Hasan Icbudak

Syntheses, characterization and crystal structures of novel amine adducts of metal saccharinates, orotates and salicylates

Abstract Seven novel adducts of ethylenediamine (en), N,N′-dimethylethylenediamine (dmen) and N,N-dimethylethylenediamine (ndmen) with saccharinate, orotate and salicylate as counter-ions were synthesized and characterized with physico-chemical methods (IR and UV/vis spectroscopy, magnetic susceptibility and thermoanalytical measurements) and X-ray diffraction. Reaction of dmen with tetraaquabis(saccharinato-N)copper(II) dihydrate yielded diaquabis(dmen)copper(II) saccharinate, whereas with the corresponding nickel derivative it afforded bis(dmen)bis(saccharinato-O)nickel(II). In the copper complex the coordinated water and the primary nitrogen end of the donor ligand interact with the saccharinate anion [O1w⋯O3=2.833(2), N1⋯N2=2.992(2)xa0A]. Adjacent molecules are linked by two more hydrogen bonds into a layer structure. In the nickel compound, the dmen ligand also chelates the metal atom, which is bonded to the carbonyl oxygen of the anionic group. The negatively-charged nitrogen atom of the anion is intramolecularly linked to the dmen [N1⋯N2=2.968(2)xa0A]; hydrogen bonds link the molecules into layers. Under mildly basic conditions, the reaction of orotic acid with cobalt(II) afforded tetraaqua(2,6-dioxo-1,2,6-trihydropyrimidine-4-carboxylato-N,O)cobalt(II) hydrate. The complex was oxidatively reacted with en to give a mixed-ligand cobalt(III) adduct which includes both mono- and bisdeprotonated orotate ions. The metal atom in tetraaqua(2,6-dioxo-1,2,6-trihydropyrimidine-4-carboxylato-N,O)cobalt(II) hydrate is chelated by the orotato dianion through the carboxyl oxygen and 3-pyrimidyl nitrogen atoms, and its octahedral geometry is completed by four water molecules. The 1-pyrimidyl nitrogen atom engages in hydrogen bonding with the lattice water molecule. The cobalt atom is similarly chelated by the orotato dianion in bis(en)(2,6-dioxo-1,2,6-trihydropyrimidine-4-carboxylato-N,O)cobalt(III) 2,6-dioxo-1,2,3,6-tetrahydropyridimidine-4-carboxylate pentahydrate. The copper atom in the five-coordinate aqua(en)orotatocopper(II) monohydrate is chelated by the en ligand, the deprotonated N1 pyrimidine atom and the orotate carboxylate oxygen; the water molecule completes the square-pyramidal coordination. The nickel and copper atoms in bis(en)bis(salicylato-O)nickel(II) and bis(ndmen)bis(salicylato-O)copper(II) monomeric octahedral complexes are coordinated by the salicylato monoanion through the carboxylate oxygen in a monodentate fashion and by the en and ndmen molecules through the two amine nitrogen atoms in a bidentate chelating manner. In the copper complex, the carboxylate oxygen atom engages in hydrogen bonding with the lattice water molecule.

Thermal Studies on Solid Complexes of Saccharin with Divalent Transition Metal Ions

The thermal decompositions of Mn(II), Fe(II), Co(II), Ni(II), Cu(II) and Zn(II) complexes of saccharin were studied in static air atmosphere. All of the complexes contain four molecules of coordination water and two molecules of crystallization water. The water molecules were removed in a single stage, except from the Zn(II) complex, which exhibited two endothermic effects. The dehydration process was usually accompanied by a sharp colour change. The anhydrous complexes exhibited a phase transition and the decomposition or combustion of saccharin occurred in the second and subsequent stages. The final decomposition products were identified by XRPD as the respective metal oxides. The kinetic parameters, such as the order of reaction and energy of activation for the dehydration stage, were evaluated and the thermal stabilities of the complexes are discussed.

Spectrothermal studies on Co(II), Ni(II), Cu(II) and Zn(II) salicylato (1,10-phenanthroline) complexes

The cobalt, nickel, copper and zinc atoms in bis(1,10-phenanthroline)bis(salicylato-O)metal(II) monomeric octahedral complexes [M(Hsal)2(phen)2]·nH2O, (M: Co(II), n=1; Cu(II), n=1.5 and Ni(II), Zn(II), n=2) are coordinated by the salicylato monoanion (Hsal) through the carboxyl oxygen in a monodentate fashion and by the 1,10-phenanthroline (phen) molecule through the two amine nitrogen atoms in a bidentate chelating manner. On the basis of the DTGmax, the thermal stability of the hydrated complexes follows order: Ni(II) (149°C)>Co(II) (134°C)>Zn(II) (132°C)>Cu(II) (68°C) in static air atmosphere. In the second stage, the pyrolysis of the anhydrous complexes takes place. The third stage of decomposition is associated with a strong exothermic oxidation process (DTA curves: 410, 453, 500 and 450°C for the Co(II), Ni(II), Cu(II) and Zn(II) complexes, respectively). The final decomposition products, namely CoO, NiO, CuO and ZnO, were identified by IR spectroscopy.

bis(nicotinamide) and bis(N,N-diethyl nicotinamide) p-hydroxybenzoate complexes of Ni(II), Cu(II) AND Zn(II)

The mixed-ligand p-hydroxybenzoate complexes of Ni(II), Cu(II) and Zn(II) with nicotinamide and N,N-diethylnicotinamide were synthesized and characterized by elemental analysis, magnetic susceptibility measurements and mass spectrometry. The thermal behavior of the complexes was studied by simultaneous TG, DTG and DTA methods in static air atmosphere. The infrared spectral characteristics of the complexes are also discussed. The complexes contain two water molecules, two p-hydroxybenzoato (p-hba) and two nicotinamide (na) (or diethylnicotinamide (dena)) ligands per formula unit. In these complexes, all ligands are coordinated to the metal ion as monodendate ligands. In Zn(II)-na and Cu(II)-dena complexes, thep-hydroxybenzoate behaves as bidentate chelating ligand through carboxylic oxygen atoms. The decomposition pathways and the stability of the complexes are interpreted in the terms of the structural data. The final decomposition products were found to be the respective metal oxides.

Synthesis, spectroscopy, thermal behaviour and molecular structure of orotatotriethanolaminecopper(II) monohydrate

Abstract The orotatotriethanolaminecopper(II) monohydrate, [Cu(C5H2N2O4)(C6H15NO3)] · H2O, has been synthesized and characterized with physico-chemical methods (IR and UV-Vis spectroscopy, magnetic susceptibility, conductivity and thermoanalytical measurements) and X-ray diffraction. The structure derived from physico-chemical methods is consistent with that of the X-ray diffraction. The compound crystallizes in the monoclinic system, space group P21/n, with a = 8.6282(12), b = 16.9919(18), c = 10.6985(15) Å, β = 110.08(3)°, V = 1473.1(3) Å3, Z = 4. The copper atom is chelated by the deprotonated nitrogen pyrimidine atom and by the carboxylate oxygen atom of the orotate dianion ligand, and by the nitrogen and oxygen atoms of the triethanolamine ligand. The title compound has a distorted octahedral coordination geometry.

Synthesis, spectroscopic and thermal studies of the copper(II) aspartame chloride complex

Abstract Aspartame adduct of copper(II) chloride Cu(Asp) 2 Cl 2 ·2H 2 O (Asp=aspartame) is synthesized and characterized by elemental analysis, FT IR, UV/vis, ESR spectroscopies, TG, DTG, DTA measurements and molecular mechanics calculations. Aqueous solution of the green solid absorbs strongly at 774 and 367xa0nm. According to the FT IR spectra, the aspartame moiety coordinates to the copper(II) ion via its carboxylate ends, whereas the ammonium terminal groups give rise to hydrogen bonding network with the water, the chloride ions or neighboring carboxylate groups. The results suggest tetragonally distorted octahedral environment of the copper ions.

Bis­(triethano­lamine-κ3N,O,O′)copper(II) squarate

In the crystal structure of the title compound, [Cu(C6H15NO3)2](C4O4), the cations and anions are located on inversion centres and a supramolecular architecture is formed. Two triethanoxadlamine (TEA) ligands coordinate to the CuII ion through four O atoms and two N atoms acting as N,O,O′-tridentate ligands, resulting in a distorted octahedral environment, with Cu—O bond distances of 2.0199u2005(17) and 2.288u2005(2)u2005A and a Cu—N distance of 2.0340u2005(18)u2005A. The squarate (C4O42−) anions and [Cu(TEA)2]2+ cations are linked to each other by hydrogen bonding between coordxadinated hydroxyl H atoms of TEA and squarate O atoms, forming layers. Adjacent layers are interlinked by hydrogen bonding between free hydroxyl H atoms of TEA and one of the squarate O atoms.

Effect of the Adsorptive Character of Filter Papers on the Concentrations Determined in Studies Involving Heavy Metal Ions

Analytical filter papers are generally made of fibrous cellulose which has the potential to adsorb metal ions. In this study, blue band ashless filter paper was used to demonstrate one of the sources of error in the determination of the concentration of Fe2+, Co2+, Mn2+, Cd2+, Cu2+, Pb2+ and Zn2+ ions. For this purpose, the metal ion content of standard solutions in the 1–100 mg/ℓ concentration range was analysed via FAAS before and after the filtration process. The corresponding results and the calculated percentage errors due to adsorption are presented. The effect of pH on the adsorption process was also investigated. Activated carbon and soil samples were spiked with each metal ion and the solid phases from the resulting solutions were separated by both filter paper methods and centrifugation. In the statistical estimation of the results, the paired t-test was applied for non-filtered and filtered solutions in the concentration range 1–100 mg/ℓ using the data analysis tools available in MS Excel®. The use of filter paper caused systematic errors, particularly at lower metal concentrations, and hence centrifugation or a filtering process using techniques other than filter paper is favoured as a better approach towards estimating the concentration of heavy metal ions from aqueous solution.

Spectroscopic and Thermal Studies of bis(N,N′‐Dimethylethylenediamine) and bis(N,N‐Dimethylethylenediamine)saccharinato Complexes of Co(II), Ni(II), and Cu(II)

The mixed‐ligand saccharin (Hsac) complexes of Co(II), Ni(II) and Cu(II) with N,N′‐dimethylethylenediamine (dmen), and N,N‐dimethylethylenediamine (ndmen) (Figure 1) were synthesized and characterized by elemental analysis, magnetic susceptibility, spectral (UV‐Vis and FT‐IR) methods, and simultaneous TG, DTG and DTA techniques. The complexes have pseudooctahedral geometries with two dimethylethylenediamine molecules coordinated to the metal ions as chelating ligands through their two nitrogen atoms and two monodentate saccharinato ligands in the trans positions for the complexes of the type [M(sac–O)2(dmen)2] (M = Co(II), Ni(II)), and [M(sac–N)2(ndmen)2] (M = Co(II), Ni(II), Cu(II)) and two aqua ligands in the trans positions in [Cu(H2O)2(dmen)2](sac)2. (sac–O; sac‐N = the saccharinato ligand may be coordinated to the metal ions through their carbonyl oxygen or their nitrogen atom, respectively). The decomposition mechanism and thermal stability of the solid complexes are interpreted in terms of their structures. The thermal stability order of the investigated complexes is Cu(II) > Co(II) > Ni(II) while the bis(N,N′,‐dimethylethylenediamine) complexes are thermally less stable than those of bis(N,N‐dimethylethylenediamine). The final decomposition products—the respective metal oxides—were identified by FT‐IR spectroscopy.

Structural studies of bis(o-sulfobenzimidato)praseodymium(III) chloride hexahydrate

Abstract A novel rare-earth metal(III) saccharinate, namely bis(o-sulfobenzimidato)praseodymium(III) chloride hexahydrate, is synthesized and its solid-state structure is suggested from the FT IR and UV/vis spectroscopic, thermoanalytical, elemental and magnetic measurements. The OH, CO, SO2 and OD stretchings (the latter isolated in H2O matrix) in the FT mid-infrared spectra of the frozen protiated and partially deuterated analogues of the complex spectra-structural correlations in other saccharinates to predict the structure of the o-sulfobenzimidate residues and the hydration water. The structure features a single crystallographic type of O-coordinated or ionic saccharinato residues, with at least three structural types of water of hydration, and chloride counter-ions in the outer-sphere.