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Ana M González-Noya

Publications and source records attributed to Ana M González-Noya.

5 recordsLinked to original sources
PubMed2006

Influence of the metal size in the structure of the complexes derived from a pentadentate [N(3)O(2)] hydrazone.

The influence of the metal size in the nuclearity of the complexes derived from the hydrazone ligand 2,6-bis(1-salicyloylhydrazonoethyl)pyridine [H(4)daps] has been investigated. We have synthesised a series of new complexes [M(H(x)daps)] x yH(2)O, (x = 2,3; y = 0-3) with M = Ag (1), Cd (2), Al (3), Sn (4) and Pb (6), using an electrochemical procedure. The crystal and molecular structures have been determined for the mononuclear complexes [Sn(H(2)daps)(H(2)O)(2)] x 4H(2)O (5) and [Pb(H(2)daps)(CN)][Et(4)N] (7). Complex is the first neutral Sn(II) complex derived from a pentadentate hydrazone Schiff base ligand. Complex shows the lead coordinated to the hydrazone donor set and a cyanide ligand, being the first reported complex with the lead atom coordinated to a monodentate cyanide group. Additionally, we have synthesised the lead complex using chemical conditions, in the presence of sodium cyanide which allowed us to isolate the neutral complex [Pb(H(2)daps)] (8). Evaporation of these mother liquors led the novel compound [Pb(Hdaphs)(CH(3)COO)] (9). Complex 9 shows the initial ligand hydrolysed in one of the imine bonds giving rise to a new tetradentate ligand [H(2)daphs] coordinated to the lead atom and a bidentate acetate group. Moreover, the solution behaviour of the complexes has been investigated by (1)H, (113)Cd, (117)Sn and (207)Pb NMR techniques. In particular multinuclear NMR has provided new useful data to correlate factors such as oxidation state, coordination number and nature of the kernel donor atoms due to the new coordination found in complexes 5 and 7. The comparative study of the structures of the complexes derived from this pentadentate [N(3)O(2)] hydrazone ligand let us to conclude that the metal size is a key factor to control the nuclearity of the complexes derived from the ligand [H(4)daps].

Journal Article↗
PubMed2006

Novel peroxidase mimics: mu-Aqua manganese-Schiff base dimers.

The interaction of manganese(II) carboxylate salts [Mn(O(2)CR)(2), where R=ethane, pentane] with H(2)L(1) [N,N'-bis(3-methoxy-2-hydroxybenzaldehyde)-1,2-phenylenediamine] and H(2)L(2) [N,N'-bis(3-ethoxy-2-hydroxybenzaldehyde)-1,2-phenylenediamine] was studied. MnL(1)(O(2)CEt)(H(2)O) (1), MnL(1)(O(2)CPe(n))(H(2)O) (2), MnL(2)(O(2)CEt)(H(2)O)(2) (3) and MnL(2)(O(2)CPe(n))(H(2)O)(2) (4) were isolated and thoroughly characterised by elemental analysis, FAB mass spectrometry, infrared and (1)H NMR spectroscopy, magnetic susceptibility measurements, molar conductivities, and cyclic and normal pulse voltammetry. Compounds 1 and 2 were crystallographically characterised revealing a tetragonally elongated octahedral geometry for the manganese coordination sphere and also a dimeric nature through mu-aqua bridges. Complexes 1-4 behave as efficient peroxidase mimics in the presence of the water-soluble trap ABTS, probably due to their ease to coordinate the substrate molecule. A correlation between rhombicity of the complexes and peroxidase activity has also been established.

Carboxylic Acids↗
PubMed2004

Syntheses and X-ray characterization of metal complexes with the pentadentate thiosemicarbazone ligand bis(4-N-methylthiosemicarbazone)-2,6-diacetylpyridine. The first pentacoordinate lead(II) complex with a pentagonal geometry.

In this paper we describe the electrochemical synthesis and characterization of new neutral manganese, iron, cobalt, nickel, copper, zinc, cadmium and lead complexes with the ligand bis(4-N-methylthiosemicarbazone)-2,6-diacetylpyridine, H4DAPTsz-Me. X-Ray structures of [Mn(H2DAPTsz-Me)(EtOH)2] 1, [Pb(H2DAPTsz-Me)] 3 and [Zn(H2DAPTsz-Me)]2.EtOH.2H2O 4, were also determined. In these complexes the ligand behaves as bis-deprotonated and SNNNS pentadentate. In the manganese complex the metal is heptacoordinated, in a distorted pentagonal-bipyramidal environment, with the N3S2 donor set of the ligand in the pentagonal girdle and two solvent molecules occupying the axial positions. In the lead complex 3 the metal is pentacoordinated, bound exclusively to the five donor atoms of the ligand, as a consequence of the existence of "inert pair effect". The bishelical zinc complex 4 shows each zinc atom with different coordination geometry, one octahedrally six-coordinate while the other is distorted tetrahedrally four-coordinate.

Cadmium↗