Showing papers by "Enrique J. Baran published in 2009"
TL;DR: In this article, an investigation of the vibrational (infrared and Raman) and 57Fe-Mossbauer spectra of FeII and FeIII oxalate complexes was performed.
Abstract: 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-Mossbauer 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 Mossbauer data, could be proposed. The 298 K Mossbauer spectrum for this complex is discussed in detail for the first time.
77 citations
TL;DR: In this paper, the infrared and Raman spectra of anhydrous lead oxalate (PbC2O4) were recorded and discussed on the basis of its structural peculiarities.
Abstract: The infrared and Raman spectra of anhydrous lead oxalate (PbC2O4) were recorded and discussed on the basis of its structural peculiarities. Some comparisons with other previously investigated metallic oxalates were made. Copyright © 2009 John Wiley & Sons, Ltd.
30 citations
TL;DR: In this article, the three known hydrates of manganese(II) oxalate, α-MnC2O4 · 2H2O, γ-mnC 2O4· 2H 2O, and MnC 2 O4 · 3H 2 O were characterized by X-ray powder diffractometry.
Abstract: The three known hydrates of manganese(II) oxalate, α-MnC2O4 · 2H2O, γ-MnC2O4 · 2H2O and MnC2O4 · 3H2O were synthesized by known procedures and characterized by X-ray powder diffractometry. Their infrared (IR) and Raman spectra were recorded and discussed on the basis of its structural peculiarities allowing to establish some interesting relations between them and with other, previously investigated, oxalate complexes. The IR spectra of partially deuterated samples of α-MnC2O4 · 2H2O were also discussed, reinforcing some of the performed assignments. Copyright © 2009 John Wiley & Sons, Ltd.
30 citations
TL;DR: In this brief review the most recent studies and the most relevant aspects of the complexes generated by interaction of carbohydrates and related molecules with the oxovanadium(IV) cation, VO(2+), are presented and discussed.
17 citations
TL;DR: The infrared and Raman spectra of the bis-chelated Zn(II) complexes of the amino acids glycine, alanine, valine, leucine, isoleucine and phenylalanine were recorded and analyzed in relation to its structural peculiarities.
13 citations
TL;DR: A series of mixed ligand oxovanadium(V) complexes of the type [VO(NH2O)2(aa)], containing the hydroxylamido ligand and simple amino acids, were prepared and characterized as discussed by the authors.
Abstract: A series of mixed ligand oxovanadium(V) complexes of the type [VO(NH2O)2(aa)], containing the hydroxylamido ligand and simple amino acids, were prepared and characterized. Seven of these complexes, with aa = valine, leucine, isoleucine, phenylalanine, tryptophan, cysteine and methionine, were described for the first time. Their infrared and Raman spectra, together with those of the previously investigated similar species with aa = glycine, serine, threonine and alanine, and those of the related [VO(NH2O)2(imidazole)2]Cl complex, were recorded and assigned. The spectroscopic behavior of the new complexes is similar to that of the other five, whose structures has been determined by X-ray crystallography, suggesting an identical structure for the full series of complexes. The spectroscopic results also give a better characterization of the vibrational behavior of the interesting O–N–“side-on” bonded hydroxylamido ligand. §Dedicated to Prof. Alfredo Mederos on the occasion of his retirement as Professor of In...
13 citations
TL;DR: The results suggest that the species of Canna show similar ability to produce biogenic silica and produce an identical type of calcium oxalate within their tissues, which can be an additional trait to support the relationship among the families of Zingiberales.
Abstract: Plant biominerals are not always well characterized, although this information is important for plant physiology and can be useful for taxonomic purposes. In this work, fresh plant material of seven wild neotropical species of genus Canna, C. ascendens, C. coccinea, C. indica, C. glauca, C. plurituberosa, C. variegatifolia and C. fuchsina sp. ined., taken from different habitats, were studied to characterize the biominerals in their internal tissues. For the first time, samples from primary and secondary veins of leaves were investigated by means of infrared spectroscopy, complemented with X-ray powder diffractometry and scanning electron microscopy. The spectroscopic results, supported by X-ray powder diffractometry, suggest that the calcium oxalate is present in the form of whewellite (CaC2O4×H2O) in all the investigated samples. It is interesting to emphasize that all IR spectra obtained were strongly similar in all species studied, thus indicating an identical chemical composition in terms of the biominerals found. In this sense, the results suggest that the species of Canna show similar ability to produce biogenic silica and produce an identical type of calcium oxalate within their tissues. These results can be an additional trait to support the relationship among the families of Zingiberales.
10 citations
TL;DR: The dihydrated potassium salt of the complex anion [VO(O2)NTA]2− (NTA = nitrilotriacetate anion, [N(CH2-COO)3]3−) was thoroughly characterized by electronic and vibrational spectroscopies.
Abstract: The potassium salt of the carbonato oxodiperoxovanadate(V) complex, obtained by a known synthetic procedure, was thoroughly characterized by infrared, Raman, and electronic spectroscopy. The bioactivity of the complex on the cell proliferation was tested on osteoblast-like cells (MC3T3E1 osteoblastic mouse calvaria-derived cells and UMR106 rat osteosarcoma-derived cells) in culture. At low doses, the complex is more toxic for the nontransformed osteoblasts than for the tumoral ones, whereas at higher doses the deleterious effects are similar for both cell lines. This peroxo complex seems to be the most toxic compound that has so far been tested on osteoblast-like cells in culture.
9 citations
TL;DR: Calcium oxalate druses were isolated from the stems and leaves of six Pereskioideae family members and investigated by infrared spectroscopy, showing that in all samples the biomineral was present in the form of whewellite.
Abstract: Calcium oxalate druses were isolated from the stems and leaves of six Pereskioideae family members and investigated by infrared spectroscopy, showing that in all samples the biomineral was present in the form of whewellite, CaC₂O₄ · H₂O. As Pereskia is thought to represent the “ancestral” condition of the leafl ess stem-succulent cacti, these results suggest that the biomineralization of calcium oxalate in Cactaceae represents a primitive characteristic of the group and also support a close genetic relationship between Pereskia and Opuntia.
9 citations
TL;DR: The powder Fourier transform (FT) and Raman spectra of the recently characterized NH4Ag3(PO3F)2 were recorded and discussed with a site-symmetry analysis based on its known structural data as mentioned in this paper.
Abstract: The powder Fourier-transform (FT) infrared (IR) and Raman spectra of the recently characterized NH4Ag3(PO3F)2 were recorded and are discussed with a site-symmetry analysis based on its known structural data. Some comparisons are made with the solution spectra of the PO3F2− anion and with those of crystalline Ag2PO3F. Copyright © 2009 John Wiley & Sons, Ltd.
9 citations
TL;DR: Mean amplitudes of vibration for the title hexafluoroanions were calculated on the basis of its vibrational-spectroscopic and structural data in the temperature range between 0 and 1000 K as mentioned in this paper.
TL;DR: Mean amplitudes of vibration of molecules and ions containing interhalogen bonds are reviewed and critically analyzed in this article, where the presented information comprises pure inter-halogen compounds as well as oxohalides.
Abstract: Mean amplitudes of vibration of molecules and ions containing interhalogen bonds are reviewed and critically analyzed. The presented information comprises pure interhalogen compounds as well as oxohalides. Correlations between mean amplitude values and structural and bond properties are discussed. Comparisons with data of related – specially isoelectronic – species are also performed. Characteristic ranges for the mean amplitudes of vibration for halogen–halogen and halogen–oxygen bonds could be established. The presented and discussed results are also of central importance for the analysis and interpretation of electron diffraction studies.
Journal Article•
TL;DR: The infrared spectrum of the Cu(II) complex of L-histidine (L-His) of composition [Cu(LHis)2].1.5 H2O, generated at physiological conditions, was recorded and analyzed in relation to its structural peculiarities and by comparison with the Spectrum of the free amino acid.
Abstract: SUMMARY. The infrared spectrum of the Cu(II) complex of L-histidine (L-His) of composition [Cu(LHis)2].1.5 H2O, generated at physiological conditions, was recorded and analyzed in relation to its structural peculiarities and by comparison with the spectrum of the free amino acid. The electronic spectrum of the complex is also briefly discussed.
TL;DR: In this article, the ionic crystals are further stabilized by an extensive H-bonding network, which links the anions and cations into an infinite three-dimensional supramolecular assembly.
Abstract: 1 with 2 molecules per unit cell, and 2 in the monoclinic space group P21/a with Z = 4. The saccharinate moiety is planar in both compounds presenting bonding characteristics comparable to those found in other saccharinate salts. The ionic crystals are further stabilized by an extensive H-bonding network, which links the anions and cations into an infinite three-dimensional supramolecular assembly. The FTIR spectra of the adducts are briefly discussed in comparison with those of the constituent molecules.