Inorganics

16 pages, 2200 KiB

Open AccessArticle

Different Patterns of Pd-Promoted C-H Bond Activation in (Z)-4-Hetarylidene-5(4H)-Oxazolones and Consequences in Photophysical Properties

by Miguel Martínez, David Dalmau, Olga Crespo, Pilar García-Orduña, Fernando Lahoz, Antonio Martín and Esteban P. Urriolabeitia

Inorganics 2024, 12(10), 271; https://doi.org/10.3390/inorganics12100271 - 18 Oct 2024

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Abstract

This work aims to amplify the fluorescence of (Z)-4-hetarylidene-5(4H)-oxazolones 1 by suppression of the hula-twist non-radiative deactivation pathway by C^N-orthopalladation of the 4-hetarylidene ring. Different (Z)-4-hetarylidene-2-phenyl-5(4H)-oxazolones, 1a–1c, prepared by the Erlenmeyer–Plöchl method, [...] Read more.

This work aims to amplify the fluorescence of (Z)-4-hetarylidene-5(4H)-oxazolones 1 by suppression of the hula-twist non-radiative deactivation pathway by C^N-orthopalladation of the 4-hetarylidene ring. Different (Z)-4-hetarylidene-2-phenyl-5(4H)-oxazolones, 1a–1c, prepared by the Erlenmeyer–Plöchl method, have been studied. The orthopalladation of (Z)-2-phenyl-4-(5-thiazolylmethylene)-5(4H)-oxazolone (1a) takes place by C-H bond activation of the H4 of the heterocycle and C^N-chelation, giving the dinuclear trifluoroacetate derivative 2a. By further metathesis of bridging ligands in 2a, complexes containing the orthometalated oxazolone and a variety of ligands 3a–5a, were prepared. The study of the photophysical properties of 1a–5a shows that the bonding of the Pd metal to the 4-hetaryliden-5(4H)-oxazolone does not promote, in these cases, an increase in fluorescence. Interestingly, the orthopalladation of (Z)-2-phenyl-4-(4-thiazolylmethylene)-5(4H)-oxazolone (1b) gives orthopalladated 2b, where the incorporation of the Pd to the oxazolone takes place by C-H bond activation of the ortho-H2 of the 2-phenyl group, ring opening of the oxazolone heterocycle and simultaneous N,N-bonding of the N atoms of the thiazole ring and the generated benzamide fragment. This N^N^C-tridentate dianionic bonding mode is obtained for the first time in oxazolones. Despite a similar lock of the hula-twist deactivation, 2b does not show fluorescence. Full article

(This article belongs to the Special Issue Synthesis and Application of Luminescent Materials)

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14 pages, 2218 KiB

Open AccessArticle

Synthesis and Characterization of Extremely Bulky Aminopyridinate Ligands and a Series of Their Groups 1 and 2 Metal Complexes

by Arif M. Earsad, Albert Paparo, Matthew J. Evans and Cameron Jones

Inorganics 2024, 12(10), 270; https://doi.org/10.3390/inorganics12100270 (registering DOI) - 15 Oct 2024

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Abstract

High-yielding synthetic routes to five new extremely bulky aminopyridine pro-ligands were developed, viz. (C₅H₃N-6-Ar¹)N(H)Ar²-2; Ar¹ = Trip, Ar² = TCHP (HAmPy¹), Ar* (HAmPy²) or Ar^† (HAmPy³); [...] Read more.

High-yielding synthetic routes to five new extremely bulky aminopyridine pro-ligands were developed, viz. (C₅H₃N-6-Ar¹)N(H)Ar²-2; Ar¹ = Trip, Ar² = TCHP (HAmPy¹), Ar* (HAmPy²) or Ar^† (HAmPy³); Ar¹ = TCHP, Ar² = Ar* (HAmPy⁴) or Ar^† (HAmPy⁵) (Trip = 2,4,6-triisopropylphenyl, TCHP = 2,4,6-tricyclohexylphenyl, Ar* = C₆H₂(CHPh₂)₂Me-2,6,4, Ar^† = C₆H₂(CHPh₂)₂Prⁱ-2,6,4. Four of these were deprotonated with LiBuⁿ in diethyl ether to give lithium aminopyridinate complexes which were dimeric for the least bulky ligand, [{Li(AmPy¹)}₂] or monomeric for the bulkier aminopyridinates, i.e., in [Li(AmPy²⁻⁴)(OEt₂)]. One aminopyridine was deprotonated with MeMgI to give monomeric [Mg(AmPy³)I(OEt₂)₂]. When treated with sodium or potassium mirrors or 5% w/w Na/NaCl, over-reduction occurred, leading to the alkali metal aminopyridinates, [M(AmPy³)(η⁶-toluene)] (M = Na or K) or [{Na(AmPy³)}_∞]. An attempted reduction of [Mg(AmPy³)I(OEt₂)₂] with a dimagnesium(I) compound led only to partial loss of diethyl ether and the formation of [(AmPy³)Mg(μ-I)₂Mg(AmPy³)(OEt₂)]. All prepared complexes have potential as ligand transfer reagents in salt metathesis reactions with metal halide complexes. Full article

(This article belongs to the Special Issue Development and Applications of Sterically Demanding Ligands in Main Group Chemistry)

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16 pages, 4343 KiB

Open AccessArticle

Structural Evolution of Olivine during Mechanochemically Assisted Mineral Carbonation under CO₂ Flow

by Costantino Cau, Alessandro Taras, Gabriele Masia, Laura Caggiu, Stefano Enzo, Sebastiano Garroni, Fabrizio Murgia and Gabriele Mulas

Inorganics 2024, 12(10), 269; https://doi.org/10.3390/inorganics12100269 - 15 Oct 2024

Viewed by 498

Abstract

The mechanism of the mechanically assisted mineral carbonation of commercial olivine under the flow of a carbon dioxide (CO₂)/nitrogen (N₂) mixture has been elucidated by ex situ powder X-ray diffraction and Fourier-transform infrared spectroscopy. The overall CO₂ conversion [...] Read more.

The mechanism of the mechanically assisted mineral carbonation of commercial olivine under the flow of a carbon dioxide (CO₂)/nitrogen (N₂) mixture has been elucidated by ex situ powder X-ray diffraction and Fourier-transform infrared spectroscopy. The overall CO₂ conversion depends on the rotational frequency of the mill’s engine, and it reaches 85% within 90 min of mechanical treatment at a flow rate of 2.5 L min⁻¹. By tuning the frequency of rotation, the kinetics of CO₂ conversion unveil a complex reaction pathway involving subsequent steps. Structural analyses suggest that clinochlore, a magnesium (Mg-)- and iron (Fe-)-containing aluminosilicate gathered among the components of olivine, is formed and consumed in different stages, thus promoting the CO₂ sequestration that eventually results in the formation of hydrated and anhydrous Mg-based carbonates. Full article

(This article belongs to the Special Issue A Themed Issue in Honor of Prof. Radovan Cerny—Materials Science, Energy Storage, Diffraction and Crystal Chemistry)

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17 pages, 4385 KiB

Open AccessArticle

Structural and Biological Comparative Studies on M(II)-Complexes (M = Co, Mn, Cu, Ni, Zn) of Hydrazone-s-Triazine Ligand Bearing Pyridyl Arm

by Mezna Saleh Altowyan, Ayman El-Faham, MennaAllah Hassan, Assem Barakat, Matti Haukka, Morsy A. M. Abu-Youssef, Saied M. Soliman and Amal Yousri

Inorganics 2024, 12(10), 268; https://doi.org/10.3390/inorganics12100268 - 14 Oct 2024

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Abstract

The molecular and supramolecular structures of some M(II) complexes (M = Co, Mn, Cu, Ni, Zn) with a hydrazone-s-triazine ligand (^BMPyTr) were discussed based on single crystal X-ray diffraction (SCXRD), Hirshfeld and DFT analyses. A new Co(II) complex [...] Read more.

The molecular and supramolecular structures of some M(II) complexes (M = Co, Mn, Cu, Ni, Zn) with a hydrazone-s-triazine ligand (^BMPyTr) were discussed based on single crystal X-ray diffraction (SCXRD), Hirshfeld and DFT analyses. A new Co(II) complex of the same ligand was synthesized and its structure was confirmed to be [Co(^BMPyTr)Cl₂]·H₂O based on FTIR and UV–Vis spectra, elemental analysis and SCXRD. The geometry around Co(II) was a distorted square pyramidal configuration (τ₅ = 0.4), where Co(II) ion is coordinated to one NNN-tridentate ligand (^BMPyTr) and two Cl^- ions. A Hirshfeld analysis indicated all potential contacts within the crystal structure, where the percentages of O⋯H, N⋯H, C⋯H, and H⋯H contacts in one unit were 11.2, 9.3, 11.4, and 45.9%, respectively, while the respective values for the other complex unit were 10.3, 8.8, 10.6, and 48.0%. According to DFT calculations, the presence of strongly coordinating anions, such as Cl^-, in addition to the large metal ion size, were found to be the main reasons for the small M-^BMPyTr interaction energies in the cases of [Mn(^BMPyTr)Cl₂] (260.79 kcal/mol) and [Co(^BMPyTr)Cl₂]·H₂O (307.46 kcal/mol) complexes. Interestingly, the Co(II) complex had potential activity against both Gram-positive (S. aureus and B. subtilis) and Gram-negative (E. coli and P. vulgaris) bacterial strains with inhibition zone diameters of 13, 15, 16, and 18 mm, respectively. Also, the new [Co(^BMPyTr)Cl₂]·H₂O (IC₅₀ = 131.2 ± 6.8 μM) complex had slightly better cytotoxic activity against HCT-116 cell line compared to ^BMPyTr (145.3 ± 7.1 μM). Full article

(This article belongs to the Special Issue Metal-Based Compounds: Relevance for the Biomedical Field)

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21 pages, 7847 KiB

Open AccessArticle

Unusual Metal–organic Multicomponent Ni(II) and Mononuclear Zn(II) Compounds Involving Pyridine dicarboxylates: Supramolecular Assemblies and Theoretical Studies

by Kamal K. Dutta, Pranay Sharma, Subham Banik, Rosa M. Gomila, Antonio Frontera, Miquel Barcelo-Oliver and Manjit K. Bhattacharyya

Inorganics 2024, 12(10), 267; https://doi.org/10.3390/inorganics12100267 - 14 Oct 2024

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Abstract

In the present work, we reported the synthesis and characterization [single crystal X-ray diffraction technique, spectroscopic, etc.] of two new Ni(II) and Zn(II) coordination compounds, viz. [Ni(2,6-PDC)₂]₂[Ni(en)₂(H₂O)₂]₂[Ni(en)(H₂O)₄ [...] Read more.

In the present work, we reported the synthesis and characterization [single crystal X-ray diffraction technique, spectroscopic, etc.] of two new Ni(II) and Zn(II) coordination compounds, viz. [Ni(2,6-PDC)₂]₂[Ni(en)₂(H₂O)₂]₂[Ni(en)(H₂O)₄]·4H₂O (1) and [Zn(2,6-PDC)(Hdmpz)₂] (2) (where 2,6-PDC = 2,6-pyridinedicarboxylate, en = ethylene-1,2-diamine, and Hdmpz = 3,5-dimethyl pyrazole). Compound 1 is found to crystallize as a multicomponent Ni(II) compound with five discrete complex moieties, whereas compound 2 is isolated as a mononuclear Zn(II) compound. A deep analysis of the crystal structure of 1 unfolds unusual dual enclathration of guest complex cationic moieties within the supramolecular host cavity stabilized by anion–π, π-stacking, N–H⋯O, C–H⋯O, and O–H⋯O hydrogen bonding interactions. Again, the crystal structure of compound 2 is stabilized by the presence of unconventional C–H⋯π(chelate ring) interactions along with C–H⋯O, C–H⋯N hydrogen bonding, π-stacking, and C–H⋯π(pyridyl) interactions. These non-covalent interactions were further studied theoretically using density functional theory (DFT) calculations, molecular electrostatic potential (MEP) surfaces, non-covalent interaction (NCI) plot index, and quantum theory of atoms in molecules (QTAIM) computational tools. The computational study displays that π-stacking or H bonds greatly tune the directionality of compound 1, although non-directional electrostatic forces dominate energetically. For compound 2, a combined QTAIM/NCI plot analysis confirms the presence of unconventional C–H⋯π(chelate ring) interactions along with other weak interactions obtained from the crystal structure analysis. Further, the individual energy contributions of these weak yet significant non-covalent interactions have also been determined computationally. Full article

(This article belongs to the Special Issue Metal Complexes with N-donor Ligands, 2nd Edition)

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18 pages, 14342 KiB

Open AccessArticle

Enhancing Thermochemical Energy Storage Performance of Perovskite with Sodium Ion Incorporation

by Zeyu Ning, Yibin He, Peiwang Zhu, Dong Chen, Fan Yang, Jinsong Zhou and Gang Xiao

Inorganics 2024, 12(10), 266; https://doi.org/10.3390/inorganics12100266 - 11 Oct 2024

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Abstract

Perovskite materials are promising for thermochemical energy storage due to their ability to undergo redox cycling over a wide temperature range. Although BaCoO₃ exhibits excellent air cycling properties, its heat storage capacity in air remains suboptimal. This study introduces Na into the [...] Read more.

Perovskite materials are promising for thermochemical energy storage due to their ability to undergo redox cycling over a wide temperature range. Although BaCoO₃ exhibits excellent air cycling properties, its heat storage capacity in air remains suboptimal. This study introduces Na into the lattice structure to enhance oxygen vacancy formation and mobility. DFT+U simulations of the surface structure of Na-doped BaCoO_3−δ indicate that incorporating Na improves surface stability and facilitates the formation of surface oxygen vacancies. Na_xBa_1−xCoO_3−δ compounds were synthesized using a modified sol–gel method, and their properties were investigated. The experimental results demonstrate that Na doping significantly enhances the redox activity of the material. The heat storage capacity increased by above 50%, with the Na_0.0625Ba_0.9375CoO_3−δ solid solution achieving a heat storage density of up to 341.7 kJ/kg. XPS analysis reveals that Na doping increases the concentration of surface defect oxygen, leading to more active oxygen release sites at high temperatures. This enhancement in redox activity aligns with DFT predictions. During high-temperature cycling, the distribution of Na within the material becomes more uniform, and no performance degradation is observed after 300 cycles. Even after 450 cycles, Na_0.0625Ba_0.9375CoO_3−δ retains over 96% of its initial redox activity, significantly outperforming fresh BaCoO_3−δ. These findings elucidate the mechanism by which Na doping enhances the thermochemical heat storage performance of BaCoO_3−δ and provide new insights for the design of perovskite-based materials. Full article

(This article belongs to the Section Inorganic Materials)

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10 pages, 1848 KiB

Open AccessArticle

Anion and Cation Dynamics in Mixed-Anion Hydroborate Na₃(BH₄)(B₁₂H₁₂): ¹H, ¹¹B, and ²³Na NMR Studies

by Olga A. Babanova, Yolanda Sadikin, Roman V. Skoryunov, Alexei V. Soloninin and Alexander V. Skripov

Inorganics 2024, 12(10), 265; https://doi.org/10.3390/inorganics12100265 - 8 Oct 2024

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Abstract

Sodium borohydride-closo-hydroborate Na₃(BH₄)(B₁₂H₁₂) exhibits high room-temperature ionic conductivity and high electrochemical stability. To study the dynamical properties of this mixed-anion compound at the microscopic level, we have measured the ¹H, ¹¹B, [...] Read more.

Sodium borohydride-closo-hydroborate Na₃(BH₄)(B₁₂H₁₂) exhibits high room-temperature ionic conductivity and high electrochemical stability. To study the dynamical properties of this mixed-anion compound at the microscopic level, we have measured the ¹H, ¹¹B, and ²³Na nuclear magnetic resonance spectra and nuclear spin-lattice relaxation rates over the temperature range of 8–573 K. Our ¹H and ¹¹B spin-lattice relaxation measurements have revealed two types of reorientational jump motion. The faster motional process attributed to reorientations of the [BH₄]⁻ anions is characterized by an activation energy of 159 meV, and the corresponding reorientational jump rate reaches ~10⁸ s⁻¹ near 130 K. The slower process ascribed to reorientations of the larger [B₁₂H₁₂]⁻ anions is characterized by an activation energy of 319 meV, and the corresponding reorientational jump rate reaches ~10⁸ s⁻¹ near 240 K. The results of the ²³Na nuclear magnetic resonance measurements are consistent with the fast long-range diffusion of Na⁺ ions in Na₃(BH₄)(B₁₂H₁₂). The diffusive jump rate of Na⁺ is found to reach ~10⁴ s⁻¹ at 300 K and ~8 × 10⁸ s⁻¹ at 530 K. A comparison of these jump rates with the ionic conductivity data suggests the importance of correlations between diffusing ions. Full article

(This article belongs to the Special Issue A Themed Issue in Honor of Prof. Radovan Cerny—Materials Science, Energy Storage, Diffraction and Crystal Chemistry)

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27 pages, 5416 KiB

Open AccessReview

Recent Advances in Aluminum Nitride (AlN) Growth by Magnetron Sputtering Techniques and Its Applications

by Nabeel Ahmad Khan Jadoon, Vaigunthan Puvanenthiram, Mayada Ahmed Hassan Mosa, Ashutosh Sharma and Kaiying Wang

Inorganics 2024, 12(10), 264; https://doi.org/10.3390/inorganics12100264 - 7 Oct 2024

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Abstract

This review explores the processes involved in enhancing AlN film quality through various magnetron sputtering techniques, crucial for optimizing performance and expanding their application scope. It presents recent advancements in growing AlN thin films via magnetron sputtering, elucidating the mechanisms of AlN growth [...] Read more.

This review explores the processes involved in enhancing AlN film quality through various magnetron sputtering techniques, crucial for optimizing performance and expanding their application scope. It presents recent advancements in growing AlN thin films via magnetron sputtering, elucidating the mechanisms of AlN growth and navigating the complexities of thin-film fabrication. Emphasis is placed on different sputtering methods such as DC, RF, pulsed DC, and high-power impulse DC, highlighting how tailored sputtering conditions enhance film characteristics in each method. Additionally, the review discusses recent research findings showcasing the dynamic potential of these techniques. The practical applications of AlN thin films, including wave resonators, energy harvesting devices, and thermal management solutions, are outlined, demonstrating their relevance in addressing real-world engineering challenges. Full article

(This article belongs to the Special Issue Advanced Inorganic Semiconductor Materials, 2nd Edition)

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18 pages, 5368 KiB

Open AccessArticle

Mesoporous Titania Nanoparticles for a High-End Valorization of Vitis vinifera Grape Marc Extracts

by Anil Abduraman, Ana-Maria Brezoiu, Rodica Tatia, Andreea-Iulia Iorgu, Mihaela Deaconu, Raul-Augustin Mitran, Cristian Matei and Daniela Berger

Inorganics 2024, 12(10), 263; https://doi.org/10.3390/inorganics12100263 - 3 Oct 2024

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Abstract

Mesoporous titania nanoparticles (NPs) can be used for encapsulation polyphenols, with applications in the food industry, cosmetics, or biomedicine. TiO₂ NPs were synthesized using the sol-gel method combined with solvothermal treatment. TiO₂ NPs were characterized through X-ray diffraction, FTIR spectroscopy, the [...] Read more.

Mesoporous titania nanoparticles (NPs) can be used for encapsulation polyphenols, with applications in the food industry, cosmetics, or biomedicine. TiO₂ NPs were synthesized using the sol-gel method combined with solvothermal treatment. TiO₂ NPs were characterized through X-ray diffraction, FTIR spectroscopy, the N₂ adsorption method, scanning and transmission electron microscopy, and thermal analysis. The sample prepared using Pluronic F127 presented a higher surface area and less agglomerated NPs than the samples synthesized with Pluronic P123. Grape marc (GM), a by-product from wine production, can be exploited for preparing extracts with good antioxidant properties. In this regard, we prepared hydroethanolic and ethanolic GM extracts from two cultivars, Feteasca Neagra (FN) and Pinot Noir. The extract components were determined by spectrometric analyses and HPLC. The extract with the highest radical scavenging activity, the hydroethanolic FN extract, was encapsulated in titania (FN@TiO₂) and compared with SBA-15 silica support. Both resulting materials showed biocompatibility on the NCTC fibroblast cell line in a 50–300 µg/mL concentration range after 48 h of incubation and even better radical scavenging potential than the free extract. Although titania has a lower capacity to host polyphenols than SBA-15, the FN@TiO₂ sample shows better cytocompatibility (up to 700 µmg/mL), and therefore, it could be used for skin-care products. Full article

(This article belongs to the Special Issue New Advances into Nanostructured Oxides, 2nd Edition)

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19 pages, 6929 KiB

Open AccessArticle

Investigating the Shape Memory Effect and Corrosion Resistance of the Fe-(17-2x) Mn-6Si-xNi-yCr-0.3C Alloys (x = 0, 1, 2, 3, 4; y = 0, 1, 3, 5)

by Aqeel Abbas, Kai-Cheng Chang, Kun-Ming Lin and Hsin-Chih Lin

Inorganics 2024, 12(10), 262; https://doi.org/10.3390/inorganics12100262 - 30 Sep 2024

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Abstract

In this study, low Mn content Fe-Mn-Si-based shape memory alloys [Fe-(17-2x) Mn-6Si-xNi-yCr-0.3C (x = 0, 1, 2, 3, 4; y = 0, 1, 3, 5)] were prepared via vacuum arc remelting. The alloys were hot-rolled and solid-solution-treated at 1150 °C for 1 h [...] Read more.

In this study, low Mn content Fe-Mn-Si-based shape memory alloys [Fe-(17-2x) Mn-6Si-xNi-yCr-0.3C (x = 0, 1, 2, 3, 4; y = 0, 1, 3, 5)] were prepared via vacuum arc remelting. The alloys were hot-rolled and solid-solution-treated at 1150 °C for 1 h followed by aging at elevated temperatures. The effects of Cr and Ni addition on the shape memory performance and corrosion resistance of the alloys in 3.5 wt% NaCl solutions were investigated using bending test and potentiodynamic polarization, respectively. It was revealed that the recoverable strain of the alloys remains larger than 2% when 1Ni is replaced with 2Mn and Cr is added. However, it becomes less than 2% in 11Mn and 9Mn alloys because of the easy formation of the α’ martensite. The shape memory effect of alloys is highly improved due to the precipitation of fine carbides in the grains by the addition of Cr and after aging treatment at elevated temperatures (≧700 °C). The highest shape recovery ratios of 88.3% for 17Mn0Ni3Cr, 94.0% for 15Mn1Ni3Cr, 94.4% for 13Mn2Ni5Cr, 88.1% for 11Mn3Ni5Cr, and 86.8% for 9Mn4Ni7Cr, respectively, were achieved after 800 °C aging treatment. The strip-like second phase (carbides) forms at the grain boundaries in the Cr-free alloys after 600 °C aging treatment. There are lots of fine carbides (M23C6 and M7C3) precipitated in the interior of the grains at the aging treatments ≧ 700 °C. However, M7C3 is eliminated at 900 °C aging treatment. The corrosion resistance results showed that the corrosion resistance of the alloys is improved by adding Cr. The maximum corrosion potentials (−0.474 V) have been observed for 13Mn2Ni5Cr, and similar mechanisms have been analyzed in all series of alloys. Full article

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19 pages, 4296 KiB

Open AccessArticle

Synthesis and Characterization of New Copper(II) Coordination Compounds with Methylammonium Cations

by Amalija Golobič, Brina Dojer, Marko Jagodič, Anja Siher, Anže Pegan and Matjaž Kristl

Inorganics 2024, 12(10), 261; https://doi.org/10.3390/inorganics12100261 - 29 Sep 2024

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Abstract

We synthesized four new copper(II) complexes with acetato and chlorido ligands and methylammonium (MA), dimethylammonium (DMA), and tetramethylammonium (TMA) counterions: (MA)₄[Cu₂Ac₄Cl₂]Cl₂·2H₂O (1), (DMA)₂[Cu₂Ac₄Cl [...] Read more.

We synthesized four new copper(II) complexes with acetato and chlorido ligands and methylammonium (MA), dimethylammonium (DMA), and tetramethylammonium (TMA) counterions: (MA)₄[Cu₂Ac₄Cl₂]Cl₂·2H₂O (1), (DMA)₂[Cu₂Ac₄Cl₂] (2), (DMA)₄[Cu₂Ac₄Cl₂]Cl₂·2H₂O (3), and (TMA)₅[Cu₂Ac₄Cl]Cl₄·4H₂O (4). All compounds were characterized by single-crystal X-ray diffraction, magnetic measurements, FTIR spectroscopy, and thermogravimetric analysis. Complexes 1, 2, and 3 consist of a dinuclear coordination anion [Cu₂(Ac)₄Cl₂]²⁻ with bridging acetato ligands arranged in a paddle-wheel conformation and square-pyramidal coordination around Cu(II) atoms, while the coordination anion in compound 4 is a polymeric chain, parallel to the c axis, with Cu₂(Ac)₄ units connected through bridging chlorido ligands. Magnetic measurements carried out between 2 K and 300 K indicate strong antiferromagnetic interactions between Cu(II) ions. The effective magnetic moments range from

1.94 μ_{B}

to

2.21 μ_{B}

, exceeding the spin-only value for Cu(II) ions (

μ_{e f f} = 1.73 μ_{B}

) and suggesting significant orbital contributions to the magnetic moment. Thermogravimetric analysis of all complexes showed a multistep decomposition behavior yielding elemental copper as the final product. Full article

(This article belongs to the Section Coordination Chemistry)

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14 pages, 2957 KiB

Open AccessArticle

Dithiodipropionate and Fumarate Ni, Cu, and Zn Mixed Ligand Complexes

by Ivana Loubalová, Kamil Kotrle, Peter Antal, Lucie Hochvaldová, Aleš Panáček, Ivana Císařová, Marcin Świątkowski and Pavel Kopel

Inorganics 2024, 12(10), 260; https://doi.org/10.3390/inorganics12100260 - 28 Sep 2024

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Abstract

Three nickel, copper, and zinc complexes with dicarboxylic acids (3,3′-dithiodipropionic acid (H₂dtdp) and fumaric acid (H₂fu)) and N-donor ligands (1,10-phenanthroline (phen), N′–methyldipropylenetriamine (mdpta), and N,N,N′,N″,N″-pentamethyldiethylenetriamine (pmdien)) were synthesized. [...] Read more.

Three nickel, copper, and zinc complexes with dicarboxylic acids (3,3′-dithiodipropionic acid (H₂dtdp) and fumaric acid (H₂fu)) and N-donor ligands (1,10-phenanthroline (phen), N′–methyldipropylenetriamine (mdpta), and N,N,N′,N″,N″-pentamethyldiethylenetriamine (pmdien)) were synthesized. These complexes were characterized using elemental analysis, IR spectroscopy, and single-crystal X-ray diffraction. Interestingly, [Ni(dtdp)(phen)(H₂O)₃]∙0.5H₂O (1) is a mononuclear complex, where the dtdp dianion employs only one carboxylate group for coordination to the central nickel atom. [(ClO₄)(mdpta)Cu(μ-dtdp)Cu(mdpta)(H₂O)](ClO₄) (2) is a dinuclear copper complex with a dtdp bridge and different coordination on the copper center. [{Zn(pmdien)(H₂O)}₂(μ-fu)](ClO₄)₂ (3) is a symmetric dimer with a bridging fumarate ligand. These coordination compounds were tested for their antibacterial activities on Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Enterococcus faecalis bacteria strains. All the complexes show moderate activities on the mentioned strains. Full article

(This article belongs to the Section Coordination Chemistry)

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14 pages, 951 KiB

Open AccessArticle

Coupled Transport of Metal Ions in Aqueous Solutions Containing NaCl and HCl

by M. Melia Rodrigo, Filipa R. L. Fernandes, Sónia I. G. Fangaia, Almudena Crespo, Ana C. F. Ribeiro and Miguel A. Esteso

Inorganics 2024, 12(10), 259; https://doi.org/10.3390/inorganics12100259 - 27 Sep 2024

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Abstract

The main objective of this work was to analyze the transport by diffusion of salts containing some metal ions (that is, CoCl₂, CrCl₃, HgCl₂, and PbCl₂), at 25.0 °C, in two different aqueous solutions with [...] Read more.

The main objective of this work was to analyze the transport by diffusion of salts containing some metal ions (that is, CoCl₂, CrCl₃, HgCl₂, and PbCl₂), at 25.0 °C, in two different aqueous solutions with varying pH levels, namely, sodium chloride and hydrochloric chloride, by using Nernst–Hartley model equations. To analyze the applicability of this model, experimental data for two aqueous systems (CoCl₂ + NaCl) and (CoCl₂ + HCl), were obtained by using the Taylor technique and compared with the predicted values. The Nernst–Hartley model equations were used in this study to estimate the mutual diffusion coefficients of the eight ternary systems, which included (CoCl₂ + NaCl), (HgCl₂ + NaCl), (PbCl₂ + NaCl), (CrCl₃ + NaCl), and (CoCl₂ + HCl), (HgCl₂ + HCl), (PbCl₂ + HCl), and (CrCl₃ + HCl). By using the limiting equations of Nernst–Hartley coefficients, we were able to understand the composition dependence of the mutual diffusion coefficients of these mixed electrolyte solutions and the electrostatic mechanism for the strongly coupled diffusion of these components. Full article

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22 pages, 21927 KiB

Open AccessArticle

Antimicrobial, Optical, and Mechanical Properties of Saliva-Contaminated Silver–Zeolite Nanoparticle-Incorporated Dental Acrylic Resins

by Çisel Kısa Yaman, Necla Demir, Uğur Arslan and Nurullah Çiftçi

Inorganics 2024, 12(10), 258; https://doi.org/10.3390/inorganics12100258 - 25 Sep 2024

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Abstract

Background and Purpose: This study aimed to evaluate the flexural strength, color change and antimicrobial effect of silver–zeolite nanoparticles (NPs) in acrylic resin materials. Methods: Fifty-six disc-shaped acrylic resin samples were divided into four groups (n = 7) according to concentrations of [...] Read more.

Background and Purpose: This study aimed to evaluate the flexural strength, color change and antimicrobial effect of silver–zeolite nanoparticles (NPs) in acrylic resin materials. Methods: Fifty-six disc-shaped acrylic resin samples were divided into four groups (n = 7) according to concentrations of silver–zeolite NPs (0%, 2%, 4%, 5%). Discs were contaminated with C. albicans and S. mutans. The antimicrobial effect was tested by inoculating contaminated discs on Tryptic soy agar (TSA), Sabouraud Dextrose Agar (SDA), Tryptic soy broth (TSB), and Sabouraud dextrose broth (SDB). Forty rectangular 65 × 10 × 2.5 mm acrylic resin specimens were also classified into four groups (n = 10) according to concentrations of silver–zeolite NPs. For the color change, L, a, and b values of rectangular specimens were examined with a spectrophotometer. A three-point bending test was also performed using a Devotrans device to determine the flexural bond strength of rectangular specimens. Scanning electron microscope analysis (SEM/EDX analysis) was also performed. Results: In this study, the antimicrobial effect increased with the concentration of silver–zeolite NPs added to acrylic resin discs. In our study, adding 2% silver–zeolite NPs was more effective against C. albicans. The antimicrobial effect against S. mutans increased with concentration of silver–zeolite NPs (<0.001). The colonization of C. albicans was significantly reduced by silver–zeolite NPs. A significant increase was observed in the color change as the nanoparticle percentage ratio increased (p < 0.001). The flexural strength values of the groups containing 2% and 4% nanoparticles were found to be clinically acceptable. Conclusions: The study showed that bacterial and fungal colonization is significantly reduced by adding silver–zeolite nanoparticles to acrylic resin discs. Based on its antimicrobial, physical, and mechanical properties, we recommend adding 2% silver–zeolite nanoparticles to the acrylic resin material for optimal results. Full article

(This article belongs to the Special Issue Functional Inorganic Biomaterials for Molecular Sensing and Biomedical Applications)

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Open AccessReview

Charge Traps in Wide-Bandgap Semiconductors for Power Electronics Applications

by Kean Chuan Lee and Martin Weis

Inorganics 2024, 12(10), 257; https://doi.org/10.3390/inorganics12100257 - 24 Sep 2024

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Abstract

Wide-bandgap semiconductors have been envisioned for power electronics applications because of their ability to operate at higher temperatures and higher applied voltages without breakdown. However, the presence of defects may cause device failure, necessitating a comprehensive understanding of material defects. This review provides [...] Read more.

Wide-bandgap semiconductors have been envisioned for power electronics applications because of their ability to operate at higher temperatures and higher applied voltages without breakdown. However, the presence of defects may cause device failure, necessitating a comprehensive understanding of material defects. This review provides a fingerprint of known defects in three envisioned semiconductors for power electronics: 4H-SiC, GaN, and β-Ga₂O₃. Via a detailed discussion of defects—the origins of electrically active charge traps—through their activation energies and capture cross-sections, we provide important insights into defect parameter distributions. This review not only serves as a reference but also offers a strategic roadmap for distinguishing between similar defects. Such knowledge is key for the development of more robust and efficient power electronic devices that can fully exploit the potential of wide-bandgap semiconductors. Full article

(This article belongs to the Section Inorganic Materials)

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Inorganics, Volume 12, Issue 10 (October 2024) – 15 articles

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