Iman T. Ahmed

Ternary complexes of N-(2-acetamido)iminodiacetic acid and some aromatic acids. Isolation and stability constants in solution

SummaryTernary 1:1:1 complexes of YIII, CoII, NiII, CuII, LaIII, CeIII and UO22+with N-(2-acetamido)iminodiacetic acid (H2ADA) as primary ligand and salicylic, anthranilic or phthalic acid as secondary ligand are described. The complexes of CoII and CuII were isolated and characterized by microanalysis, molar conductance measurements, thermal analysis, i.r. and u.v.-vis. spectra. The formation constants of the 1∶1∶1 ternary complexes were determined potentiometrically in 20% (w/w) EtOH-H2O at 24 °C. The stabilities of the 1∶1∶1 Mn+:ADA2−:aromatic acid ternary complexes are higher than those of the corresponding 1∶1 Mn+:aromatic acid binary complexes.

Mixed-Ligand Complexes of Some Metal Ions with N-(2-Acetamido)Iminodiacetic Acid and Salicylic Acid Derivatives: Synthesis, Solution Equilibria and Characterization Studies

Abstract The formation constants of the binary and ternary complexes formed in solution of Pb2+, Co2+, Ni2+, Cu2+, Cd2+, Ce3+ and UO2 2+ with N-(2-acetamido)-iminodiacetic acid (H2ADA) and salicylic acid derivatives [thiosalicylic (TSA) and 3,5-dinitrosalicylic acid (DNSA)] have been determined pH-metrically at t = 25 ± 0.1 °C and ionic strength μ = 0.1 mol dm−3 (KNO3) The stability of the different complexes formed are discussed in terms of the nature of the ligands and metalions. The mixed ligand complexes of the type [M2+(ADA)(TSA)] (M2+ = Co2+, Ni2+, Cu2+) were synthesized and characterized. Referee I: C. E. Barnes Referee II: J. B. Vincent

DIVALENT TRANSITION METAL ION MIXED-LIGAND COMPLEXES OF TRICINE OR GLYCYLGLYCINE AND 8-HYDROXYQUINOLINE: SYNTHESIS, CHARACTERIZATION, AND FORMATION CONSTANTS

ABSTRACT The ternary metal complexes [M(II)-(tricine or glycylglycine)-8-hydroxyquinoline], where M(II)=Co(II), Ni(II) and Cu(II), were prepared and characterized by elemental and thermogravimetric analyses as well as molar conductance, infrared and electronic spectral measurements. Formation constants of the various binary and ternary complexes formed in the systems under investigation have been determined pH-metrically [at 25°C and at constant ionic strength I=0.10 mol dm−3 (KNO3)] and are discussed in terms of the nature of both the ligand and metal ion.

Spectral and thermal studies of divalent transition metal complexes with indole-2-carboxylic acid and 4-substituted hydrazinethiocarbamide

Ternary complexes of Co(II), Ni(II) and Cu(II) with indole-2-carboxylic acid (A) and 4-substituted hydrazinethiocarbamide (L) [4-phenylhydrazinethiocarbamide (L1), 4-benzylhydrazinethiocarbamide (L2) and 4-(2-propenyl)hydrazinethiocarbamide (L3)] were prepared. The structures of the complexes were proposed by molar conductance, electronic, IR, 1H NMR, mass spectra as well as thermogravimetric (TG) studies. An octahedral structure is suggested for Co(II), Ni(II) and Cu(II) ternary complexes.

Divalent Transition Metal Ion Ternary Complexes of N-(2-Acetamido)iminodiacetic Acid and Some Bi- and Tricarboxylic Aliphatic Acids

Abstract Ternary complexes of Co(II), Ni(II), Cu(II) with N-(2-acetamido)iminodiacetic acid (disodium salt, Na2ADA) and some bi- or tricarboxylic aliphatic acids (succinic, malic, tartaric and citric, H2L or H3L) were prepared. The structure of the complexes was determined by elemental and thermal analyses, IR and electronic spectra as well as conductivity measurements. The general formulas [M(ADA) (L) (H2O)]Na2 (H2O)× and [M(ADA) (L)]Na3 (H2O)× are deduced for the secondary ligand bi- and tricarboxylate aliphatic acid anions, respectively. An octahedral structure is suggested for the Co(II) and Ni(II) complexes, while a tetragonally distorted structure is proposed for the Cu(II) complexes. Stability constant of the different binary and ternary complexes formed in such system were determined at 25°C and μ=0.1 mol dm−3 KNO3 using the pH-titrimetric technique. It is deduced that the mixed complex is more stable than the corresponding binary aliphatic acid anion complex. The order of stability of the binary ...

Synthesis and Equilibrium Studies of Mixed‐Ligand Complexes of Co(II), Ni(II), and Cu(II) with Some Aliphatic Dicarboxylic Acids and Creatinine

Abstract Ternary mixed‐ligand metal complexes [M(L1)(L2)2](H2O) n , where M = Co(II), Ni(II), or Cu(II), L1 = the dianion of succinic, malic, or tartaric acid, and L2 = creatinine, were synthesized and characterized using microchemical and thermal analyses, molar conductance, infrared, and electronic spectral measurements. A square–planar structure is suggested for the Co(II) and Cu(II) ternary complexes, whereas Ni(II) ternary complexes have tetrahedral stereochemistry. Formation constants of the binary and ternary complexes in such systems were determined by pH‐metric titrations at 25 ± 0.1 °C and at a constant ionic strength I = 0.1 M (KNO3). The stability of the various complexes was discussed in terms of the nature of both the ligands and metal ions. The thermodynamic functions (ΔH, ΔG o, and ΔS o) associated with the complex formation of [Cu(II) + aliphatic acids + creatinine] were also determined and examined.

Divalent Transition Metal Ternary Complexes of N-(2-Acetamido)iminodiacetic Acid and Thiosemicarbazide as Well as Dithiocarbazate Derivatives

Abstract Ternary mixed ligand complexes of the type Na[M(ADA)L] (H2O)x where M = Co(II), Ni(II) and Cu(II); ADA = divalent anion of N-(2-acetamido)-iminodiacetic acid, L = S-methyl dithiocarbazate (L1) and benzalhydrazono methyl dithioformate (L2), thiosemicarbazide (L3) and benzalthiosemicarbazone (L4) have been prepared and characterized by elemental and thermal analyses, IR as well as conductivity measurements.

Divalent Metal Ion Ternary Complexes of Tricine and Mercaptobenzazoles

The mixed‐ligand complexes of the type [M(II)‐tricine‐mercaptobenzazoles], where M(II)=Co(II), Ni(II) and Cu(II), mercaptobenzazoles=(2‐mercaptobenzothiazole) (HL1), 2‐mercaptobenzoxazole (HL2) and 2‐mercaptobenzimidazole (HL3), were prepared and characterized by elemental and thermogravimetric analyses as well as molar conductance, infrared and electronic spectral measurements. The formation constants of the various binary and ternary complexes formed in solutions of Co(II), Ni(II), Zn(II) and Cd(II) ions with the systems under investigation have been determined potentiometrically [at 25 °C and at constant ionic strength I = 0.10 mol dm–3 (KNO3) and are discussed in terms of the nature of both the ligands and metal ions.

Synthesis and Spectroscopic Characterization of Some Divalent Metal Complexes Derived from 1,4-Dibenzoylthiosemicarbazide and N-[2-(3-Benzoylthioureido)ethyl]benzamide

The binary metal complexes [M(II)-L 1 or L 2 ], where M(II) = Co(II), Ni(II), Cu(II), Zn(II), Pb(II), Cd(II) and UO 2 (II); L 1 = 1,4-dibenzoylthiosemicarbazide; and L 2 = N-[2-(3-benzoylthioureido)ethyl]benzamide; were prepared and characterized by elemental analysis, thermogravimetric analysis, molar conductance, and electronic spectro-scopies (IR, 1 H-, and 13 C-NMR) in addition to mass spectra.

Synthesis, spectral, thermal and electrochemical characterization of metal(II) complexes with 1-S-methylcarbodithioate-4-substituted thiosemicarbazides

1-S-Methylcarbodithioate-4-substituted thiosemicarbazides (L1-L3) have been prepared and confirmed by spectral data and elemental analysis. Co(II), Ni(II), Cu(II), Cd(II) and Zn(II) complexes with L1-L3 have been prepared and characterized by elemental and thermal analyses, molar conductance, magnetic moment, as well as spectral data (IR, 1H NMR, mass and electronic spectra). The molar conductance data reveal that the chelates are non-electrolytes. The IR and 1H NMR spectra showed that L1-L3 are deprotonated in the complexes and act as binegative SNNS donors. The electronic spectra of the complexes as well as their magnetic moments provide information about geometries. Thermogravimetric analysis of some complexes suggests different decomposition steps and ending with metal sulfide as final product. The redox properties of the complexes are explored by cyclic voltammetry.