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Chişinău, Moldova

Racles C.,Petru Poni Institute of Macromolecular Chemistry | Iacob M.,Petru Poni Institute of Macromolecular Chemistry | Iacob M.,Institute of Chemistry of ASM | Butnaru M.,Grtpopa University Of Medicine And Pharmacy | And 2 more authors.
Colloids and Surfaces A: Physicochemical and Engineering Aspects | Year: 2014

Siloxane surfactants containing tromethamol or carboxylate groups, with very good surface properties, are tested for the first time for biocompatibility using MTT cytotoxicity test. They are used for encapsulation of superparamagnetic iron oxide nanoparticles (SPION), and of a combination of these with nystatin as model un-soluble drug, in order to obtain stable aqueous dispersions. The initial magnetite and chromite nanoparticles have been synthesized previously by thermal decomposition thus being covered by dodecylamine and oleic acid. Their aqueous dispersions were obtained by physical methods using very low concentrations of siloxane surfactants, and were investigated by DLS, TEM, cryo-TEM and EDX. One such formulation was tested by MTT method and the results showed high cell viability. The nanoparticles covered with siloxane surfactants exhibited various types of morphology: individual particles, vesicle-like aggregates or composite particles, all having diameters roughly between 20 and 200. nm. The encapsulation of both SPION and nystatin confirmed our previous results on nystatin solubilization by encapsulation within the hydrophobic wall of surfactant vesicles. © 2014 Elsevier B.V. Source


Dumitriu A.-M.-C.,Petru Poni Institute of Macromolecular Chemistry | Cazacu M.,Petru Poni Institute of Macromolecular Chemistry | Shova S.,Petru Poni Institute of Macromolecular Chemistry | Shova S.,Institute of Applied Physics of ASM | And 4 more authors.
Polyhedron | Year: 2012

The research goal was to synthesize and structurally characterize a silatrane intended to be subsequently incorporated into metal complex structures. 3-Aminopropyltrialkoxysilane was reacted with triethanolamine in 1:1 molar ratio, either in bulk, in the presence of metallic sodium, or in a solvent mixture. 1-(3-Aminopropyl)silatrane in carbamate form or having free amine groups was obtained. The latter was reacted with 2-hydroxybenzaldehyde, 2,4-dihydroxybenzaldehyde and CoCl 2 or with CoCl 2 only. The crystalline reaction products were characterized by elemental and spectral (FTIR and 1H NMR) analyses and single crystal X-ray diffractometry, which revealed the formation of new, either sought (1-(3-aminopropyl)silatrane, 1-(3-salicyliminopropyl)silatrane) or unexpected (N-carboxylated 1-(3-aminopropyl)silatrane and 1-chlorocobaltrane) structures. © 2011 Elsevier Ltd. All rights reserved. Source


Cazacu M.,Petru Poni Institute of Macromolecular Chemistry | Vlad A.,Petru Poni Institute of Macromolecular Chemistry | Turta C.,Petru Poni Institute of Macromolecular Chemistry | Turta C.,Institute of Chemistry of ASM | Lisa G.,Technical University Gheorghe Asachi
Central European Journal of Chemistry | Year: 2012

For the first time, silicon-containing dicarboxylic acids were used to prepare two new heterotrinuclear carboxylates of the composition [Fe 2 IIICo IIO(Bcpdps) 3(H 2O) 3], I, where H 2Bcpdps ≡ HOOC-C 6H 4-Si(C 6H 5) 2-C 6H 4COOH, and [Fe 2 IIICo IIO(Ipds) 3(H 2O) 3], II, where H 2Ipds ≡ [HOOC-C 6H 3(CO) 2N-(CH 2) 3-(CH 3) 2Si] 2O. The precursor for these two complexes was trinuclear μ 3-oxo-hexaacetate triaqua diiron(III)cobalt(II) cluster, {Fe 2CoO}, in which the acetate anions were subsequently substituted by silicon-containing dianions. The resulting products were characterized by elemental analysis, thermogravimetry, Fourier Transform Infrared (FTIR), Energy-Dispersive X-ray Fluorescence (EDXRF), and Mossbauer spectroscopies (MS). The investigation by MS revealed the presence of the iron(3+) ions in high spin state and having the close environment. Thermogravimetric analysis results indicated an improving in the thermal stability by replacing acetate anions with silicon-containing carboxyl ligands. This widens the temperature range in which such compounds can be used in practical applications. © Versita Sp. z o.o. Source


Soroceanu A.,Petru Poni Institute of Macromolecular Chemistry | Shova S.,Petru Poni Institute of Macromolecular Chemistry | Shova S.,Institute of Applied Physics of ASM | Cazacu M.,Petru Poni Institute of Macromolecular Chemistry | And 4 more authors.
Journal of Chemical Crystallography | Year: 2013

The Schiff base ligand H2L·C2H5OH derived from the condensation reaction between o-phenylenediamine and 2,4-dihydroxybenzaldehyde as well as its mononuclear complex [CoL]·2H2O have been synthesized and characterized by X-ray crystallography, IR, 1H NMR and UV-Vis analyses, and density functional theory (DFT B3LYP) calculations. The CoII ion has a slightly distorted square-planar coordination provided by tetradentate dianionic N2O2 ligand L2-. The spin state of the complex was determined as being S = 1/2. On the basis of DFT calculations, the UV-Vis absorption bands of the ligand can be assigned to the 1A1 → 1B2 (two) and 1A1 → 1A1 transitions, while for complex they correspond to the 2A2 → 2B1 (two) and 2A2 → 2A2 ones. Graphical Abstract: Index Abstract The Schiff base ligand H2L·C 2H5OH derived from the condensation reaction between o-phenylenediamine and 2,4-dihydroxybenzaldehyde as well as its mononuclear complex [CoL]·2H2O have been synthesized and characterized by X-ray crystallography, IR, 1H NMR and UV-Vis analyses, and density functional theory (DFT B3LYP) calculations.© 2013 Springer Science+Business Media New York. Source


Iacob M.,Petru Poni Institute of Macromolecular Chemistry | Iacob M.,Institute of Chemistry of ASM | Cazacu M.,Petru Poni Institute of Macromolecular Chemistry | Racles C.,Petru Poni Institute of Macromolecular Chemistry | And 9 more authors.
RSC Advances | Year: 2014

Organic-coated iron-chromium oxide (chromite) nanoparticles have been prepared by using the thermal decomposition procedure. For this purpose, the substrate-bimetallic acetate-was treated with oleic acid and dodecylamine as co-ligands in trichloroacetic acid solvent at high temperature (320 °C). The main characteristics and behaviors of the obtained nanoparticles were investigated by combined techniques. The size of the obtained nanoparticles was around 11 nm, as estimated by TEM, WAXD and SAXS, which were in good agreement. The bimetallic nature of the nanoparticles was emphasized by X-ray energy dispersive spectrometry (EDX) and their structure was confirmed by WAXD. The Fourier transform infrared (FTIR) spectrum revealed the bands characteristic to metal oxides as well as to the organic components and confirmed the replacement of the acetate with long chain ligands. The co-existence of the organic coatings and metallic core induced a special behavior that was studied by thermogravimetric analysis, differential scanning calorimetry and polarized optical microscopy. The coated bimetallic nanoparticles proved to be thermostable up to 252 °C and thermotropic showing a highly organized crystalline smectic mesophase (3D plastic mesophase). The organic part alone, in the absence of the inorganic component, did not develop this self-assembly. The results of the magnetic measurements suggest superparamagnetic behavior of the iron-chromium oxide nanoparticles and a weak ferromagnetic behavior. © 2014 The Royal Society of Chemistry. Source

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