable structure of the 1·Cs⁺ complex species was solved. In this complex having C ₃ symmetry, the cation Cs⁺ synergistically interacts with the polar ethereal oxygen fence and with the central hydrophobic benzene bottom via cation–π interaction. Finally, the calculated binding energy of the resulting complex 1·Cs⁺ is −220.0 kJ/mol, confirming relatively high stability of the considered cationic complex species.     

Kinetics, mechanism, and DFT calculations of thermal degradation of a Zn(II) complex with N-benzyloxycarbonylglycinato ligands

Abstract  

A Zn(II) complex with N-benzyloxycarbonylglycinato ligands was studied by non-isothermal methods, in particular Kissinger–Akahira–Sunose’s method, and further analysis of these results was performed by Vyazovkin’s algorithm and an artificial compensation effect. Density functional theory calculations of thermodynamic quantities were performed, and results obtained by both methods are consistent, thus clarifying the mechanism of this very interesting multi-step degradation.     

A combined extraction and DFT study on the complexation of H3O+ with a hexaarylbenzene-based receptor

Abstract  

By means of theoretical calculations at density functional level, the complex structure of a hexaarylbenzene-based receptor with Na⁺ was derived. In the resulting complex having C ₃ symmetry, the sodium cation synergistically interacts with the hydrophilic polar ethereal oxygen fence and with the central hydrophobic benzene bottom of the parent receptor via cation–π interaction.     

A Combined Experimental and Theoretical Study on the Complexation of Ag<Superscript>+</Superscript> with a Hexaarylbenzene-Based Receptor

From extraction experiments and γ-activity measurements, the exchange extraction constant corresponding to the equilibrium Ag⁺(aq) + 1⋅Cs⁺(nb) ⇆ 1⋅Ag⁺(nb) + Cs⁺(aq) taking part in the two-phase water–nitrobenzene system (where 1 = hexaarylbenzene-based receptor; aq = aqueous phase, nb = nitrobenzene phase) was evaluated to be log ₁₀ K _ex(Ag⁺, 1⋅Cs⁺) = −1.0±0.1. Further, the stability constant of the hexaarylbenzene-based receptor⋅Ag⁺ complex (abbreviation 1⋅Ag⁺) in nitrobenzene saturated with water, was calculated at a temperature of 25 °C: log ₁₀ β _nb(1⋅Ag⁺) = 5.5±0.2. By using quantum mechanical DFT calculations, the most probable structure of the 1⋅Ag⁺ complex species was solved. In this complex having C₃ symmetry, the cation Ag⁺ synergistically interacts with the polar ethereal oxygen fence and with the central hydrophobic benzene ring via cation–π interaction.     

Experimental and theoretical study on the complexation of the cesium cation with dibenzo-30-crown-10

From extraction experiments and γ-activity measurements, the extraction constant corresponding to the equilibrium Cs⁺ (aq) + A⁻ (aq) + 1(nb) \rightleftarrows \rightleftarrows 1·Cs⁺(nb) + A⁻(nb) taking place in the two-phase water–nitrobenzene system (A⁻ = picrate, 1 = dibenzo-30-crown-10; aq = aqueous phase, nb = nitrobenzene phase) was evaluated as log K _ex (1·Cs⁺, A⁻) = 4.0 ± 0.1. Further, the stability constant of the 1·Cs⁺ complex in nitrobenzene saturated with water was calculated for a temperature of 25 °C: log β _nb (1·Cs⁺) = 5.9 ± 0.1. Finally, by using quantum–mechanical DFT calculations, the most probable structure of the resulting cationic complex species 1·Cs⁺ was derived.     

A one-pot synthesis of alkyl acylcarbamodithioates from acid chlorides, thiols, and ammonium thiocyanate

Abstract  

An efficient synthesis of alkyl acylcarbamodithioates by reaction of acid chlorides with ammonium thiocyanate in the presence of thiols is described. The unusually large values of ⁵ J _FH = 12–15 Hz, observed for alkyl (2-fluorobenzoyl)carbamodithioates provide information about Ar–C–N–H torsion in these compounds.     

Self-assembled cobalt(II) Schiff base complex: synthesis, structure, and magnetic properties

Abstract  

A mononuclear complex [CoL₂Cl₂]·3.5H₂O (L = 2-[(2,2-diphenylethylimino)methyl]pyridine-1-oxide) has been synthesized and characterized by X-ray structure analysis. The crystal structure confirms the formation of an interesting porous framework with channel diameters of about 8 ? through weak C–H···π and C–H···Cl interactions. The magnetic properties of this complex have also been studied, and the susceptibility and magnetization data were analyzed in terms of the spin Hamiltonian formalism. They confirm substantial zero-field splitting, D/hc = 75 cm⁻¹.