Mn Acetate Research Articles

Polymeric Manganese(II) Acetate Derivatives: Syntheses, Crystal Structures and Magnetic Properties

AbstractThree novel polymeric Mn(II) acetate derivatives, identified as {[Mn2.5(OH)(CH3COO)4] ⋅ 0.5CH3OH ⋅ 0.5CH3CN}n (1), {[Mn3(CH3CO O)6] ⋅ 0.5CH3CN}n (2) and {Mn1.5K(CH3COO)4}n (3), have been successfully prepared by systematically adjusting the ratio of reactants and using the 2‐mercapto‐5‐methyl‐1,3,4‐thiadiazole (Hmmt) as the template agent. These three complexes can be regarded as the different crystalline forms of Mn(CH3COO)2 under different reaction conditions. Single‐crystal X‐ray diffraction analyses revealed that 1 and 2 feature the unique three‐dimensional (3D) framework. For 3, it displays a 2D structure, which is further assembled to form a 3D extended network via the weak hydrogen bond interactions. Magnetic studies confirmed that 1 and 2 show antiferromagnetic interactions, and 1 displays a long‐range ordering phase below the critical temperature (Tc) of 7.8 K. In addition, magnetisation data collected for 1–2 yield low magnetic entropy changes, which can be attributed to the strong antiferromagnetic interactions among the Mn(II) centres.

Layered sodium manganese oxides for toxic nitrogen dioxide gas removal in ambient conditions

In this study, Na0.7MnO2 samples were successfully synthesized using a solid-state synthesis route with Na and Mn acetate precursors. The resulting Na0.7MnO2 crystallized in a hexagonal lattice with space group P63/mmc. These materials were investigated for their capacity to adsorb 100 ppm of NO2 gas at room temperature. Na0.7MnO2 exhibited an exceptional NO2 adsorption capacity of 163.3 mg/g, surpassing many previously reported porous and non-porous materials. Comprehensive experimental and spectroscopic analyses confirmed the formation of NO, NO2–, and NO3– species, following NO2 adsorption on the Na0.7MnO2 surface. Theoretical calculations further supported the chemisorption of NO2 gas molecules on the Na0.7MnO2 surface, with a maximum adsorption energy of –1.937 eV. Spectroscopic and Bader charge analyses confirmed that the NO2 gas molecule acted as a charge acceptor species on the oxide surface. This work represents the first detailed study validating Na0.7MnO2 as an effective room-temperature adsorbent for capturing and mineralizing NO2 gas. The exceptional NO2 adsorption capacity and the mechanistic insights into the adsorption process suggest the promising potential of Na0.7MnO2 and related oxides for applications in NO2 gas capture and conversion.

Chinese-Lantern shaped [MnII2MnIII6NaI3] cluster assembled from Schiff base and azide bridges: Synthesis, magnetic study and catecholase-like activity

A multisite Schiff base, H2damp, derived from the condensation of o-vanillin and a sterically constrained amino-alcohol (2-amino-2-methylpropan-1-ol) was utilized to isolate a new mixed valence heterometallic complex [Na3MnIII6MnII2(damp)6(µ4-O)2(µ1,3-O2CCH3)2(µ1,1-N3)6(µ1,1,3-N3)(H2O)2]·5H2O·CH3OH (1). Room temperature reaction of H2damp in MeOH with Mn(II) acetate and NaN3 provided the complex having MnII2MnIII6NaI3 core. X-ray structure determination revealed the use of azide ancillary ligands for the growth of the complex on ligand-bound MnIII3O fragments. The variable temperature magnetic characterization of 1 revealed intramolecular anti-ferromagnetic exchange interactions. Complex 1 also showed catalytic property for the aerial oxidation of 3,5-di-tert-butyl catechol (3,5-DTBCH2) with a turnover number (kcat) of 392 h−1. EPR and mass spectrometric analysis established the probable mechanism of catalytic oxidase reactivity on the model substrate. In EPR study the characteristic peak at g ∼ 2 allowed us to spot the presence of an organic radical confirming the conversion of DTBCH2 to DTBQ in radical pathway.

Crystal and Molecular Structure of The Mixed-Metal Manganese(II) and Cobalt(II) Maleate Complex: [CoхMn1-x(OOCCH=CHCOO).(H2O)2

For the first time, by the interaction of cobalt maleate tetrahydrate with Mn(II) acetate, a polymeric polynuclear mixed-metal maleate complex of manganese(II) and cobalt(II) was obtained: [CoхMn1-x(OOCCH=CHCOO).(H2O)2]n. The composition and structure of the resulting complexes were studied by IR spectroscopy, UV-Vis spectroscopy, EPR, and elemental and thermogravimetric analysis. The crystal structure of the complex was established by X-ray diffraction. The results of X-ray diffraction analysis showed that maleic acid dianions coordinate with Mn(II) and Co(II) ions in the bidentate bridging form, forming seven-membered chelate rings with manganese and cobalt ions. Each metal ion achieves octahedral symmetry with coordination from two oxygen atoms of two water molecules and two bridging oxygen atoms of the maleate ligands of neighboring complex molecules. The electronic absorption spectra show the absorption band at 965 nm, which should be attributed to the Mn(II) complex. The band at 516 nm refers to the cobalt complex. In the EPR spectrum, a wide single band with g = 2.031 is observed, indicating an electronic exchange interaction between Mn(II) and Co(II) ions. The presence of two metal ions in the complex was also confirmed by cyclic voltammetry. The voltammograms clearly show two reduction waves related to the two-electron reduction of Co2+ (Ec= -0.69 V) and Mn2+ (Ec= -0.985 V) ions.

Comparative outcomes of the voltage-dependent current density, charge transportation and rectification ratio of electronic devices fabricated using mechanically flexible supramolecular networks.

In this study, we report the synthetic method of two distinct supramolecular metallogels, namely Mn-BDA and Cd-BDA, using Mn(II) acetate tetrahydrate, Cd(II) acetate dihydrate and butane-1,4-dicarboxylic acid (BDA). DMF, a polar aprotic solvent, was immobilized in both metallogel-networks for their synthesis. The metallogelation of Mn-BDA was successfully attained through the instant mixing of a Mn(II)-source and BDA in DMF solvent media. By applying ultrasonication, a Cd-BDA metallogel was prepared. The stoichiometry of gel-forming components concerning metal salts and the LMWG are accountable to obtain respective stable metallogels. Rheological parameters such as storage modulus (G') and loss modulus (G'') explored the mechanical flexibility of the synthesized metallogels through amplitude and angular frequency sweep experiments. Both the metallogels possess significant mechanical stability, which was determined by monitoring diverse gel-to-sol transition shear strain values (γ%). Distinctive morphological visualizations of both of these metallogels (i.e., Mn-BDA and Cd-BDA) were made via field emission scanning electron microscopic (FESEM) studies, demonstrating a fibrous inter-connected network with a hierarchical self-assembled arrangement for Mn(II)-based metallogels and a typical stacked-flake-like association with hierarchical motifs for Cd(II)-based metallogels. EDAX elemental mapping substantiated the presence of metallogel-forming agents such as individual metal acetate salts, BDA acting as a low-molecular weight gelator, and gel-immobilized solvents such as DMF. Furthermore, Fourier transform infrared spectroscopy and ESI-mass spectroscopy were performed for both these supramolecular metallogels. FT-IR spectroscopic and ESI-mass spectroscopic results clearly substantiate the possible non-covalent supramolecular interactions among basic molecular repeating moieties, i.e., butane-1,4-dicarboxylic acid (the low-molecular weight gelator), individual metal salts and gel-immobilized polar aprotic solvent DMF for the construction of distinct stable supramolecular metallogel-systems. The semiconducting property of the fabricated metallogels was investigated. Two Schottky diodes (SDs) composed of ITO/Cd-BDA/Al and ITO/Mn-BDA/Al in a sandwich pattern with Al serving as the metal electrode were fabricated. Both these metallogel-based devices effectively offer significant semiconducting diode features with non-linear J-V characteristics. The non-ohmic conduction protocol of the fabricated metallogel-based devices was explored. Mn-BDA and Cd-BDA metallogel-based fabricated devices have rectification ratios of 6.67 and 23.50, respectively. The gel-based diode performances were examined by observing the voltage-dependent current density, charge transportation and rectification ratio.

Catalytic oxidation of toluene over highly dispersed Mn-Ce solid solutions synthesized with weakly acidic precursors

In this paper, a series of Mn-Ce composite oxide catalysts were prepared by different preparation methods using different Mn and Ce acidic precursors for the catalytic oxidation of toluene. The activity test results revealed that the Mn-Ce composite catalysts, synthesized through the sol-gel method using weakly acidic Mn acetate and Ce acetate as precursors, exhibited the highest performance for the catalytic oxidation of toluene. The T50 and T90 values for this catalyst were measured at 208 °C and 235 °C, respectively. The relatively weak acidity of manganese acetate and cerium acetate facilitates the presence of acidic -OH groups, which interact with the oxygen-negative charge sites on each other. Furthermore, during the calcination process, there was a strong interaction between hydrated Mn and Ce ions, resulting in the formation of highly dispersed metal oxide species. The formation of Mn-Ce solid solution demonstrated by Raman, XRD. The H2-TPR characterization indicated that the superior redox performance of the MnOx species on the catalyst surface played a pivotal role in achieving high activity. Moreover, the catalytic activity of the CeO2 species was further enhanced by employing the sol-gel method. XPS and O2-TPD results revealed a significantly higher amount of reactive oxygen species on the catalyst surface, which was identified as the primary reason for the increased activity. This study provides a new strategy for the selection of the catalyst precursors, thereby enhancing the catalytic activity of Mn-Ce composite oxides.

Molecular mechanism for the activation of the potent hepatotoxin acetylhydrazine: Identification of the initial N-centered radical and the secondary C-centered radical intermediates.

Acetylhydrazine (AcHZ), a major human metabolite of the widely-used anti-tuberculosis drug isoniazid (INH), was considered to be responsible for its serious hepatotoxicity and potentially fatal liver injury. It has been proposed that reactive radical species produced from further metabolic activation of AcHZ might be responsible for its hepatotoxicity. However, the exact nature of such radical species remains not clear. Through complementary applications of ESR spin-trapping and HPLC/MS methods, here we show that the initial N-centered radical intermediate can be detected and identified from AcHZ activated by transition metal ions (Mn(III)Acetate and Mn(III) pyrophosphate) and myeloperoxidase. The exact location of the radical was found to be at the distal-nitrogen of the hydrazine group by 15N-isotope-labeling techniques via using 15N-labeled AcHZ we synthesized. Additionally, the secondary C-centered radical was identified unequivocally as the reactive acetyl radical by complementary applications of ESR spin-trapping and persistent radical TEMPO trapping coupled with HPLC/MS analysis. This study represents the first detection and unequivocal identification of the initial N-centered radical and its exact location, as well as the reactive secondary acetyl radical. These findings should provide new perspectives on the molecular mechanism of AcHZ activation, which may have potential biomedical and toxicological significance for future research on the mechanism of INH-induced hepatotoxicity.

MRI Contrasting Agent Based on Mn-MOF-74 Nanoparticles with Coordinatively Unsaturated Sites.

The development of magnetic resonance imaging (MRI) contrasting agents (CAs) that are safer and have a higher relaxivity than Gd(III)-based agents is a significant research topic. Herein, we propose the use of a Mn-based metal organic framework (MOF), Mn-MOF-74, characterized by a safe paramagnetic center, a coordinatively unsaturated site (CUS) for aquation, and a long rotational correlation time, endowing high relaxivity. Furthermore, biocompatibility and delivery to the tumor are generally expected for MOFs that are obtainable in the nanometer size range. Drop-wise mixing of 2,5-dihydroxyterephthalic acid (DHTP) and Mn(II) acetate yielded Mn-MOF-74 with a diameter of < 150nm, which was then modified with 1-fivefold higher amounts of poly(ethylene glycol) (M.W. = 5000) to afford MOFs stably dispersed in water for at least 24h. The longitudinal and transverse relaxivity of the PEG-modified MOF was in the range of r1 = 8.08-13.5 and r2 = 32.7-46.8mM-1s-1, respectively (1.0T, 23.7-23.9°C), being larger than those of typical Gd(III)- and Mn(II)-based CAs of single-nuclear metal complexes. The in vivo imaging of a tumor-bearing mouse clearly showed that the tumor could be readily recognized due to signal enhancement (117%) in T1-weighted images, whereas other tissues showed small signal changes. These results suggest that PEG-Mn-MOF-74 can be passively delivered to tumors and can act as a high-relaxivity T1 agent.

Structural and morphological study of Mn, Zn and Zr freeze-dried transition metal acetates

Manganese (II) acetates tetrahydrate, zinc dihydrate and anhydrous zirconium, processed by freeze-drying, were heat-treated in free atmosphere at different temperatures and times, generating the main oxides of these metals. These acetates were structurally characterized by scanning electron microscopy (SEM), thermogravimetry (TG), differential scanning calorimetry (DSC) and, along with all the oxides generated, by X-ray diffraction (XRD). Calculations obtained from TG data showed that manganese acetate lost two waters after freeze-drying, also confirmed by X-ray data and that the same phenomenon may be occurring for zinc acetate. The results indicate that exothermic events occurred at lower temperatures for freeze-dried acetates, which may be related to the high surface area of the material, and consequent greater reactivity. The total decomposition temperatures of the acetates in the ZnO and ZrO2 semiconducting oxides and the manganese oxides Mn2O3 and Me3O4, with excellent crystallization, were obtained.

A Novel Metal-Containing Mesoporous Silica Composite for the Decolorization of Rhodamine B: Effect of Metal Content on Structure and Performance.

A series of novel MnxFey@SiO2 (x,y = 1-20%) nanocomposites were synthesized for the first time via the sol-gel/combustion method with different content of precursors (Mn and Fe acetate salts). The effect of precursor content and ratio on physicochemical properties were observed by various characterization methods. Moreover, Rhodamine B (RhB) was chosen as the target pollutant to test the performance of these nanocomposites under a photocatalytic Fenton-like reaction. The results showed that the nanocomposite morphology improved by increasing Fe and Mn content. In this study, interesting behavior was observed in BET results which were different from the fact that increasing metal content can decrease the surface area. This study revealed that one metal could be more critical in controlling the properties than another. Moreover, the precursor ratio appears to have a more tangible effect on the surface area than the effect of precursor content. Among all synthesized nanocomposites, Mn1Fe5@SiO2 showed the highest surface area of 654.95 m2/g. At optimum batch conditions (temp = 25 °C, catalyst dosage = 1 g L-1, H2O2 = 75 mmolL-1, and initial RhB concentration = 50 mg L-1), complete removal (simultaneous adsorption/degradation) occurred using Mn1Fe5@SiO2 at neutral pH. This study showed that the designed nanomaterial could be used as a dual functional adsorbent/photocatalyst in different environmental applications.

Efficient All Solid State Rechargeable Zinc-Air Batteries with a Spinel Type MnCo2O4/Carbon Fiber Bifunctional Electrocatalyst

Rechargeable zinc-air batteries (ZABs) stand out as promising candidates in the ever increasing search for sustainable energy storage devices. ZABs are inexpensive devices that exhibit relatively high energy density, safe operation with no environmental issues and long shelf life (when sealed).ZABs are composed of an electrolyte and two electrodes parallel to one another: the air electrode and the zinc electrode. The efficiency and cycle life of rechargeable ZABs are affected by the reactions that take place at the air electrode. The oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) happen at the air electrode during discharge and charge, respectively.The poor kinetics for ORR/OER necessitate the use of electrocatalysts at the air electrode. Traditionally, precious metals like Pt and Ru have been used as ORR and OER catalysts, respectively, to lower the energy barrier for these reactions. However, these catalysts are rare and expensive and suffer from poor cycling stability. Transition metal oxides are inexpensive, abundant and safe alternative electrocatalyst options for air electrodes in ZABs. Mn and Co based oxides have been shown to have reasonable activities towards ORR and OER, respectively.In this work, high performance and efficient all solid state ZABs were prepared. Mn-Co mixed oxide (MnCo2O4) was employed as the bifunctional electrocatalyst. Hydrogel electrolytes, containing polyacrylic acid (PAA), KOH and N,N’-methylenebis (acrylamide) or MBAA as the crosslinker, were used. MnCo2O4 coated carbon fibers (MnCo2O4/CF) were utilized to prepare the air electrodes, with asphaltene based carbon fibers as a conductive substrate for the MnCo2O4 coating. A facile one pot sonication method for coating MnCo2O4 onto the CF, using an ultrasonic bath, was employed. CFs were sonicated in a mixture of 30 ml of reagent alcohol, 100 mg of NaOH, 167 mg of Mn(II) acetate (Mn(Ac)2 or C4H6MnO4) and 333 mg of Co(II) acetate (Co(Ac)2 or C4H6CoO4) for 5 h. A paste, consisting of 90 mg of MnCo2O4/CF, 5 mg of carbon black and 5 mg of PTFE (polytetrafluoroethylene) was used to prepare the air electrodes. Because all the CFs were coated with MnCo2O4 and then used to prepare the air electrodes, the MnCo2O4 bifunctional electrocatalyst was distributed throughout the whole thickness of the air electrode as opposed to only on the surface (which is the case for methods like electrodeposition or spray coating).Initially, different crosslinker concentrations in the hydrogel electrolytes were tested; a crosslinker concentration of 30 mM (referred to as Hydrogel-30-mM) provided the best ZAB performance. Concentrations higher than 30 mM were too viscous and stiff so the O2/electrocatalyst/electrolyte three phase boundary area was not sufficient for efficient ZAB performance. Concentrations less than 30 mM did not have the rheological performance of a gel polymer electrolyte.Charge/discharge battery performance at different current densities, cycling behavior (at 10 mA cm-2), polarization curves and power density values for MnCo2O4/CF and the benchmark Pt-RuO2 electrocatalyst in Hydrogel-30-mM were evaluated. MnCo2O4/CF had a very efficient and stable performance, compared with that of Pt-RuO2. The initial and final efficiencies for MnCo2O4/CF were 62.6% and 56.1%, respectively, for 200 cycles (100 hours: 10 min charge, 5 min rest, 10 min discharge) at 10 mA cm-2, while the initial efficiency for Pt-RuO2 was 61.3% and the battery failed after ~100 cycles.MnCo2O4/CF also had a superior performance to that of Pt-RuO2 in Hydrogel-30-mM, in terms of the maximum power density delivered; i.e., ~ 240 mW cm-2 for MnCo2O4/CF versus 165 mW cm-2 for Pt-RuO2.

Search for Structurally Resembled Mn/Ca Cubane Core of the Oxygen Evolving Complex of Photosystem II Yielded MnIV, MnIII3MnII and MnIII2CaII2Entities: Structure and Magnetism

AbstractThe aim of the paper was to synthesize Mn/Ca entities that are structurally similar to the reported oxygen‐evolving complex (OEC) of photosystem II (PSII). Here we have ventured Schiff base combinations of racemic (±)‐3‐Aminopropane‐1,2‐diol and Salicyladehyde (H3L1)/o‐Vanillin (H3L2) with varied ratios of ligand : CaIIsalt : MnIIIsalt. Interestingly, H3L2 : CaCl2 : MnCl2 (2 : 1 : 1) afforded [{MnIII2CaII2(HL2)2Cl2(μ3‐OH)2(H2O)6}Cl2 ⋅ 2H2O] (3) whereas H3L1 : CaCl2 : Mn(acetate)2 (2 : 1 : 1) and H3L1 : CaCl2 : MnCl2 (2 : 1 : 2), generated [{MnIV(HL1)2}2 ⋅ 6H2O](1) and [{MnIII3MnII(HL1)3(μ2‐Cl)3(μ3‐O)} ⋅ 2CH3OH ⋅ 2H2O] (2) respectively. More importantly, we have been able to get a structure which offers partial similarity to reported structure of the OEC. Variable temperature magnetic susceptibility measurements have been performed in the 1.8–30 K region for all the compounds. Overall, these studies provide a critical understanding for the rational design and construction of synthetic OEC.

Enhanced red emission of glycothermally synthesized Ce:YAG nanophosphors via Mn2+ addition

Mn2+ was shown to be incorporated as a co-dopant in glycothermally synthesized Ce:YAG-based nanophosphors to enhance the red component of the emission spectrum. Structural characterization showed a preferential inclusion of Mn2+ in the Y site. AlIV/AlVI ratios were found to decrease from 0.25 in Ce:YAG nanophosphors to 0.11 with the addition of Mn2+, indicating a ∼10x increase in octahedral Al sites over bulk Ce:YAG, particularly on the particle surface. Luminescence of Mn2+ at 594 nm, indicating octahedral Al site occupation was also observed, likely due to the high doping concentration of Mn2+. Strategies to improve the luminescence of Mn2+ included adding Si4+ in the form of tetraethyl orthosilicate (TEOS) for charge compensation and the addition of an intrinsic shell layer to enhance the local crystal field. XPS confirmed no change of Mn2+ valence after reaction, indicating Mn (II) acetate to be a precursor compatible with the glycothermal method for the synthesis of Ce:YAG-based nanophosphors. 3 mol% Mn2+ was found to be a suitable doping concentration, with quenching observed at 5%. Addition of an intrinsic shell layer greatly improved the optical characteristics of the Mn2+ emission, and the photoluminescence quantum yield (PLQY) increased from 44% to 73%. Fluorescence lifetimes of nanocrystalline Ce:YAG and Mn2+ containing samples dropped from 101.1 ns to 90.7 ns, respectively, indicating the presence of a non-radiative energy transfer mechanism from Ce to Mn2+.

Highly Enhanced Enzymatic Activity of Mn-Induced Carbon Dots and Their Application as Colorimetric Sensor Probes.

Nanomaterial-based enzyme mimetics (nanozymes) have attracted significant interest because of their lower cost and higher stability compared to natural enzymes. In this study, we focused on improving the enzymatic properties of metal induced N-doped carbon dots (N-CDs), which are nanozymes of interest, and their applications for sensory systems. For this purpose, Mn(acetate)2 was introduced during the synthetic step of N-doped carbon dots, and its influence on the enzymatic properties of Mn-induced N-CDs (Mn:N-CDs) was investigated. Their chemical structure was analyzed through infrared spectroscopy and X-ray photoelectron spectrometry; the results suggest that Mn ions lead to the variation in the population of chemical bonding in Mn:N-CDs, whereas these ions were not incorporated into N-CD frameworks. This structural change improved the enzymatic properties of Mn:N-CDs with respect to those of N-CDs when the color change of a 3,3′,5,5′-tetramethylbenzidine/H2O2 solution was examined in the presence of Mn:N-CDs and N-CDs. Based on this enhanced enzymatic property, a simple colorimetric system with Mn:N-CDs was used for the detection of γ-aminobutyric acid, which is an indicator of brain-related disease. Therefore, we believe that Mn:N-CDs will be an excellent enzymatic probe for the colorimetric sensor system.

A simple process to resynthesize the LiCoO2 and LiNi1/3Co1/3Mn1/3O2 compounds from the cathode material extracted from a batch of spent LCO batteries

A low-cost and straightforward resynthesis process based on the complete thermal decomposition of the cathode material extracted from a batch of discarded LiCoO2 (LCO) batteries is described. After leaching the thermally decomposed products, the residue and the filtered solution were employed as feedstock for the resyntheses. The Co3O4 powder residue, filtered from the leached solution, and commercial Li2CO3 were employed to resynthesize the LiCoO2 compound by solid-state reaction. The filtered leached solution containing Li+ and Co2+ ions was used to resynthesize the LiCoO2 and LiNi1/3Co1/3Mn1/3O2 compounds by the sol-gel technique. In these resyntheses, commercial Li, Ni, and Mn acetates were used for compositional adjustments. The charge capacity of electrodes manufactured with the resynthesized compounds was measured by charge and discharge curves in a Li-metal oxide/LiClO4-EC:DMC/Li° electrochemical cell.

A Carbonate-Templated Decanuclear Mn Nanocage with Two Different Silsesquioxane Ligands.

The mild reaction of the preorganized silsesquioxane precursor with Mn(II) acetate under ambient conditions results in a mixed-valent {MnII6MnIII4} nanocage (SD/Mn10) which is protected by both acyclic trimer [Si3] and cyclic tetramer [Si4]. Serendipitous capture of atmospheric CO2 as a μ5-carbonate anion placed at the center supports the formation of the cluster. The magnetic analysis reveals the strong antiferromagnetic interactions between Mn ions. Moreover, the drop-casting film of SD/Mn10 shows photoelectric activity indicating its great potential as a semiconductor for photoelectric conversion applications.

Mn(II), Co(II), Ni(II) and Zn salicylates: Synthesis, structure and biological properties studies

Reaction of acetylsalicylic acid (aspirin) (H2L) with Mn(II), Co(II), Ni(II) and Zn acetates allow to obtain salicylates of related metals. The solid-state structures of prepared complexes were determined by single crystal X-ray crystallography and spectroscopic techniques. Zinc, nickel and cobalt(II) complexes are mononuclear and their crystal structures composed of neutral discrete molecules [Zn(sal)2(H2O)2], [Ni(sal)2(H2O)4] and [Co(sal)2(H2O)4] while manganese derivative has 2D polymeric structure. The cardiorespiratory and skin microcirculation activity of these metal complexes was evaluated. Particularly, the promising therapeutic activities displayed by 1–4 complexes make them potential candidates for the development of a promising drugs.

Sülfonamid Grubu İçeren Yeni Karboksamid Ligand ve Metal Kompleksleri: Sentez, Karakterizasyon, DNA Bölünmesi ve Antimikrobiyal Aktivite

In this work, N-(4-(N-acetylsulfamoyl)phenyl)-2-benzoyl-3-oxo-3-phenylpropanamide (HL) was synthesized by treating the appropriate dibenzoylaceticacid-N-carboxyethylamide with N-(4-aminophenyl)sulfonylacetamide and also characterized by using various analytical and spectroscopic techniques. Further, six metal complexes were synthesized from Zn(II), Ni(II), Mn(II), Cu(II), Co(II), and Pd(II) acetate and ligand in 1:2 ratio respectively. While Cu(II) and Pd(II) complexes exhibited square planar geometry, the others displayed octahedral geometry. Newly synthesized compounds were performed for antioxidant, DNA cleavage and antimicrobial activities. Tested compounds exhibited great potential antioxidant activity, especially Zn and Pd complexes. DNA cleavage results indicated that DNA could cleave with compounds through interaction. These compounds were investigated for their antimicrobial activity against seven microorganism species and showed moderate antimicrobial activity.

Modular Synthesis of Polysubstituted Quinolin-3-amines by Oxidative Cyclization of 2-(2-Isocyanophenyl)acetonitriles with Organoboron Reagents.

Polysubstituted quinolin-3-amines are vital structural motifs because of their broad biological activities as well as versatile transformational abilities. However, they are not easily accessible. We disclose a protocol with Mn(III) acetate as a mild one-electron oxidant promoting a radical process to construct polysubstituted quinolin-3-amines. 2-(2-Isocyanophenyl)acetonitriles and organoboron reagents are suitable substrates for this reaction. The remarkable advantages of this protocol are the practical method, mild approach, high reaction efficiency, and good compatibility of functional groups, providing straightforward access to functional quinoline derivatives.

Nano/Micro-Sized Morphologies of Hydroxyapatite Coatings Containing Mn and Si on an Oxidized Ti-6Al-4V Alloy Surface for Dental Implants.

To improve the surface characteristics of Ti-6Al-4V dental implants and the binding between the bone and implant surface, biocompatible oxide films were formed by plasma electrolytic oxidation (PEO). The PEO treatment was performed using electrolyte solutions containing Ca (calcium acetate monohydrate), P(calcium glycerophosphate), Mn (manganese(II) acetate tetrahydrate), and Si (sodium metasilicate nonahydrate), which are the major constituents of bone, for 3 min at 280 V. The morphology and crystalline phase of the PEO-treated surfaces were characterized using field-emission scanning electron microscopy, energy-dispersive X-ray spectrometry, X-ray diffraction, and Fourier transform infrared spectroscopy. All the obtained PEO-treated samples exhibited a morphology comprising porous structures. Oval and irregular pore structures were observed as the Mn content increased. As the Si content increased, the areas occupied by the pores increased. When both, Si and Mn were used for the PEO treatment, the number of nano- to micro-sized pores gradually decreased with the increasing ratios of the constituents.