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15 pages, 4270 KiB

Open AccessArticle

Sustainable Solvent-Free Selective Oxidation of Benzyl Alcohol Using Ru(0) Supported on Alumina

by Eleonora Aneggi, Filippo Campagnolo, Daniele Zuccaccia, Walter Baratta, Jordi Llorca and Alessandro Trovarelli

Inorganics 2023, 11(5), 177; https://doi.org/10.3390/inorganics11050177 - 22 Apr 2023

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Abstract

The selective oxidation of primary alcohols into their corresponding carbonyl compounds is challenging because of the easy over oxidization to acids and esters. The traditional reaction requires large amounts of solvent and oxidant, causing serious environmental issues. Recently, several efforts have been made [...] Read more.

The selective oxidation of primary alcohols into their corresponding carbonyl compounds is challenging because of the easy over oxidization to acids and esters. The traditional reaction requires large amounts of solvent and oxidant, causing serious environmental issues. Recently, several efforts have been made to transform the reaction into a more sustainable process. Here, we investigated the solvent-free oxidation of benzyl alcohol using air as a green oxidant in the presence of ruthenium supported on alumina and zirconia, thereby meeting atom economy and environmental requirements. The materials were extensively characterized and, in addition to their activity, selectivity, and reusability, the environmental sustainability of the process was assessed according to green chemistry metrics. XRD, TEM, and XPS analyses suggest that the formation of metallic Ru on the support plays a key role in the catalytic activity. Ru supported on alumina, after a reduction treatment, achieves good activity (62% conversion) and a complete selectivity in a very sustainable process (without a solvent and with air as oxidant), as indicated by the very low E-factor value. The formulation is very stable and maintains high activity after recycling. Full article

(This article belongs to the Special Issue Inorganics: 10th Anniversary)

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22 pages, 4776 KiB

Open AccessArticle

Synthesis and Characterization of Pt(II) and Pd(II) Complexes with Planar Aromatic Oximes

by Mikala Meadows, Lei Yang, Cody Turner, Mikhail Berezin, Sergiy Tyukhtenko and Nikolay Gerasimchuk

Inorganics 2023, 11(3), 116; https://doi.org/10.3390/inorganics11030116 - 10 Mar 2023

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Abstract

A series of four Werner-type complexes of Pd(II) and Pt(II) with planar, isomeric conjugated aromatic naphtoquinone oximes were synthesized for the first time. These ligands were 1-oxime-2-naphtoquinone (HL¹) and 2-oxime-1-napthoquinone (HL²). Compounds were characterized using thermal analysis, [...] Read more.

A series of four Werner-type complexes of Pd(II) and Pt(II) with planar, isomeric conjugated aromatic naphtoquinone oximes were synthesized for the first time. These ligands were 1-oxime-2-naphtoquinone (HL¹) and 2-oxime-1-napthoquinone (HL²). Compounds were characterized using thermal analysis, spectroscopic methods, and X-ray analysis. TG/DSC data were collected for pure starting organic ligands, their complexes, and indicated vigorous exothermic decomposition with at ~155 °C for starting HL and ~350 °C for transition metal complexes. Crystal structures for two Pt compounds with 2-oxime-1-quinone were determined and revealed the formation of the cis-geometry complexes and incorporation of molecules of stoichiometric solvents in the lattice: acetonitrile and nitrobenzene. Both solvents of crystallization displayed attractive interactions between their C-H groups and the oxygen atoms of the nitroso groups in complexes, leading to short distances in those fragments. Despite the presence of solvents of inclusion, the overall structure motifs in both compounds represent 1D columnar coordination polymer, in which the PtL₂ units are held together via metallophilic interactions, thereby forming ‘Pt-wires’. The Hirshfield surface analysis was performed for both crystallographically characterized complexes. The results showed intermolecular π–π stacking and Pt–Pt interactions among the planar units of both complexes. In addition, the analysis also verified the presence of hydrogen bonding interactions between the platinum unit and solvent molecules. Solid bulk powdery samples of both PtL¹₂ and PtL²₂ demonstrated pronounced photoluminescence in the near infrared region of spectrum at ~980 nm, being excited in the range of 750–800 nm. The NIR emission was observed only for Pt-complexes and not for pure starting organic ligands or Pd-complexes. Additionally, synthesized Pt-naphtoquinone oximes do not show luminescence in solutions, which suggests the importance of a 1D ‘metal wire’ structure for this process. Full article

(This article belongs to the Special Issue Inorganics: 10th Anniversary)

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10 pages, 1700 KiB

Open AccessArticle

Neptunyl(VI) Nitrate Coordination Polymer with Bis(2-pyrrolidone) Linkers Highlighting Crystallographic Analogy and Solubility Difference in Actinyl(VI) Nitrates

by Tomoyuki Takeyama, Juliane März, Ryoma Ono, Satoru Tsushima and Koichiro Takao

Inorganics 2023, 11(3), 104; https://doi.org/10.3390/inorganics11030104 - 1 Mar 2023

Cited by 1 | Viewed by 1863

Abstract

NpO₂(NO₃)₂ units are connected by bis(2-pyrrolidone) linker molecules with the trans-1,4-cyclohexyl bridging part (L1) to form a one-dimensional coordination polymer, [NpO₂(NO₃)₂(L1)]_n. Molecular and crystal structures [...] Read more.

NpO₂(NO₃)₂ units are connected by bis(2-pyrrolidone) linker molecules with the trans-1,4-cyclohexyl bridging part (L1) to form a one-dimensional coordination polymer, [NpO₂(NO₃)₂(L1)]_n. Molecular and crystal structures of this compound are nearly identical to that of the UO₂²⁺ analogue, while its aqueous solubility is greatly enhanced, probably owing to weaker thermodynamic stability of the complexation in NpO₂²⁺ compared with that in UO₂²⁺. Full article

(This article belongs to the Special Issue Inorganics: 10th Anniversary)

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12 pages, 5909 KiB

Open AccessArticle

Effect of the Solvent on the Crystallographic and Magnetic Properties of Rhenium(IV) Complexes Based on 2,2′-Bipyrimidine Ligand

by Adrián Sanchis-Perucho, Marta Orts-Arroyo, Nicolas Moliner and José Martínez-Lillo

Inorganics 2023, 11(2), 78; https://doi.org/10.3390/inorganics11020078 - 9 Feb 2023

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Abstract

Two solvated rhenium(IV) complexes with formula [ReCl₄(bpym)]·MeCN (1) and [ReCl₄(bpym)]·CH₃COOH·H₂O (2) (bpym = 2,2′-bipyrimidine) have been prepared and characterized by means of Fourier transform infrared spectroscopy (FT–IR), scanning electron microscopy and [...] Read more.

Two solvated rhenium(IV) complexes with formula [ReCl₄(bpym)]·MeCN (1) and [ReCl₄(bpym)]·CH₃COOH·H₂O (2) (bpym = 2,2′-bipyrimidine) have been prepared and characterized by means of Fourier transform infrared spectroscopy (FT–IR), scanning electron microscopy and energy dispersive X-ray analysis (SEM–EDX), single-crystal X-ray diffraction (XRD) and SQUID magnetometer. 1 and 2 crystallize in the monoclinic system with space groups P2₁/n and P2₁/c, respectively. In both compounds, the Re(IV) ion is six-coordinate and bound to four chloride ions and two nitrogen atoms of a 2,2′-bipyrimidine molecule forming a distorted octahedral geometry around the metal ion. In the crystal packing of 1 and 2, intermolecular halogen⋯halogen and π⋯halogen-type interactions are present. Hydrogen bonds take place only in the crystal structure of 2. Both compounds exhibit a similar crystal framework based on halogen bonds. Variable temperature dc magnetic susceptibility measurements performed on microcrystalline samples of 1 and 2 show a similar magnetic behavior for both compounds, with antiferromagnetic exchange between the Re(IV) ions connected mainly through intermolecular Re-Cl⋯Cl-Re interactions. Full article

(This article belongs to the Special Issue Inorganics: 10th Anniversary)

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17 pages, 14505 KiB

Open AccessArticle

Phases and Interfaces in the Cr–Fe–Si Ternary System: X-ray Diffraction and Electron Microscopy Study

by Elena I. Suvorova, Natalya A. Arkharova, Anna G. Ivanova, Fedor Yu. Solomkin and Philippe A. Buffat

Inorganics 2023, 11(2), 73; https://doi.org/10.3390/inorganics11020073 - 3 Feb 2023

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Abstract

The ternary Cr-Fe-Si system was investigated with X-ray diffraction, energy dispersive X-ray spectrometry, scanning and transmission electron microscopy, and electron diffraction. Samples melted at 1723 K were examined right after cooling or after annealing at 1073 K for 3 days to determine phases, [...] Read more.

The ternary Cr-Fe-Si system was investigated with X-ray diffraction, energy dispersive X-ray spectrometry, scanning and transmission electron microscopy, and electron diffraction. Samples melted at 1723 K were examined right after cooling or after annealing at 1073 K for 3 days to determine phases, grain sizes, and interphase interfaces. During annealing, a polymorphic transformation of the tetragonal α-FeSi₂ to the orthorhombic β-FeSi₂ phase occurs, while CrSi₂ retains its hexagonal structure at high-temperature treatment. Thin layers of ε-FeSi with a cubic structure were observed and identified within the CrSi₂ grains. Crystallographic orientation relationships are determined at the interphase interfaces. The contributions of lattice mismatch and thermal expansion coefficient misfit to deformation are discussed. Full article

(This article belongs to the Special Issue Inorganics: 10th Anniversary)

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15 pages, 1378 KiB

Open AccessArticle

Peroxidative Oxidation of Cyclohexane Using 3d Metal Complexes with Hydrazone-Derived Ligands as Catalysts: Exploring (Un)Conventional Conditions

by Nuno Reis Conceição, Beatriz P. Nobre, Atash V. Gurbanov, António M. F. Palavra, M. Fátima C. Guedes da Silva, Kamran T. Mahmudov and Armando J. L. Pombeiro

Inorganics 2023, 11(2), 62; https://doi.org/10.3390/inorganics11020062 - 28 Jan 2023

Cited by 5 | Viewed by 1901

Abstract

Two tetranuclear and two mononuclear Cu(II) complexes with arylhydrazones of malononitrile derived ligands (compounds 1–2 and 3–4, respectively), one trinuclear Co(II/III) complex with an arylhydrazone of acetoacetanilide (5) and one tetranuclear Zn(II) complex of 3-(2-carboxyphenyl-hydrazone)pentane-2,4-dione ( [...] Read more.

Two tetranuclear and two mononuclear Cu(II) complexes with arylhydrazones of malononitrile derived ligands (compounds 1–2 and 3–4, respectively), one trinuclear Co(II/III) complex with an arylhydrazone of acetoacetanilide (5) and one tetranuclear Zn(II) complex of 3-(2-carboxyphenyl-hydrazone)pentane-2,4-dione (6) were screened as potential catalysts in the peroxidative oxidation of cyclohexane by aqueous H₂O₂ in acetonitrile. The best results were attained in the presence of pyrazine-2-carboxylic acid (PCA) with 1 (26% yield, TON = 52.0) and with 2 (24%, TON = 48.0) after 4 h at 40 °C. In the presence of complexes 5 and 6, no oxygenated products were detected in the studied conditions. The employment of non-conventional conditions like supercritical carbon dioxide (scCO₂) as reaction medium or microwave (MW) irradiation was assessed for complexes 1 and 2. After 6 h in acetonitrile–scCO₂, at 50 °C and with HNO₃ as promoter, only 17% yield was achieved using 1 as catalyst, and 21% using 2. Total yields of oxygenates up to 14 (with 1) and 13% (2) and TOFs of 56.0 and 52.0 h⁻¹, respectively, were obtained working under MW irradiation at 70 °C and for the much shorter time of 0.5 h. Full article

(This article belongs to the Special Issue Inorganics: 10th Anniversary)

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12 pages, 3788 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

The Influence of Different Recombination Pathways on Hysteresis in Perovskite Solar Cells with Ion Migration

by Biao Li, Kun Chen, Pengjie Hang, Yuxin Yao, Chenxia Kan, Zechen Hu, Ying Wang, Yiqiang Zhang, Deren Yang and Xuegong Yu

Inorganics 2023, 11(2), 52; https://doi.org/10.3390/inorganics11020052 - 19 Jan 2023

Viewed by 1993

Abstract

The impact of hysteresis on the power conversion efficiency (PCE) of perovskite solar cells (PSCs) still faces uncertainties despite the rapid development of perovskite photovoltaics. Although ion migration in perovskites is regarded as the chief culprit for hysteresis, charge carrier recombination pathways in [...] Read more.

The impact of hysteresis on the power conversion efficiency (PCE) of perovskite solar cells (PSCs) still faces uncertainties despite the rapid development of perovskite photovoltaics. Although ion migration in perovskites is regarded as the chief culprit for hysteresis, charge carrier recombination pathways in PSCs are proposed to be necessary for the occurrence of hysteresis. Here, the impact of both bulk recombination and interface recombination on hysteresis in PSCs is investigated via drift–diffusion modeling. The simulation results demonstrate a direct correlation between recombination pathways and hysteresis in PSCs with ion migration. The simulation reveals that recombination pathways in PSCs will react to the variation in charge carrier distribution under different voltage scanning directions induced by ion migration in absorber layers, which leads to hysteresis in PSCs. Moreover, the hysteresis in normal (N-I-P) PSCs with different electron transport layers (ETLs) including sintered SnO₂, SnO₂ nano crystals and TiO₂ is experimentally explored. The results demonstrate that multiple recombination pathways coupled with ion migration can lead to obvious hysteresis in fabricated PSCs which is consistent with simulation results. This work provides great insight into hysteresis management upon composition, additive and interface engineering in PSCs. Full article

(This article belongs to the Special Issue Inorganics: 10th Anniversary)

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14 pages, 1581 KiB

Open AccessArticle

Heterogenous Preparations of Solution-Processable Cobalt Phthalocyanines for Carbon Dioxide Reduction Electrocatalysis

by Elahe Tajbakhsh, Declan McKearney, Daniel B. Leznoff and Jeffrey J. Warren

Inorganics 2023, 11(1), 43; https://doi.org/10.3390/inorganics11010043 - 15 Jan 2023

Cited by 6 | Viewed by 2497

Abstract

The development and implementation of technology that can capture and transform carbon dioxide (CO₂) is of ongoing interest. To that end, the integration of molecular electrocatalysts into devices is appealing because of the desirable features of molecules, such as the ability [...] Read more.

The development and implementation of technology that can capture and transform carbon dioxide (CO₂) is of ongoing interest. To that end, the integration of molecular electrocatalysts into devices is appealing because of the desirable features of molecules, such as the ability to modify active sites. Here, we explore how the identity of the aliphatic group in 1,4,8,11,15,18,22,25-octaalkoxyphthalocyanine cobalt(II) affects the catalytic behavior for heterogeneous CO₂ reduction electrocatalysis. The alkyl R-groups correspond to n-butoxy, sec-butoxy, and 2-ethylhexoxy. All of the catalysts are soluble in organic solvents and are readily solution-processed. However, the larger 2-ethylhexoxy group showed solution aggregation behavior at concentrations ≥1 mM, and it was, in general, an inferior catalyst. The other two catalysts show comparable maximum currents, but the octa sec-butoxy-bearing catalyst showed larger CO₂ reduction rate constants based on foot-of-the-wave analyses. This behavior is hypothesized to be due to the ability of the sec-butoxy groups to eliminate the ability of the alkoxy oxygen to block Co Sites via ligation. CO₂ reduction activity is rationalized based on solid-state structures. Cobalt(II) phthalocyanine and its derivatives are known to be good CO₂ reduction catalysts, but the results from this work suggest that straightforward incorporation of bulky groups can improve the processability and per site activity by discouraging aggregation. Full article

(This article belongs to the Special Issue Inorganics: 10th Anniversary)

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15 pages, 7296 KiB

Open AccessArticle

Low-Temperature Synthesis Approach for Calcium Hydroxyapatite Coatings on Titanium Substrate

by Rasa Karalkeviciene, Greta Briedyte, Anton Popov, Skirmante Tutliene, Aleksej Zarkov and Aivaras Kareiva

Inorganics 2023, 11(1), 33; https://doi.org/10.3390/inorganics11010033 - 7 Jan 2023

Cited by 2 | Viewed by 1989

Abstract

In this study, a low-temperature synthetic approach was developed for the fabrication of calcium hydroxyapatite (CHAp) coatings on a titanium substrate. The titanium substrates were first coated with CaCO₃ by a spin-coating technique using a sol–gel chemistry approach, and the obtained product [...] Read more.

In this study, a low-temperature synthetic approach was developed for the fabrication of calcium hydroxyapatite (CHAp) coatings on a titanium substrate. The titanium substrates were first coated with CaCO₃ by a spin-coating technique using a sol–gel chemistry approach, and the obtained product was transformed into CHAp during a dissolution–precipitation reaction. The phase purity and structural and morphological features of the obtained CHAp coatings were evaluated by X-ray diffraction (XRD) analysis, FTIR spectroscopy, Raman spectroscopy, scanning electron microscopy (SEM) and using a 3D optical profilometer. It was demonstrated that almost-single-phase CHAp formed on the titanium substrate with a negligible number of side phases, such as Na₂HPO₄ (starting material) and TiO₂. In the Raman spectrum of the CHAp coating, the peaks of phosphate group vibrations were clearly seen. Thus, the obtained results of Raman spectroscopy correlated well with the results of X-ray diffraction analysis. The corrosive behaviour of CHAp coatings on a titanium substrate was also evaluated using electrochemical methods. It was found that the corrosion resistance of titanium coated with CHAp increased significantly. These CHAp thin films may be potential candidates for use in not only in regenerative medicine but also in the development of different sensors. Full article

(This article belongs to the Special Issue Inorganics: 10th Anniversary)

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18 pages, 4081 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Latonduine-1-Amino-Hydantoin Hybrid, Triazole-Fused Latonduine Schiff Bases and Their Metal Complexes: Synthesis, X-ray and Electron Diffraction, Molecular Docking Studies and Antiproliferative Activity

by Christopher Wittmann, Tim Gruene, Alexander Prado-Roller, Sandra Aranđelović, Jóhannes Reynisson and Vladimir B. Arion

Inorganics 2023, 11(1), 30; https://doi.org/10.3390/inorganics11010030 - 3 Jan 2023

Cited by 3 | Viewed by 2276

Abstract

A series of latonduine derivatives, namely 11-nitro-indolo[2,3-d]benzazepine-7-(1-amino-hydantoin) (B), triazole-fused indolo[2,3-d]benzazepine-based Schiff bases HL¹ and HL² and metal complexes [M(p-cymene)(HL¹)Cl]Cl, where M = Ru (1), Os (2), and [...] Read more.

A series of latonduine derivatives, namely 11-nitro-indolo[2,3-d]benzazepine-7-(1-amino-hydantoin) (B), triazole-fused indolo[2,3-d]benzazepine-based Schiff bases HL¹ and HL² and metal complexes [M(p-cymene)(HL¹)Cl]Cl, where M = Ru (1), Os (2), and [Cu(HL²)Cl₂] (3) were synthesized and characterized by spectroscopic techniques (UV–vis, ¹H, ¹³C, ¹⁵N–¹H HSQC NMR) and ESI mass spectrometry. The molecular structures of B and HL¹ were confirmed by single-crystal X-ray diffraction, while that of 3 by electron diffraction of nanometer size crystalline sample. Molecular docking calculations of species B in the binding pocket of PIM-1 enzyme revealed that the 1-amino-hydantoin moiety is not involved in any hydrogen-bonding interactions, even though a good accommodation of the host molecule in the ATP binding pocket of the enzyme was found. The antiproliferative activity of organic compounds B, HL¹ and HL², as well as complexes 1–3 was investigated in lung adenocarcinoma A549, colon adenocarcinoma LS-174 and triple-negative breast adenocarcinoma MDA-MB-231 cells and normal human lung fibroblast cells MRC-5 by MTT assays; then, the results are discussed. Full article

(This article belongs to the Special Issue Inorganics: 10th Anniversary)

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13 pages, 4196 KiB

Open AccessArticle

A Manganese(II) 3D Metal–Organic Framework with Siloxane-Spaced Dicarboxylic Ligand: Synthesis, Structure, and Properties

by Alexandru-Constantin Stoica, Madalin Damoc, Sergiu Shova, Ghenadie Novitchi, Mihaela Dascalu and Maria Cazacu

Inorganics 2023, 11(1), 21; https://doi.org/10.3390/inorganics11010021 - 1 Jan 2023

Cited by 1 | Viewed by 2412

Abstract

A new metal–organic framework {[Mn₄(Cx)₃(etdipy)₅]·2ClO₄}_n (1) was prepared via the complexation of manganese ion from a Mn(ClO₄)₂ source with 1,3-bis(carboxypropyl)tetramethyldisiloxane (Cx) and 1,2-di(4-pyridyl)ethylene (etdipy) in the presence of 2,4-lutidine [...] Read more.

A new metal–organic framework {[Mn₄(Cx)₃(etdipy)₅]·2ClO₄}_n (1) was prepared via the complexation of manganese ion from a Mn(ClO₄)₂ source with 1,3-bis(carboxypropyl)tetramethyldisiloxane (Cx) and 1,2-di(4-pyridyl)ethylene (etdipy) in the presence of 2,4-lutidine as a deprotonating agent. The single-crystal X-ray diffraction analysis revealed a dense 3D framework structure. The presence in the structure of flexible tetramethyldisiloxane moieties, which tend to orient themselves at the interface with the air, gives the compound a highly hydrophobic character, as indicated by the result of the water vapor sorption analysis in the dynamic regime, as well as the shape and stability of the water droplet on the crystalline mass of the compound. The compound is an electrical insulator, and due to its hydrophobicity, this characteristic is unaffected by environmental dampness. The thermal analysis indicated thermal stability up to about 300 °C and an unusual thermal transition for an MOF structure, more precisely a glass transition at 24 °C, the latter also being attributed to the flexible segments in the structure. The magnetic studies showed dominant antiferromagnetic interactions along the metal ion chain in compound 1. Full article

(This article belongs to the Special Issue Inorganics: 10th Anniversary)

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12 pages, 3405 KiB

Open AccessArticle

Association of Keplerate-Type Polyoxometalate {Mo₇₂Fe₃₀} with Tetracycline: Nature of Binding Sites and Antimicrobial Action

by Kirill Grzhegorzhevskii, Margarita Tonkushina, Pavel Gushchin, Ilya Gagarin, Alexander Ermoshin, Kseniya Belova, Anna Prokofyeva, Alexander Ostroushko and Alexander Novikov

Inorganics 2023, 11(1), 9; https://doi.org/10.3390/inorganics11010009 - 25 Dec 2022

Cited by 3 | Viewed by 2249

Abstract

The association process between the tetracycline (TC) antibiotic molecule and Keplerate-type nanocluster polyoxometalate (POM) {Mo₇₂Fe₃₀} was studied in aqueous solution. The novel supramolecular ensemble {Mo₇₂Fe₃₀}@TC_12.5 was produced, its composition and structure were revealed by [...] Read more.

The association process between the tetracycline (TC) antibiotic molecule and Keplerate-type nanocluster polyoxometalate (POM) {Mo₇₂Fe₃₀} was studied in aqueous solution. The novel supramolecular ensemble {Mo₇₂Fe₃₀}@TC_12.5 was produced, its composition and structure were revealed by means of elemental analysis (C, N, H) and vibrational spectroscopy (IR and Raman). Based on the spectral data, the POM structure’s integrity was confirmed and binding sites of TC with the Keplerate {Mo₇₂Fe₃₀} surface were found. Due to thermogravimetric analysis (TG) and in-situ Raman spectroscopy during the process of {Mo₇₂Fe₃₀}@TC_12.5 thermal destruction, we showed a significant change in the phase composition of POM’s destruction products after association with TC. The antibacterial activity of the obtained complex {Mo₇₂Fe₃₀}@TC_12.5 was examined. The experimental results allowed us to note the partial inhibition of TC’s antibacterial activity owing to the coordination of TC to Fe^III centers, in turn, which hinders the participation of TC in coordination via Mg²⁺ of ribosomal subunits 30S in bacteria. Full article

(This article belongs to the Special Issue Inorganics: 10th Anniversary)

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16 pages, 2488 KiB

Open AccessArticle

Hydrogen Evolution Reaction, Electrochemical CO₂ Reduction, and Oxidative Photodegradation of Organic Dyes Catalyzed by Co(II) Trimethoxy-Meso-Arylporphyrin

by Mouhieddinne Guergueb, Azhar Kechiche, Frédérique Loiseau, Florian Molton, Habib Nasri, Johannes Hohnsen and Axel Klein

Inorganics 2023, 11(1), 6; https://doi.org/10.3390/inorganics11010006 - 22 Dec 2022

Viewed by 2175

Abstract

In search of robust catalysts for redox transformations such as the hydrogen evolution reaction (HER) or CO₂ to CO reduction, we stepped on the previously reported meso-tetrakis(3,4,5-trimethoxyphenyl)porphyrinato cobalt(II) complex [Co(TTMPP)]. We prepared [Co(TTMPP)] in good yields and characterized it by IR, [...] Read more.

In search of robust catalysts for redox transformations such as the hydrogen evolution reaction (HER) or CO₂ to CO reduction, we stepped on the previously reported meso-tetrakis(3,4,5-trimethoxyphenyl)porphyrinato cobalt(II) complex [Co(TTMPP)]. We prepared [Co(TTMPP)] in good yields and characterized it by IR, UV-vis absorption, photoluminescence spectroscopy, and cyclic voltammetry (CV). The [Co(TTMPP)] was used as a homogeneous catalyst for the electrochemical formation of H₂ (HER) in DMF (N,N’-dimethylformamide)/TFA (trifluoroacetic acid) and DMF/EtN₃BF₄ solutions, with high faradic efficiencies (FE). Additionally, the reduction of CO₂ to CO in DMF under a CO₂ atmosphere was catalyzed in DMF/TFE (TFE = 2,2,2-trifluoroethanol) and DMF/PhOH with high FE and only traces of H₂ as a by-product. Turnover frequencies of 15.80 or 9.33 s⁻¹, respectively were determined from CV experiments or controlled potential electrolysis in the presence of 1eq. TFE. They were lower with PhOH as proton source with 13.85 or 8.31 s⁻¹, respectively. Further, [Co(TTMPP)] as a solid catalyst (suspension) allowed the photodecomposition of the organic dyes methylene blue (MB) and rhodamine B (RhB) using H₂O₂ under visible light irradiation. The photocatalyst was photostable over five cycles. A photocatalytic mechanism was proposed based on trapping experiments of reactive oxygen species. Full article

(This article belongs to the Special Issue Inorganics: 10th Anniversary)

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13 pages, 2723 KiB

Open AccessArticle

Regioselective One-Pot Synthesis of Novel Functionalized Organoselenium Compound by Bis-Alkoxyselenenylation of Alkenes with Selenium Dibromide and Alcohols

by Vladimir A. Potapov, Maxim V. Musalov, Alfiya G. Khabibulina, Arkady A. Maylyan, Tatyana N. Borodina, Sergey V. Zinchenko and Svetlana V. Amosova

Inorganics 2022, 10(12), 239; https://doi.org/10.3390/inorganics10120239 - 5 Dec 2022

Cited by 2 | Viewed by 1704

Abstract

The one-pot efficient synthesis of novel functionalized organoselenium compound by bis-alkoxyselenenylation of alkenes with selenium dibromide and alcohols was developed. The reaction of the selenium dibromide with cyclopentene or cyclohexene in the system alcohol/sodium bicarbonate/methylene chloride at room temperature afforded bis(2-alkoxycycloalkyl) selenides in [...] Read more.

The one-pot efficient synthesis of novel functionalized organoselenium compound by bis-alkoxyselenenylation of alkenes with selenium dibromide and alcohols was developed. The reaction of the selenium dibromide with cyclopentene or cyclohexene in the system alcohol/sodium bicarbonate/methylene chloride at room temperature afforded bis(2-alkoxycycloalkyl) selenides in 90–99% yields. The regioselective and efficient method for bis-alkoxylation of terminal alkenes was developed based on the addition of selenium dibromide with 1-alkenes in acetonitrile followed by refluxing of addition products in alcohols in the presence of traces of sulfuric acid. This method made it possible to selectively obtain bis(2-alkoxyalkyl) selenides in 94–98% yields. Full article

(This article belongs to the Special Issue Inorganics: 10th Anniversary)

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11 pages, 2796 KiB

Open AccessArticle

Copper Catalyst-Supported Modified Magnetic Chitosan for the Synthesis of Novel 2-Arylthio-2,3-dihydroquinazolin-4(1H)-one Derivatives via Chan–Lam Coupling

by Nastaran Ghasemi, Ali Yavari, Saeed Bahadorikhalili, Ali Moazzam, Samanehsadat Hosseini, Bagher Larijani, Aida Iraji, Shahram Moradi and Mohammad Mahdavi

Inorganics 2022, 10(12), 231; https://doi.org/10.3390/inorganics10120231 - 29 Nov 2022

Cited by 7 | Viewed by 1694

Abstract

In this paper, magnetic chitosan is used as a support for the immobilization of copper catalyst (Cu@MChit). The fabricated catalyst is successfully synthesized and characterized by several techniques. The activity of Cu@MChit catalyst is evaluated in the synthesis of novel derivatives of 3-alkyl-2-arylthio-2,3-dihydroquinazolin-4(1 [...] Read more.

In this paper, magnetic chitosan is used as a support for the immobilization of copper catalyst (Cu@MChit). The fabricated catalyst is successfully synthesized and characterized by several techniques. The activity of Cu@MChit catalyst is evaluated in the synthesis of novel derivatives of 3-alkyl-2-arylthio-2,3-dihydroquinazolin-4(1H)-ones. The products are synthesized in three simple steps via Chan–Lam coupling reaction. The synthetic route is based on the reaction of isatoic anhydride and an amine, followed by the reaction with carbon disulfide. Cu@MChit-catalyzed reaction of the obtained intermediate with phenylboronic acid leads to the desired products. The scope of the reaction is confirmed by using various amine and phenylboronic acid derivatives and the products are obtained in high isolated yields. Full article

(This article belongs to the Special Issue Inorganics: 10th Anniversary)

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12 pages, 2878 KiB

Open AccessArticle

Microstructural Investigations of VO₂ Thermochromic Thin Films Grown by Pulsed Laser Deposition for Smart Windows Applications

by Ayushi Rai, Nicusor Iacob, Aurel Leca, Claudiu Locovei, Victor Kuncser, Cristian N. Mihailescu and Andreas Delimitis

Inorganics 2022, 10(12), 220; https://doi.org/10.3390/inorganics10120220 - 24 Nov 2022

Cited by 3 | Viewed by 2073

Abstract

The structural properties of VO₂ thin films, grown on either LSAT or Si substrates by pulsed laser deposition (PLD), are elucidated by means of transmission electron microscopy (TEM) methods. The TEM observations confirmed the successful growth of VO₂ by PLD in [...] Read more.

The structural properties of VO₂ thin films, grown on either LSAT or Si substrates by pulsed laser deposition (PLD), are elucidated by means of transmission electron microscopy (TEM) methods. The TEM observations confirmed the successful growth of VO₂ by PLD in variable thicknesses, by optimizing the O₂ partial pressure and growth temperature. The films adopt a columnar polycrystalline morphology with narrow columns, up to the film thickness height. Four VO₂ polymorphs have been detected by electron diffraction and high-resolution TEM (HRTEM) analysis, with M1 being by far the most abundant phase. Post-experimental strain measurements in HRTEM images have revealed that the actual residual strain is minimized due to the columnar morphology of the VO₂ grains, as well as intrinsic oxide layers in the VO₂/Si epitaxy. The TEM outcomes confirmed the complementary electrical and magnetic measurements in the films, where a transition from a monoclinic M1 to a rutile VO₂ R phase has been identified, influenced by the initial percentage of phases in thick VO₂ films. Full article

(This article belongs to the Special Issue Inorganics: 10th Anniversary)

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13 pages, 3963 KiB

Open AccessArticle

A 2D Porous Zinc-Organic Framework Platform for Loading of 5-Fluorouracil

by Liang Qin, Fenglan Liang, Yan Li, Jiana Wu, Shiyuan Guan, Meiyin Wu, Shiling Xie, Manshi Luo and Deyun Ma

Inorganics 2022, 10(11), 202; https://doi.org/10.3390/inorganics10110202 - 9 Nov 2022

Cited by 119 | Viewed by 3047

Abstract

A hydrostable 2D Zn-based MOF, {[Zn(5-PIA)(imbm)]·2H₂O}_n (1) (5-H₂PIA = 5-propoxy-isophthalic acid, imbm = 1,4-di(1H-imidazol-1-yl)benzene), was synthesized and structurally characterized. Complex 1 shows good water and thermal stability based on the TGA and PXRD analyses and displays [...] Read more.

A hydrostable 2D Zn-based MOF, {[Zn(5-PIA)(imbm)]·2H₂O}_n (1) (5-H₂PIA = 5-propoxy-isophthalic acid, imbm = 1,4-di(1H-imidazol-1-yl)benzene), was synthesized and structurally characterized. Complex 1 shows good water and thermal stability based on the TGA and PXRD analyses and displays a 2D framework with 1D channels of 4.8 × 13.8 and 10.0 × 8.3 Å² along the a axis. The 5-fluorouracil (5-FU) payload in activated complex 1 (complex 1a) is 19.3 wt%, and the cumulative release value of 5-FU at 120 h was about 70.04% in PBS (pH 7.4) at 310 K. In vitro MTT assays did not reveal any cytotoxic effect of NIH-3T3 and HEK-293 cells when the concentration of 1 was below 500 μg/mL and 5 μg/mL, respectively. No morphological abnormalities were observed on zebrafish exposed to complex 1. Full article

(This article belongs to the Special Issue Inorganics: 10th Anniversary)

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12 pages, 2349 KiB

Open AccessArticle

Highly Porous Cyanometallic Spin-Crossover Frameworks Employing Pyridazino[4,5-d]pyridazine Bridge

by Volodymyr M. Hiiuk, Sergiu Shova, Kostiantyn V. Domasevitch and Il’ya A. Gural’skiy

Inorganics 2022, 10(11), 195; https://doi.org/10.3390/inorganics10110195 - 2 Nov 2022

Viewed by 1809

Abstract

Single crystals of two spin-crossover (SCO) cyanometallic coordination polymers based on the pyridazino[4,5-d]pyridazine ligand (pp) of the composition [Fe(pp)M(CN)₄]∙G (where M = Pd, Pt; G = guest molecules) were obtained by a slow diffusion technique. A single-crystal [...] Read more.

Single crystals of two spin-crossover (SCO) cyanometallic coordination polymers based on the pyridazino[4,5-d]pyridazine ligand (pp) of the composition [Fe(pp)M(CN)₄]∙G (where M = Pd, Pt; G = guest molecules) were obtained by a slow diffusion technique. A single-crystal X-ray analysis showed that both compounds adopted the structure of porous 3D frameworks, consisting of heterometallic cyano-bridged layers and interlayer pillar pp ligands, with a total solvent accessible volume of ca. 160 Å³ per iron(II) ion (about 37% of the unit cell volume). These frameworks displayed hysteretic SCO behaviour with T_1/2 of 150/190 K (heating/cooling) for Pd complex and 135/170 K (heating/cooling) for Pt complex, which was confirmed by variable-temperature SCXRD experiments. This research shows the perspective of using pp ligand for building porous MOFs with spin transitions. Full article

(This article belongs to the Special Issue Inorganics: 10th Anniversary)

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14 pages, 3620 KiB

Open AccessArticle

Trivalent Cobalt Complexes with NNS Tridentate Thiosemicarbazones: Preparation, Structural Study and Investigation of Antibacterial Activity and Cytotoxicity against Human Breast Cancer Cells

by Amany Fathy, Ahmed B. M. Ibrahim, S. Abd Elkhalik, Alexander Villinger and S. M. Abbas

Inorganics 2022, 10(9), 145; https://doi.org/10.3390/inorganics10090145 - 19 Sep 2022

Cited by 7 | Viewed by 1855

Abstract

New complexes of trivalent cobalt with substituted thiosemicarbazone ligands having an NNS donor system {HL¹ = 4-(4-nitrophenyl)-1-((pyridin-2-yl)methylene)thiosemicarbazide and HL² = 4-(2,5-dimethoxyphenyl)-1-((pyridin-2-yl)methylene)thiosemicarbazide} were synthesized via the in situ oxidation of divalent cobalt chloride accompanying its addition to the ligands. The complexes [...] Read more.

New complexes of trivalent cobalt with substituted thiosemicarbazone ligands having an NNS donor system {HL¹ = 4-(4-nitrophenyl)-1-((pyridin-2-yl)methylene)thiosemicarbazide and HL² = 4-(2,5-dimethoxyphenyl)-1-((pyridin-2-yl)methylene)thiosemicarbazide} were synthesized via the in situ oxidation of divalent cobalt chloride accompanying its addition to the ligands. The complexes C1 and C2 were characterized via elemental (CHNS) analysis and ¹H NMR, FT-IR and UV-Vis. spectroscopic data. Further, conductometric studies on the DMF solutions of the complexes indicated their 1:1 nature, and their diamagnetism revealed the low-spin trivalent oxidation state of the cobalt in the complexes. The X-ray diffraction analysis of complex C1 indicated that it crystallizes in the triclinic space group P-1. The metal exhibits an octahedral environment built by two anionic ligands bound via pyridine nitrogen, imine nitrogen and thiol sulfur atoms. The complex is counterbalanced by a chloride ion. In addition, two lattice water molecules were detected in the asymmetric unit of the unit cell. The ligand HL² (20 mg/mL in DMSO) displayed inhibition zones of 10 mm against both S. aureus and E. coli, and the same concentration of the respective complex raised this activity to 15 and 12 mm against these bacterial strains, respectively. As a comparison, ampicillin inhibited these bacterial strains by 21 and 25 mm, respectively. Screening assay by HL¹ on four human cancer cells revealed the most enhanced activity against the breast MCF-7 cells. The induced growth inhibitions in the MCF-7 cells by all compounds (0–100 μg/mL) have been detected. The ligands {HL¹ and HL²} and complex C2 gave inhibitions with IC₅₀ values of 52.4, 145.4 and 49.9 μM, respectively. These results are more meaningful in comparison with similar cobalt complexes, but less efficient compared with the inhibition with IC₅₀ of 9.66 μM afforded by doxorubicin. In addition, doxorubicin, HL¹ and HL² induced cytotoxicity towards healthy BHK cells with IC₅₀ values of 36.42, 54.8 and 110.6 μM, but surviving fractions of 66.1% and 62.7% of these cells were detected corresponding to a concentration of 100 μg/mL of the complexes (136.8 μM of C1 and 131.4 μM of C2). Full article

(This article belongs to the Special Issue Inorganics: 10th Anniversary)

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11 pages, 3824 KiB

Open AccessArticle

High-Temperature Interactions of Silicon-Aluminum Oxynitrides (Sialons) with Sodium Fluoride

by Nailya S. Akhmadullina, Vladimir P. Sirotinkin, Nikolay A. Ovsyannikov, Anton S. Lysenkov and Yury F. Kargin

Inorganics 2022, 10(9), 140; https://doi.org/10.3390/inorganics10090140 - 16 Sep 2022

Cited by 2 | Viewed by 1732

Abstract

The high-temperature interactions of β-SiAlONs with sodium fluoride NaF at 1650 °C under a nitrogen atmosphere are described in this paper. It was found that in case of Si₅AlON₇ the formation of phases enriched with aluminum occurred, including Si₄ [...] Read more.

The high-temperature interactions of β-SiAlONs with sodium fluoride NaF at 1650 °C under a nitrogen atmosphere are described in this paper. It was found that in case of Si₅AlON₇ the formation of phases enriched with aluminum occurred, including Si₄Al₂O₂N₆ at an NaF loading of 0.5 wt.% and Si₄Al₂O₂N₆ and Si_3.1Al_2.9O_2.9N_5.1 at an NaF loading of 2.0 wt.%, although Si₅AlON₇ still was a major phase. For Si₄Al₂O₂N₆, a kind of disproportionation was observed, and Si₅AlON₇ formed together with Si₃Al₃O₃N₅ and Si_3.1Al_2.9O_2.9N_5.1. Moreover, the initial phase Si₄Al₂O₂N₆ was not identified at all, while Si₅AlON₇ was found to be a major phase at an NaF loading of 0.5 wt.% and Si_3.1Al_2.9O_2.9N_5.1 prevailed at an NaF loading of 2.0 wt.%. All the samples showed a high degree of densification when studied with scanning electronic microscopy. Full article

(This article belongs to the Special Issue Inorganics: 10th Anniversary)

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16 pages, 4686 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

The Crystal Structure of Carbonic Acid

by Sebastian Benz, Da Chen, Andreas Möller, Michael Hofmann, David Schnieders and Richard Dronskowski

Inorganics 2022, 10(9), 132; https://doi.org/10.3390/inorganics10090132 - 3 Sep 2022

Cited by 6 | Viewed by 9187

Abstract

Ubiquitous carbonic acid, H₂CO₃, a key molecule in biochemistry, geochemistry, and also extraterrestrial chemistry, is known from a plethora of physicochemical studies. Its crystal structure has now been determined from neutron-diffraction data on a deuterated sample in a specially [...] Read more.

Ubiquitous carbonic acid, H₂CO₃, a key molecule in biochemistry, geochemistry, and also extraterrestrial chemistry, is known from a plethora of physicochemical studies. Its crystal structure has now been determined from neutron-diffraction data on a deuterated sample in a specially built hybrid clamped cell. At 1.85 GPa, D₂CO₃ crystallizes in the monoclinic space group P2₁/c with a = 5.392(2), b = 6.661(4), c = 5.690(1) Å, β = 92.66(3)°, Z = 4, with one symmetry-inequivalent anti-anti shaped D₂CO₃ molecule forming dimers, as previously predicted. Quantum chemistry evidences π bonding within the CO₃ molecular core, very strong hydrogen bonding between the molecules, and a massive influence of the crystal field on all bonds; phonon calculations emphasize the locality of the vibrations, being rather insensitive to the extended structure. Full article

(This article belongs to the Special Issue Inorganics: 10th Anniversary)

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13 pages, 3196 KiB

Open AccessArticle

Facile Construction of Bi₂Sn₂O₇/g-C₃N₄ Heterojunction with Enhanced Photocatalytic Degradation of Norfloxacin

by Zhengru Zhu, Haiwen Xia, Hong Li and Songlin Han

Inorganics 2022, 10(9), 131; https://doi.org/10.3390/inorganics10090131 - 1 Sep 2022

Cited by 13 | Viewed by 2233

Abstract

To mitigate antibiotic residues in the water environment, Bi₂Sn₂O₇/g-C₃N₄ (BSCN) heterojunction was fabricated by a facile ultrasound-assisted hydrothermal method. The microstructure, morphology, and optical properties of Bi₂Sn₂O₇/g-C₃ [...] Read more.

To mitigate antibiotic residues in the water environment, Bi₂Sn₂O₇/g-C₃N₄ (BSCN) heterojunction was fabricated by a facile ultrasound-assisted hydrothermal method. The microstructure, morphology, and optical properties of Bi₂Sn₂O₇/g-C₃N₄ heterojunction was studied by XRD, FTIR, XPS, SEM, TEM, UV–Vis DRS, and PL. The degradation rate of 20 mg/L norfloxacin (NOR) under visible light for 3 h was adopted as one of the indexes to evaluate the photocatalytic performance of Bi₂Sn₂O₇/g-C₃N₄ heterojunction. Embellished with 20% Bi₂Sn₂O₇ (BSO), the Bi₂Sn₂O₇/g-C₃N₄ heterojunction decomposed 94% NOR in the experimental solution, which was 2.35 and 3.03 times as much as pristine g-C₃N₄ and bare Bi₂Sn₂O₇, respectively. In addition, the Bi₂Sn₂O₇/g-C₃N₄ heterojunction still eliminated 89% of NOR after five cycles, portending outstanding stability and cyclability of photocatalytic activity. A possible photocatalytic mechanism of Bi₂Sn₂O₇/g-C₃N₄ heterojunction for NOR degradation is proposed. Full article

(This article belongs to the Special Issue Inorganics: 10th Anniversary)

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13 pages, 3288 KiB

Open AccessArticle

Effect of CuO Loading on the Photocatalytic Activity of SrTiO₃ for Hydrogen Evolution

by Xuan Truong Mai, Duc Nguyen Bui, Van Khang Pham, Thi Hien Lan Nguyen, Thi To Loan Nguyen, Hung Dung Chau and Thi Kim Ngan Tran

Inorganics 2022, 10(9), 130; https://doi.org/10.3390/inorganics10090130 - 31 Aug 2022

Cited by 12 | Viewed by 1898

Abstract

A CuO-loaded SrTiO₃ catalyst showed highly photocatalytic activity for H₂ evolution. This catalyst was prepared by an impregnation method and characterized by XRD, TEM, BET, XPS, Uv-vis DRS and PL techniques. Under optimum conditions, the best rate of H₂ evolution [...] Read more.

A CuO-loaded SrTiO₃ catalyst showed highly photocatalytic activity for H₂ evolution. This catalyst was prepared by an impregnation method and characterized by XRD, TEM, BET, XPS, Uv-vis DRS and PL techniques. Under optimum conditions, the best rate of H₂ evolution of the CuO-loaded SrTiO₃ catalyst is 5811 µmol h⁻¹g⁻¹, whereas it is a mere 34 µmol h⁻¹g⁻¹ for the pure SrTiO₃. High efficiency, low cost and good stability are some of the merits that underline the promising potential of CuO-loaded SrTiO₃ in the photocatalytic hydrogen. Full article

(This article belongs to the Special Issue Inorganics: 10th Anniversary)

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12 pages, 4393 KiB

Open AccessArticle

Rearrangement of Diferrocenyl 3,4-Thiophene Dicarboxylate

by Asma Ghazzy, Deeb Taher, Marcus Korb, Khaled Al Khalyfeh, Wissam Helal, Hazem Amarne, Tobias Rüffer, Zakariyya Ishtaiwi and Heinrich Lang

Inorganics 2022, 10(7), 96; https://doi.org/10.3390/inorganics10070096 - 6 Jul 2022

Cited by 6 | Viewed by 1815

Abstract

Treatment of 3,4-(ClC(O))₂-^cC₄H₂S (1) with [FcCH₂OLi] (2-Li) (Fc = Fe(η⁵-C₅H₅)(η⁵-C₅H₄)) in a 1:2 ratio gave 3,4-(FcCH₂ [...] Read more.

Treatment of 3,4-(ClC(O))₂-^cC₄H₂S (1) with [FcCH₂OLi] (2-Li) (Fc = Fe(η⁵-C₅H₅)(η⁵-C₅H₄)) in a 1:2 ratio gave 3,4-(FcCH₂OC(O))₂-^cC₄H₂S (3). Compound 3 decomposes in solution during crystallization to produce FcCH₂OH (2) along with 3,4-thiophenedicarboxylic anhydride (4). The cyclic voltammogram of 3 exhibits a reversible ferrocene-related redox couple (E_1/₂ = 108 mV, vs. Cp₂Fe/Cp₂Fe⁺) using [NⁿBu₄] [B(C₆F₅)₄] as the supporting electrolyte. DFT calculations reveal that the energy values of the LUMO orbitals of 3 (3,4-thiophene core) show 1 eV higher energies than that one of 2,5-(FcCH₂OC(O))₂-^cC₄H₂S (5), both compounds’ HOMO orbitals are close to each other. Compound 4 was characterized by single X-ray structure analysis. It forms a band-type structure based on intermolecular O1···S1 interactions being parallel to (110) and (1–10) in the solid state, while electrostatic C···O interactions between the C=O functionalities of adjacent molecules connect both 3D-networks. Hirshfeld surface analysis was used to gain more insight into the intermolecular interactions in 4, the enrichment ratios (E) suggest that O···H, S···S, and O···C are the most favored intermolecular interactions, as shown by E values above 1.20. The relevance of the weak O···H, O···O, and O···C contacts in stabilizing the molecular structure of 4 was highlighted by the interaction energies between molecular pairs. Full article

(This article belongs to the Special Issue Inorganics: 10th Anniversary)

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17 pages, 3527 KiB

Open AccessArticle

Synthesis, Structures and Chemical Reactivity of Dithiolato-Bridged Ni-Fe Complexes as Biomimetics for the Active Site of [NiFe]-Hydrogenases

by Li-Cheng Song, Shuai Chen, Xiao-Feng Han, Zhen-Qing Zhang, Yin-Peng Wang and Yi-Xiong Dong

Inorganics 2022, 10(7), 90; https://doi.org/10.3390/inorganics10070090 - 24 Jun 2022

Cited by 2 | Viewed by 1805

Abstract

To develop the structural and functional modeling chemistry of [NiFe]-H₂ases, we have carried out a study regarding the synthesis, structural characterization and reactivity of a new series of [NiFe]-H₂ase model complexes. Thus, treatment of diphosphine dppb-chelated Ni complex (dppb)NiCl [...] Read more.

To develop the structural and functional modeling chemistry of [NiFe]-H₂ases, we have carried out a study regarding the synthesis, structural characterization and reactivity of a new series of [NiFe]-H₂ase model complexes. Thus, treatment of diphosphine dppb-chelated Ni complex (dppb)NiCl₂ (dppb = 1,2-(Ph₂P)₂C₆H₄) with (dppv)Fe(CO)₂(pdt) (dppv = 1,2-(Ph₂P)₂C₂H₂, pdt = 1,3-propanedithiolate) and NaBF₄ gave dicarbonyl complex [(dppb)Ni(pdt)Fe(CO)₂(dppv)](BF₄)₂ ([A](BF₄)₂). Further treatment of [A](BF₄)₂ with Me₃NO and Bu₄NCN or KSCN afforded t-cyanido and t-isothiocyanato complexes [(dppb)Ni(pdt)Fe(CO)(t-R)(dppv)]BF₄ ([1]BF₄, R = CN; [2]BF₄, R = NCS), respectively. While azadiphosphine MeN(CH₂PPh₂)₂-chelated t-hydride complex [MeN(CH₂PPh₂)₂Ni(pdt)Fe(CO)(t-H)(dppv)]BF₄ ([3]BF₄) was prepared by treatment of dicarbonyl complex [MeN(CH₂PPh₂)₂Ni(pdt)Fe(CO)₂(dppv)](BF₄)₂ ([B](BF₄)₂) with Me₃NO and 1.5 MPa of H₂, treatment of dicarbonyl complex [B](BF₄)₂ with Me₃NO (without H₂) in pyridine resulted in formation of a novel monocarbonyl complex [MeN(CH₂PPh₂)₂Ni(SCHCH₂CH₂S)Fe(CO)(dppv)]BF₄ ([4]BF₄) via the unexpected sp³ C-H bond activation reaction. Furthermore, azadiphosphine PhN(CH₂PPh₂)₂-chelated µ-mercapto complex [PhN(CH₂PPh₂)₂Ni(pdt)Fe(CO)(µ-SH)(dppv)]BF₄ ([5]BF₄) was prepared by treatment of dicarbonyl complex [PhN(CH₂PPh₂)₂Ni(pdt)Fe(CO)₂(dppv)](BF₄)₂ ([C](BF₄)₂) with Me₃NO and H₂S gas, whereas treatment of azadiphosphine Ph₂CHN(CH₂PPh₂)₂-chelated dicarbonyl complex [Ph₂CHN(CH₂PPh₂)₂Ni(pdt)Fe(CO)₂(dppe)](BF₄)₂ ([D](BF₄)₂, dppe = 1,2-(Ph₂P)₂C₂H₄) with Me₃NO⋅2H₂O gave rise to µ-hydroxo complex [Ph₂CHN(CH₂PPh₂)₂Ni(pdt)Fe(CO)(µ-OH)(dppe)]BF₄ ([6]BF₄). All the possible pathways for formation of the new model complexes are briefly discussed, and their structures were fully characterized by various spectroscopic techniques and for six of them by X-ray crystallography. Full article

(This article belongs to the Special Issue Inorganics: 10th Anniversary)

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12 pages, 4253 KiB

Open AccessArticle

Luminescence and Scintillation in the Niobium Doped Oxyfluoride Rb₄Ge₅O₉F₆:Nb

by Darren Carone, Vladislav V. Klepov, Scott T. Misture, Joseph C. Schaeperkoetter, Luiz G. Jacobsohn, Mina Aziziha, Juliano Schorne-Pinto, Stuart A. J. Thomson, Adrian T. Hines, Theodore M. Besmann and Hans-Conrad zur Loye

Inorganics 2022, 10(6), 83; https://doi.org/10.3390/inorganics10060083 - 16 Jun 2022

Cited by 5 | Viewed by 2437

Abstract

A new niobium-doped inorganic scintillating oxyfluoride, Rb₄Ge₅O₉F₆:Nb, was synthesized in single crystal form by high-temperature flux growth. The host structure, Rb₄Ge₅O₉F₆, crystallizes in the orthorhombic space group [...] Read more.

A new niobium-doped inorganic scintillating oxyfluoride, Rb₄Ge₅O₉F₆:Nb, was synthesized in single crystal form by high-temperature flux growth. The host structure, Rb₄Ge₅O₉F₆, crystallizes in the orthorhombic space group Pbcn with lattice parameters a = 6.98430(10) Å, b = 11.7265(2) Å, and c = 19.2732(3) Å, consisting of germanium oxyfluoride layers made up of Ge₃O₉ units connected by GeO₃F₃ octahedra. In its pure form, Rb₄Ge₅O₉F₆ shows neither luminescence nor scintillation but when doped with niobium, Rb₄Ge₅O₉F₆:Nb exhibits bright blue luminescence and scintillation. The isostructural doped structure, Rb₄Ge₅O₉F₆:Nb, crystallizes in the orthorhombic space group Pbcn with lattice parameters a = 6.9960(3) Å, b = 11.7464(6) Å, and c = 19.3341(9) Å. X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) measurements suggest that the niobium is located in an octahedral coordination environment. Optical measurements inform us that the niobium dopant acts as the activator. The synthesis, structure, and optical properties are reported, including radioluminescence (RL) measurements under X-ray irradiation. Full article

(This article belongs to the Special Issue Inorganics: 10th Anniversary)

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14 pages, 2312 KiB

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Electron-Deficient Ru(II) Complexes as Catalyst Precursors for Ethylene Hydrophenylation

by Xiaofan Jia, Songyuan Tian, Philip J. Shivokevich, W. Dean Harman, Diane A. Dickie and T. Brent Gunnoe

Inorganics 2022, 10(6), 76; https://doi.org/10.3390/inorganics10060076 - 31 May 2022

Cited by 4 | Viewed by 2554

Abstract

Ruthenium(II) complexes with the general formula TpRu(L)(NCMe)Ph (Tp = hydrido(trispyrazolyl)borate, L = CO, PMe₃, P(OCH₂)₃CEt, P(pyr)₃, P(OCH₂)₂(O)CCH₃) have previously been shown to catalyze arene alkylation via Ru-mediated arene C–H [...] Read more.

Ruthenium(II) complexes with the general formula TpRu(L)(NCMe)Ph (Tp = hydrido(trispyrazolyl)borate, L = CO, PMe₃, P(OCH₂)₃CEt, P(pyr)₃, P(OCH₂)₂(O)CCH₃) have previously been shown to catalyze arene alkylation via Ru-mediated arene C–H activation including the conversion of benzene and ethylene to ethylbenzene. Previous studies have suggested that the catalytic performance of these TpRu(II) catalysts increases with reduced electron-density at the Ru center. Herein, three new structurally related Ru(II) complexes are synthesized, characterized, and studied for possible catalytic benzene ethylation. TpRu(NO)Ph₂ exhibited low stability due to the facile elimination of biphenyl. The Ru(II) complex (Tp^Br3)Ru(NCMe)(P(OCH₂)₃CEt)Ph (Tp^Br3 = hydridotris(3,4,5-tribromopyrazol-1-yl)borate) showed no catalytic activity for the conversion of benzene and ethylene to ethylbenzene, likely due to the steric bulk introduced by the bromine substituents. (Ttz)Ru(NCMe)(P(OCH₂)₃CEt)Ph (Ttz = hydridotris(1,2,4-triazol-1-yl)borate) catalyzed approximately 150 turnover numbers (TONs) of ethylbenzene at 120 °C in the presence of Lewis acid additives. Here, we compare the activity and features of catalysis using (Ttz)Ru(NCMe)(P(OCH₂)₃CEt)Ph to previously reported catalysis based on TpRu(L)(NCMe)Ph catalyst precursors. Full article

(This article belongs to the Special Issue Inorganics: 10th Anniversary)

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13 pages, 4397 KiB

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Regio- and Stereoselective Synthesis of (Z,Z)-Bis(3-amino-3-oxo-1-propenyl) Selenides and Diselenides Based on 2-propynamides: A Novel Family of Diselenides with High Glutathione Peroxidase-like Activity

by Vladimir A. Potapov, Mikhail V. Andreev, Maxim V. Musalov, Irina V. Sterkhova, Svetlana V. Amosova and Lyudmila I. Larina

Inorganics 2022, 10(6), 74; https://doi.org/10.3390/inorganics10060074 - 30 May 2022

Cited by 3 | Viewed by 1903

Abstract

The efficient regio- and stereoselective syntheses of (Z,Z)-bis(3-amino-3-oxo-1-propenyl) selenides and diselenides in high yields based on the nucleophilic addition of sodium selenide to 2-propynamides and sodium diselenide to 3-(trimethylsilyl)-2-propynamides have been developed. The first examples of the addition of a selenium-centered nucleophile to [...] Read more.

The efficient regio- and stereoselective syntheses of (Z,Z)-bis(3-amino-3-oxo-1-propenyl) selenides and diselenides in high yields based on the nucleophilic addition of sodium selenide to 2-propynamides and sodium diselenide to 3-(trimethylsilyl)-2-propynamides have been developed. The first examples of the addition of a selenium-centered nucleophile to 2-propynamides with a terminal triple bond and diselenide anion to 3-(trimethylsilyl)-2-propynamides have been carried out. Bis(3-amino-3-oxo-1-propenyl) diselenides are a novel family of compounds, none of which has yet been described in the literature. The glutathione peroxidase-like activity of the obtained compounds has been evaluated and products with high activity have been found. It was established that diselenides are superior to selenides with the same substituents in glutathione peroxidase-like activity. The results of the structural studying of products by single-crystal X-ray diffraction analysis and ⁷⁷Se-NMR data are discussed. Full article

(This article belongs to the Special Issue Inorganics: 10th Anniversary)

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11 pages, 3714 KiB

Open AccessArticle

Kinetic Control of Anion Stoichiometry in Hexagonal BaTiO₃

by Keisuke Kageyama, Yang Yang, Toki Kageyama, Kantaro Murayama, Kazuki Shitara, Takashi Saito, Hiroki Ubukata, Cédric Tassel, Akihide Kuwabara and Hiroshi Kageyama

Inorganics 2022, 10(6), 73; https://doi.org/10.3390/inorganics10060073 - 27 May 2022

Viewed by 2788

Abstract

The cubic oxyhydride perovskite BaTiO_3−xH_x, where the well-known ferroelectric oxide BaTiO₃ is partially hydridized, exhibits a variety of functions such as being a catalyst and precursor for the synthesis of mixed-anion compounds by utilizing the labile nature [...] Read more.

The cubic oxyhydride perovskite BaTiO_3−xH_x, where the well-known ferroelectric oxide BaTiO₃ is partially hydridized, exhibits a variety of functions such as being a catalyst and precursor for the synthesis of mixed-anion compounds by utilizing the labile nature of hydride anions. In this study, we present a hexagonal version, BaTi(O_3−xH_x) (x < 0.6) with the 6H-type structure, synthesized by a topochemical reaction using hydride reduction, unlike reported hexagonal oxyhydrides obtained under high pressure. The conversion of cubic BaTiO₃ (150 nm) to the hexagonal phase by heat treatment at low temperature (950~1025 °C) using a Mg getter allows the introduction of large oxygen defects (BaTiO_3−x; x − 0.28) while preventing the crystal growth of hexagonal BaTiO₃, which has been accessible at high temperatures of ~1500 °C, contributing to the increase of the hydrogen content. Hydride anions in 6H-BaTiO_3−xH_x preferentially occupy face-sharing sites, as do other oxyhydrides. Full article

(This article belongs to the Special Issue Inorganics: 10th Anniversary)

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30 pages, 4112 KiB

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MOFs for Electrochemical Energy Conversion and Storage

by Claudio Pettinari and Alessia Tombesi

Inorganics 2023, 11(2), 65; https://doi.org/10.3390/inorganics11020065 - 30 Jan 2023

Cited by 18 | Viewed by 5783

Abstract

Metal organic frameworks (MOFs) are a family of crystalline porous materials which attracts much attention for their possible application in energy electrochemical conversion and storage devices due to their ordered structures characterized by large surface areas and the presence in selected cases of [...] Read more.

Metal organic frameworks (MOFs) are a family of crystalline porous materials which attracts much attention for their possible application in energy electrochemical conversion and storage devices due to their ordered structures characterized by large surface areas and the presence in selected cases of a redox-active porous skeleton. Their synthetic versatility and relevant host-guest chemistry make them suitable platform for use in stable and flexible conductive materials. In this review we summarize the most recent results obtained in this field, by analyzing the use of MOFs in fuel and solar cells with special emphasis on PEMFCs and PSCs, their application in supercapacitors and the employment in batteries by differentiating Li-, Na- and other metal ion-batteries. Finally, an overview of the water splitting reaction MOF-catalyzed is also reported. Full article

(This article belongs to the Special Issue Inorganics: 10th Anniversary)

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20 pages, 17074 KiB

Open AccessReview

The Role of Inorganic Fillers in Electrostatic Discharge Composites

by Roberto Nisticò, Massimiliano D’Arienzo, Barbara Di Credico, Silvia Mostoni and Roberto Scotti

Inorganics 2022, 10(12), 222; https://doi.org/10.3390/inorganics10120222 - 25 Nov 2022

Cited by 2 | Viewed by 2640

Abstract

The occurrence of uncontrolled electrostatic discharge (ESD) is among the major causes of damage in unprotected electronic components during industrial processes. To counteract this undesired phenomenon, ESD composites showing static-dissipative and antistatic responses are developed. In particular, static-dissipative materials are able to slow [...] Read more.

The occurrence of uncontrolled electrostatic discharge (ESD) is among the major causes of damage in unprotected electronic components during industrial processes. To counteract this undesired phenomenon, ESD composites showing static-dissipative and antistatic responses are developed. In particular, static-dissipative materials are able to slow down the flow of electric charges, whereas antistatic materials directly suppress the initial charges induced by undesired charging by properly dispersing conductive fillers within an insulant matrix and thus forming a conductive filler network. In this context, the purpose of this review is to provide a useful resume of the main fundamentals of the technology necessary for facing electrostatic charging. The formation mechanisms of electrostatic charges at the material surface were described, providing a classification of ESD composites and useful characterization methods. Furthermore, we reported a deep analysis of the role of conductive fillers in the formation of filler networks to allow electric charge movements, along with an overview of the different classes of inorganic conductive fillers exploitable in ESD composites, evidencing pros/cons and criticalities of each category of inorganic fillers. Full article

(This article belongs to the Special Issue Inorganics: 10th Anniversary)

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