Transition Metal Picrates Research Articles

Promising agent for the efficient extraction of Co(II) ions from aqueous medium and its metal complexes: Synthesis, theoretical calculations and solvent extraction

A novel ligand 2,2′-((ethane-1,2-diylbis(azanylylidene))bis(methanylylidene))bis(4-((3-(4-methyl-1H-imidazol-1-yl)-5-(trifluoromethyl)phenyl)diazenyl)phenol) and its Co(II), Ni(II) and Cu(II), complexes were synthesized. These compounds were identified using elemental analysis, ICP-OES, FT-IR, thermal analysis, magnetic susceptibility, and molar conductivity techniques. 1H-, 13C-, and 19F-NMR spectra were used to describe the ligand further. 2,2′-((ethane-1,2-diylbis(azanylylidene))bis(methanylylidene))bis(4-((3-(4-methyl-1H-imidazol-1-yl)-5-(trifluoromethyl)phenyl)diazenyl)phenol) behaved as a bidentate, and the metal:ligand ratio of the complexes was 1:1, according to elemental analysis, stoichiometric analysis, and spectroscopic data on the synthesized molecules. Using DFT/B3LYP method and the 6-311G(d,p) basis set, the optimized molecular geometries, chemical shifts, vibrational frequencies, HOMO(SOMO)-LUMO energies, and molecular electrostatic potential diagrams of the synthesized compounds in the ground state were determined. In the calculations, the LANL2DZ basis set, which is the effective core potentials for Co(II), Ni(II) and Cu(II) ions, was used. When all of the theoretical data produced by quantum chemical calculations were compared to the experimental data, it was found that there was a good agreement between the two. Additionally, utilizing several transition metal picrates, including Mn(II), Pb(II), Cd(II), Zn(II), Ni(II), Co(II), Cu(II), Hg(II) and Fe(II) cations, the extraction capacity of the ligand was examined. The ligand demonstrated a significant rate of Co(II) cation removal from the aqueous medium in solvent extraction investigations, which also showed a great affinity for Co(II) ions.

Synthesis, characterization, theoretical calculations of novel benzoic acid based azo molecules and their use in effective extraction of Hg(II) ions from aqueous medium

In this study, two series of benzoic acid derivative azo compounds were synthesized using coupling reaction and characterized by various spectroscopic techniques. By using o-, m-, p-chloroaniline and o-, m-, p-nitroaniline as starting materials, the effects of the directing groups on the color intensity of azo dyes were investigated. It was concluded that the nitro group increased both the reaction efficiency and the color intensity. Optimized molecular structures, vibrational and electronic transition spectra, NMR chemical shift values, frontier molecular orbitals and MEP diagrams of each molecule were calculated using the 6-311G(d,p) basis set. All calculations were performed and compared with both Density Functional Theory (DFT) and Hartree-Fock (HF) methods. Experimental and theoretical results were found to be quite compatible with each other. The extraction capabilities of all synthesized azo derivatives were investigated using various transition metal picrates such as Mn2+, Co2+, Ni2+, Cu2+, Zn2+, Cd2+, Hg2+, Pb2+ cations. Solvent extraction studies of azo derivatives revealed that all compounds showed strong binding ability against Cu2+ and especially Hg2+ ions and were able to remove the Hg2+ cation from aqueous medium at a high rate (97.3%).

Synthesis, characterization and electrochemical behavior of a new diimine-dioxime compound and its application in developing Hg(II)-selective membrane electrode

In this work, a new diimine-dioxime compound (N,N′-bis[1-biphenyl-2-hydroxyimino-2-(4-chloroanilino)-1-ethylidene]-1,4-phenylenediamine) was synthesized and characterized by a combination of elemental analyses, FT-IR, 1H- and 13C-NMR spectra. The extraction ability of the new compound has been examined in chloroform by using several transition metal picrates such as Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Pb(II), Cd(II) and Hg(II). It has been observed that diimine-dioxime compound shows a high affinity to Hg(II) ion. The electrochemical measurements of the compound were performed by cyclic voltammetry in acetonitrile solution at room temperature, and two irreversible oxidation waves were observed. A Hg(II)-selective electrode based on the diimine-dioxime compound has been developed. The electrode showed linear responses with Nernstian slopes of 33 ± 1 mV per decade over a wide concentration range (1.0 × 10−2–8.0 × 10−6 M). The limit of detection was 2.4 × 10−6 M. The electrode has a response time about 10–15 s and it did not show a considerable divergence in its potential response over a period of 1 month. The proposed electrode revealed selectivity towards Hg(II) ion in the presence of various cations. The electrode could be used over a wide pH range of 4.0–9.0. The electrode can be successfully used as an indicator electrode for potentiometric titration of Hg(II) with EDTA.

Synthesis of crescent aromatic oligoamides with preorganized chelating groups and their extraction towards transition metal ions

Three crescent aromatic oligoamides 1–3 with their backbones rigidified by intramolecular hydrogen bonds were designed and synthesized. The liquid–liquid extraction by these compounds has been investigated using UV–vis spectrometry towards Pb2+ picrate and some transition metal picrates including Ag+, Hg2+, Cd2+, Zn2+, Cu2+, Co2+, Ni2+ salts. The results revealed higher selectivity and efficiency towards Hg2+ over other metal cations; pentameric ligand 1 with six oxygen donor atoms provided the highest extractability of 83.3%, while dimeric ligand 3 extracted almost exclusively Hg2+. The stoichiometry of the extracted complex between ligand 1 and Hg2+, and the extraction constant (logKex) were determined in solvent extraction.

Syntheses, spectroscopic and structural characterizations and metal ion binding properties of Schiff bases derived from 4′-aminobenzo-15-crown-5

A series of benzyloxybenzaldehyde derivatives ( 1– 4) were synthesized by the reactions of 4-(bromomethyl)benzonitrile with 4-hydroxy-3-methoxybenzaldehyde (vanillin), 2-hydroxy-3-methoxybenzaldehyde ( o-vanillin), 2-hydroxy-4-methoxybenzaldehyde and 2-hydroxy-5-methoxybenzaldehyde. Condensation reactions among the new benzyloxybenzaldehyde derivatives ( 1– 4) with 4′-aminobenzo-15-crown-5 yielded the new Schiff base compounds ( 5– 8). Sodium complexes ( 5a– 8a) and potassium complexes ( 5b– 8b) were prepared with NaClO 4 and KI, respectively. All of these synthesized compounds were characterized on the basis of FT-IR, 1H and 13C NMR, mass spectrometry and elemental analyses data. The solid state structures of compounds 8 and 5a were determined by X-ray crystallography. The extraction abilities of compounds 5– 8 were also evaluated in CH 2Cl 2 by using several main group and transition metal picrates, such as Na +, K +, Pb 2+, Cr 3+, Ni 2+, Cu 2+ and Zn 2+.

Syntheses, spectroscopic characterization and metal ion binding properties of benzo-15-crown-5 derivatives and their sodium and nickel(II) complexes

New benzo-15-crown-5 derivatives containing nitro, amine and imine groups were prepared. Nitro compound (1) was prepared after the reaction 4′,5′-bis(bromethyl)benzo-15-crown-5 and o-nitrophenol in the presence of NaOH. After reduction process by using hydrazine hydrate and Pd/C amine compound (2) was formed. New crown ether imine compounds (3–5) were synthesized by the condensation of corresponding crown ether diamine (2) with salicylaldehyde derivatives. Sodium complexes of the crown compounds (1a–5a) form crystalline 1:1 (Na+: ligand) complexes with sodium perchlorate. Nickel(II) complexes (3b–5b) with 1:1 (Ni2+:ligand) stoichiometries were also been synthesized from the Schiff bases (3–5). The results indicated that the Schiff base ligands coordinated through the azomethine nitrogen and phenolic oxygen. The extraction ability of compounds (1, 3, 4 and 5) were also evaluated in chloroform by using several alkali and transition metal picrates such as Li+, Na+, K+, Cr3+, Mn2+, Ni2+, Cu2+, Zn2+ and Pb2+.

Synthesis, structure, and solvent-extraction properties of tridentate oxime ligands and their cobalt(II), nickel(II), copper(II), zinc(II) complexes

AbstractSynthesis of four different types of ligands Ar[COC(NOH)R]n (Ar = biphenyl, n = 1, HL1; Ar = biphenyl, n = 2, H2L2; Ar = diphenylmethane, n = 1, HL3; Ar = diphenylmethane, n = 2, H2L4; R = furfurylamine in all ligands) and their dinuclear Co2+, Ni2+, Cu2+, and Zn2+ complexes is reported herein. These compounds were characterized by elemental analysis, ICP-OES, FT-IR spectra, and magnetic susceptibility measurements. The ligands were further characterized by 1H NMR. The results suggest that dinuclear complexes of HL1 and HL3 have a metal to ligand mole ratio of 2: 2 and dinuclear complexes H2L2 and H2L4 have a metal to ligand mole ratio of 2: 1. Square pyramidal or octahedral structures are proposed for complexes of oxime ligands. Furthermore, extraction abilities of the four ligands were also evaluated in chloroform using selected transition metal picrates such as Mn2+, Co2+, Ni2+, Cu2+, Zn2+, Cd2+, Hg2+, Pb2+. The ligands show strong binding ability towards Hg2+ and Cu2+ ions.

Synthesis, characterization, catalase functions and DNA cleavage studies of new homo and heteronuclear Schiff base copper(II) complexes

A new tetradentate diimine–dioxime ligand containing a donor set of N 4, and its homo-, heterodinuclear and homotrinuclear copper(II) complexes were prepared and characterized on the basis of their elemental analysis, FT-IR, 1H and 13C NMR spectra, molar conductivity and magnetic moment measurements. The extraction ability of N,N′′-bis[1-biphenyl-2-hydroxyimino-1-ethylidene]-diethylenetriamine was also evaluated in chloroform by using several transition metal picrates such as Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Pb(II), Cd(II) and Hg(II). It has been seen that the ligand shows strong binding ability toward the copper(II) ion. Moreover, the catalytic activities of the complexes for the disproportionation of hydrogen peroxide were investigated in the presence of imidazole. The synthesized complexes display efficiency in the disproportion reactions of hydrogen peroxide, producing water and dioxygen in catalase-like activity. The interaction between these complexes and DNA has also been investigated by agarose gel electrophoresis. We found that the homo- and heterodinuclear copper complexes can cleave supercoiled pBR322 DNA to nicked and linear forms. The dinuclear complexes including phenanthroline ( 2– 4), with H 2O 2 as a co-oxidant, exhibited the strongest cleaving activity.

Synthesis, characterization and extraction studies of N,N″-bis[1-biphenyl-2-hydroxyimino-2-(4-acetylanilino)-1-ethylidene]-diamines and their homo-and heteronuclear copper(II) complexes

A new series of homo- and heteropolynuclear copper(II) complexes of N,N″-bis[1-biphenyl-2-hydroxyimino-2-(4-acetylanilino)-1-ethylidene]-diamines have been prepared and characterized by different physical techniques. The starting point of the research was the reaction of chloroacetyl chloride with biphenyl in the presence of aluminum chloride. 4-Biphenylhydroximoyl chloride was obtained by reacting synthesized 4-(chloroacetyl)biphenyl with alkyl nitrite. Substituted 4-(alkylaminoisonitrosoacetyl) biphenyl (ketooxime) was prepared by reacting 4-biphenylhydroximoyl chloride with 4-aminoacetophenone in EtOH. Homodi-, homotrinuclear and heterodinuclear copper(II) perchlorate complexes of tetradentate Schiff bases which possess N4 donor sets derived from the condensation of 4-(arylaminoisonitrosoacetyl)biphenyl and diamine derivatives were synthesized and characterized. Elemental analysis, FT-IR, ESR, molar conductivity, magnetic moment measurements and thermal analyses studies were utilized for the investigation of the complexes. The free ligands were also characterized by 1H- and 13C-NMR spectra. Elemental analyses, stoichiometric and spectroscopic data of the metal complexes indicated that the metal:ligand ratio of dinuclear copper(II) complexes were found to be 2: 1 while this ratio was 3: 2 in trinuclear copper(II) complexes and the metal complexes indicated that the metal ions are coordinated to the oxime and imine nitrogen atoms. The extraction abilities of the novel ligands were also evaluated in chloroform by using several transition metal picrates such as Mn2+, Co2+, Ni2+, Cu2+, Zn2+, Pb2+, Cd2+, Hg2+. It has been observed that both ligands show a high affinity to Cu2+ ions.

Control of Conformational Flexibility in Calix[6]Arenes: Synthesis and Characterisation of Triply Bridged Calix[6]Arene–-10,15-Dihydro-5H-Tribenzo [a,d,g]Cyclononene Conjugates

A series of triply bridged symmetrical tert-butylcalix[6]arene–-10,15-dihydro-5 H-tribenzo[ a,d,g]cyclononene conjugates have been synthesised in excellent yields. It has been observed that the synthesised multi-cavity molecular receptors retain the calix[6]arene and derivatised 10,15-dihydro-5 H-tribenzo[ a,d,g]cyclononene units in their cone conformations in solution. While the employed alkyl spacers confer flexibility to the conjugate units at room temperature, the synthesised receptors have been observed to exist in flattened cone conformations at low temperatures as determined by variable temperature NMR measurements. It has been observed that 6b shows a significant selectivity towards Ba2+ over other metal ions while compound 6c shows selectivity towards NH4+ ions from amongst alkali, alkaline-earth and transition metal picrates. Alkali and transition metal ions are poorly extracted by the hosts 6a–c. The extraction abilities of host molecules 5a–c towards metal picrates were found to be much less than that of 6a–c.

Synthesis and Characterization of a Novel Quinoxaline-Substituted vic-Dioxime and Its Complexes Containing Bis(12-Diazacrown-4) Derivatives

Abstract A new quinoxaline-substituted vicinal dioxime ligand containing bis(12-diazacrown-4) units (H2L) was synthesized by the reaction of cyanogen di-N-oxide with compound 4. Mononuclear NiII and CuII complexes with a metal:ligand ratio of 1:2 for H2L and a trinuclear CuII complex were also synthesized. The mononuclear CuII species coordinated to two CuII ions through the deprotonated oximate oxygens to yield a trinuclear structure cis-bridged by the oximate groups, with 1,10-phenanthroline as an end-cap ligand. The mononuclear CoIII complex of H2L was isolated with pyridine and chlorine as axial ligands. In addition, a CoIII complex containing the BF2+ bridge macrocycle was synthesized using a precursor hydrogen-bridged CoIII complex via a template effect. The extraction abilities of 1, 3, and 11 were also evaluated in 1,2-dichloroethane by using several alkali (Li+, Na+, K+, and Cs+) and transition-metal picrates, such as Ag+, Pb2+, Cd2+, Cu2+, and Zn2+. Structures of the ligands and metal complexes were solved by elemental analyses, 1H and 13C NMR, FT-IR, UV–vis, and mass spectra.

Novel phthalocyanine polymers with very flexible pentathiatetraethylene units

A series of polymeric metal-free and metallophthalocyanine (M = 2H, Ni, Co, Fe, Pb, Cu and Zn) polymers were prepared by polymeric tetramerization reaction of bisphthalonitrile monomer with proper materials. The Co–phthalocyanine polymer was prepared by two different methods. The metal-free ( 3) and the Co-containing phthalocyanine polymer ( 5) were chemically doped with iodine (I 2) and nitrosyl tetrafluoroborate (NOBF 4), respectively. The electrical conductivities of the polymeric phthalocyanines measured as gold sandwiches were found to be 10 −8–10 −4 S cm −1 in vacuum and in argon. The electrical conductivities of I 2-doped metal-free phthalocyanine ( 3a) and NOBF 4-doped Co–phthalocyanine ( 5a) polymers were found to be approximately 110 and 89 times higher than those of undoped versions, respectively. The extraction ability of 3 was also evaluated in tetrahydrofuran using several transition metal picrates such as Ag +, Hg 2+, Pb 2+, Cd 2+, Cu 2+ and Zn 2+. The extraction affinity of 3 for Ag + was found to be highest in the heterogeneous phase extraction experiments. The aggregation and disaggregation properties of 3 were investigated with silver(I), mercury(II) and methanol as solvent. All the novel compounds were characterized by using elemental analysis, UV–vis, FT-IR, NMR and MS spectral data and DTA/TG.

Synthesis, characterization and extraction studies of a new vic-dioxime and its complexes containing bis(diazacrown ether) moieties

A new vicinal dioxime ligand containing bis(diazadioxa-12-crown-4 ethoxy) units ( H 2 L) has been synthesized by the reaction of cyanogendi- N-oxide with 3,4-bis(2-{10-[(4-methylphenyl)sulfonyl]-1,7-dioxa-4,10-diazacyclododecan-4-yl}ethoxy)aniline, which was prepared by the reduction of 4-[(4-methlyphenyl)sulfonyl]-10-[2-((4-nitro-2-{2-[10-phenylsulfonyl)-1,7-dioxa-4,10-diazacyclododecan-4-yl]ethoxy}phenoxy)ethyl]-1,7dioxa-4,10-diazacyclododecan. A mononuclear nickel(II) and copper(II) complexes with a metal:ligand ratio of 1:2 for H 2 L were also synthesized. The mononuclear cobalt(III) complex of H 2 L has been isolated with L′ = pyridine, together with chlorine as an axial ligand. In addition, a cobalt(III) complex containing the BF 2 + bridge macrocycle was synthesized using a precursor hydrogen-bridged cobalt(III) complex via the template effect. The extraction abilities of 1, 3, 6 and 10 were also evaluated in 1,2-dichloroethane by using several alkali (Li +, Na +, K +, Cs +) and transition metal picrates such as Ag +, Pb 2+, Cd 2+, Cu 2+, Zn 2+. The structure of the dioximes and their complexes are proposed according to elemental analyses, 1H and 13C NMR, FT-IR UV–Vis and mass spectra.

Novel Network Polymeric Phthalocyanines: Synthesis and Characterization

AbstractSummary: New p‐xylylenebis‐(oxa‐thia‐propan) bridged metal‐free and metallophthalocyanine polymers were synthesized. The metal‐free phthalocyanine polymer (3) was prepared by the reaction of a tetranitrile monomer with 1,8‐diazabicyclo[5.4.0]undec‐7‐ene (DBU) in pentanol. Ni‐ and Co‐phthalocyanine polymers were prepared by reaction of the tetranitrile compound with the chlorides of Ni(II) and Co(II) in quinoline. Cu‐ and Zn‐phthalocyanine polymers were prepared by the reaction of the tetranitrile compound with the acetates of Cu(II) and Zn(II) and DBU in amyl alcohol. Yellow PbO and Fe(CO)5 were used to prepare Pb‐ and Fe‐analog polymers, respectively. The Co‐phthalocyanine polymer was also prepared using ethylene glycol instead of quinoline in the presence of the catalyst ammonium molybdate. (3) was chemically doped with iodine. The electrical conductivities of the polymeric phthalocyanines measured as gold sandwiches were found to be 10−9–10−7 S · cm−1 in a vacuum and in argon. The electrical conductivity of iodine doped metal‐free phthalocyanine (3a) was found to be approximately 57 times higher than that of the undoped version. The extraction ability of (3) was also evaluated in THF using transition metal picrates, such as Ag1+, Hg2+, Pb2+, Cd2+, Cu2+ and Zn2+. The extraction affinity of (3) for Ag1+ was found to be highest in the heterogeneous phase extraction experiments. All the novel compounds were characterized using elemental analysis, UV‐Vis, FT‐IR, NMR and MS spectral data and DSC.Synthesis of new network polymeric phthalocyanines.magnified imageSynthesis of new network polymeric phthalocyanines.

The Synthesis and Characterization of a Novel vic-Dioxime and its Mononuclear Complexes Bearing an 18-Membered2O2S2Macro-Cycle and Their Characteristics as Extractants for Transition Metal Ions

A new (E, E)-dioxime (H2L) containing a diazadioxadithia macrocyclic moieties has been synthesized by reaction of an aromatic primary amine with cyanogendi-N-dioxide. The BF2+-capped Ni2+ mononuclear complex of this new oxime has been synthesized using a precursor hydrogen-bridged mononuclear Ni2+ complex. The solvent extraction of transition metal cations by (3) and (6) with picrate anion into chloroform has been studied at 25 °C and UV-visible spectroscopy. The extractability and selectivity of transition metal picrates, (Pb2+, Ni2+, Co2+, Cd2+, Zn2+, Cu2+, Ag+) has been evaluated. The structures of new compounds are identified by using elemental analysis, 1H and 13C-NMR, IR and MS spectral data.

The inclusion behavior of benzo-15-crown-5 with hydrated transition metal picrates

Six kinds of benzo-15-crown-5 (L) adducts having the stoichiometric formula M(Pic) 2 · L · xH 2O (M=Mn, Cu, x=2; M=Co, Ni, Zn, Cd, x=4; Pic means picrate anion) have been synthesized and characterized by EA, IR, UV and molar conductance. The X-ray crystal structural analysis of the benzo-15-crown-5 adduct with hydrated copper(II) picrate revealed that the benzo-15-crown-5 molecule virtually acts as a second-sphere ligand, which associates with the copper(II) ion by hydrogen bonding of the coordinating water molecule. By the comparison of the IR, UV spectra and molar conductance of the new adducts prepared, it can be deduced that the other adducts exhibit the similar coordination environment to that of the copper adduct.

The Transport Properties of Metal Picrates by Two New Calixarene Types

Abstract The possibility of transporting several transition metal picrates (Cu2+, Ni2+, Co2+, and Fe3+) through an active transport membrane with a pH gradient was investigated. Two new macrocyclic ligands used as carriers, 5, 11, 17, 23, 29, 35-hexa-t- butyl-37, 38, 39, 40, 41, 42-hexakis -[n-(1 -epoxyethyl)methoxy]calix[6]arene (I6-EPO) and 5, 11, 17, 23, 29, 35-hexa-t-butyl-37, 38, 39, 40, 41, 42-hexakis-[n-(2-hydroxyaminoethyl)methoxy]calix[6]arene I6-HPA), were synthesized from p-tert-butylcalix[6]arene. It was found that the membrane system studied allows separation of some transition metal cations.