UV/Vis spectroelectrochemistry of o-vanillin: Study of the antioxidant properties

UV/Vis absorption spectroelectrochemistry is a very useful technique to study complex electrochemical mechanisms. In this work, we have studied the electrochemistry of o-vanillin in presence and absence of oxygen. This compound exhibits good antioxidant properties. The products of the reaction of o-vanillin with the superoxide anion, electrogenerated when oxygen is reduced in an aprotic medium, have been detected using UV/Vis absorption spectroelectrochemistry. This technique allows us to shed more light on the antioxidant properties of o-vanillin, providing valuable information not only on the antioxidant properties of this compound but also about other compounds that follow a similar mechanism. In this work we have deconvolved the electrochemical signal in the different components that are related to the processes taking place at the electrode and in the solution adjacent to it.Ministerio de Economía y Competitividad (CTQ2017-83935-R-AEI/FEDERUE), Junta de Castilla y León (BU297P18), Ministerio de Ciencia, Innovación y Universidades (RED2018- 102412-T)

Spectroscopic investigations of iron(II) and iron(III) oxalates

In an attempt to contribute to a better characterization of FeII and FeIII oxalate complexes, an investigation of their vibrational (infrared and Raman) and 57Fe-Mössbauer spectra was performed. It is shown that the two polymorphs, α and β, of FeC2O4.2H2O cannot be accurately differentiated with any of these spectroscopic methods, demonstrating the high structural similarity of these two crystalline forms. Partially deuterated samples of β-FeC2O4·2H2O were also investigated to improve the vibrational-spectroscopic analysis. In the case of Fe2(C2O4)3·4H2O, a structural model, derived from results of combined vibrational and Mössbauer data, could be proposed. The 298 K Mössbauer spectrum for this complex is discussed in detail for the first time.Facultad de Ciencias ExactasCentro de Química Inorgánic

Structure, tautomerism, spectroscopic and DFT study of o-vanillin derived Schiff bases containing thiophene ring

Two Schiff bases derived from o-vanillin (o-HVA), a well-known antioxidant hydroxo aldehyde, have been obtained from condensation with 2-thiophenecarboxilic acid hydrazide (TPNNH) and 2-thiophenemethylamine (TPNH2), respectively. The inclusion of thiophene is based on its significance in the development of effective therapeutic agents. The study of the compounds oVATPNNH and oVATPNH2 includes solid state structural and spectroscopic analysis by single-crystal X-ray diffraction and vibrational spectroscopy (FTIR and Raman). The crystal structure of oVATPNH2 shows a peculiar rotational disorder in the heterocycle. Tautomeric equilibria in solution, which depends on the molecule structure and the nature of the solvent, were analysed by means of 1H and 13C{1H} NMR along with electronic spectroscopy. Tautomerism plays an important role not only in the molecular interactions but also in the behaviour of the Schiff base when acting as a ligand in coordination compounds. Results obtained from DFT calculations were used in the interpretation of the experimental data and in the spectral assignments.CONICET and UNLP, Argentina and by Ministerio de Economía y Competitividad Español (CTQ2014-58812-C2-1-R, CTQ2015-70371-REDT

Spectroscopic investigations of iron(II) and iron(III) oxalates

In an attempt to contribute to a better characterization of FeII and FeIII oxalate complexes, an investigation of their vibrational (infrared and Raman) and 57Fe-Mössbauer spectra was performed. It is shown that the two polymorphs, α and β, of FeC2O4•2H2O cannot be accurately differentiated with any of these spectroscopic methods, demonstrating the high structural similarity of these two crystalline forms. Partially deuterated samples of β-FeC2O4•2H2O were also investigated to improve the vibrational-spectroscopic analysis. In the case of Fe2(C2O4)3•4H2O, a structural model, derived from results of combined vibrational and Mössbauer data, could be proposed. The 298 K Mössbauer spectrum for this complex is discussed in detail for the first time

A novel oxidovanadium(V) compound with an isonicotinohydrazide ligand: A combined experimental and theoretical study and cytotoxity against K562 cells

The interaction of oxidovanadium(V) with INHOVA (the condensation product of isoniazid and o-vanillin) lead to the formation of the ester-like complex [VO(INHOVA)EtO(OH2)]Cl·H2O (1). Crystals suitable for X-ray diffraction methods were obtained. The complex crystallizes as a dimer in the space group P21/c of the monoclinic system. A detailed analysis, including solid-state vibrational spectroscopy and electronic spectroscopy in DMSO solution, was performed for both INHOVA and complex (1). A complete theoretical study based on DFT was also carried out. The calculations were of valuable assistance in the spectra assignments and interpretation. The electrochemical characterization allows determining the redox behavior of INHOVA and complex (1). Cytotoxicity was assayed against the chronic myelogenous leukemia K562 cell line. The IC50 values obtained denote that both the ligand and complex (1) are good candidates for further studies.Centro de Química Inorgánic

Spectroscopic investigations of iron(II) and iron(III) oxalates

In an attempt to contribute to a better characterization of FeII and FeIII oxalate complexes, an investigation of their vibrational (infrared and Raman) and 57Fe-Mössbauer spectra was performed. It is shown that the two polymorphs, α and β, of FeC2O4.2H2O cannot be accurately differentiated with any of these spectroscopic methods, demonstrating the high structural similarity of these two crystalline forms. Partially deuterated samples of β-FeC2O4·2H2O were also investigated to improve the vibrational-spectroscopic analysis. In the case of Fe2(C2O4)3·4H2O, a structural model, derived from results of combined vibrational and Mössbauer data, could be proposed. The 298 K Mössbauer spectrum for this complex is discussed in detail for the first time.Facultad de Ciencias ExactasCentro de Química Inorgánic

Synthesis, crystal structure and cytotoxicity assays of a copper(II) nitrate complex with a tridentate ONO acylhydrazone ligand. Spectroscopic and theoretical studies of the complex and its ligand

The new copper complex, [Cu(HL)(OH2)2](NO3), including the tridentate N-acyhydrazone derived from 4-hydroxy-benzohydrazide and 2-hydroxy-3-methoxybenzaldehyde, (H2L), has been synthesized and characterized in the solid state and in solution by spectroscopic (FTIR, Ra, UV–vis, EPR) methods. The results were compared with those obtained for the hydrazone ligand and complemented with computational methods based on DFT. The crystal structure of the complex has been determined by X-ray diffraction. It crystallizes in the triclinic space group with Z = 2. The Cu(II) ion is in a distorted square pyramidal environment, coordinated to a planar HL- anion acting as a tridentate ligand. The 5-fold coordination is completed with two water molecules. It is arranged in the lattice as H-bonded ribbon-like polymers that extends along the [1 2 1] crystal direction. The cytotoxicity of the complex together with that of the H2L ligand and the copper ion were evaluated in vitro against five different human cancer cell lines namely A549 (lung), MG-63 (bone), MCF-7 and MDA-MB-231 (breast) and Jurkat (leukemia). The copper complex inhibits the cell viability in a dose dependent manner with a greater potency than the H2L ligand and the free copper ion displaying even higher antitumor activity than the well-known anticancer metallodrug cisplatin.CONICET (PIP 11220130100651CO and PIP 0034), UNLP (111/X673) and ANPCyT (PICT 2014-2223) of Argentina. Consejería de Educación CyL and FFEDER BU076U16, BU022G18 and Ministerio de Economía y Competitividad CTQ2016-75023-C2-1-P and CTQ2015-70371-REDTMetDrugs Network (Spain

Cu(ii) and Zn(ii) complexes with a poly-functional ligand derived from o-vanillin and thiophene. Crystal structure, physicochemical properties, theoretical studies and cytotoxicity assays against human breast cancer cells

The interaction of a poly-functional ligand derived from o-vanillin and 2-thiophenemethylamine (oVATPNH2) with transition metal ions Cu(II) and Zn(II) leads to the formation of stable coordination compounds, namely [Cu(oVATPNH2)2] and [Zn(oVATPNH2)2]. Their crystal structures have been determined by X-ray diffraction methods. Two molecules of the deprotonated ligand acting in a bidentate fashion build a nearly square planar environment around Cu(II) and a distorted tetrahedral coordination arrangement for Zn(II). The complexes were characterized by spectroscopic techniques, including solid state FTIR, Raman, EPR and diffuse reflectance and solution UV-vis and EPR. Their thermal behavior has been analyzed by means of TGA and DTA. DFT theoretical studies, using computational methods based on DFT, were employed to assist the interpretation and assignment of spectroscopic data. Cytotoxicity assays against two human breast cancer cell lines, namely MCF-7 and MDA-MB-231, revealed an enhancement of the effectiveness of the complexes as compared with both the ligand and the free metal ions. The results for the copper compound are promising, as its cytotoxic effect was stronger than the reference metallodrug cisplatin in both cancer cell lines tested.CONICET-CCT-La Plata (PIP 0651 and 0034), ANPCyT (PICT 2016-1574) and UNLP (11/X-473) (Argentina) and also by Consejerı´a de Educacio´n CyL and FFEDER BU076U16, BU022G18 and Ministerio de Economı´a y Competitividad CTQ2016-75023-C2-1-P and CTQ2015-70371- REDT MetDrugs Network (Spai

Megaproyectos urbanos y productivos. Impactos socio-territoriales

El desarrollo de megaproyectos productivos trae consigo oportunidades para el crecimiento económico, la generación de empleos y el desarrollo regional. No obstante, en la actualidad, los grandes temas como la expansión urbana, el desarrollo industrial, las cementeras, la minería, el uso intensivo del agua y demás recursos naturales, preocupan a las comunidades por los impactos generados y porque en lo general, no consideran la racionalidad y responsabilidad ambiental y social hacia el entorno. En este contexto son diversos los estudios científicos que, en el marco de la política de económica imperante, intentan posicionarse como alternativas a proyectos económicos que confrontan los intereses particulares y comunitarios y que afectan la salud humana y ambiental. Megaproyectos urbanos y productivos. Impactos socio-territoriales, reúne veinticinco textos académicos sobre las afectaciones que éstos emprendimientos tienen para la sociedad y el entorno. Los temas expuestos recogen experiencias en el desarrollo urbano, industrial, turístico, portuario y aeroportuario, entre otros. Así mismo se retoman temas como la ética, la dialéctica, la política y la economía y su relación en el emprendimiento de megaproyectos. La búsqueda de esquemas productivos racionales y responsables con el entorno, que reivindiquen el derecho de las comunidades a un medio ambiente sano, a la preservación del territorio y sus recursos y de las formas de vida tradicionales, son los referentes para la realización del presente libro. Como elemento central se concibe el territorio como contenedor de identidad y vida, siendo preocupación y tema de estudio de la comunidad académica, las organizaciones de la sociedad civil y las redes de activistas organizados.UAEM, CONACyT, se