Inorganics

17 pages, 2953 KiB

Open AccessReview

Cyclodextrins’ Internal Cavity Hydration: Insights from Theory and Experiment

by Silvia Angelova, Stiliyana Pereva, Todor Dudev and Tony Spassov

Inorganics 2025, 13(1), 28; https://doi.org/10.3390/inorganics13010028 - 20 Jan 2025

Viewed by 420

In this short review, recent findings from both theory and experiment regarding the process of hydration of α-, β-, and γ-cyclodextrins are summarized and critically assessed. Key important questions are addressed, including: What factors govern the number of water molecules entrapped in the [...] Read more.

In this short review, recent findings from both theory and experiment regarding the process of hydration of α-, β-, and γ-cyclodextrins are summarized and critically assessed. Key important questions are addressed, including: What factors govern the number of water molecules entrapped in the internal cavity of the host macrocycle? What is the driving force behind this process? What are the “hot spots” for water entrapment inside the host cavity? What is the underlying mechanism of water hydration and dehydration of cyclodextrins? What is the role of the confined water cluster in determining the outcome of the host–guest complexation between cyclodextrins and molecules of inorganic/organic nature? To what extent does water hydration affect the crystalline structure of the cavitand? Full article

► Show Figures

Graphical abstract

24 pages, 5030 KiB

Open AccessArticle

^EtIDip (^EtIPr)—Synthesis, Characterisation and Reactivity of a Robust, Backbone-Modified N-Heterocyclic Carbene and Group 13 Element Complexes

by Huanhuan Dong, Albert Martinez-Segura, Riley W. Kelehan, Connor Bourne, Aidan P. McKay, Alexandra M. Z. Slawin, David B. Cordes and Andreas Stasch

Inorganics 2025, 13(1), 27; https://doi.org/10.3390/inorganics13010027 - 17 Jan 2025

Viewed by 531

Abstract

We report the synthesis, characterisation and reactivity of the stable imidazol-2-ylidene ^EtIDip (^EtIPr), {EtCN(Dip)}₂C:, Dip = 2,6-iPr₂C₆H₃, as a chemically robust alternative to IDip (IPr), {HCN(Dip)}₂C:. The N-heterocyclic [...] Read more.

We report the synthesis, characterisation and reactivity of the stable imidazol-2-ylidene ^EtIDip (^EtIPr), {EtCN(Dip)}₂C:, Dip = 2,6-iPr₂C₆H₃, as a chemically robust alternative to IDip (IPr), {HCN(Dip)}₂C:. The N-heterocyclic carbene ^EtIDip could be further converted to the oxidised species [^EtIDipCl]Cl, ^EtIDipF₂, ^EtIDipO, and ^EtIDipSe, and the group 13 element complexes ^EtIDipEX₃, with E = B, X = Br; E = Al, X = I; E = Ga, X = I; E = Al, X = H. The properties of the ^EtIDip and IDip ligands are compared and the molecular structures of (DipNCEt)₂, [^EtIDipH]Cl, [^EtIDipH]I, ^EtIDip, [^EtIDipCl]Cl, ^EtIDipF₂, ^EtIDipO, ^EtIDipBBr₃, ^EtIDipAlI₃, ^EtIDipGaI₃, and ^EtIDipAlH₃ have been determined. Full article

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

► Show Figures

Graphical abstract

14 pages, 5173 KiB

Open AccessArticle

Synthesis, Characterization, and Cytotoxicity Research of Sulfur-Containing Metal Complexes

by Yanting Yang, Danqin Li and Mei Luo

Inorganics 2025, 13(1), 26; https://doi.org/10.3390/inorganics13010026 - 17 Jan 2025

Viewed by 363

Abstract

In this experiment, the excellent coordination ability of sulfur-containing ligands was utilized. Diphenylacetyl disulfide and 3,3′-diaminodiphenyl sulfone were selected as ligands, and Cu(NO₃)₂·3H₂O, Ni(NO₃)₂·6H₂O and ZnCl₂ were reacted under one-pot [...] Read more.

In this experiment, the excellent coordination ability of sulfur-containing ligands was utilized. Diphenylacetyl disulfide and 3,3′-diaminodiphenyl sulfone were selected as ligands, and Cu(NO₃)₂·3H₂O, Ni(NO₃)₂·6H₂O and ZnCl₂ were reacted under one-pot conditions to synthesize three mononuclear complexes: [C₄H₁₈CuO₁₂S₂](I), [C₁₂H₁₈N₄NiO₁₁S](II) and [C₂₄H₂₄Cl₂N₄O₄S₂Zn](III). Complex (I) belongs to the orthorhombic crystal system with space group Pbca, while complexes (II) and (III) belong to the monoclinic crystal system with space groups P21/n and P2/n. The crystal structure of the complex was determined using X-ray diffraction (XRD). The structure of the complex was analyzed using infrared Fourier transform infrared spectroscopy (FT-IR), ultraviolet–visible spectroscopy (UV–Vis), nuclear magnetic resonance (NMR), and electrospray mass spectrometry (ESI-MS), and the thermal stability and composition of the complex were detected via thermogravimetry (TGA). In terms of application, the biological activity of complexes (I)–(III) in human cancer cell lines (lung cancer A549, liver cancer SMMC-7721, breast cancer MDA-MB-231, and colon cancer SW480) was tested using the MTS method. The results showed that complex (II) had a good inhibitory effect on breast cancer MDA-MB-231. Full article

(This article belongs to the Special Issue Metal Complexes Containing Bioactive Ligands: Structure and Biological Evaluation)

► Show Figures

Figure 1

12 pages, 3093 KiB

Open AccessArticle

Tetrazenyl-, Imido-, and Azidoaluminate Derivatives of a Sterically Demanding Bis-Silazide Ligand

by Han-Ying Liu, Ryan J. Schwamm, Jakub Kenar, Mary F. Mahon and Michael S. Hill

Inorganics 2025, 13(1), 25; https://doi.org/10.3390/inorganics13010025 - 16 Jan 2025

Viewed by 388

Abstract

The potassium alumanyl [{SiN^Dipp}AlK]₂ (SiN^Dipp = {CH₂SiMe₂NDipp}₂; Dipp = 2,6-i-Pr₂C₆H₃) reacts with organic azides via reductive N₂ elimination. With the less sterically encumbered azides [...] Read more.

The potassium alumanyl [{SiN^Dipp}AlK]₂ (SiN^Dipp = {CH₂SiMe₂NDipp}₂; Dipp = 2,6-i-Pr₂C₆H₃) reacts with organic azides via reductive N₂ elimination. With the less sterically encumbered azides PhN₃ and C₁₀H₁₅N₃ (1-azidoadamantane), the putative initially formed aluminium imide undergoes facile [2 + 3] cycloaddition to provide the tetrazenylaluminates [{SiN^Dipp}Al-κ²-N,N′-({N(R)}₂N₂)]K (R = Ph, C₁₀H₁₅). In contrast, each Al(I) centre of [{SiN^Dipp}AlK]₂ only reacts with a single equivalent of 2,4,6-Me₃C₆H₂N₃ to provide the imidoaluminate [{SiN^Dipp}AlN(2,4,6-Me₃C₆H₂)(K∙C₆H₆)], which crystallises as a monomer and displays a short Al-N distance of 1.7040(13) Å. Attempts to synthesise the azide [{SiN^Dipp}AlN₃] by reaction of [{SiN^Dipp}AlI] with an excess of KN₃ resulted in exclusive formation of the bis(azido)aluminate [{SiN^Dipp}Al(N₃)₂K], which crystallises as an infinite 1-dimensional polymer propagated by μ-(1,3)-N₃ bridging interactions between the potassium cations and azide anions. Although the THF-adducted azide [{SiN^Dipp}AlN₃(THF)] may be synthesised and characterised by more stringent control of the reaction stoichiometry, the synthetic viability of this route remains compromised by competitive generation of [{SiN^Dipp}Al(N₃)₂K]. Full article

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

► Show Figures

Graphical abstract

12 pages, 649 KiB

Open AccessArticle

High-Coercivity Ferrimagnet Co₂FeO₂BO₃: XMCD Insights into Charge-Ordering and Cation Distribution

by Mikhail S. Platunov

Inorganics 2025, 13(1), 24; https://doi.org/10.3390/inorganics13010024 - 15 Jan 2025

Viewed by 576

Abstract

The multi-sublattice ferrimagnet Co₂FeO₂BO₃, a prominent example of lanthanide-free magnets, was the subject of element-selective studies using X-ray magnetic circular dichroism (XMCD) observations at the L- and K- X-ray absorption edges. Research findings indicate that [...] Read more.

The multi-sublattice ferrimagnet Co₂FeO₂BO₃, a prominent example of lanthanide-free magnets, was the subject of element-selective studies using X-ray magnetic circular dichroism (XMCD) observations at the L- and K- X-ray absorption edges. Research findings indicate that the distinct magnetic characteristics of Co₂FeO₂BO₃, namely its remarkable high coercivity (which surpasses 7 Tesla at low temperatures), originate from an atypical arrangement of magnetic ions in the crystal structure (sp.gr. Pbam). The antiferromagnetic nature of the Co²⁺-O-Fe³⁺ exchange interaction was confirmed by identifying the spin and orbital contributions to the total magnetization from Co (m_L = 0.27 ± 0.1 μ_B/ion and m^eff_S = 0.53 ± 0.1 μ_B/ion) and Fe (m_L = 0.05 ± 0.1 μ_B/ion and m^eff_S = 0.80 ± 0.1 μ_B/ion) ions through element-selective XMCD analysis. Additionally, the research explicitly revealed that the strong magnetic anisotropy is a result of the significant unquenched orbital magnetic moment of Co, a feature that is also present in the related compound Co₃O₂BO₃. A complex magnetic structure in Co₂FeO₂BO₃, with infinite Co²⁺O₆ layers in the bc-plane and strong antiferromagnetic coupling through Fe³⁺ ions, is suggested by element-selective hysteresis data, which revealed that Co²⁺ ions contribute both antiferromagnetic and ferromagnetic components to the total magnetization. The findings underline the suitability of Co₂FeO₂BO₃ for applications in extreme environments, such as low temperatures and high magnetic fields, where its unique magnetic topology and anisotropy can be harnessed for advanced technologies, including materials for space exploration and quantum devices. This XMCD study opens the door to the production of novel high-coercivity, lanthanide-free magnetic materials by showing that targeted substitution at specific crystallographic sites can significantly enhance the magnetic properties of such materials. Full article

(This article belongs to the Special Issue Inorganic Materials for Applications in Extreme Environments)

► Show Figures

Graphical abstract

15 pages, 4270 KiB

Open AccessArticle

The Homopolyatomic Sulfur Cation [S₂₀]²⁺

by Janis Derendorf, Lara Heiderich, Carsten Jenne and Marc C. Nierstenhöfer

Inorganics 2025, 13(1), 23; https://doi.org/10.3390/inorganics13010023 - 15 Jan 2025

Viewed by 356

Abstract

Homopolyatomic cations of the main group elements and of the element sulfur, in particular, are used as tutorial examples to teach structure and bonding in inorganic chemistry. So far, the cations [S₄]²⁺, [S₈]²⁺, [S₁₉ [...] Read more.

Homopolyatomic cations of the main group elements and of the element sulfur, in particular, are used as tutorial examples to teach structure and bonding in inorganic chemistry. So far, the cations [S₄]²⁺, [S₈]²⁺, [S₁₉]²⁺, [S₅]^•+, and [S₈]^•+ are known experimentally. In this report, the generation and crystal structure determination of the salt Na₂[S₂₀]₂[B₁₂Cl₁₂]₃, containing the new homopolyatomic sulfur cation [S₂₀]²⁺, is reported. The structure of the latter cation consists of two seven-membered homocycles, which are bridged by a six-membered sulfur chain. This structure is strongly related to that of [S₁₉]²⁺. The heptasulfur rings show pronounced bond alternation. Comparison with the experimental structures of [S₇X]⁺ (X = I, Br) and the application of quantum chemical calculations show unambiguously that the observed structural features are intrinsic properties of the cationic cyclo-heptasulfur moieties. The latter can occupy different conformations, which only slightly differ in energy. Charge delocalization and negative hyperconjugation contribute to the stability of the observed structures. The discovery of the [S₂₀]²⁺ cation fits well into range of known homopolyatomic sulfur cations, which can be classified by their averaged oxidation state of sulfur. Full article

(This article belongs to the Special Issue State-of-the-Art Inorganic Chemistry in Germany)

► Show Figures

Graphical abstract

17 pages, 8279 KiB

Open AccessArticle

Understanding Dioxygen Activation in the Fe(III)-Promoted Oxidative Dehydrogenation of Amines: A Computational Study

by Ricardo D. Páez-López, Miguel Á. Gómez-Soto, Héctor F. Cortés-Hernández, Alejandro Solano-Peralta, Miguel Castro, Peter M. H. Kroneck and Martha E. Sosa-Torres

Inorganics 2025, 13(1), 22; https://doi.org/10.3390/inorganics13010022 - 15 Jan 2025

Viewed by 441

Abstract

Hydrogenation and dehydrogenation reactions are fundamental in chemistry and essential for all living organisms. We employ density functional theory (DFT) to understand the reaction mechanism of the oxidative dehydrogenation (ODH) of the pyridyl-amine complex [Fe^IIIL³]³⁺ (L³, [...] Read more.

Hydrogenation and dehydrogenation reactions are fundamental in chemistry and essential for all living organisms. We employ density functional theory (DFT) to understand the reaction mechanism of the oxidative dehydrogenation (ODH) of the pyridyl-amine complex [Fe^IIIL³]³⁺ (L³, 1,9-bis(2′-pyridyl)-5-[(ethoxy-2″-pyridyl)methyl]-2,5,8-triazanonane) to the mono-imine complex [Fe^IIL⁴]²⁺ (L⁴, 1,9-bis(2′-pyridyl)-5-[(ethoxy-2″-pyridyl)methyl]-2,5,8-triazanon-1-ene) in the presence of dioxygen. The nitrogen radical [Fe^IIL³_N8•]²⁺, formed by deprotonation of [Fe^IIIL³]³⁺, plays a crucial role in the reaction mechanism derived from kinetic studies. O₂ acts as an oxidant and is converted to H₂O. Experiments with the deuterated ligand L³ reveal a primary C-H kinetic isotope effect, k^CH/k^CD = 2.30, suggesting C-H bond cleavage as the rate-determining step. The DFT calculations show that (i) ³O₂ abstracts a hydrogen atom from the α-pyridine aliphatic C-H moiety, introducing a double bond regio-selectively at the C₇N₈ position, via the hydrogen atom transfer (HAT) mechanism, (ii) O₂ does not coordinate to the iron center to generate a high-valent Fe oxo species observed in enzymes and biomimetic complexes, and (iii) the experimental activation parameters (ΔH^≠ = 20.38 kcal mol⁻¹, ΔS^≠ = −0.018 kcal mol⁻¹ K⁻¹) fall within in the range of values reported for HAT reactions and align well with the computational results for the activated complex [Fe^IIL³_N8•]²⁺···³O₂. Full article

(This article belongs to the Special Issue Transition Metal Catalysts: Design, Synthesis and Applications)

► Show Figures

Graphical abstract

17 pages, 5740 KiB

Open AccessArticle

Unveiling the Electrocatalytic Performances of the Pd-MoS₂ Catalyst for Methanol-Mediated Overall Water Splitting

by Aviraj M. Teli, Sagar M. Mane, Rajneesh Kumar Mishra, Wookhee Jeon and Jae Cheol Shin

Inorganics 2025, 13(1), 21; https://doi.org/10.3390/inorganics13010021 - 15 Jan 2025

Viewed by 627

Abstract

Herein, this work elucidates the synthesis of the Pd-MoS₂ catalyst for application in methanol-mediated overall water splitting. The scanning electron microscope (SEM) and transmission electron microscope (TEM) pictures offer an exciting nanostructured shape of the Pd-MoS₂, depicting a high surface [...] Read more.

Herein, this work elucidates the synthesis of the Pd-MoS₂ catalyst for application in methanol-mediated overall water splitting. The scanning electron microscope (SEM) and transmission electron microscope (TEM) pictures offer an exciting nanostructured shape of the Pd-MoS₂, depicting a high surface area. Further, high-resolution TEM (HRTEM) pictures confirm the lattice plane (100), lattice spacing (0.26 nm), and hexagonal crystal structure of the Pd-MoS₂. Moreover, high-angle annular dark-field (HAADF) images and related color maps disclose the Mo, S, and Pd elements of the Pd-MoS₂. The Pd-MoS₂ catalyst exhibits lower overpotentials of 224.6 mV [methanol-mediated hydrogen evolution reaction (MM-HER)] at −10 mA cm⁻² and 133 mV [methanol-mediated oxygen evolution reaction (MM-OER)] at 10 mA cm⁻². Further, the Pd-MoS₂ illustrates noteworthy stability for 15.5 h for MM-HER and 18 h for MM-OER by chronopotentiometry test. Excitingly, the Pd-MoS₂∥Pd-MoS₂ cell reveals a small potential of 1.581 V compared to the MoS₂∥MoS₂ cell (1.648 V) in methanol-mediated overall water splitting. In addition, the Pd-MoS₂∥Pd-MoS₂ combination reveals brilliant durability over 18 h at 10 mA cm⁻². Full article

(This article belongs to the Special Issue Inorganic Electrode Materials in High-Performance Energy Storage Devices)

► Show Figures

Graphical abstract

15 pages, 6979 KiB

Open AccessArticle

Analysis of Biomolecular Changes in HeLa Cervical Cancer Cell Line Induced by Interaction with [Pd(dach)Cl₂]

by Vanja Ralić, Maja D. Nešić, Tanja Dučić, Milutin Stepić, Lela Korićanac, Katarina Davalieva and Marijana Petković

Inorganics 2025, 13(1), 20; https://doi.org/10.3390/inorganics13010020 - 14 Jan 2025

Viewed by 587

Abstract

Transition metal complexes have been used in medicine for several decades, but their intracellular effects are not yet fully elucidated. Therefore, in this study, we investigate biomolecular changes induced by a palladium(II) complex in cervical carcinoma (HeLa) cells as a model to study [...] Read more.

Transition metal complexes have been used in medicine for several decades, but their intracellular effects are not yet fully elucidated. Therefore, in this study, we investigate biomolecular changes induced by a palladium(II) complex in cervical carcinoma (HeLa) cells as a model to study the subtle changes caused by transition metal ions ingested by the cells. The impact of dichloro(1,2-diaminocyclohexane)palladium(II), [Pd(dach)Cl₂], was studied by synchrotron radiation-based Fourier transform infrared (SR FTIR) spectroscopy, a powerful tool for studying alterations in cellular components’ biochemical composition and biomolecular secondary structure on a single-cell level. A spectral analysis, complemented by statistics, revealed that the Pd(II) complex considerably affected all major types of macromolecules in HeLa cells and induced structural changes in proteins through an increased formation of cross-β-sheets and causes structural rearrangement in deoxyribonucleic acid (DNA) through potential chromosome fragmentation. Although a certain level of lipid peroxidation was detectable by SR FTIR spectroscopy and confirmed by an analysis of cellular lipids by matrix-assisted laser desorption and ionisation time-of-flight mass spectrometry, the oxidative stress is not a significant mechanism by which Pd(II) expresses the effect on the HeLa cells. Full article

(This article belongs to the Special Issue Evaluation of the Potential Biological Activity of Metallo-Drugs)

► Show Figures

Figure 1

8 pages, 905 KiB

Open AccessArticle

CO₂@C₈₄: DFT Calculations of Structure and Energetics

by Zdeněk Slanina, Filip Uhlík, Takeshi Akasaka, Xing Lu and Ludwik Adamowicz

Inorganics 2025, 13(1), 19; https://doi.org/10.3390/inorganics13010019 - 14 Jan 2025

Viewed by 363

Abstract

Encapsulations of carbon dioxide into

D_{2}

(22)-

C_{84}

and

D_{2 d}

(23)-

C_{84}

fullerenes are evaluated. The encapsulation energy is computed with the DFT M06-2X/6-31+

G^{*}

approach corrected for the basis set superposition error evaluated by the counterpoise [...] Read more.

Encapsulations of carbon dioxide into

D_{2}

(22)-

C_{84}

and

D_{2 d}

(23)-

C_{84}

fullerenes are evaluated. The encapsulation energy is computed with the DFT M06-2X/6-31+

G^{*}

approach corrected for the basis set superposition error evaluated by the counterpoise method. The resulting encapsulation energy for

{CO}_{2}

@

D_{2}

(22)-

C_{84}

and

{CO}_{2}

@

D_{2 d}

(23)-

C_{84}

amounts to substantial values of −14.5 and −13.9 kcal/mol, respectively. The energy gain is slightly larger than for CO@

C_{60}

, already synthesized with a high-temperature and high-pressure treatment—so that a similar preparation of

{CO}_{2} {@ C}_{84}

could be possible. The calculated rotational constants and IR vibrational spectra are presented for possible use in detection. The stability of

{({CO}_{2})}_{2}

{@ C}_{84}

is also briefly discussed. Full article

(This article belongs to the Special Issue Carbon Nanomaterials for Advanced Technology)

► Show Figures

Figure 1

11 pages, 1159 KiB

Open AccessArticle

Reactions of 1-Alkyl-3-phenylbenzimidazolium Salts with Ag₂O: The Formation of a Ring-Opening Formamide Derivative and a Ag Complex with an N-heterocyclic Carbene Ligand

by Satoshi Sakaguchi, Takashi Higashino, Yudai Tasaki, Ryo Ichihara and Tatsuo Yajima

Inorganics 2025, 13(1), 18; https://doi.org/10.3390/inorganics13010018 - 10 Jan 2025

Viewed by 360

Abstract

This study investigated the reactions of 1-alkyl-3-phenylbenzimidazolium salts with Ag₂O. It was found that the selectivity of the reaction products was influenced by the N-alkyl substituent on the azolium ring. For example, treating 1-methyl-3-phenylbenzimidazolium iodide (2) with Ag [...] Read more.

This study investigated the reactions of 1-alkyl-3-phenylbenzimidazolium salts with Ag₂O. It was found that the selectivity of the reaction products was influenced by the N-alkyl substituent on the azolium ring. For example, treating 1-methyl-3-phenylbenzimidazolium iodide (2) with Ag₂O for 24 h produced the ring-opening formamide derivative N-[2-(phenylamino)phenyl]-N-methylformamide (2b) in an 85% yield. In contrast, the reaction of 1-benzyl-3-phenylbenzimidazolium chloride (3) with Ag₂O under the same conditions yielded the corresponding N-heterocyclic carbene (NHC)–Ag complex (1-benzyl-3-phenylbenzimidazol-2-ylidene) silver(I) chloride (3a) in an 86% yield. Furthermore, the corresponding monodentate NHC–Au complex 2c could be synthesized by allowing 2 to react with AuCl(SMe₂) in the presence of Ag₂O. Full article

(This article belongs to the Special Issue N-Heterocyclic Carbene Metal Complexes: Synthesis, Properties and Applications, 2nd Edition)

► Show Figures

Graphical abstract

13 pages, 9272 KiB

Open AccessArticle

Synthesis and Characterization of Pd/La₂O₃/ZnO Catalyst for Complete Oxidation of Methane, Propane and Butane

by Ralitsa Velinova, Nina Kaneva, Georgi Ivanov, Daniela Kovacheva, Ivanka Spassova, Silviya Todorova, Genoveva Atanasova and Anton Naydenov

Inorganics 2025, 13(1), 17; https://doi.org/10.3390/inorganics13010017 - 9 Jan 2025

Viewed by 540

Abstract

The catalytic oxidation of volatile organic compounds (VOCs) is the subject of considerable interest due to its applications in environmental protection. Noble metal-based catalysts are widely employed to remove toxic compounds from gas mixtures. The objective of the present study was the synthesis [...] Read more.

The catalytic oxidation of volatile organic compounds (VOCs) is the subject of considerable interest due to its applications in environmental protection. Noble metal-based catalysts are widely employed to remove toxic compounds from gas mixtures. The objective of the present study was the synthesis of a palladium-containing catalyst deposited on a support modified with La₂O₃ zinc oxide. The composite support was initially obtained by a simple method, and then palladium was deposited on it by impregnation. Various methods, including N₂-physisorption, XRD, HRTEM, XPS, TPD, TPR, and FTIR, were used to characterize the material. The obtained catalyst was studied in the reaction of the complete oxidation of butane, propane, and methane. It was found that the addition of La₂O₃ to ZnO led to an improved pore texture. The catalytic tests showed that the reaction of the complete oxidation of butane on Pd/La₂O₃/ZnO proceeded at the lowest temperatures. Full article

(This article belongs to the Special Issue Metal Catalyst Discovery, Design and Synthesis)

► Show Figures

Graphical abstract

14 pages, 3510 KiB

Open AccessArticle

In-Situ Polymerization for Catalytic Graphitization of Boronated PAN Using Aluminum and Zirconium Containing Co-Catalysts

by Taewoo Kim, Byoung-Suhk Kim, Tae Hoon Ko and Hak Yong Kim

Inorganics 2025, 13(1), 16; https://doi.org/10.3390/inorganics13010016 - 8 Jan 2025

Viewed by 462

Abstract

In-situ polymerization is an effective method for integrating co-catalysts homogeneously into the polymer matrix. Polyacrylonitrile (PAN)-derived highly graphitized carbon is a state-of-the-art material with diverse applications, including materials for energy storage devices, electrocatalysis, sensing, adsorption, and making structural composites of various technologies. Such [...] Read more.

In-situ polymerization is an effective method for integrating co-catalysts homogeneously into the polymer matrix. Polyacrylonitrile (PAN)-derived highly graphitized carbon is a state-of-the-art material with diverse applications, including materials for energy storage devices, electrocatalysis, sensing, adsorption, and making structural composites of various technologies. Such highly graphitized materials can be effectively obtained through in-situ polymerization. The addition of external catalysts during in-situ polymerization not only enhances the polymerization rate but also facilitates the degree of graphitization and quality of graphitic carbon upon graphitization at moderate temperatures. In this study, we apply an in-situ polymerization technique to integrate aluminum triflate (Al(OTf)₃) and zirconocene dichloride (C₅H₅)₂ZrCl₂ co-catalyst into a boronated polyacrylonitrile (B-PAN) matrix. The in-situ polymerization ensures the uniform distribution of the co-catalyst without aggregation, facilitating the formation of a well-ordered graphitic structure at a moderated temperature. Boronated polyacrylonitrile (B-PAN) solutions, with and without co-catalyst (Al(OTf)₃, (C₅H₅)₂ZrCl₂ or both) were prepared through polymerization process, dried in an oven, and then subjected to graphitization at 1250 °C with a heating rate of 1 °C min⁻¹ for 1 h under an N₂ atmosphere. The resulting graphitic carbon was characterized to determine the impact of co-catalyst on the degree of graphitization. This study provides valuable insights into synthesizing high-quality graphitic carbon materials, offering promising pathways for their scalable production through the strategic use of in-situ polymerization and co-catalysis. These materials have potential applications in various fields, including environmental technologies, energy storage, and conversion, offering a pathway to design facile and economical graphitic carbon materials. Full article

(This article belongs to the Special Issue Carbon Nanomaterials for Advanced Technology)

► Show Figures

Figure 1

11 pages, 6093 KiB

Open AccessArticle

Promoted Formation of Photoactive α-Formamidinium Cesium Lead Triiodide Perovskite Crystals by Germanium Addition

by Ayu Enomoto, Atsushi Suzuki, Takeo Oku and Haruto Shimada

Inorganics 2025, 13(1), 15; https://doi.org/10.3390/inorganics13010015 - 7 Jan 2025

Viewed by 405

Abstract

Germanium (Ge) was added to formamidinium cesium lead triiodide perovskite crystals and the microstructures and photovoltaic properties were investigated. The Ge addition stabilized the α-phase of the perovskites and suppressed formation of the δ-phase. X-ray diffraction peaks of the α-phase increased by increasing [...] Read more.

Germanium (Ge) was added to formamidinium cesium lead triiodide perovskite crystals and the microstructures and photovoltaic properties were investigated. The Ge addition stabilized the α-phase of the perovskites and suppressed formation of the δ-phase. X-ray diffraction peaks of the α-phase increased by increasing the Ge contents. The highest conversion efficiency of 6.05% was obtained for the 12.5% Ge added device in an air atmosphere and the increase of efficiencies would be due to the promoted formation of photoactive α-formamidinium cesium lead triiodide perovskite crystals. Full article

► Show Figures

Figure 1

12 pages, 2120 KiB

Open AccessArticle

First Principles Study of Electronic and Optical Properties of Cadmium-Tin-Oxide

by Adel Bandar Alruqi

Inorganics 2025, 13(1), 14; https://doi.org/10.3390/inorganics13010014 - 7 Jan 2025

Viewed by 383

Abstract

Cadmium-tin-oxide (CTO), also referred to as cadmium stannate (Cd₂SnO₄), is known for its interesting electrical, electronic, and optical properties, making it useful in various applications such as in transparent conducting oxides for optoelectronic devices and also in photovoltaic applications. [...] Read more.

Cadmium-tin-oxide (CTO), also referred to as cadmium stannate (Cd₂SnO₄), is known for its interesting electrical, electronic, and optical properties, making it useful in various applications such as in transparent conducting oxides for optoelectronic devices and also in photovoltaic applications. While its properties have been investigated experimentally, there is not much record in the literature on the computational study of the electronic and optical properties of CTO. This study employed density functional theory to explore the two properties of CTO. The hybrid functionals were used to widen the band gap from 0.381 eV (for PBE) to 3.13 eV, which replicates the experimental values very well. The other properties obtained were a refractive index of 2.53, absorption coefficient of 1.43 × 10⁴ cm⁻¹, and dielectric constant of 6.401 eV. The optical energy loss of 0.00691 that was investigated for the first time in this work adds to the literature on the properties of CTO. However, the electrical properties of CTO, which also play a key role in the working of optoelectronic devices, need to be investigated. Full article

► Show Figures

Figure 1

8 pages, 810 KiB

Open AccessArticle

Getting to the Heart of the Matter: Control over the Photolysis of PbI₂ Through Partial Lead Substitution

by Marina I. Ustinova, Gennadii V. Shilov, Pavel A. Troshin, Sergey M. Aldoshin and Lyubov A. Frolova

Inorganics 2025, 13(1), 13; https://doi.org/10.3390/inorganics13010013 - 6 Jan 2025

Viewed by 397

Abstract

A crucial problem of the photoinduced degradation of perovskite semiconductors based on complex lead halides has been addressed here by suppressing PbI₂ photolysis to metallic lead. The systematic screening of >30 modifying cations introduced as substituents for 5% of Pb²⁺ in [...] Read more.

A crucial problem of the photoinduced degradation of perovskite semiconductors based on complex lead halides has been addressed here by suppressing PbI₂ photolysis to metallic lead. The systematic screening of >30 modifying cations introduced as substituents for 5% of Pb²⁺ in the PbI₂ composition has revealed their tremendous effects on the rate of material degradation under light exposure. Thus, the most successful stabilizing cations could maintain a high absorbance of the Pb_0.95M_0.1/nI₂ films and block Pb⁰ formation after 400 h of continuous illumination, when the non-modified PbI₂ films completely decomposed to Pb⁰ and I₂. The obtained results present a promising solution for the problem of metallic lead formation in the active layer of perovskite solar cells during their operation, which can pave the way for the development of a new generation of highly efficient and stable perovskite photovoltaics. Full article

(This article belongs to the Special Issue New Semiconductor Materials for Energy Conversion)

► Show Figures

Figure 1

20 pages, 14116 KiB

Open AccessArticle

Preparation of Ca-Mg Double-Doped Mesoporous Silica Nanoparticles and Their Drug-Loading and Drug-Releasing Properties

by Qian Zhang, Jiamin Huang, Chao Liu, Ruihua Chen, Tao Jiang, Yusufu Hailili, Telieke Bahetibieke, Xiaohui Tang and Mei Wang

Inorganics 2025, 13(1), 12; https://doi.org/10.3390/inorganics13010012 - 4 Jan 2025

Viewed by 551

Abstract

Breast cancer is a common clinical malignant tumor that seriously threatens women’s physical and mental health. Chemotherapy, as the first choice of breast cancer treatment, has limited its application in the clinic due to problems of poor stability, short half-life, and serious toxic [...] Read more.

Breast cancer is a common clinical malignant tumor that seriously threatens women’s physical and mental health. Chemotherapy, as the first choice of breast cancer treatment, has limited its application in the clinic due to problems of poor stability, short half-life, and serious toxic side effects. With the emergence of nanotechnology, inorganic materials to prepare mesoporous silica nanoparticles (MSNs) have been widely used in anti-tumor drug carriers. However, their slow degradation rate limits their application in the biomedical field. Therefore, developing low-toxicity MSNs with good biocompatibility, biodegradability, and rapid release at the tumor site is a key scientific issue to be addressed. Here, we prepared DOX-loaded Ca-Mg-doped MSNs by electrostatic adsorption to obtain Ca-Mg@DOX@MSNs with suitable particle sizes and zeta potential, and the incorporation of calcium and magnesium also led to an increase in the degradation rate under acidic conditions and an accelerated release, which reduced the toxicity of DOX and promoted cellular uptake with good anti-tumor effects. This study provides a new idea for the clinical treatment of breast cancer. Full article

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

► Show Figures

Figure 1

13 pages, 3375 KiB

Open AccessArticle

Effect of Deposition Temperature and Thermal Annealing on the Properties of Sputtered NiO_x/Si Heterojunction Photodiodes

by Roumen Nedev, David Mateos-Anzaldo, Eddue Osuna-Escalante, Oscar Perez-Landeros, Mario Curiel-Alvarez, Esteban Osorio-Urquizo, Jhonathan Castillo-Saenz, Javier Lopez-Medina, Benjamin Valdez-Salas and Nicola Nedev

Inorganics 2025, 13(1), 11; https://doi.org/10.3390/inorganics13010011 - 3 Jan 2025

Viewed by 455

Abstract

NiO_x is a p-type semiconductor with excellent stability, which makes it interesting for a wide range of applications. Broadband photodetectors with high responsivity (R) were fabricated by depositing r.f.-sputtered NiO_x layers on n-Si at room temperature (RT), 50 °C [...] Read more.

NiO_x is a p-type semiconductor with excellent stability, which makes it interesting for a wide range of applications. Broadband photodetectors with high responsivity (R) were fabricated by depositing r.f.-sputtered NiO_x layers on n-Si at room temperature (RT), 50 °C and 100 °C. In self-powered mode the RT diodes have R between 0.95 and 0.39 A/W for wavelengths between 365 and 635 nm, while at a reverse bias of −4 V, the responsivity increases to values between 22 A/W and 10.7 A/W for wavelengths in the same range. The increase of the deposition temperature leads to a decrease of R but also to a smaller reverse dark current. Thus, the 100 °C photodiodes might be more appropriate for applications where high responsivity is required, because of their smaller power consumption compared to the RT diodes. In addition, it was found that the increase of the deposition temperature leads to an increase of the diodes’ series resistance and the resistivity of NiO_x. The effect of Rapid Thermal Annealing (RTA) on the properties of the photodiodes was studied. Annealing at 550 °C for 6 min leads to much higher responsivity compared to R of diodes with as-deposited NiO_x. However, a disadvantage of the annealed diode is that the reverse current depends on the amplitude and polarity of previously applied bias voltage. The higher responsivity of the RTA photodiodes makes them useful as light sensors. Full article

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

► Show Figures

Figure 1

28 pages, 11393 KiB

Open AccessArticle

A Rapid General Synthesis and the Spectroscopic Data of 2,2′-Bis-(di-isopropylphosphino)-1,1′-dibromoferrocene, (bpdbf), 1,1′,2,2′-Tetrakis-(di-isopropylphosphino) Ferrocene, (tdipf) and Related Ligands: Taking dppf into the Future

by Peter N. Horton, Simon J. Coles, William Clegg, Ross W. Harrington and Ian R. Butler

Inorganics 2025, 13(1), 10; https://doi.org/10.3390/inorganics13010010 - 2 Jan 2025

Viewed by 535

Abstract

In this paper, the clean high yielding, synthesis, and structure of the tetraphosphine ligand, 1,1′,2,2′-tetrakis-(di-isopropyl-phosphino)ferrocene, (tdipf), is described. In addition, improved synthesis methods for 1,1′,2,2′-tetrakis(diphenylphosphino)ferrocene, (tppf), and 2,2′-bis-(diphenylphosphino)-1,1′-dibromoferrocene are also reported, and the synthetic method is generalised to include [...] Read more.

In this paper, the clean high yielding, synthesis, and structure of the tetraphosphine ligand, 1,1′,2,2′-tetrakis-(di-isopropyl-phosphino)ferrocene, (tdipf), is described. In addition, improved synthesis methods for 1,1′,2,2′-tetrakis(diphenylphosphino)ferrocene, (tppf), and 2,2′-bis-(diphenylphosphino)-1,1′-dibromoferrocene are also reported, and the synthetic method is generalised to include the synthesis of 3,3′-bis-(diphenylphosphino)-1,1′,2,2′-tetrabromoferrocene. The related ligands 2,2′-bis-(iso-propylphosphino)-1,1′-bis-diphenylphosphinoferrocene (diprdppf) and 2,2′-bis-(di-isopropylphosphino)-dibromoferrocene have also been prepared and characterised. The crystal structure of the square planar bimetallic nickel (II) dichloride of tdipf is also described, together with a brief NMR study investigating the synthesis of this and related metal complexes. The crystal structures of the palladium and platinum dichloride complexes of 2,2′-bis-(di-isopropylphosphino)-1,1′-dibromoferrocene, bpdbf, are also discussed in the context of comparison with previously known crystal structures in the same general family. A general discussion on the synthetic methodology is given, along with indications for future research that other researchers might explore. Full article

(This article belongs to the Special Issue Current Advances in Coordination and Bioinorganic Chemistry)

► Show Figures

Graphical abstract

11 pages, 1453 KiB

Open AccessArticle

Synthesis and Use of Complex Titanium-Containing Coagulant in Water Purification Processes

by Evgenii Kuzin

Inorganics 2025, 13(1), 9; https://doi.org/10.3390/inorganics13010009 - 1 Jan 2025

Viewed by 720

Abstract

Titanium-containing coagulants are a new development in physical and chemical water purification processes. Despite their high efficiency and the absence of the drawbacks that are typical of traditional reagents, the high cost of titanium compounds restrains their extensive implementation. As part of this [...] Read more.

Titanium-containing coagulants are a new development in physical and chemical water purification processes. Despite their high efficiency and the absence of the drawbacks that are typical of traditional reagents, the high cost of titanium compounds restrains their extensive implementation. As part of this work, a concept technology for the synthesis of complex titanium-containing reagents using chemical dehydration processes was proposed. It was found that the composition of a complex titanium-containing coagulant consists of a mixture of aluminum sulfate 50–87 wt.%, aluminum chloride 10–40 wt.%, and titanium oxysulfate 2.5–10.0 wt.%. It was ascertained that the optimal content of the modifying additive in titanium compounds is 5.0–7.5 wt.%. The comparison of the coagulation efficiency of traditional aluminum- and iron-containing reagents and freshly synthesized reagents showed that the use of complex titanium-containing coagulants allows us not only to minimize the residual concentrations of various pollutants (phosphates, turbidity, oxidizable organic compounds) but also to reduce the reagent consumption by 20–25%, as well as to intensify the processes of sedimentation and filtration of coagulation sludge. Based on the data set obtained, the prospects for the production and use of complex titanium-containing coagulants for natural and wastewater of different origins are proven. Full article

(This article belongs to the Section Inorganic Materials)

► Show Figures

Figure 1

17 pages, 4224 KiB

Open AccessArticle

The Origin of Synergetic Effect in Mixed Mn-Co Oxide with Spinel Structure for Catalytic Oxidation of CO

by Olga A. Bulavchenko, Vladimir A. Rogov, Evgeny Yu. Gerasimov, Egor E. Aydakov and Anna M. Kremneva

Inorganics 2025, 13(1), 8; https://doi.org/10.3390/inorganics13010008 - 31 Dec 2024

Viewed by 378

Abstract

In this work, the origin of the synergetic effect in mixed Mn_xCo_3-xO₄ oxides with the spinel structure in the CO oxidation reaction was tested. A series of Mn_xCo_3-x oxide catalysts were synthesized by the coprecipitation [...] Read more.

In this work, the origin of the synergetic effect in mixed Mn_xCo_3-xO₄ oxides with the spinel structure in the CO oxidation reaction was tested. A series of Mn_xCo_3-x oxide catalysts were synthesized by the coprecipitation method with further calcination at 600 °C and varying manganese content from x = 0 to x = 3. The catalysts were characterized using XRD, TEM, N₂ adsorption, TPR, EXAFS, and XPS. The catalytic activity of Mn_xCo_3-x oxide catalysts was tested in CO oxidation reactions. The addition of manganese to cobalt oxide results in the formation of mixed Mn-Co oxides based on a cubic or tetragonal spinel structure, a change in microstructural properties, such as surface area and crystal size, as well as local distortions and a decrease in the surface concentration of Co ions and Co in the octahedral sites in spinel structure; it also decreases catalyst reducibility. For all catalysts, the activity of CO oxidation decreases as follows: Mn_0.1Co_2.9 > Co₃O₄~Mn_0.3Co_2.7 > Mn_0.5Co_2.5 > MnO_x > Mn_0.7Co_2.3 > Mn_0.9Co_2.1~Mn_1.1Co_1.9~Mn_2.5Co_0.5 > Mn_2.9Co_0.1 > Mn_1.7Co_1.3 > Mn_2.1Co_0.9 > Mn_1.3Co_1.7~Mn_1.5Co_1.5~Mn_2.3Co_0.7. The Mn_0.1Co_2.9 catalyst displays the best catalytic activity, which is attributed to its small crystal size and the maximum surface ratio between Co³⁺ and Co²⁺. A further increase in the manganese content (x > 0.3) provokes drastic changes in the catalytic properties due to a decrease in the cobalt content on the surface and in the volume of mixed oxide, changes in the oxidation states of cations, and structure transformation. Full article

(This article belongs to the Special Issue Metal Catalyst Discovery, Design and Synthesis)

► Show Figures

Figure 1

16 pages, 8338 KiB

Open AccessArticle

Physical Methods for the Preparation of Cobalt Nanoparticles for Use in the Synthesis of Multiwalled Carbon Nanotubes

by Nicolas Moreau, Antonio Fonseca, Danilo Vuono, Joseph Delhalle, Zineb Mekhalif, Pierantonio De Luca and Janos B.Nagy

Inorganics 2025, 13(1), 7; https://doi.org/10.3390/inorganics13010007 - 29 Dec 2024

Viewed by 605

Abstract

The aim of this work was to obtain cobalt nanoparticles through a physical method, which could be formed simultaneously during the Catalytic Chemical Vapour Deposition (CCVD) synthesis of carbon nanotubes, under conditions suitable for both carbon nanotube synthesis and Co-nanoparticle formation. Co nanoparticles [...] Read more.

The aim of this work was to obtain cobalt nanoparticles through a physical method, which could be formed simultaneously during the Catalytic Chemical Vapour Deposition (CCVD) synthesis of carbon nanotubes, under conditions suitable for both carbon nanotube synthesis and Co-nanoparticle formation. Co nanoparticles were prepared by Physical Vapour Deposition (PVD) using a 0.05 m³ magnetron on two different substrates, SiO₂/Si and C, followed by a reduction treatment in an H₂ atmosphere. Transmission Electron Microscopy (TEM) and Field Enhanced Scanning Electron Microscopy (FE-SEM) were used to characterize the Co nanoparticles. On the SiO₂/Si substrate, cobalt silicate is formed, which stabilizes the Co nanoparticles, while the nanoparticles obtained on the C-substrate are sometimes surrounded by a layer of Co₃O₄, which deactivates the cobalt nanoparticles. To obtain suitable Co nanoparticles for carbon nanotube synthesis, the optimal Co-layer thickness is between 20 and 30 Å, and the optimal reduction temperature is 800 °C and 450 °C for SiO₂/Si and C substrates, respectively. Full article

(This article belongs to the Section Inorganic Materials)

► Show Figures

Figure 1

22 pages, 7851 KiB

Open AccessArticle

1,10-Phenanthroline and 4,5-Diazafluorene Ketones and Their Silver(I) and Platinum(II) Complexes: Syntheses and Biological Evaluation as Antiproliferative Agents

by Leonardo Sandin-Mazzondo, Jesús M. Martínez-Ilarduya, Jesús A. Miguel, Camino Bartolomé and Concepción Alonso

Inorganics 2025, 13(1), 6; https://doi.org/10.3390/inorganics13010006 - 28 Dec 2024

Viewed by 531

Abstract

Using non-classical polyfluorophenyl ligands in Pt(II) complexes and other transition metals such as silver is a promising approach in the search for more effective and safer antitumoral drugs. In this work, a series of chelating N-donor ligands with 1,10-phenanthroline and 4,5-diazafluorene backbones [...] Read more.

Using non-classical polyfluorophenyl ligands in Pt(II) complexes and other transition metals such as silver is a promising approach in the search for more effective and safer antitumoral drugs. In this work, a series of chelating N-donor ligands with 1,10-phenanthroline and 4,5-diazafluorene backbones and ketone groups were synthesized (1,10-phenanthroline-5,6-dione, 1; (R/S)-6-hydroxy-6-(2-oxypropyl)-1,10-phenanthroline-5(6H)-one, 2; 4,5-diazafluoren-9-one, 3; 9-hydroxy-9-(2-oxypropyl)-4,5-diazafluorene, 4). The corresponding [Ag(N,N)₂]NO₃ (1Ag–4Ag) and [Pt(C₆F₅)₂(N,N)] (1Pt–4Pt) complexes were prepared. The stability of these complexes in DMSO solution was studied, showing no dissociation over 48 h for almost all complexes, except 3Pt. The compounds were characterized by NMR (¹H, ¹³C, and ¹⁹F), MS, and X-ray diffraction (2, 4, 1Ag, 3Ag, 1Pt, and 3Pt). A study of the cytotoxicity of the compounds in lung carcinoma (A-549) and fetal lung fibroblast (MRC-5) cell lines was performed. Compounds 1, 2, 1Ag, 2Ag, 3Ag, 1Pt, 3Pt, and 4Pt were more active against A-549 cells than cisplatin. Complexes 3Ag and 1Pt showed an acceptable SI and better selectivity than cisplatin, proving that silver(I) complexes and Pt(polyfluorophenyl) complexes are valuable options in searching for new antitumoral drugs. Full article

(This article belongs to the Special Issue Noble Metals in Medicinal Inorganic Chemistry)

► Show Figures

Figure 1

15 pages, 7521 KiB

Open AccessArticle

A Novel Fluorescent Chemosensor Based on Rhodamine Schiff Base: Synthesis, Photophysical, Computational and Bioimaging Application in Live Cells

by Oyedoyin Aduroja, Roosevelt Shaw, Sisay Uota, Isaac Abiye, James Wachira and Fasil Abebe

Inorganics 2025, 13(1), 5; https://doi.org/10.3390/inorganics13010005 - 27 Dec 2024

Viewed by 504

Abstract

A novel rhodamine-6G derivative RdN was synthesized by condensing rhodamine glyoxal and 3-hydroxy-2-naphthoic hydrazide using a microwave irradiation-assisted reaction. Colorimetric and photophysical studies have demonstrated that the molecule produced can selectively sense Pb²⁺ and Cu²⁺ ions in a solution of CH [...] Read more.

A novel rhodamine-6G derivative RdN was synthesized by condensing rhodamine glyoxal and 3-hydroxy-2-naphthoic hydrazide using a microwave irradiation-assisted reaction. Colorimetric and photophysical studies have demonstrated that the molecule produced can selectively sense Pb²⁺ and Cu²⁺ ions in a solution of CH₃CN/H₂O (9:1, v/v). The spirolactam ring of RdN opens upon complexation with the cations, forming a highly fluorescent complex and a visible color change in the solution. The compound RdN was further studied with the help of computational methods such as the Density Functional Theory (DFT) method and time-dependent density theory (TD-DFT) calculations to study the binding interactions and properties of the molecule. DFT calculations and job plot data supported the 2:1 complex formation between RdN and Pb²⁺/Cu²⁺. The limit of detection for Pb²⁺ was determined to be 0.112 µM and 0.130 µM for Cu²⁺. The probe RdN was applied to the image of Pb²⁺ and Cu²⁺ ions in living cells and is safe for biomedical applications. It is used to monitor Pb²⁺ in environmental water samples. Full article

(This article belongs to the Special Issue Synthesis and Application of Luminescent Materials, 2nd Edition)

► Show Figures

Figure 1

31 pages, 6154 KiB

Open AccessReview

Recent Advances and Future Prospects of Lithium Recovery from Low-Grade Lithium Resources: A Review

by Jihan Gu, Binjun Liang, Xianping Luo, Xin Zhang, Weiquan Yuan, Bin Xiao and Xuekun Tang

Inorganics 2025, 13(1), 4; https://doi.org/10.3390/inorganics13010004 - 26 Dec 2024

Viewed by 658

Abstract

The growing demand for lithium, driven by the widespread adoption of electric vehicles and renewable energy storage systems, has sparked interest in developing low-grade lithium resources. This comprehensive review explores the types, distribution, extraction technologies, challenges, and future prospects of low-grade lithium resources. [...] Read more.

The growing demand for lithium, driven by the widespread adoption of electric vehicles and renewable energy storage systems, has sparked interest in developing low-grade lithium resources. This comprehensive review explores the types, distribution, extraction technologies, challenges, and future prospects of low-grade lithium resources. This article focuses on low-grade lithium sources such as clays, brines, coal, and coal by-products, and analyzes the principles, advantages, and limitations of key extraction techniques, including acid-alkaline leaching, bioleaching, adsorption, and membrane separation. Furthermore, this review discusses the technical, economic, and environmental sustainability challenges associated with developing low-grade lithium resources and proposes corresponding strategies. Future research should focus on improving the selectivity and efficiency of extraction and processing technologies, optimizing separation processes, and developing green and cost-effective extraction methods. Establishing supportive policy frameworks, strengthening international cooperation, and knowledge sharing are crucial for promoting the sustainable development of low-grade lithium resources. This review provides stakeholders with comprehensive insights and recommendations for addressing the growing lithium demand and achieving the Sustainable Development Goals. Full article

(This article belongs to the Special Issue Novel Materials in Li–Ion Batteries)

► Show Figures

Figure 1

41 pages, 13240 KiB

Open AccessReview

Beyond Cations: Expanding the Horizons of Ferrocene-Based Electrochemical Sensors for Neutral and Anionic Molecules

by Angel A. J. Torriero, Alma M. Torriero, Kiara T. Miller and Ashwin K. V. Mruthunjaya

Inorganics 2025, 13(1), 3; https://doi.org/10.3390/inorganics13010003 - 26 Dec 2024

Viewed by 447

Abstract

Ferrocene (Fc) has long been celebrated for its remarkable redox properties and structural versatility, making it a cornerstone of electrochemical sensor development. While extensive research has focused on cation detection using Fc-based systems, the equally critical recognition of neutral and anionic molecules remains [...] Read more.

Ferrocene (Fc) has long been celebrated for its remarkable redox properties and structural versatility, making it a cornerstone of electrochemical sensor development. While extensive research has focused on cation detection using Fc-based systems, the equally critical recognition of neutral and anionic molecules remains underexplored despite their significance in biological, environmental, and industrial contexts. This review addresses this gap by exploring the latest advancements in Fc-based electrochemical sensors designed to overcome the unique challenges posed by these species—including diverse geometries, high hydration enthalpies, and the absence of formal charge. Molecular architectures such as amide-functionalised receptors, urea derivatives, Lewis acid-containing receptors, triazolium, and carboxylic acid-containing systems are examined, highlighting how these sensors achieve high selectivity and sensitivity. Furthermore, the influence of solvent environments on sensor performance is discussed, providing a critical analysis of how different receptor functionalities and solvents affect sensor behaviour. Emphasising the advantages of redox-based detection, this review aims to inspire further innovation in developing Fc-based technologies for detecting neutral and anionic species. Full article

(This article belongs to the Special Issue Research on Ferrocene and Ferrocene-Containing Compounds)

8 pages, 525 KiB

Open AccessArticle

Evaluation of Solubility and Complexation Ability of Vanillic, Syringic and Gallic Acids Towards Aluminum Cation

by Donatella Aiello, Tiziana Marino, Anna Napoli, Emilia Furia and Pierluigi Plastina

Inorganics 2025, 13(1), 2; https://doi.org/10.3390/inorganics13010002 - 25 Dec 2024

Viewed by 355

Abstract

Chelation therapy is currently successfully applied to reduce the aluminum burden and its neurodegenerative consequences. In view of a possible application to aluminum chelation therapy, here we have studied the complexation of hydroxybenzoic acids, namely, vanillic, syringic and gallic acids, towards aluminum ion [...] Read more.

Chelation therapy is currently successfully applied to reduce the aluminum burden and its neurodegenerative consequences. In view of a possible application to aluminum chelation therapy, here we have studied the complexation of hydroxybenzoic acids, namely, vanillic, syringic and gallic acids, towards aluminum ion at physiologically relevant conditions as regards temperature (37 °C) and ionic strength (i.e., 0.16 M NaCl). The solubility values and the protonation constants of the hydroxybenzoic acids were primarily assessed to estimate the competition of these acids towards aluminum and H⁺ ions. Then, potentiometric titrations were carried out, and the speciation analysis indicated a pH-dependent complexation occurring at a 1:1 hydroxybenzoic acid-to-aluminum ratio for vanillic and syringic, and 1:1, 2:1 and 3:1 ligand-to-Al(III) ratios for gallic. Gallic acid forms more stable complexes with Al(III) ion than vanillic and syringic acids and could therefore represent a good candidate for being used as sequestering agents for Al(III) ion. Full article

► Show Figures

Figure 1

14 pages, 4053 KiB

Open AccessArticle

Allosteric Fluorescent Detection of Saccharides and Biomolecules in Water from a Boronic Acid Functionalized Arene Ruthenium Assembly Hosting Fluorescent Dyes

by Alaa Maatouk, Thibaud Rossel and Bruno Therrien

Inorganics 2025, 13(1), 1; https://doi.org/10.3390/inorganics13010001 - 24 Dec 2024

Viewed by 537

Abstract

A water-soluble arene ruthenium metalla-rectangle (MR1) functionalized with boronic acid groups was used to host various fluorescent dyes (fluorescein, eosin Y, and erythrosin B). These simple host–guest systems partially quench the natural fluorescence of the dyes, which can be regained in the presence [...] Read more.

A water-soluble arene ruthenium metalla-rectangle (MR1) functionalized with boronic acid groups was used to host various fluorescent dyes (fluorescein, eosin Y, and erythrosin B). These simple host–guest systems partially quench the natural fluorescence of the dyes, which can be regained in the presence of saccharides, phosphorylated molecules, and other analytes. The intensity of the regained fluorescence is directly linked to the nature of the analyte, and it shows some dose–response relationships with saccharides and phosphorylated molecules that are not compatible with a displacement assay, thus suggesting an allosteric mechanism. Interestingly, when fluorescein is trapped by the metalla-rectangle in the presence of D-fructose, half of the maximum fluorescence intensity is recovered at a fructose concentration of 17.2 ± 4.7 μM, while, for D-glucose, a concentration of 50.6 ± 2.5 μM is required for the same effect. Indeed, all combinations of analyte–host–dye (seven analytes, one host, three dyes) show a unique dose–response relationship in water at pH 8.0. However, in the presence of naphthalene and pyrene, fluorescein⸦MR1 shows a different behavior, acting as an indicator displacement assay with the full recovery of fluorescence. All data were analyzed by unsupervised machine learning technologies (PCA and cluster analysis), suggesting that such systems with multiple analyte–response behaviors are offering new perspectives for the development of highly sensitive, easily tunable, water-soluble, fluorescent-based sensing arrays for biomolecules and other analytes. Full article

► Show Figures

Graphical abstract

Journal Menu

Journal Browser

Inorganics, Volume 13, Issue 1 (January 2025) – 28 articles

Further Information

Guidelines

MDPI Initiatives

Follow MDPI