Cis-and Trans-Coordination Assembly of Nitrogen Heterocycle with Copper(II) and Silver(I)

After the preparation of 1,4-bis(4,5-dihydro-1H-imidazol-2-yl)benzene(bdib),a nitrogen heterocycle with potential coordination manners of both cis-and tram-configuration forms,three complexes,including successfully self-assembled.Complexes 1 and 2 crystallized in the monoclinic system with P21/n space group and complex 3 in the triclinic system with P1 space group.     

Electronic Structures of Copper(I) and Silver(I) beta-Diketonate Complexes

The valence electronic structures of [Cu(hfac)L] (hfac = CF(3)C(O)CHC(O)CF(3); L = PMe(3), CNMe), [Ag(hfac)(PMe(3))], and [Ag(fod)(PEt(3))] (fod = t-BuC(O)CHC(O)C(3)F(7)) have been studied by recording their photoelectron spectra and by performing Xalpha-SW calculations on the model compounds [M(dfm)(PH(3))] (dfm = HC(O)CHC(O)H; M = Cu, Ag) and [Cu(dfm)(CNH)]. For the copper complexes, the spectra were recorded between 21 and 160 eV using He I, He II and synchrotron radiation; while, for the silver complexes, He I and He II, spectra were recorded. Assignments were made by comparison of experimental and calculated values of band energies, and, for the copper complexes, by similar comparison of experimental and theoretical branching ratios as a function of photon energy. For the silver complexes, a more limited comparison of band intensities in the He I and He II spectra was made. In analogous compounds, it is shown that the binding energies follow the sequence Ag 4d > Cu 3d, with an energy difference of almost 2 eV.     

Ion-Exchange Sorption of Palladium(II) from Hydrochloric Acid Solutions in the Presence of Silver(I)

Russian Journal of Physical Chemistry A - The sorptive extraction of palladium(II) chloride complexes in the presence of silver(I) chloride complexes from 2 and 4 M aqueous solutions of HCl with a...     

First Copper(I) and Silver(I) Complexes Containing Phosphanylphosphido Ligands

Three new complexes with phosphanylphosphido ligands, [Cu₄{μ₂‐P(SiMe₃)‐PtBu}₄] ( 1 ), [Ag₄{μ₂‐P(SiMe₃)‐PtBu₂}₄] ( 2 ) and [Cu{η¹‐P(SiMe₃)‐PiPr₂}₂]^–[Li(Diglyme)₂]⁺ ( 3 ) were synthesized and structurally characterized by X‐ray diffraction, NMR spectroscopy, and elemental analysis. Complexes 1 and 2 were obtained in the reactions of lithium derivative of diphosphane tBu₂P‐P(SiMe₃)Li · 2.7THF with CuCl and [iBu₃PAgCl]₄, respectively. The X‐ray diffraction analysis revealed that the complexes 1 and 2 present macrocyclic, tetrameric form with Cu₄P₄ and Ag₄P₄ core. Complex 3 was prepared in the reaction of CuCl with a different derivative of lithiated diphosphane iPr₂P‐P(SiMe₃)Li · 2(Diglyme). Surprisingly, the X‐ray analysis of 3 revealed that in this reaction instead of the tetramer the monomeric form, ionic complex [Cu{η¹‐P(SiMe₃)‐PiPr₂}₂]^–[Li(Diglyme)₂]⁺ was formed.     

Sorption of Water-Soluble Copper(II) Compounds on Clinoptilolite

Copper(II) sorption on clinoptilolite from aqueous solutions with different pH was studied. The results were analyzed using the calculated distribution of water-soluble copper(II) species at different pH. The best conditions of copper(II) sorption on clinoptilolite from aqueous solutions were determined.     

Sorption of Copper(II) from Chloride Solutions by Carbonate-containing Technological Waste

Absorption of copper(II) ions from copper chloride solutions by a technological carbonate-containing waste was studied in relation to concentration of starting solutions (1-25 wt %), amount of sorbent added, and time.     

Ion-Exchange Reaction of Silver(I) and Copper(II) in Optical Sensors Based on Thiaglutaric Diamide

Bulk optode membranes based on a recently reported thiaglutaric diamide ionophore were developed for measurements of silver(I) and copper(II) ions in aqueous solutions. The response properties of optical films containing ionophore and chromoionophores with different pK(a) values were investigated at different sample pH. At certain pH the measuring range of the optode can be shifted when choosing different chromoionophores. Optode with ionophore and chromoionophore V exhibited good responses to silver ions from 10(-6) - 10(-1) M at pH 5.5. The proposed sensor showed high selectivity, good reproducibility and stability. With a different chromoionophore ETH 5418 the optode could response to copper(II) ions from 10(-6) - 10(-2) M.     

Sorption of Copper(II) Ions with Nanosized Magnesium Phosphate

A new approach to the preparation of a nanosized sorbent based on magnesium phosphate has been developed. The patterns of copper(II) ions sorption with nanosized magnesium phosphate from aqueous solutions have been investigated. The sorption parameters have been determined, and the kinetics and mechanism of the processes have been elucidated. The high sorption ability of the nanoscale sorbent has been shown in comparison with existing sorbents based on magnesium phosphate.     

Lead(II) Sulfide. Synthesis in Lead(II) Tetraoxophosphate(V) Gelatin-immobilized Matrix Implantates and Sorption Activity Toward Silver(I) Ions

Processes that occur in lead(II) tetraoxophosphate(V) gelatin-immobilized matrix systems on their contact with aqueous solutions containing the sulfide anion S₂ ^- were studied. As a result of this contact, lead(II) sulfide is formed. The sorption activity of the resulting metal sulfide gelatin-immobilized matrix systems with respect to Ag(I) ions is associated with substitution of Pb(II) by Ag(I) ions.     

Sorption of Copper(II) Ions by Apple Pectin Modified with Organic Pharmacophores

Russian Journal of Physical Chemistry A - The sorption properties of apple pectin, native and modified by pharmacophores (nicotinic, salycilic, 5-aminosalycilic, and anthroic acids), are...     

Synthesis and Structures of Silver(I) and Copper(I) 3,5-Dipentyl-1,2,4-Triazolates

The Ag(I) and Cu(I) complexes of 4-amino-3,5-dipentyl-4H-1,2,4-triazole (4-NH₂-3,5-(C₅H₁₁)₂tz) and 3,5-dipentyl-1H-1,2,4-triazole (3,5-(C₅H₁₁)₂tzH) have been synthesized and characterized. X-Ray analysis shows that {Ag₄[4-NH₂-3,5-(C₅H₁₁)₂tz]₆}(BF₄)₄ is a tetranuclear complex featuring an Ag₄tz₆ cluster; {Ag[3,5-(C₅H₁₁)₂tz]}_n exhibits a 3D structure of lvt-a topology; and {Cu₂[3,5-(C₅H₁₁)₂tz]Br}_n is a Cu₄Br₄-cluster based 3D complex with the dia topology.     

Cis- and Trans-Coordination Assembly of Nitrogen Heterocycle with Copper（Ⅱ） and Silver（Ⅰ）

After the preparation of 1,4-bis（4,5-dihydro-lH-imidazol-2-yl）benzene（bdib）, a nitrogen heterocycle with potential coordination manners of both cis- and trans-configuration forms, three complexes, including cis-[Cuz（bdib ）2（/L-OCH3）2]Cl2·2MeOH（1）, trans-[Cu（bdib）（AcO）2]n（2）, and cis-[Ag2（bdib）2]（NO3）2.2H20（3）, were successfully self-assembled. Complexes 1 and 2 crystallized in the monoclinic system with P21/n space group and complex 3 in the triclinic system with P1 space group.     

Effect of Polyethylenimine on the Selectivity of Determining Silver(I) by Stripping Voltammetry in the Presence of Copper(II)

It has been proposed that a water-soluble complexing polymer, polyethylenimine (PEI), be used to lower intermetallic interactions at the surface of solid electrodes in the determination of Ag(I) by stripping voltammetry in the presence of Cu(II). The introduction of PEI in the binary Ag(I)–Cu(II) system weakened the effect of Cu(II) on the anodic peak of Ag(I) and enhanced the selectivity in determining Ag(I) in the presence of excess amounts of Cu(II). With the use of PEI, Ag(I) can be determined at a Cu(II)-to-Ag(I) concentration ratio of 1000 : 1, compared to that of 20 : 1 in the absence of the polymer.     

Sorption Behavior of Copper(II) on Freshly Precipitated Aluminum Hydroxide

The isotherms of copper(II) sorption from aqueous solutions on freshly precipitated aluminum hydroxide obtained by hydrolysis of pentahydroxomonochlorodialuminum were studied. The sorption efficiency of copper(II) was studied as influenced by pH. Sorption of copper(II) by two different mechanisms is discussed.     

Nanocomposites of Metallic Silver with Octamolybdate Amine Complexes of Nickel(II) and Copper(II)

Theoretical and Experimental Chemistry - It was shown that interaction of photoreduced octamolybdate amine complexes of nickel(II) and copper(II) with silver(I) nitrate in aqueous solutions leads...     

Silver(I) and Copper(II) Catalysis for Oxidation of Histidine by Cerium(IV) in Acid Medium: A Comparative Kinetic Study

The catalytic effect of silver(I) and copper(II) ions on the oxidation of histidine by cerium(IV) in aqueous sulfuric acid solutions was studied spectrophotometrically at a constant ionic strength of 3.0 mol dm⁻³ and at 25°C. In both uncatalyzed and metal ions‐catalyzed paths, the reactions exhibited first‐order kinetics with respect to [Ce(IV)] and [catalyst], and fractional first‐order dependences with respect to [His] and [H⁺]. The oxidation rates increased as the ionic strength and dielectric constant of the reactions media increased. The catalytic efficiency of Ag(I) was higher than that of Cu(II). Plausible mechanistic schemes for both uncatalyzed and catalyzed reactions were proposed, and the rate laws associated with the suggested mechanisms were derived. In both cases, the final oxidation products of histidine were identified as 2‐imidazole acetaldehyde, ammonium ion, and carbon dioxide. The activation parameters associated with the second‐order rate constants were evaluated.