Nitrobenzene Phase Research Articles

Solvent extraction of europium(III) trifluoromethanesulfonate into nitrobenzene by using [2.2.2]paracyclophane – Experimental and theoretical study

The extraction constant corresponding to the equilibrium Eu3+(aq) + 3A-(aq) + 1(nb) ⇌ 1 Eu3+(nb) + 3A–(nb) occurring in the two-phase water–nitrobenzene system (A-=CF3SO3-; 1 = [2.2.2]paracyclophane; aq = aqueous phase, nb = nitrobenzene phase) was determined as logKex(Eu3+,3A–) = -5.7 ± 0.1. Further, the stability constant of the 1 Eu3+ complex in nitrobenzene saturated with water was calculated as log Knb(1 Eu3+) = 7.4 ± 0.1. Finally, by using quantum chemical calculations, the most probable conformation of the cationic complex species 1 Eu3+ was derived. In the resulting complex, the “central” cation Eu3+, fully located in the cavity of the parent [2.2.2]paracyclophane ligand, is bound to all three benzene rings of [2.2.2]paracyclophane via cation-π interaction.

Mode Bifurcation on Contact Line Dynamics at Oil/Water Interface Depending on the Contact Line Length

The motion of the contact line at the oil/water interface caused by chemical reactions is well known as a typical example of artificial active matter in the field of nonlinear science. When water (containing trimethylstearylammonium chloride) and nitrobenzene (containing iodide anion) phases are in contact, the regulated traveling-wave patterns appear along the inner wall of the glass container. In this study, we demonstrate a new dynamical mode of the contact line, an up-and-down motion, which becomes dominant with the decrease in the size of a glass tube, and the probability of occurrence is extremely high when the diameter of the glass tube is below 1 mm. A physicochemical model of the contact line motion that incorporates the spatiotemporal variation of the surfactant concentration on a glass surface is proposed, and its effect on the wettability of oil/water phases on the walls of the glass tubes is studied. The present model can reproduce the mode bifurcation of the dynamical motion depending on the inner diameter of the glass tubes.

Solvent Extraction of Some Univalent Cations into Nitrobenzene by Using Cesium Dicarbollylcobaltate and Four Bis(crown-6) Ether Derivatives of Calix[4]arene

On the basis of extraction experiments and $$\gamma$$ -activity measurements, the exchange extraction constants corresponding to the general equilibrium M+(aq) + CsL+(nb) ⇌ ML+(nb) + Cs+(aq) occurring in the two-phase water–nitrobenzene system (M+ = K+, Rb+, Ag+, Tl+; L = bis(crown-6) ether derivatives of calix[4]arene, where aq = aqueous phase and nb = nitrobenzene phase) were evaluated. Moreover, the stability constants of the proven ML+ complexes in water-saturated nitrobenzene were calculated and are discussed.

Spontaneous Generation of Hydrogen Gas Using a Photochemical Reaction of Fullerene (C60) in the Presence of Tetraphenylborate in a Photovoltaic Cell with Oil and Water Phases

We have shown that an anion radical of C60 (C60•−) is readily formed in a nitrobenzene (NB) solution containing tetraphenylborate by solar-light irradiation. Applying this photochemical reaction of C60, we examined a voltammetric behavior of C60•− by using an electron conductor separating oil-water (ECSOW) system consisting of NB and water (W) phases. Based on the behavior, we can successfully attain spontaneous generation of hydrogen gas in a photovoltaic cell with NB and W phases.

Interfacial Behavior of Cs+, K+, Na+, and Rb+ Extraction in the Presence of Dibenzo-18-Crown-6 from the Nitrobenzene-Water Biphasic System: Experimental, Quantum Chemical, and Molecular Dynamic Studies.

Extraction of metal ions (i.e., Cs+, K+, Na+, and Rb+) in the presence of ionophore such as dibenzo-18-crown-6 (DB18C6) from the nitrobenzene–water biphasic system is reported by COSMO-RS (conductor-like screening model for real solvents) predictions, molecular dynamics simulation, along with experimental validation. The predicted values of selectivity as obtained for the Na+–DB18C6 complex were 4.571, 4.877, and 4.947 at 298.15, 308.15, and 318.15 K, respectively. This was then confirmed by the experimental distribution coefficient (D) as obtained in the diluent systems along with by varying the metal ion to crown ether ligand (M–L) mole ratios: 10:1 (0.1 M M+ and 0.01 M DB18C6), 1:1 (0.01 M M+ and 0.01 M DB18C6), and 1:10 (0.001 M M+ and 0.01 M DB18C6). The experimentally determined values of DNa (i.e., 0.059, 0.060, and 0.056) were found to be very large as compared to the values of DCs (i.e., 0.001, 0.010, and 0.024) in the nitrobenzene phase. It indicates an excellent extraction ability of DB18C6 for Na+. The rate of phase separation for the Cs+NO3– system was slow as compared to other metal ion systems. The binding energies, free energies, and nonbonded interaction energies of the complexed metal ion in solution were calculated with both explicit and implicit solvent models. A higher interaction energy between Na+–DB18C6 complex and nitrobenzene was observed (i.e., −289.92 in the explicit model and −143.12 kcal/mol in the implicit model) when compared with other metal ions (i.e., Cs+, K+, and Rb+).

Interaction of the univalent silver cation with [Gly6]-antamanide: Experimental and theoretical study

On the basis of extraction experiments and γ-activity measurements, the extraction constant corresponding to the equilibrium Ag+(aq) + 1.Na+(nb) ⇄ 1.Ag+ (nb) + Na+(aq) occurring in the two–phase water – nitrobenzene system (1 = [Gly6]-antamanide; aq = aqueous phase, nb = nitrobenzene phase) was determined as log Kex (Ag+,1·Na+) = 1.5 ± 0.1. Further, the stability constant of the 1·Ag+ complex in nitrobenzene saturated with water was calculated for a temperature of 25 °C: log βnb (1·Ag+) = 4.5 ± 0.2. Finally, by using quantum chemical DFT calculations, the most probable structure of the cationic complex species 1·Ag+ was derived. In the resulting complex, the “central” cation Ag+ is coordinated by four noncovalent interactions to the corresponding four carbonyl oxygen atoms of the parent ligand 1. Besides, the whole 1·Ag+ complex structure is stabilized by two intramolecular hydrogen bonds. The interaction energy of the considered 1·Ag+ complex was found to be −465.5 kJ/mol, confirming also the formation of this cationic species.

Behaviors of the Interfacial Consecutive Multistep Electron Transfer Controlled by Varied Transition Metal Ions in Porphyrin Cores.

Almost all life activities involve the process of multistep electron transfer (ET) which occurs on biomembrane. Metalloporphyrins (MTPPs) are a class of molecules which are closely related to life course. Here, the n-step (n = 1, 2) ET behaviors controlled by different metal ions in porphyrin cores were investigated by thin-layer cyclic voltammetry (TLCV). The bimolecular ET was reacted between the MTPP (M = Fe, Zn, Co, Cu, Ni) and Fe(CN)64- in nitrobenzene and aqueous phase, respectively, and the interface between nitrobenzene and aqueous phase was considered as a bionic membrane. The thin-layer theory, which has been revised, was used to calculate the kinetic constants for each step electron transfer reactions. It was shown that the kinetic data were affected dramatically by the different coordinated ions in porphyrin complexes.

N,N,N',N'-Tetrabutyl-1,10-phenanthroline-2,9-dicarboxamide as Very Effective Extraction Agent for Trivalent Europium and Americium.

Solvent extraction of microamounts of Eu3+ and Am3+ from water into nitrobenzene by means of a mixture of hydrogen dicarbollylcobaltate (H+B-) and N,N,N',N'-tetrabutyl-1,10-phenanthroline-2,9-dicarboxamide (L) was studied. The equilibrium data were explained assuming that the species HL+, H2L2+, HL+2, ML3+2, and ML3+3 (M3+ = Eu3+, Am3+; L = N,N,N',N'-tetrabutyl-1,10-phenanthroline-2,9-dicarboxamide) are extracted into the nitrobenzene phase. Extraction and stability constants of the cationic complex species in nitrobenzene saturated with water were determined and discussed. From the experimental results it is evident that this effective N,N,N',N'-tetrabutyl-1,10-phenanthroline-2,9-dicarboxamide receptor for the Eu3+ and Am3+ cations could be considered as a potential extraction agent for nuclear waste treatment.

Extraction and DFT study on complexation of the barium cation with [Gly6]-antamanide

On the basis of extraction experiments and γ-activity measurements, the extraction constant corresponding to the equilibrium Ba2+(aq) + 1·Sr2+(nb) ⇄1·Ba2+ (nb) + Sr2+(aq) occurring in the two–phase water – nitrobenzene system (1 = [Gly6]-antamanide; aq = aqueous phase, nb = nitrobenzene phase) was determined as log Kex (Ba2+,1·Sr2+) = 0.6 ± 0.1. Further, the stability constant of the 1·Ba2+ complex in nitrobenzene saturated with water was calculated for a temperature of 25 °C: log βnb (1·Ba2+) = 9.5 ± 0.2. Finally, by using quantum chemical DFT calculations, the most probable structure of the cationic complex species 1·Ba2+ was derived. In the resulting complex, the “central” cation Ba2+ is bound by six bonding interactions to the corresponding six carbonyl oxygen atoms of the parent ligand 1. The interaction energy of the considered 1·Ba2+ complex was found to be −943.5 kJ/mol, confirming the formation of this cationic species as well

Experimental and theoretical study on complexation of the calcium cation with [Gly6]-antamanide

On the basis of extraction experiments and γ-activity measurements, the extraction constant corresponding to the equilibrium Ca2+(aq)+1∙Sr2+(nb)⇄1∙Ca2+ (nb)+Sr2+(aq) occurring in the two–phase water–nitrobenzene system (1=[Gly6]-antamanide; aq=aqueous phase, nb=nitrobenzene phase) was determined as log Kex (Ca2+,1·Sr2+)=0.6±0.1. Further, the stability constant of the 1·Ca2+ complex in nitrobenzene saturated with water was calculated for a temperature of 25°C: log βnb (1∙Ca2+)=10.2±0.2. Finally, by using quantum chemical DFT calculations, the most probable structure of the cationic complex species 1∙Ca2+ was derived. In the resulting complex, the “central” cation Ca2+ is bound by six bonding interactions to the corresponding six carbonyl oxygen atoms of the parent ligand 1. The interaction energy of the considered 1∙Ca2+ complex was found to be −1221.2kJ/mol, confirming the formation of this cationic species as well.

Synergistic Extraction of Some Univalent Cations from Water into Nitrobenzene Using Sodium Dicarbollylcobaltate and Antamanide

On the basis of extraction experiments and γ-activity measurements, the exchange extraction constants corresponding to the general equilibrium M+(aq) + 1·Na+(nb) $$ \rightleftharpoons $$ 1·M+(nb) + Na+(aq) taking place in the two–phase water–nitrobenzene system (M+ = Li+, H3O+, $$ \text{NH}_{\text{4}}^{ + } $$ , Ag+, K+, Rb+, Tl+, Cs+; 1 = antamanide; aq = aqueous phase, nb = nitrobenzene phase) were evaluated. Furthermore, the stability constants of the 1·M+ complexes in nitrobenzene saturated with water were calculated; they were found to increase in the cation series Cs+ < Rb+ < Tl+ < K+ < Ag+ < $$ \text{NH}_{\text{4}}^{ + } $$ < H3O+ < Li+, Na+.

Experimental and theoretical study on complexation of the lithium cation with [Gly6]-antamanide

ABSTRACTOn the basis of extraction experiments and γ-activity measurements, the extraction constant corresponding to the equilibrium Li+(aq) + 1⋅Na+(nb) 1⋅Li+ (nb) + Na+(aq) occurring in the two-phase water–nitrobenzene system (1 = [Gly6]-antamanide; aq = aqueous phase, nb = nitrobenzene phase) was determined as log Kex(Li+,1·Na+) = 0.6 ± 0.1. Further, the stability constant of the 1⋅Li+ complex in nitrobenzene saturated with water was calculated for a temperature of 25 °C: logβnb(1⋅Li+) = 5.8 ± 0.2. Finally, by using quantum chemical calculations, the most probable structure of the cationic complex species 1⋅Li+ was derived. In the resulting complex, the ‘central’ cation Li+ is bound by four bonding interactions to the corresponding four carbonyl oxygen atoms of the parent ligand 1. Besides, the whole 1⋅Li+ complex structure is stabilised by two intramolecular hydrogen bonds. The interaction energy of the considered 1⋅Li+ complex was found to be –553.5 kJ/mol, confirming also the formation of this cationic species.

Protonation of calix[4]arene-(2,3-naphthylene-crown-6,crown-6): Experimental and theoretical study

On the basis of extraction experiments and γ-activity measurements, the extraction constant corresponding to the equilibrium H3O+ (aq) + 1·Na+ (nb) ⇄1·H3O+ (nb) + Na+ (aq) occurring in the two–phase water–nitrobenzene system (1 = calix[4]arene-(2,3-naphthylene-crown-6,crown-6); aq = aqueous phase, nb = nitrobenzene phase) was determined as log Kex(H3O+,1·Na+) = −0.2 ± 0.1. Further, the stability constant of the 1·H3O+ complex in nitrobenzene saturated with water was calculated for a temperature of 25 °C: log βnb(1·H3O+) = 5.9 ± 0.2. Finally, applying quantum chemical DFT calculations, the most probable structure of the cationic complex species 1·H3O+ was derived. In the resulting complex, the “central” cation H3O+ is bound by three strong hydrogen bonds to two phenoxy oxygen atoms and to one ethereal oxygen from the crown-6 moiety of the parent ligand 1. The interaction energy, E(int), of the considered 1·H3O+ complex was found to be −416.0 kJ/mol, confirming the formation of this cationic species as well.

Calix[4]arene-(1,2-phenylene-crown-6,crown-6) as an extraordinarily effective macrocyclic receptor for the univalent silver cation

ABSTRACTOn the basis of extraction experiments and γ-activity measurements, the extraction constant corresponding to the equilibrium Ag+(aq) + 1·Cs+ (nb) 1·Ag+(nb) + Cs+ (aq) occurring in the two-phase water–nitrobenzene system (1 = calix[4]arene-(1,2-phenylene-crown-6,crown-6); aq = aqueous phase, nb = nitrobenzene phase) was evaluated as log Kex(Ag+, 1·Cs+) = −1.3 ± 0.1. Further, the very high stability constant of the 1·Ag+ complex in nitrobenzene saturated with water was calculated for a temperature of 25 °C: log βnb(1·Ag +) = 9.3 ± 0.2. Finally, by using quantum mechanical DFT calculations, the most probable structures A and B of this cationic complex species, which are obviously in a dynamic equilibrium, were derived.

Complexation of the lithium cation with N,N,N’,N’-tetracyclohexyl-1,2-phenylenedioxydiacetamide: experimental and theoretical study

ABSTRACTOn the basis of extraction experiments and γ-activity measurements, the extraction constant corresponding to the equilibrium Li+ (aq) + 1·Na+ (nb) 1·Li+ (nb) + Na+ (aq) taking part in the two-phase water–nitrobenzene system (1 = N,N,N’,N’-tetracyclohexyl-1,2-phenylenedioxydiacetamide called Sodium ionophore III; aq = aqueous phase, nb = nitrobenzene phase) was determined as log Kex (Li+,1·Na+) = 0.7 ± 0.1. Further, the stability constant of the 1·Li+ complex in nitrobenzene saturated with water was calculated for a temperature of 25 °C: log βnb (1·Li+) = 8.1 ± 0.2. Finally, applying quantum mechanical DFT calculations, the most probable structures of the nonhydrated 1·Li+ and the hydrated 1·Li+·H2O cationic complex species were derived. In both of these complexes, the ‘central’ cation Li+ is bound by four bonding interactions to the corresponding four oxygen atoms of the parent ligand 1. Besides, in case of the 1·Li+·H2O complex, the considered hydrated structure is stabilised by one water molecule bound to the ‘central’ lithium cation.

Magnesium ionophore II as an extraction agent for trivalent europium and americium

Abstract Solvent extraction of microamounts of trivalent europium and americium into nitrobenzene by using a mixture of hydrogen dicarbollylcobaltate (H+B−) and magnesium ionophore II (L) was studied. The equilibrium data were explained assuming that the species HL+, H L 2 + ${\rm{HL}}_2^ + $ , M L 2 3 + ${\rm{ML}}_2^{3 + }$ , and M L 3 3 + ${\rm{ML}}_3^{3 + }$ (M3+ = Eu3+, Am3+; L=magnesium, ionophore II) are extracted into the nitrobenzene phase. Extraction and stability constants of the cationic complex species in nitrobenzene saturated with water were determined and discussed. From the experimental results it is evident that this effective magnesium ionophore II receptor for the Eu3+ and Am3+ cations could be considered as a potential extraction agent for nuclear waste treatment.

Evidences of Electron Transfer of a Fullerene Anion Radical (C60(•-)) Prepared under Visible-Light Illumination at a Nitrobenzene/Water Interface.

Fullerene (C60) changes to its anion radical (C60(•-)) in the presence of tetraphenylborate (TPB(-)) under visible-light illumination. Using voltammetry at a liquid/liquid interface, we investigated the electron transfer (ET) between C60(•-), previously prepared based on this photochemical reaction, in a nitrobenzene (NB) solution and hexacyanoferrate(III) ([Fe(CN)6](3-)) or proton in an aqueous solution. We suggest that positive currents appearing in voltammograms are due to the ion transfer of decomposition products of TPB(-) and ET from C60(•-) in the NB phase to [Fe(CN)6](3-), or proton in the W phase. (11)B NMR revealed that TPB(-) decomposed to some borate anions during the photochemical reaction of fullerene. Furthermore, when the NB solution containing C60(•-) was mixed with an aqueous solution containing [Fe(CN)6](3-) or proton, absorption bands of C60(•-) in a visible/near infrared absorption spectrum disappeared. This disappearance supports the ET across the NB/W interface. This finding is significant as both an example of ET at a liquid/liquid interface including photochemical reactions and the photochemistry of C60.

Extraction and DFT study on interaction of the univalent thallium cation with calix[4]arene-(1,2-phenylene-crown-6,crown-6)

On the basis of extraction experiments and γ-activity measurements, the extraction constant corresponding to the equilibrium Tl+ (aq)+1·Cs+ (nb)⇄1·Tl+ (nb)+Cs+ (aq) occurring in the two-phase water–nitrobenzene system (1=calix[4]arene-(1,2-phenylene-crown-6,crown-6); aq=aqueous phase, nb=nitrobenzene phase) was determined as log Kex(Tl+,1·Cs+)=0.4±0.1. Further, the very high stability constant of the 1·Tl+ complex in nitrobenzene saturated with water was calculated for a temperature of 25°C: log β(1·Tl+)=9.9±0.2. Finally, by using quantum mechanical DFT calculations, the most probable structures A and B of this cationic complex species, which are obviously in a dynamic equilibrium, were derived.

Brief Determination of Standard Formal Potentials for the Transfers of Several Pairing Anions across the Nitrobenzene/Water Interface by Na(I) Extraction with 18-Crown-6 Ether

Extraction constants (Kex±) for the extraction of sodium salts (NaA) with 18-crown-6 ether (18C6) from water (w) into nitrobenzene (NB) were determined at 298 K, together with the determination of individual distribution constants (KD,A) of several pairing anions A−. The symbols Kex± and KD,A were defined as [NaL+]NB[A−]NB/([Na+][L]NB[A−]) at L = 18C6 and [A−]NB/[A−], respectively; the subscript “NB” shows the NB phase. Also, ion-pair formation constants for sodium 2,4-dinitrophenolate (NaDnp) and its ion pair complex with 18C6 in water were determined by potentiometry with a Na+-selective electrode. Standardized (S) KD,A values were briefly calculated from the following thermodynamic cycle: KD,A S = Kex±/KD,Na SKNaL,NB. Here, KD,Na S and KNaL,NB denote the standardized individual distribution-constant of Na+ into and a complex formation constant for NaL+ in the NB phase, respectively. Moreover, equilibrium potential differences (Δφeq) at the NB/w interface were estimated from the relation Δφeq = 0.05916log (KD,A S/KD,A) at 298 K. The Δφeq values of A− = F3CCO2 −, MnO4 −, ReO4 − and Dnp− were determined for comparison with the value of picrate ion. The plot of log Kex± versus Δφeq gave a positive correlation at (correlation coefficient)2 = 0.748.

Complexation of the strontium cation with a macrocyclic lactam receptor: Experimental and theoretical study

On the basis of extraction experiments and γ-activity measurements, the extraction constant corresponding to the equilibrium Sr2+(aq)+2A−(aq)+1(nb)⇄1·Sr2+(nb)+2A−(nb) occurring in the two-phase water–nitrobenzene system (A−=picrate, 1=macrocyclic lactam receptor — see Scheme 1; aq=aqueous phase, nb=nitrobenzene phase) was evaluated as log Kex (1·Sr2+, 2A−)=−4.0±0.1. Further, the stability constant of the 1·Sr2+ cationic complex in nitrobenzene saturated with water was calculated for a temperature of 25°C: log βnb (1·Sr2+)=5.1±0.1. Finally, applying quantum mechanical DFT calculations, the most probable structure of the cationic complex species 1·Sr2+ was derived. In the resulting complex, which is most energetically favored, the “central” cation Sr2+ is bound by five bonding interactions to two ethereal oxygen atoms and two carbonyl oxygens, as well as to one carbon atom of the corresponding benzene ring of the parent macrocyclic lactam receptor 1 via cation–π interaction.