An Oxalate-Bridged Copper(II) Complex Combining Monodentate Benzoate, 2,2'-bipyridine and Aqua Ligands:Synthesis, Crystal Structure and Investigation of Magnetic Properties

A dinuclear copper(II) complex of formula [{Cu(bipy)(bzt)(OH2)}2(μ-ox)] (1) (where bipy = 2,2'-bipyridine, bzt = benzoate and ox = oxalate) was synthesised and characterised by diffractometric (powder and single-crystal XRD) and thermogravimetric (TG/DTG) analyses, spectroscopic techniques (IR, Raman, electron paramagnetic resonance spectroscopy (EPR) and electronic spectroscopy), magnetic measurements and density functional theory (DFT) calculations. The analysis of the crystal structure revealed that the oxalate ligand is in bis(bidentate) coordination mode between two copper(II) centres. The other four positions of the coordination environment of the copper(II) ion are occupied by one water molecule, a bidentate bipy and a monodentate bzt ligand. An inversion centre located on the ox ligand generates the other half of the dinuclear complex. Intermolecular hydrogen bonds and π-π interactions are responsible for the organisation of the molecules in the solid state. Molar magnetic susceptibility and field dependence magnetisation studies evidenced a weak intramolecular-ferromagnetic interaction (J = +2.9 cm-1) between the metal ions. The sign and magnitude of the calculated J value by density functional theory (DFT) are in agreement with the experimental data

Structure and magnetic properties of two new lanthanide complexes with the 1-((E)-2-pyridinylmethylidene)semicarbazone ligand

Two novel semicarbazone-lanthanide(III) complexes were prepared and structurally characterized as [Ln (Hscpy)2 (NO3)2]NO3·MeOH (Ln = Gd and Tb; Hscpy = 1-((E)-2-pyridinylmethylidene)semicarbazone). The 4f metal ions experience deca-coordination geometry. Each molecular formula contains two neutral Hscpy molecules in the keto form coordinated through two nitrogen atoms and one oxygen atom, while two nitrate ligands are both coordinated in a chelate mode. The 1 + charge of the cation-complex is balanced by a nitrate anion. Extensive intermolecular hydrogen bonds are formed through the methanol solvate molecule, which acts both as a donor and an acceptor molecule. The chemical composition of the compounds was confirmed by high resolution mass spectra (ESI-MS); peaks at m/z = 122.07 and 148.05, assigned to the fragments C6H8N3+ and C7H6N3O+, respectively, are in agreement with the coordination of Hscpy. Alternating current magnetic susceptibility analysis was performed in the 10–10000 Hz range, and the terbium-complex showed slow relaxation of the magnetization when immersed in a static magnetic field of 1 kOe and 1.5 kOe, with an activation barrier to the relaxation (21.9(4) cm−1) among the highest found for ten-coordinated Tb(III) complexes. This behavior of slow relaxation of the magnetization is relevant as a memory effect regarding the development of Single Molecule Magnets (SMM)

The intricate determination of magnetic anisotropy in quasi-octahedral vanadium(III): An HF-EPR and magnetic study

We report here the synthesis and a preliminary characterization of the tetranuclear complex of formula [Ga3V(LEt)2(dpm)6], Ga3VEt, in which H3LEt = 2-Ethyl-2-(hydroxymethyl)-propane-1,3-diol and Hdpm = dipivaloylmethane, containing a single paramagnetic vanadium(III) center, from a structural, magnetic, and spectroscopic point of view. Structural characterization by X-ray diffraction evidenced that this derivative is isostructural with the star-shaped Single-Molecule Magnet [Fe3V(LEt)2(dpm)6], Fe3VEt, and can, thus, be considered a model to analyze the magnetic anisotropy of the vanadium(III) ion in that system. The observed results confirm the complexity in obtaining a rationalization of the magnetic behavior of this metal ion, with magnetization data and High Field Electron Paramagnetic Resonance (HF-EPR) spectroscopy providing apparently conflicting results. Indeed, the former were rationalized assuming a rhombic distortion of the ligand field and a dominant easy-axis type anisotropy (equivalent to D ≈ −14.1 cm−1, E ≈ 1.2 cm−1), while a simple axial Spin Hamiltonian approach could explain HF-EPR data (|D| ≈ 6.98 cm−1)

Methyl Ester Functionalized Phenalenyl Arene- and Bipyridine-Ruthenium-Based Complexes for Electroactive Langmuir-Blodgett Films

We report the synthesis of a new phenalenyl ligand, functionalized with a methyl ester electron withdrawing group, named 9-hydroxy-1-oxo-1H-phenalen-5-methyl carboxylate (L), and the generated complexes [Ru(bpy)2L]PF6 and [(η6-C6H6)Ru(L)Cl]. Compounds were characterized by spectroscopic and X-ray diffraction methods, and their electrochemical behavior was investigated via cyclic voltammetry and UV-vis spectroelectrochemistry. The one-electron oxidized compounds have an unpaired electron located in the phenalenyl ring, as supported by theoretical calculations (DFT) and EPR results. Langmuir-Blodgett (LB) films deposited by [Ru(bpy)2L]2+/3+ species mixed with stearic acid are electroactive, showing a quasi-reversible wave with E1/2Film1 = 0.74 V and E1/2Film2 = 0.81, which are promising systems that allow access to immobilized open-shell species in the film

Aborto: análise das recentes modificações legais e suas implicações éticas

O aborto é uma questão de saúde pública e a sua discussão abrange aspectos éticos, morais e legais. Apesar das posições contrárias, o abortamento legal propicia acesso seguro e humanizado à assistência, diminuindo a mortalidade materna. Nesse contexto, o objetivo deste trabalho é discutir as recentes modificações no ordenamento jurídico pátrio relacionadas ao aborto e a suas implicações na prática médica. Trata-se de revisão crítica da literatura, realizada nas bases de dados LILACS e SciELO. Evidenciou-se que nas últimas décadas ocorreram várias modificações jurídicas relacionadas ao abortamento. Tais alterações tornaram-se alvo de críticas por violarem a autonomia das pacientes e estarem, em alguns casos, em desacordo com o Código de Ética Médica. Constata-se que, mesmo havendo previsão legal para a prática, muitas mulheres enfrentam a negação de seus direitos.Abortion is a public health issue encompassing ethical, moral, and legal aspects. Despite contrary opinions, legal abortion provides humane and safe access to medical assistance, reducing maternal mortality. This work aimed to discuss the recent modifications in the national legal order related to abortion and their implications for medical practice. A critical literature review was carried out on LILACS and SciELO databases. The results showed that various legal changes related to abortion occurred in the last decades. Such alterations have been the subject of criticism as they violate patient autonomy and are, in some situations, in disagreement with the Code of Medical Ethics. Despite the existence of legal provisions for the procedure, many women have their rights denied

Rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART): Study protocol for a randomized controlled trial

Background: Acute respiratory distress syndrome (ARDS) is associated with high in-hospital mortality. Alveolar recruitment followed by ventilation at optimal titrated PEEP may reduce ventilator-induced lung injury and improve oxygenation in patients with ARDS, but the effects on mortality and other clinical outcomes remain unknown. This article reports the rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART). Methods/Design: ART is a pragmatic, multicenter, randomized (concealed), controlled trial, which aims to determine if maximum stepwise alveolar recruitment associated with PEEP titration is able to increase 28-day survival in patients with ARDS compared to conventional treatment (ARDSNet strategy). We will enroll adult patients with ARDS of less than 72 h duration. The intervention group will receive an alveolar recruitment maneuver, with stepwise increases of PEEP achieving 45 cmH(2)O and peak pressure of 60 cmH2O, followed by ventilation with optimal PEEP titrated according to the static compliance of the respiratory system. In the control group, mechanical ventilation will follow a conventional protocol (ARDSNet). In both groups, we will use controlled volume mode with low tidal volumes (4 to 6 mL/kg of predicted body weight) and targeting plateau pressure <= 30 cmH2O. The primary outcome is 28-day survival, and the secondary outcomes are: length of ICU stay; length of hospital stay; pneumothorax requiring chest tube during first 7 days; barotrauma during first 7 days; mechanical ventilation-free days from days 1 to 28; ICU, in-hospital, and 6-month survival. ART is an event-guided trial planned to last until 520 events (deaths within 28 days) are observed. These events allow detection of a hazard ratio of 0.75, with 90% power and two-tailed type I error of 5%. All analysis will follow the intention-to-treat principle. Discussion: If the ART strategy with maximum recruitment and PEEP titration improves 28-day survival, this will represent a notable advance to the care of ARDS patients. Conversely, if the ART strategy is similar or inferior to the current evidence-based strategy (ARDSNet), this should also change current practice as many institutions routinely employ recruitment maneuvers and set PEEP levels according to some titration method.Hospital do Coracao (HCor) as part of the Program 'Hospitais de Excelencia a Servico do SUS (PROADI-SUS)'Brazilian Ministry of Healt

An Oxalate-Bridged Copper(II) Complex Combining Monodentate Benzoate, 2,2′-bipyridine and Aqua Ligands: Synthesis, Crystal Structure and Investigation of Magnetic Properties

A dinuclear copper(II) complex of formula [{Cu(bipy)(bzt)(OH2)}2(μ-ox)] (1) (where bipy = 2,2′-bipyridine, bzt = benzoate and ox = oxalate) was synthesised and characterised by diffractometric (powder and single-crystal XRD) and thermogravimetric (TG/DTG) analyses, spectroscopic techniques (IR, Raman, electron paramagnetic resonance spectroscopy (EPR) and electronic spectroscopy), magnetic measurements and density functional theory (DFT) calculations. The analysis of the crystal structure revealed that the oxalate ligand is in bis(bidentate) coordination mode between two copper(II) centres. The other four positions of the coordination environment of the copper(II) ion are occupied by one water molecule, a bidentate bipy and a monodentate bzt ligand. An inversion centre located on the ox ligand generates the other half of the dinuclear complex. Intermolecular hydrogen bonds and π-π interactions are responsible for the organisation of the molecules in the solid state. Molar magnetic susceptibility and field dependence magnetisation studies evidenced a weak intramolecular–ferromagnetic interaction (J = +2.9 cm−1) between the metal ions. The sign and magnitude of the calculated J value by density functional theory (DFT) are in agreement with the experimental data

Study on the influence of N- and O-donors ligands towards copper(II), cobalt(II) and manganese(II) ions in the formation of coordination compounds

The organization and stability of coordination compounds could be correlated to structural features, as the number and nature of ligands coordinated to the metallic ions and with noncovalent interactions established between the ligands and with crystallization solvents. The present work evaluated the influence of the pre-ligands 2,6-dihydroxybenzoic acid (Hdhb), benzoic acid (Hbzt), oxalic acid (H2ox), and 2,2' bipyridine (bipi), capable to perform noncovalent interactions, in its reactivity to copper(II), cobalt(II) and manganese(II) salts. For each metallic ion, and reaction condition were evaluated with different combinations of ligands, producing 10 different structures characterized by single crystal XRD. Among them, the complexes [Cu2( ox)(bzt)2(bipi)2(H2O)2] (A), [Co(H2O)6](dhb)2·2H2O (B), and [Mn(H2O)6](dhb)2·2H2O (C) were synthesized for the first time in this work. Those products were characterized by elemental analysis and diffractometric (powder and single crystal XRD) and spectroscopic (IR, Raman, EPR and Uv/Vis) techniques. Moreover, spectroscopic, thermogravimetric and magnetic properties of A, B and C, were attempt correlated with their structural features. Product A was obtained with 90% of yield from the reaction of Cu(CH3COO)2·H2O with the pre-ligands Hbzt, H2ox, and bipy, in methanol at 70 °C. Single crystal XRD analysis of A evidenced that all ligands interact through noncovalent interactions, as hydrogen bonds and  interaction. EPR and magnetic susceptibility measurements strongly suggest the existence of magnetic interaction between the copper(II) centres. In addition, magnetic susceptibility measurement varying temperature revealed a ferromagnetic exchange (J = 3.26 cm-1) stronger than those observed for analogous complexes. Thermal decomposition of A starts at 55 °C with the loss of two water molecules, succeed by the loss of the organic ligands (136 – 900 °C). Product B and C showed similar structures and were obtained in 97 and 99 % of yield, respectively, from the reaction of CoCl2·6H2O or Mn2Cl2·4H2O with Hdhb, in water at 70° C. Single crystal XRD analysis revealed that dhb ion remains as counterion of the aqua complexes, probably due the stabilization of the free carboxylate by two intramolecular charge-assisted hydrogen bonds. The crystal lattice of B and C is also stabilized by  interactions and intermolecular hydrogen bonds from both coordinated and crystallization water molecules. According to TGA curves, the thermal decomposition of B and C starts with the loss of water molecules below 55° C, and a complete weight-loss of organic ligands occurs above 600° C for both complexes. The correlation between the nature of all products obtained with synthetic conditions revealed that the structure and degree of aggregation depends on the coordination ability of the ligand to the metallic ion and on the noncovalent interactions in the free ligands and complexes formed.A organização e a estabilidade de compostos de coordenação, no estado sólido, pode ser correlacionada com os ligantes diretamente coordenados a íons metálicos e com as interações não covalentes estabelecidas entre os ligantes e solventes de cristalização. O presente trabalho avaliou a influência dos pré ligantes ácido 2,6-dihidróxibenzoico (Hdhb), ácido benzoico (Hbzt), ácido oxálico (H2ox) e 2,2’-bipiridina (bipi), capazes de realizar interações não covalentes, em sua reatividade frente a sais de cobre(II), cobalto(II) e manganês(II). Foram avaliadas diferentes combinações de ligantes para cada íon metálico e condições de reação, gerando um total de dez produtos caracterizados por DRX de monocristal. Dentre eles, os complexos [Cu2( ox)(bzt)2(bipi)2(H2O)2] (A), [Co(H2O)6](dhb)2·2H2O (B) e [Mn(H2O)6](dhb)2·2H2O (C) são inéditos. Estes produtos foram avaliados em sua composição elementar, analisados por técnicas difratométricas (DRX de pó e de monocristal) e espectroscópicas (IV, Raman, RPE e Uv/Vis). Os dados estruturais foram correlacionados com as propriedades espectroscópicas, termogravimétricas e magnéticas. O produto A foi obtido em 90 % de rendimento a partir da reação de Cu(CH3COO)2·H2O com os pré-ligantes Hbzt, H2ox e bipi, em metanol a 70 °C. A análise por DRX de monocristal revelou que em A todos os ligantes contribuem para a manifestação de interações não covalentes do tipo ligações de hidrogênio e interação . A análise por RPE e medidas de susceptibilidade magnética à temperatura ambiente indicaram a existência de interação magnética entre os centros de cobre(II). Medidas de susceptibilidade magnética com variação de temperatura revelaram uma interação ferromagnética (J = 3,26 cm-1) mais forte que a apresentada por complexos análogos. Medidas termogravimétricas mostraram que a decomposição de A se inicia em 55 °C com a perda de 2 H2O, seguida da perda dos ligantes orgânicos entre 136 e 900 °C. Os produtos B e C, de estruturas análogas, foram obtidos em 97 e 99 % de rendimento, respectivamente, a partir da reação de CoCl2·6H2O ou MnCl2·4H2O com o pré-ligante Hdhb, em água a 70 °C. A análise por DRX de monocristal revelou que não ocorreu a coordenação do íon dhb, provavelmente devido a estabilização do carboxilato livre por duas ligações de hidrogênio intramoleculares assistidas por carga. A rede cristalina de B e C também é estabilizada por interações  e por ligações de hidrogênio intermoleculares formadas a partir das águas coordenadas e de cristalização. A decomposição térmica de B e C se inicia com a perda de moléculas de água a temperaturas inferiores a 55 °C e a perda total da parte orgânica ocorre acima de 600 °C. Os compostos obtidos neste trabalho evidenciaram que a estrutura e o grau de agregação dos compostos são dependentes da habilidade de coordenação do ligante ao íon metálico e das interações não covalentes nos ligantes livres e nos complexos formados

Crystal structures of binuclear complexes of gadolinium(III) and dysprosium(III) with oxalate bridges and chelating N,N′-bis(2-oxidobenzyl)-N,N′-bis(pyridin-2-ylmethyl)ethylenediamine (bbpen2−)

The reaction between mononuclear [Ln(bbpen)Cl] [Ln = Gd or Dy; H2bbpen = N,N′-bis(2-hydroxybenzyl)-N,N′-bis(pyridin-2-ylmethyl)ethylenediamine, C28H30N4O2] and potassium oxalate monohydrate in water/methanol produced the solvated centrosymmetric isostructural binuclear (μ-oxalato)bis{[N,N′-bis(2-oxidobenzyl-κO)-N,N′-bis(pyridin-2-ylmethyl-κN)ethylenediamine-κ2N,N′]dilanthanide(III)}–methanol–water (1/4/4) complexes, [Ln2(C28H28N4O2)2(C2O4)]·4CH3OH·4H2O, with lanthanide(III) = gadolinium(III) (Ln = Gd) and dysprosium(III) (Ln = Dy), in high yields (ca 70%) directly from the reaction mixtures. In both complexes, the lanthanide ion is eight-coordinate and adopts a distorted square-antiprismatic coordination environment. The triclinic (P\overline{1}) unit cell contains one dimeric unit together with four water and four methanol molecules; in the final structural model, two of each type of solvating molecule refine well. In each lanthanide(III) dimeric molecule, the medium-strength O...H—O hydrogen-bonding pattern involves four oxygen atoms, two of them from the phenolate groups that are `bridged' by one water and one methanol molecule. These interactions seem to contribute to the stabilization of the relatively compact shape of the dimer. Electron densities associated with an additional water and methanol molecule were removed with the SQUEEZE procedure in PLATON [Spek (2015). Acta Cryst. C71, 9–18]. These two new compounds are of interest with respect to magnetic properties

Rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART): Study protocol for a randomized controlled trial

Background: Acute respiratory distress syndrome (ARDS) is associated with high in-hospital mortality. Alveolar recruitment followed by ventilation at optimal titrated PEEP may reduce ventilator-induced lung injury and improve oxygenation in patients with ARDS, but the effects on mortality and other clinical outcomes remain unknown. This article reports the rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART). Methods/Design: ART is a pragmatic, multicenter, randomized (concealed), controlled trial, which aims to determine if maximum stepwise alveolar recruitment associated with PEEP titration is able to increase 28-day survival in patients with ARDS compared to conventional treatment (ARDSNet strategy). We will enroll adult patients with ARDS of less than 72 h duration. The intervention group will receive an alveolar recruitment maneuver, with stepwise increases of PEEP achieving 45 cmH(2)O and peak pressure of 60 cmH2O, followed by ventilation with optimal PEEP titrated according to the static compliance of the respiratory system. In the control group, mechanical ventilation will follow a conventional protocol (ARDSNet). In both groups, we will use controlled volume mode with low tidal volumes (4 to 6 mL/kg of predicted body weight) and targeting plateau pressure <= 30 cmH2O. The primary outcome is 28-day survival, and the secondary outcomes are: length of ICU stay; length of hospital stay; pneumothorax requiring chest tube during first 7 days; barotrauma during first 7 days; mechanical ventilation-free days from days 1 to 28; ICU, in-hospital, and 6-month survival. ART is an event-guided trial planned to last until 520 events (deaths within 28 days) are observed. These events allow detection of a hazard ratio of 0.75, with 90% power and two-tailed type I error of 5%. All analysis will follow the intention-to-treat principle. Discussion: If the ART strategy with maximum recruitment and PEEP titration improves 28-day survival, this will represent a notable advance to the care of ARDS patients. Conversely, if the ART strategy is similar or inferior to the current evidence-based strategy (ARDSNet), this should also change current practice as many institutions routinely employ recruitment maneuvers and set PEEP levels according to some titration method.13Hospital do Coracao (HCor) as part of the Program 'Hospitais de Excelencia a Servico do SUS (PROADI-SUS)'Brazilian Ministry of Healt