Solvent extraction of europium and americium into phenyltrifluoromethyl sulfone by using synergistic mixture of hydrogen dicarbollylcobaltate and “classical” CMPO

Extraction of microamounts of europium and americium by a nitrobenzene solution of hydrogen dicarbollylcobaltate (H⁺B⁻) in the presence of tetraisopropyl methylene diphosphonate [T(iPr)MDP, L] has been investigated. The equilibrium data have been explained assuming that the complexes HL⁺, HL₂ ⁺, ML₂ ³⁺, ML₃ ³⁺ and ML₄ ³⁺ (M³⁺ = Eu³⁺, Am³⁺) are extracted into the organic phase. The values of extraction and stability constants of the species in nitrobenzene saturated with water have been determined. It was found that the stability constants of the corresponding complexes EuL _n ³⁺ and AmL _n ³⁺, where n = 2, 3, 4 and L is T(iPr)MDP, in water-saturated nitrobenzene are comparable.     

Synthesis,characterization, antimicrobial activity and ultrastructure of the affected bacteria of new quinoline compounds

The reaction on 8-hydroxy quinoline-7-aldehyde azo compounds (HL _n ) (where n = 1–5) with 4-amino-1,2-dihydro-2,3-dimethyl-1-phenylpyrazol-5-one to obtain HL _n (where n = 6–10) have been characterized by means of TLC, melting point and spectral data, such as IR, ¹H NMR, mass spectra and thermal studies. The X-ray diffraction patterns of two starting materials 8-hydroxy quinoline-7-aldehyde (start 1), 4-amino-1,2-dihydro-2,3-dimethyl-1-phenylpyrazol-5-one (start 2) and the ligands (HL_5,10) are investigated in powder form. All the ligands have been screened for their antimicrobial activity against four local bacterial species, two Gram-positive bacteria (Bacillus cereus and Staphylococcus aureus) and two Gram-negative bacteria (Escherichia coli and Klebsiella pneumoniae) as well as against four local fungi; Aspergillus niger, Alternaria alternata, Penicillium italicum and Fusarium oxysporium. The results show that the azo ligands (HL _n ) (where n = 1–5) have no antimicrobial activity against bacteria and fungi while most azomethine ligands (HL _n ) (where n = 6–10) are good antibacterial agents against E. coli and K. pneumoniae as well as antifungal agents against P. italicum and A. alternata. The results were compared to standard substances (start 1) and (start 2). Among the azomethine ligands, HL₁₀ was the most effective against the most microorganisms tested. The size of clear zone was ordered as p-(OCH₃ < CH₃ < H < Cl < NO₂) as expected from Hammett’s constant (σ ^R ). Also, the ultrastructure study of the affected bacteria confirmed that HL₈ is good antibacterial agent against E. coli and S. aureus.     

Extraction of calcium and strontium into nitrobenzene by using a synergistic mixture of hydrogen dicarbollylcobaltate and tetraisopropyl methylene diphosphonate

Extraction of microamounts of calcium and strontium by a nitrobenzene solution of hydrogen dicarbollylcobaltate (H⁺B⁻) in the presence of tetraisopropyl methylene diphosphonate [T(iPr)MDP, L] has been investigated. The equilibrium data have been explained assuming that the species HL⁺, \textHL₂ ⁺ {\text{HL}}_{2}^{ + } , \textML₂^{2 +} {\text{ML}}_{2}^{2 + } and \textML₃^{2 +} {\text{ML}}_{3}^{2 + } (M²⁺ = Ca²⁺, Sr²⁺) are extracted into the organic phase. The values of extraction and stability constants of the cationic complexes in nitrobenzene saturated with water have been determined. In the considered nitrobenzene medium, it was found that the stability constants of the \textCaL_n^{2 +} {\text{CaL}}_{n}^{2 + } complexes, where n = 2, 3 and L is T(iPr)MDP, are somewhat higher than those of the corresponding complex species \textSrL_n^{2 +} {\text{SrL}}_{n}^{2 + } .     

Molecular structure and conformation of nitrobenzene reinvestigated by combined analysis of gas-phase electron diffraction,rotational constants,and theoretical calculations

The molecular structure and conformation of nitrobenzene has been reinvestigated by gas-phase electron diffraction (GED), combined analysis of GED and microwave (MW) spectroscopic data, and quantum chemical calculations. The equilibrium r _e structure of nitrobenzene was determined by a joint analysis of the GED data and rotational constants taken from the literature. The necessary anharmonic vibrational corrections to the internuclear distances (r _e ? r _a) and to rotational constants (B _e ⁽ⁱ⁾  ? B ₀ ⁽ⁱ⁾ ) were calculated from the B3LYP/cc-pVTZ quadratic and cubic force fields. A combined analysis of GED and MW data led to following structural parameters (r _e) of planar nitrobenzene (the total estimated uncertainties are in parentheses): r(C–C)_av = 1.391(3) Å, r(C–N) = 1.468(4) Å, r(N–O) = 1.223(2) Å, r(C–H)_av = 1.071(3) Å, \({\angle}\)C2–C1–C6 = 123.5(6)°, \({\angle}\)C1–C2–C3 = 117.8(3)°, \({\angle}\)C2–C3–C4 = 120.3(3)°, \({\angle}\)C3–C4–C5 = 120.5(6)°, \({\angle}\)C–C–N = 118.2(3)°, \({\angle}\)C–N–O = 117.9(2)°, \({\angle}\)O–N–O = 124.2(4)°, \({\angle}\)(C–C–H)_av = 120.6(20)°. These structural parameters reproduce the experimental B ₀ ⁽ⁱ⁾ values within 0.05 MHz. The experimental results are in good agreement with the theoretical calculations. The barrier height to internal rotation of nitro group, 4.1±1.0 kcal/mol, was estimated from the GED analysis using a dynamic model. The equilibrium structure was also calculated using the experimental rotational constants for nitrobenzene isotopomers and theoretical rotation–vibration interaction constants.     

Solvent extraction of Li+, H3O+ and NH4 + into nitrobenzene by using sodium dicarbollylcobaltate and calix[4]arene-bis(t-octylbenzo-18-crown-6)

From extraction experiments and $ \gamma $ -activity measurements, the exchange extraction constants corresponding to the general equilibrium M⁺ (aq) + NaL⁺ (nb) ? ML⁺ (nb) + Na⁺ (aq) taking place in the two–phase water–nitrobenzene system (M⁺= Li⁺, H₃O⁺, NH₄ ⁺; L = calix[4]arene-bis(t-octylbenzo-18-crown-6); aq = aqueous phase, nb = nitrobenzene phase) were evaluated. Furthermore, the stability constants of the ML⁺ complexes in nitrobenzene saturated with water were calculated; they were found to increase in the following cation order: H₃O⁺ < Li⁺ < NH₄ ⁺.     

Synergistic extraction of some univalent cations into nitrobenzene by using cesium dicarbollylcobaltate and calix[4]arene-bis(t-octylbenzo-18-crown-6)

From extraction experiments and γ-activity measurements, the exchange extraction constants corresponding to the general equilibrium M⁺ (aq) + CsL⁺ (nb) ? ML⁺ (nb) + Cs⁺ (aq) taking place in the two–phase water–nitrobenzene system (M⁺ = K⁺, Rb⁺, $ {\text{NH}}_{4}^{ + } $ , Ag⁺, Tl⁺; L = calix[4]arene-bis(t-octylbenzo-18-crown-6); aq = aqueous phase, nb = nitrobenzene phase) were evaluated. Furthermore, the stability constants of the ML⁺ complexes in nitrobenzene saturated with water were calculated; they were found to increase in the following cation order: $ {\text{NH}}_{4}^{ + } $  < K⁺ < Ag⁺ < Rb⁺ < Tl⁺.     

Extraction of microamounts of europium and americium into nitrobenzene by using hydrogen dicarbollylcobaltate in the presence of diphenyl-N-butylcarbamoylmethyl phosphine oxide

Extraction of microamounts of europium and americium by a nitrobenzene solution of hydrogen dicarbollylcobaltate (H⁺B⁻) in the presence of diphenyl-N-butylcarbamoylmethyl phosphine oxide (DPBCMPO, L) has been investigated. The equilibrium data have been explained assuming that the complexes HL⁺, HL₂⁺, ML₂³⁺, ML₃³⁺ and ML₄³⁺ (M³⁺ = Eu³⁺, Am³⁺) are extracted into the organic phase. The values of extraction and stability constants of the species in nitrobenzene saturated with water have been determined. It has been found that the stability constants of the corresponding complexes EuL _n ³⁺ and AmL _n ³⁺, where n = 2, 3, 4 and L is DPBCMPO, in water saturated nitrobenzene are comparable.     

Solvent extraction of calcium and strontium into nitrobenzene by using synergistic mixture of hydrogen dicarbollylcobaltate and diphenyl-<Emphasis Type="Italic">N</Emphasis>-butylcarbamoylmethyl phosphine oxide

Extraction of microamounts of calcium and strontium by a nitrobenzene solution of hydrogen dicarbollylcobaltate (H⁺B^?) in the presence of diphenyl-N-butylcarbamoylmethyl phosphine oxide (DPBCMPO, L) has been investigated. The equilibrium data have been explained assuming that the species HL⁺, \( {\text{HL}}_{2}^{ + } \), \( {\text{ML}}_{2}^{2 + } \), \( {\text{ML}}_{3}^{2 + } \) and \( {\text{ML}}_{4}^{2 + } \) (M²⁺ = Ca²⁺, Sr²⁺) are extracted into the organic phase. The values of extraction and stability constants of the cationic complexes in nitrobenzene saturated with water have been determined. In the considered nitrobenzene medium, it was found that the stability of the \( {\text{SrL}}_{2,{\text{org}}}^{2 + } \) complex is somewhat higher than that of species \( {\text{CaL}}_{2,{\text{org}}}^{2 + } \), while the stability constants of the remaining strontium complexes \( {\text{SrL}}_{3,{\text{org}}}^{2 + } \) and \( {\text{SrL}}_{4,{\text{org}}}^{2 + } \) are smaller than those of the corresponding complex species \( {\text{CaL}}_{n}^{2 + } \) (n = 3, 4).     

Exact treatment of generalized modifications of finite-dimensional systems by the LRM approach

LRM (Low Rank Modification) is a mathematical method that produces eigenvalues and eigenstates of generalized eigenvalue equations. It is similar to the perturbation expansion in that it assumes the knowledge of the eigenvalues and eigenstates of some related (unperturbed) system. However, unlike perturbation expansion, LRM produces correct results however large the modification of the original system. LRM of finite-dimensional systems is here generalized to the combined (external and internal) modifications. Parent n-dimensional system A _n containing n eigenvalues λ _i and n eigenstates \({| {\Phi_i}\rangle}\) is described by the generalized n × n eigenvalue equation. In an external modification system A _n interacts with another ρ-dimensional system B _ρ which is situated outside the system A _n . In an internal modification relatively small σ-dimensional subsystem of the parent system A _n is modified. Modified system C _n+ρ that contains external as well as internal modifications is described by the generalized (n + ρ) × (n + ρ) eigenvalue equation. This system has (n + ρ) eigenvalues \({\varepsilon_s}\) and (n + ρ) corresponding eigenstates \({| {\Psi_s}\rangle}\) . In LRM this generalized (ρ + n) × (ρ + n) eigenvalue equation is replaced with a (nonlinear) (ρ + σ) × (ρ + σ) equation which produces all eigenvalues \({\varepsilon_s \notin \left\{ {\lambda_i}\right\}}\) and all the corresponding eigenstates \({| {\Psi_s}\rangle }\) of C _{n + ρ}. Another equation produces remaining solutions (if any) that satisfy \({\varepsilon_s \in \left\{ {\lambda_i}\right\}}\) . Those two equations produce exact solution of the modified system C _{n + ρ}. If (ρ + σ) is small with respect to n, this approach is numerically much more efficient than a standard diagonalization of the original generalized eigenvalue equation. Unlike perturbation expansion, LRM produces exact results, however large modification of the parent system A _n .     

Solvent extraction of strontium and barium into nitrobenzene by using synergistic mixture of hydrogen dicarbollylcobaltate and dibenzo-24-crown-8

Extraction of microamounts of strontium and barium by a nitrobenzene solution of hydrogen dicarbollylcobaltate (H⁺B^?) in the presence of dibenzo-24-crown-8 (DB24C8, L) has been investigated. The equilibrium data have been explained assuming that the species HL⁺, HL₂ ⁺, ML²⁺, ML₂ ²⁺ and MHL₂ ³⁺ (M²⁺ = Sr²⁺, Ba²⁺) are extracted into the organic phase. The values of extraction and stability constants of the complexes in nitrobenzene saturated with water have been determined. It was found that the stability constants of the cationic complex species BaL²⁺ and BaL₂ ²⁺ in the considered nitrobenzene medium are somewhat higher than those of the corresponding complexes SrL²⁺ and SrL₂ ²⁺.     

Solvent extraction of strontium and barium into nitrobenzene by using hydrogen dicarbollylcobaltate in the presence of dicyclohexano-24-crown-8

Extraction of microamounts of strontium and barium by a nitrobenzene solution of hydrogen dicarbollylcobaltate (H⁺B^?) in the presence of dicyclohexano-24-crown-8 (DCH24C8, L) has been investigated. The equilibrium data have been explained assuming that the complexes HL⁺, $ {\text{HL}}_{2}^{ + }, $ ML²⁺ and $ {\text{ML}}_{ 2}^{2 + } $ (M²⁺ = Sr²⁺, Ba²⁺) are extracted into the organic phase. The values of extraction and stability constants of the species in nitrobenzene saturated with water have been determined. It was found that in water–saturated nitrobenzene, the stability constants of the complexes BaL²⁺ and $ {\text{BaL}}_{ 2}{^{2 + }}, $ where L = DCH24C8, are somewhat higher than those of the corresponding species SrL²⁺ and $ {\text{SrL}}_{ 2}{^{2 + }} $ with the same ligand L.     

Synergistic extraction of europium and americium into nitrobenzene by using hydrogen dicarbollylcobaltate and 1,2-(diphenylphosphino)ethane dioxide

Extraction of microamounts of europium and americium by a nitrobenzene solution of hydrogen dicarbollylcobaltate (H⁺B⁻) in the presence of 1,2-(diphenylphosphino)ethane dioxide (DPPEtDO, L) has been investigated. The equilibrium data have been explained assuming that the species HL⁺, HL₂ ⁺, ML₂ ³⁺ and ML₄ ³⁺ (M³⁺ = Eu³⁺, Am³⁺) are extracted into the organic phase. The values of extraction and stability constants of the species in nitrobenzene saturated with water have been determined. It was found that the stability constants of the corresponding complexes EuL _n ³⁺ and AmL _n ³⁺, where n = 2, 4 and L is DPPEtDO, in water-saturated nitrobenzene are comparable.     

Solvent extraction of microamounts of strontium and barium into nitrobenzene by using synergistic mixture of hydrogen dicarbollylcobaltate and dicyclohexano-18-crown-6

Extraction of microamounts of strontium and barium by a nitrobenzene solution of hydrogen dicarbollylcobaltate (H⁺B^?) in the presence of dicyclohexano-18-crown-6 (DCH18C6, L) has been investigated. The equilibrium data have been explained assuming that the complexes HL⁺, $ {\text{HL}}_{ 2}^{ + } $ , ML²⁺ and $ {\text{ML}}_{ 2}^{ 2+ } $ (M²⁺ = Sr²⁺, Ba²⁺) are extracted into the organic phase. The values of extraction and stability constants of the species in nitrobenzene saturated with water have been determined. It was found that in the mentioned medium the stability constants of the complexes BaL²⁺ and $ {\text{BaL}}_{2}^{2 + }, $ where L = DCH18C6, are somewhat higher than those of the species SrL²⁺ and $ {\text{SrL}}_{2}^{2 + } $ with the same ligand L.     

Probing Structure,Thermochemistry, Electron Affinity and Magnetic Moment of Erbium-Doped Silicon Clusters ErSi<Subscript><Emphasis Type="Italic">n</Emphasis></Subscript> (<Emphasis Type="Italic">n</Emphasis> = 3–10) and Their Anions with Density Functional Theory

The lowest energy structures and electronic properties of ErSi _n (n = 3–10) and their anions were probed using the ABCluster global search technique combined with the PBE, TPSSh and B3LYP schemes. The lowest energy energies of neutral ErSi _n (n = 3–10) can be regarded as substituting a Si atom of the lowest energy structure of Si_n+1 with a Er atom. The additional electron effects on the geometries are very strong, resulting the lowest energy structures of ErSi _n ^? with n > 6 are different from their neutral counterparts. Starting from n = 7, the potential energy surfaces of ErSi _n ^? are very flat, resulting isomeric arrangements occur and functional dependence of the predicted most stable structures exist. The AEAs, VDEs and simulated PES of ErSi _n (n = 3–10) are reported. Introducing Er to Si cluster can significantly improve photochemical reactivity of the cluster. The 4f electron of Er atom in ErSi₄, ErSi _n ^? (n = 4, 7–10) prefers to take part in bonding. The total magnetic moments of ErSi _n and their anions are mainly provided by the 4f electrons of Er atom. The dissociation energies of Er from ErSi _n and their anions were evaluated to inspect relative stability.     

Extraction of cesium into nitrobenzene by using ammonium and thallium dicarbollylcobaltates in the presence of polypropylene glycol PPG 425

Extraction of microamounts of cesium by nitrobenzene solutions of ammonium dicarbollylcobaltate (NH₄ ⁺B^?) and thallium dicarbollylcobaltate (Tl⁺B^?) in the presence of polypropylene glycol PPG 425 (L) has been investigated. The equilibrium data have been explained assuming that the complexes ML⁺ (M⁺ = NH ₄ ⁺ , TI⁺, Cs⁺; L = PPG 425) are present in the organic phase. Furthermore, the stability constants of the cationic complex species NH₄L⁺ and TlL⁺ in nitrobenzene saturated with water have been determined as log β (NH₄L _org ⁺ ) = 4.58 and log β (TlL _org ⁺ ) = 5.27.     

Synthesis,experimental and theoretical characterization,and antimicrobial studies of some Fe(II), Co(II), and Ni(II) complexes of 2-(4,6-dihydroxypyrimidin-2-ylamino)naphthalene-1,4-dione

The work reported the synthesis and characterisation of Fe²⁺, Co²⁺, and Ni²⁺ complexes of 2-(4,6-dihydroxypyrimidin-2-ylamino)naphthalene-1,4-dione (HL). The spectroscopic and elemental analysis results obtained were consistent with the adoption of the formulas, [ML₂] (M = Fe and Co) and [ML₂(H₂O)] (M = Ni) for the metal complexes. Electronic spectra and magnetic moments of the metal complexes corroborated octahedral geometry for Ni(II) complex and tetrahedral geometry for Fe(II) and Co(II) complexes. However, quantum-chemical calculations using density functional theory predicted trigonal bipyramidal geometry for Ni(II) complex and provided corroborative explanations for the structures of the other complexes. Conductance measurements in dimethylsulfoxide indicate that the complexes are non-electrolytes. The antimicrobial potential of the compounds was evaluated against Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Bacillus cereus, Proteus mirabilis, Klebsiella oxytoca, Aspergillus niger, A. flavus, and Rhizopus stolonifer. The compounds gave moderate to good antimicrobial activity. However, the bacterial and fungal organisms were more susceptible to the cobalt complex and ligand respectively than the other compounds at concentration of 10 mg/mL. The compounds were also assessed for their antioxidant potential using 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay. The compounds displayed good DPPH radical scavenging activities. The nickel complex exhibited the best DPPH radical scavenging activity compared to the other compounds.     

Synthesis and characterization of a new monophosphate (C<Subscript>6</Subscript>H<Subscript>16</Subscript>N<Subscript>2</Subscript>)(H<Subscript>2</Subscript>PO<Subscript>4</Subscript>)<Subscript>2</Subscript>

Chemical preparation, crystal structure, and NMR spectroscopy of a new trans-2,5-dimethylpiperazinium monophosphate are given. This new compound crystallizes in the triclinic system, with the space group P-1 and the following parameters: a = 6.5033(3), b = 7.6942(4), c = 8.1473(5) Å, α = 114.997(3), β = 92.341(3), γ = 113.136(3), V = 329.14(3) ų, Z = 1, and D_x = 1.565 g cm^?3. The crystal structure has been determined and refined to R = 0.030 and R _w(F ²) = 0.032 using 1558 independent reflections. The structure can be described as infinite [H₂PO₄] _n ^n? chains with (C₆H₁₆N₂)²⁺ organic cations anchored between adjacent polyanions to form columns of anions and cations running along the b axis. This compound has also been investigated by IR, thermal, and solid-state, ¹³C and ³¹P MAS NMR spectroscopies and Ab initio calculations.     

Synergistic extraction of some divalent cations into nitrobenzene by using strontium dicarbollylcobaltate and hexaethyl p- tert-butylcalix[6]arene hexaacetate

From extraction experiments and γ-activity measurements, the exchange extraction constants corresponding to the general equilibrium M²⁺ (aq) + SrL²⁺ (nb) $ \Leftrightarrow $ ML²⁺ (nb) + Sr²⁺ (aq) taking place in the two-phase water–nitrobenzene system (M²⁺ = Ca²⁺, Pb²⁺, Cu²⁺, Zn²⁺, Cd²⁺, $ {\text{UO}}_{2}^{2 + } $ , Mn²⁺, Co²⁺, Ni²⁺; L = hexaethyl p-tert-butylcalix[6]arene hexaacetate; aq = aqueous phase, nb = nitrobenzene phase) were evaluated. Moreover, the stability constants of the ML²⁺ complexes in nitrobenzene saturated with water were calculated; they were found to increase in the following order: Cd²⁺ < Ca²⁺ < Mn²⁺ < Cu²⁺, Zn²⁺ <  $ {\text{UO}}_{2}^{2 + } $ , Co²⁺ < Ni²⁺ < Sr²⁺ < Pb²⁺.     

A one-dimensional silver(I) coordination polymer with saccharin and pyrazine: synthesis,crystal structure,thermal analysis,FTIR spectra,and DFT studies

A silver(I) complex of saccharinate (sac) with pyrazine (pyz), [Ag(sac)(pyz)] _n , has been synthesized and characterized by elemental analysis, IR, thermal analysis, and single-crystal X-ray diffractometry. The complex crystallizes orthorhombic space group Pnma with unit cell parameters of a = 13.0073(9) Å, b = 6.4907(6) Å, c = 13.4007(9) Å, V = 1131.37(15) Å³, and Z = 4. [Ag(sac)(pyz)] _n is a one-dimensional coordination polymer, in which the sac ligand acts as a monodentate ligand through the N atom and the trigonal silver centers are linked by the bridging pyz ligands. The individual chains are connected into two-dimensional supramolemular network by aromatic π(sac)···π(pyz) stacking interactions. The FTIR spectrum of [Ag(sac)(pyz)] _n has been recorded in the region and 4,000–400 cm^?1. The optimized geometry, frequency, and intensity of the vibrational bands of [Ag(sac)(pyz)] _n were obtained by density functional theory (DFT) at the B3LYP level. The vibrational frequencies were calculated and the scaled values have been compared with the experimental FTIR data. The observed and calculated frequencies are found to be in good agreement.     

Extractive distribution of microamounts of europium and americium in the two phase water — HCl — nitrobenzene — N,N,N′,N′-tetraethyl-2,6-dipicolinamide — hydrogen dicarbollylcobaltate system

Extraction of microamounts of europium and americium by a nitrobenzene solution of hydrogen dicarbollylcobaltate (H⁺B⁻) in the presence of N,N,N′,N′-tetraethyl-2,6-dipicolinamide (TEtDPA, L) has been investigated. The equilibrium data have been explained assuming that the cations HL⁺, HL₂³⁺, ML₂³⁺ and ML₃³⁺ (M³⁺ = Eu³⁺, Am³⁺) are extracted into the organic phase. The values of extraction and stability constants of the species in nitrobenzene saturated with water have been determined. It has been found that the stability constants of the corresponding complexes EuL _n,org³⁺ and AmL _n,org³⁺, where n = 2, 3 and L is TEtDPA, in the mentioned medium are comparable.