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A. Matilla

Bio: A. Matilla is an academic researcher from University of Granada. The author has contributed to research in topics: Stability constants of complexes & Potentiometric titration. The author has an hindex of 4, co-authored 6 publications receiving 71 citations.

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TL;DR: A series of ternary complexes of palladium(II) with ethylenediamine (en) and dicarboxylate ligands of the type [Pd(en)L] were synthesized and characterized by elemental analysis, IR spectroscopy and TG-DTA thermal analysis.

37 citations

Journal ArticleDOI
TL;DR: The crystal structures of two mixed-ligand copper(II) complexes having iminodiacetate(2-) (IDA) or N-carboxymethyl-D,L-threoninato (2-) ion (CMT) as terdentate ligands and imidazole (ImH) as an N-heterocyclic ligand are reported in this paper.
Abstract: The crystal structures of two mixed-ligand copper(II) complexes having iminodiacetate(2-) (IDA) or N-carboxymethyl-D,L-threoninato(2-) ion (CMT) as terdentate ligands and imidazole (ImH) as an N-heterocyclic ligand are reported. Both compounds crystallize in the orthorhombic system, space group Pbca with Z = 8. Aqua(imidazole)(iminodiacetato)copper(II) monohydrate (I,R = 0.065, R w = 0.075) consists of H2O molecules and [Cu(IDA)(ImH)(H2O)] complex units in a hydrogen bonding network. The structure of imidazole(N-carboxymethyl)-D,L-threoninatocopper(II) (IV, R = 0.066, Rω 0.078) is built up of hydrogen bonded polynuclear chains. In both compounds the Cu(II) ion exhibits a flattened and distorted square-based pyramidal coordination, with a terdentate aminoacidate ion, IDA or CMT, and one ImH ligand at the base and H2O (in I) or the oxygen atom of the OH side chain from one adjacent CMT ion (in IV) as the fifth apical ligand. The nearly coplanar conformation of the two five-membered chelate rings in...

22 citations

Journal ArticleDOI
TL;DR: In this paper, the structure of [Ni2(ALADTO)-(H2O)6] was determined by single crystal X-ray analysis and the temperature dependence of the magnetic susceptibility of the new dinuclear complexes was measured over the range 2 to 300 K.
Abstract: New dinuclear complexes of the types [Ni2(L)-(H2O)2] and [Ni2(L)(H2O)6] [H4L = N,N′-bis(carboxymethyl) dithiooxamide (H4GLYDTO), N,N′-bis(1-carboxyethyl) dithiooxamide (H4ALADTO), N,N′-bis(1-carboxy-2-methylpropyl) dithiooxamide (H4VALDTO) and N,N′-bis-(1-carboxy-3-methylbutyl) dithiooxamide (H4LEUDTO)] have been prepared and characterized by IR and electronic absorption spectroscopy, and the structure of [Ni2(ALADTO)-(H2O)6] crystals has been determined by single crystal X-ray analysis. This compound is composed of discrete dinuclear units in which two NiII atoms with NO4S kernels are linked by a single [ALADTO]4- group that coordinates through its carboxylato oxygen, amino nitrogen and thiolato sulphur atoms. In each dimer unit the two nickel(II) ions in distorted octahedral coordination are separated by 5.863(2) A The temperature dependence of the magnetic susceptibility of the new compounds was measured over the range 2 to 300 K. In the complexes of [GLYDTO]4- and [ALADTO]4- the two Ni atoms are antiferromagnetically coupled, with J = -23.51(4) and -20.95(8) cm-1, respectively. By constrast, [Ni2(VALDTO)(H2O)2], [Ni2(VALDTO)(H2O)6] and [Ni2-(LEUDTO)(H2O)2] remain paramagnetic down to 2 K, with magnetic moment values between 2.8 and 3.3 M.B. © WILEY-VCH Verlag GmbH, 2001.

11 citations

Journal ArticleDOI
TL;DR: In this paper, the formation constants for Cu(II) complexes with N-carboxymethyl-D, L-threonine (H2CMT = H2L) have been determined using the HYPERQUAD program with 652 potentiometric data from the titration of twelve solutions having different H 2L concentrations and/or Cu(2)/H2L ratios.
Abstract: Formation constants for Cu(II) complexes with N-carboxymethyl-D,L-threonine (H2CMT = H2L) have been determined (I = 0.1M KNO3, 25°C) using the HYPERQUAD program with 652 potentiometric data from the titration of twelve solutions having different H2L concentrations and/or Cu(II)/H2L ratios. Refined values of long βpqr for the species CupLqLr = CuL, CuL2, CuL(OH) and CuL(OH)2 allow simulation of experimental titration curves with good agreement. Aqua (N-carboxymethyl-D,L-threoninato (2-)) copper(II) was synthesized and studied by X-ray diffraction and other physical methods. The structure (monoclinic system, space group P21/c, final R = 0.044 and Rw = 0.051) consists of infinite zigzag chains of [Cu(CMT) (H2O)] groups linked together by hydrogen bonds. The Cu(II) atom exhibits square pyramidal coordination with an additional sixth weak interaction (Cu-O = 2.568(4)A) which involves a terdentate-bridged carboxy-late group closely related to that already claimed in the structure of [Cu(CMPhe) (H2O)], ...

4 citations

Journal ArticleDOI
A. Matilla1, J. M. Tercero1, C. Valenzuela1, C.F Moreno1, M. A. Sanjuan1 
TL;DR: In this article, the formation of complexes of Zn(II), Cd(II, Hg(II) ion, and Pb(II)-II ion for N-carboxymethyl-D,L-threonine (H2CMT, H2L) was studied by spectrophotometric and potentiometric methods.
Abstract: The formation of complexes of Zn(II), Cd(II), Hg(II), and Pb(II) and N-carboxymethyl-D,L-threonine (H2CMT, H2L) in aqueous solutions has been studied by spectrophotometric and potentiometric methods. The complexation model for each system has been established by the HYPERQUAD program from the potentiometric data. Three different behaviors are found: ML2H, MLH, ML, MLOH, and ML2 complexes are formed by Zn(II) and Cd(II) ions, ML2H, ML, MLOH, and ML2 are formed by Hg(II) ion, and only 1/1 complexes MLH, ML, and MLOH are formed by the Pb(II) ion. The formation constants determined for all these complexes allow simulation of experimental titration curves with good agreement. The speciation of multimetal systems with H2CMT shows that this compound is a good and selective ligand at low pH for the Hg(II) ion.

1 citations


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TL;DR: In this article, a detailed analysis of Hirshfeld surfaces and fingerprint plots facilitates a comparison of intermolecular interactions, which are crucial in building different supramolecular architectures.
Abstract: Mononuclear copper(II) and nickel(II) complexes, [(C5H6N2)Cu(IDA)(H2O)] (1) and (C5H7N2)2[Ni(IDA)2(H2O)] (2) [H2IDA = iminodiacetic acid; C5H6N2 = 4-aminopyridine; C5H7N2 = protonated 2-aminopyridine], have been synthesized, and their crystal structures were solved using single crystal X-ray diffraction data. A detailed analysis of Hirshfeld surfaces and fingerprint plots facilitates a comparison of intermolecular interactions, which are crucial in building different supramolecular architectures. Molecules are linked by a combination of N–H···O, O–H···O and C–H···O hydrogen bonds into two-dimensional framework, whose formation is readily analyzed in terms of substructures of lower dimensionality with zero finite zero-dimensional dimeric units as the building blocks within the structures. Moreover, the aromatic molecules that are engaged in lone pair···π interactions with the noncoordinated carbonyl moieties play a crucial role in stabilizing the self-assembly process observed for both complexes. Intricate...

291 citations

Journal ArticleDOI
TL;DR: Metal complexes with open coordination sites serve as binding sites in the development of chemosensors to study metalloenzyme function in bioinorganic chemistry or to direct supramolecular self-assembly.
Abstract: Metal complexes with open coordination sites have found wide use in molecular recognition. They serve as binding sites in the development of chemosensors to study metalloenzyme function in bioinorganic chemistry or to direct supramolecular self-assembly. Lewis-acidic metal complexes can target a large variety of Lewis basic functional groups, which makes them very suitable for the design of synthetic receptors. Coordination to metal ions occurs typically with large enthalpies compared to those for hydrogen bond formation, salt-bridges, or dipole-dipole interactions.

203 citations

Journal ArticleDOI
TL;DR: In this paper, three new copper(II) complexes of formula [Cu(Memal)(H2O)]n (1), [Cu2(pyz)(Memal)2] (2) and [cu2(4,4′-bpy)2(H 2O)2 (3) were obtained and structurally characterized by X-ray diffraction.
Abstract: Three new copper(II) complexes of formula [Cu(Memal)(H2O)]n (1), [Cu2(pyz)(Memal)2] (2) and [Cu2(4,4′-bpy)(Memal)2(H2O)2] (3) (Memal = methylmalonate, pyz = pyrazine and 4,4′-bpy = 4,4′-bipyridine) were obtained and structurally characterized by X-ray diffraction. Complex 1 is a square grid of aquacopper(II) units which are linked by carboxylate-methylmalonate groups in the anti–syn (equatorial–equatorial) coordination mode. The crystal structures of 2 and 3 consist of corrugated layers of copper(II) (2) and aquacopper(II) (3) units with intralayer carboxylate-methylmalonate bridges in the anti–syn (equatorial–apical) coordination mode which are linked through pyrazine (2) and 4,4′-bipyridine (3) ligands; to build up a 3-D network. Magnetic susceptibility measurements of complexes 1–3 in the temperature range 2–300 K show the occurrence of an overall ferromagnetic behaviour with a weak intralayer ferromagnetic coupling (J = +1.61(1) cm−1) in 1 whereas two opposite magnetic interactions occur in 2 and 3, one ferromagnetic through the anti–syn carboxylate (2 and 3) and the other antiferromagnetic through pyz (2) and 4,4′-bpy) (3).

91 citations

Journal ArticleDOI
TL;DR: In this article, the stoichiometric reaction of copper(II) hydroxycarbonate with iminodiacetic acid (H2IDA) in water under reduced pressure yields good crystalline samples of [Cu(IDA)(H2O)2] (compound I).

58 citations

Journal ArticleDOI
TL;DR: In this article, a mononuclear complex Pt(pq)(bdt) (where pq = 2-(2′pyridyl)quinoxaline and bdt = benzene-1,2-dithiolate) has been prepared and characterized by NMR spectroscopy, ES mass spectrography and elemental analysis.

55 citations