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International audience; Bimetallic Ni2xMn2−2xP2S6phases, where 2X= 0.4 (Ni0.4), 0.8 (Ni0.8) and 1.2 (Ni1.2), were synthesized by a microwave assisted method, starting from the corresponding potassium intercalates K0.8Mn1.6P2S6·2H2O, K0.8Ni0.4Mn1.2P2S6·2H2O, and K0.8Ni0.8Mn0.8P2S6·2H2O. The magnetic, optical, and electrical properties were recorded, in order to visualize the influence of the secondary nickel(ii) ions on the physical properties of the pristine Mn2P2S6phase. Both dc susceptibility and EPR data show that the antiferromagnetic interactions are attenuated in the layers of the bimetallic phases, while the critical temperature remains constant (ca.80 K) for all the bimetallic phases, similar to that of Mn2P2S6. Conversely, the absorption edge of the solid state UV-visible spectra shifted to lower energies as the percentage of nickel(ii) increased, tending to that of the band gap value of the pristine Ni2P2S6phase. Moreover, the electric conductivity ofNi0.4was similar to that of the pristine Mn2P2S6phase, while that ofNi0.8andNi1.2approached the values of the electric conductivity of the pristine Ni2P2S6phase. On the other hand, the potassium intercalates K0.8Mn1.6P2S6·2H2O and K0.8Ni0.4Mn1.2P2S6·2H2O showed magnetization at 16 K, the latter being much weaker as compared to the first. The detrimental effect of the secondary nickel(ii) ions in the layers of the bimetallic phases became evident for K0.8Ni0.8Mn0.8P2S6·2H2O, where the magnetization at low temperatures was not observed. The absorption edge shifted to higher energy values for K0.8Mn1.6P2S6·2H2O and K0.8Ni0.4Mn1.2P2S6·2H2O, as compared to Mn2P2S6andNi0.4, respectively, but the value remained close to that of Ni2P2S6for K0.8Ni0.8Mn0.8P2S6·2H2O. InNi0.8andNi0.4, the electrical conductivity at low frequencies stems from polarization processes such as Maxwell/Wagner/Sillars electrode polarization. Moreover, an additional polarization process is observed in the intercalates because K+ions in the interlayer act as charge transport carriers. Consequently, the interacalates present higher electrical conductivity compared with the pristine Mn2P2S6phase, by a factor ofca.102 © The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2021.

International audience; Four bimetallic phases of the thiophosphate family have been synthesized by the cationic exchange reaction using a freshly prepared K0.5Cd0.75PS3 precursor phase and methanolic solutions of nitrates of the divalent cations Zn II , Ni II , Co II , and Mn II. All the materials were characterized by FTIR, PXRD, SEM-EDXS and (in the case of the diamagnetic compounds) by solid state NMR. For the K0.5Cd0.75PS3 precursor, the X-ray powder diffraction data suggest a modification of the structure, while solid state NMR results confirm that this phase possesses an ordered arrangement of Cd vacancies. The cationic exchange reaction achieves a complete removal of potassium ions (no potassium detected by SEM-EDXS) and re-occupation of the vacancies by divalent cations. Therefore, the obtained compounds have an average composition of M0.25Cd0.75PS3 (M = Zn II , Ni II , Co II , Mn II) and possess an ordered distribution of the substituent cations. Even with the paramagnetic substitution level of 25%, antiferromagnetic behaviour is present in the phases with Mn II , Co II and Ni II , as evidenced by dc susceptibility and in the case of the Mn II substituted phase by EPR. The cooperative magnetic interactions confirm the conclusion that the paramagnetic ions adopt an ordered arrangement. The analysis by broad band impedance spectroscopy allows to attribute the conductivity in these materials to charge movements in the layers due to the difference in electronegativity of the metal ions. Zn0.25Cd0.75PS3 is the phase that shows the highest conductivity values. Finally, the band gap energies of the bimetallic phases tend to be lower than those of the single-metal phases, probably due to an overlap of the band structures.

Two new ligands, 2-[(bis(2-pyridylmethyl)amino)methyl]-4-methylphenol (HL) and 2-[(bis(2-pyridylmethyl)amino)methyl]-4-methyl-6-(methylthio)phenol (HSL), were synthesized and were used to prepare the trinuclear copper(II) complex {[CuSL(Cl)]2Cu}(PF6)2.H2O

The hybrid organic/inorganic copper oxovanadium diphosphonates of formula [Cu(bipy)(VO2)2(O3PCH2PO3)H2O] 1, which crystallizes in the orthorhombic symmetry, and [Cu(bipy)(VO2)(O3P(CH2)2PO2OH)] · 1.5H2O 2, which crystallizes in the monoclinic symmetry, wer

Two new hybrid organic/inorganic copper oxovanadium diphosphonates [Cu2(phen)2(O3PCH2PO3)(V2O5)(H2O)]·H2O (1) and [(Cu2(phen)2(O3P(CH2)3PO3)(V2O5)]·C3H8 (2) have been obtained by hydrothermal synthesis. The compounds are monoclinic, and they crystallize i

The copper (II) complexes (CuL(2)) were prepared by reaction of Cu(CH(3)COO)(2) with the corresponding derivatives of acylthioureas in a Cu:HL molar ratio of 1:2. Acylthiourea ligands, N,N-diethyl-N'-(R-benzoyl) thiourea (HL(1-3)) [R=H, o-Cl and p-NO(2)] were synthesized in high yield (78-83%) and characterized by elemental analysis, infrared spectroscopy, (1)H and (13)C NMR spectroscopy. The complexes CuL(2) were characterized by elemental analysis, IR, FAB(+)-MS, magnetic susceptibility measurements, EPR and cyclic voltammetry. The crystal structure of the complex Cu(L(2))(2) shows a nearly square-planar geometry with two deprotonated ligands (L) coordinated to Cu(II) through the oxygen and sulfur atoms in a cis arrangement. The antitumor activity of the copper(II) complexes with acylthiourea ligands was evaluated in vitro against the mouse mammary adenocarcinoma TA3 cell line. These complexes exhibited much higher cytotoxic activity (IC(50) values in the range of 3.9-6.9 muM) than their corresponding ligands (40-240 muM), which indicates that the coordination of the chelate ligands around the Cu(II) enhances the antitumor activity and, furthermore, this result confirmed that the participation of the nitro and chloro substituent groups in the complex activities is slightly relevant. The high accumulation of the complexes Cu(L(2))(2) and Cu(L(3))(2) in TA3 tumor cells and the much faster binding to cellular DNA than Cu(L(1))(2) are consistent with the in vitro cytotoxic activities found for these copper complexes.

The oxidation product of the binuclear copper (I) complex Cu2L(ClO4)2 (L = N,N'-bis-(6-methyl-2-pyridil) (2'-pyridyl)methyl m-xylylidene imine) has been isolated and structurally characterised. In the cupric species, [Cu2L(Me-O)2](ClO4 )2, the metal centr

The solvothermal reaction of (N(C4H9)4)2[Re2Cl8] with trifluoroacetic acid and acetic anhydride leads to the new rhenium trifluoroacetate dimer N(C4H9)4[Re2(OOCCF3)Cl6] (1) and to the rhenium carbonyl dimer Re2(μ2-Cl)2(CO)8 as the rhenium-reduced byproduc

Reaction of CpFe(dppe)I with dithiopyridine in methanol and in presence of NH4PF6 affords the new mixed valence complex {[CpFe(dppe)]2 - m - S - Py}(PF6)2 (1). Observation of an intervalence electron transfer affords the Hush parameters that permit to cla

In this work we present the synthesis and characterization of iron oxide nanoparticles (IONPs), which were structurally and magnetically characterized. The use of iron salts and an organic acid (l-serine or ascorbic acid) as precursors under solvothermal conditions yielded these coated IONPs. The powder X-ray diffraction pattern of FeO-1 and FeO-2 is consistent with hematite (α-Fe2O3) and hematite-maghemite ((α-Fe2O3/γ-Fe2O3) respectively. The TEM analysis permits to estimate an average size of 10 nm for the FeO-1 sample. The magnetic characterization of the samples through the M(H) plots showed a very low coercivity value for both samples, being 53 Oe for FeO-1 and 10 Oe for FeO-2, indicating the very weak ferromagnetic character of the synthesized iron oxide species. Even though both organic acids under solvothermal conditions permit to obtain coated IONPs in one pot reaction, l-serine produces a more narrow-size distribution.

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En el presente trabajo de tesis se estudió la reacción de intercalación en calcogenofosfatos de metales de transición del tipo MPS3 (M = Mn, Cd) con compuestos macrocíclicos de cinc (II) y manganeso (III). El objetivo principal fue el estudio de las propi FONDAP DOCTOR EN CIENCIAS DE LA INGENERIA, MENCION CIENCIAS DE LOS MATERIALES FONDAP CIMAT

Esta tesis doctoral abordó la síntesis, caracterización estructural y el estudio catalítico de una serie de sistemas multidimensionales que contienen redes inorgánicas oxometaladas V-P-O y V-B-O, coordinadas a complejos de cobre (II), generándose material FONDAP Doctor en Química FONDAP CIMAT

Los valores experimentales de los potenciales de reducción de la familia de nitroimidazoles sustituidos están en el rango de -80 y -550 mV. Estos valores fueron correlacionados con los calculados usando la teoría de funcionales de la densidad. Las estruct Químico FONDAP FONDAP CIMAT

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