Search Results (48)

Effective forest planning in Mediterranean environments requires tools capable of managing ecological complexity, socio-economic pressures, and fragmented governance. This study develops and applies a GIS- and GNSS-based methodological framework for regional forest planning, tested in the “Bosco della Ficuzza, Rocca Busambra, Bosco del Cappelliere, Gorgo del Drago” Regional Nature Reserve (western Sicily, Italy). The main objective is to create a multi-layered Territorial Information System (TIS) that integrates high-resolution cartographic data, a Digital Terrain Model (DTM), and GNSS-based field surveys to support adaptive, participatory, and replicable forest management. The methodology combines the following: (i) DTM generation using Kriging interpolation to model slope and aspect with ±1.2 m accuracy; (ii) road infrastructure mapping and classification, adapted from national and regional forestry survey protocols; (iii) spatial analysis of fire-risk zones and accessibility, based on slope, exposure, and road pavement conditions; (iv) the integration of demographic and land use data to assess human–forest interactions. The resulting TIS enables complex spatial queries, infrastructure prioritization, and dynamic scenario modeling. Results demonstrate that the framework overcomes the limitations of many existing GIS-based systems—fragmentation, static orientation, and limited interoperability—by ensuring continuous data integration and adaptability to evolving ecological and governance conditions. Applied to an 8500 ha Mediterranean biodiversity hotspot, the model enhances road maintenance planning, fire-risk mitigation, and stakeholder engagement, offering a scalable methodology for other protected forest areas. This research contributes an innovative approach to Mediterranean forest governance, bridging ecological monitoring with socio-economic dynamics. The framework aligns with the EU INSPIRE Directive and highlights how low-cost, interoperable geospatial tools can support climate-resilient forest management strategies across fragmented Mediterranean landscapes. Full article

Photocatalysis using complexes of d⁰ metals with ligand-to-metal charge-transfer (LMCT) excited states is an active area of research. Because titanium is the second most abundant transition metal in the earth’s crust, d⁰ complexes of Ti^IV are an appropriate target for this research. Recently, our group has demonstrated that the arylethynyltitanocene Cp₂Ti(C₂Ph)₂CuBr is not emissive in room-temperature fluid solution, whereas the corresponding Cp* complex, Cp*₂Ti(C₂Ph)₂CuBr, is emissive. The Cp* ligand is hypothesized to provide steric constraint that inhibits excited-state structural rearrangement. However, modifying the structure also changes the orbital character of the excited state. To investigate the impact of the excited-state orbital character on the photophysics, herein we characterize complexes similar to Cp*₂Ti(C₂Ph)₂CuBr—but one with a more electron-rich arylethynyl ligand, ethynyldimethylaniline (C₂DMA), and one with a more electron-poor arylethynyl ligand, ethynyl-α,α,α-trifluorotoluene. We have also prepared complexes with the C₂DMA ligand but with different Cp ligands that adjust the steric bulk and constraint around the Ti, by replacing the Cp* ligands with either indenyl ligands or an ansa-cyclopentadienyl ligand where the two Cp ligands are bridged by a dimethylsilylene. All four target complexes have been characterized crystallographically and structure activity relationships are highlighted. Full article

The motivation for increasing the efficiency of renewable energy sources is the basic problem of ongoing research. Currently, intensive research is underway in technology based on the use of dye-sensitized solar cells (DSSCs). The aim of this work is to investigate the effect of modifying the iodide electrolyte with liquid crystals (LCs) known for the self-organization of molecules into specific mesophases. The current–voltage (I-V) and power–voltage (P-V) characteristics were determined for the ruthenium-based dyes N3, Z907, and N719 to investigate the influence of their structure and concentration on the efficiency of DSSCs. The addition of a nematic LC of 4-n-pentyl-4-cyanobiphenyl (5CB) to the iodide electrolyte influences the I-V and P-V characteristics. A modification of the I-V characteristics was found, especially a change in the values of short circuit current (I_SC) and open circuit voltage (V_OC). The conversion efficiency for cells with modified electrolyte shows a complex dependence that first increases and then decreases with increasing LC concentration. It may be caused by the orientational interaction of LC molecules with the titanium dioxide (TiO₂) layer on the photoanode. A too high concentration of LC may lead to a reduction in total ionic conductivity due to the insulating effect of the elongated polar molecules. Full article

Diphosphine compounds have been used as ligands for a variety of metals, and studies on their structures and reactivities are still of interest. We investigated the coordination chemistry of P–P-bonded diphosphine by conducting reactions of bis(1,1′-dibenzophospholyl) (Db)₂P–P(Db)₂ 1 with d⁰-titanium(IV) reagents. The reaction of 1 with TiCl₄ afforded the dinuclear titanium complex Cl₃Ti{μ-(Db)₂P–P(Db)₂}(μ-Cl)₂TiCl₃ 2. The final structure of titanium complex 2 was determined by single-crystal X-ray structural analysis. The molecular structure of the complex was found to be a dinuclear d⁰-titanium complex coordinated to diphosphine on the same side, and the central titanium atoms were bridged to each other by chlorides. To further elucidate this complex, density functional theory (DFT) calculations were conducted to analyze its structure. Full article

This study explores poly(methyl methacrylate) (PMMA)-based composites as potential alternatives to conventional TiO₂-based photocatalysts. Specifically, it examines PMMA composites enriched with oxo–titanium(IV) complexes, [Ti₈O₂(OⁱPr)₂₀(man)₄] (1), [Ti₄O(OⁱPr)₁₀(O₃C₁₄H₈)₂] (2), and [Ti₆O₄(OⁱPr)₂(O₃C₁₄H₈)₄(O₂CEt)₆] (3), alongside ruthenium(III) complexes, K[Ru(Hedta)Cl]∙2H₂O (4) and [Ru(pic)₃]·H₂O (5). We assessed the physicochemical, adsorption, and photocatalytic properties of these composites with structural analyses (Raman spectroscopy, X-ray absorption (XAS), and SEM-EDX), confirming the stability of complexes within the PMMA matrix. Composites containing titanium(IV) compounds demonstrated notably higher photocatalytic efficiency than those with ruthenium(III) complexes. Based on activity profiles, composites were categorized into three types: (i) UV-light active (complexes (1) and (2)), (ii) visible-light active (complexes (4) and (5)), and (iii) dual-range active (complex (3)). The results highlight the strong potential of titanium(IV)–PMMA composites for UV-driven photocatalysis. Moreover, their activity can be extended to the visible range after structural modifications. Ruthenium(III)–PMMA composites, in turn, showed superior performance under visible light. Overall, PMMA composites with titanium(IV) or ruthenium(III) complexes demonstrate promising photocatalytic properties for applications using both UV and visible light ranges. Full article

The recycling of lithium-ion batteries is increasingly important for both resource recovery and environmental protection. However, the complex composition of cathode and anode materials in these batteries makes the efficient separation of metal mixtures challenging. Hydrometallurgical methods, particularly liquid extraction, provide an effective means of separating metal ions, though they require periodic updates to their extraction systems. This study introduces a hydrophobic deep eutectic solvent composed of trioctylphosphine oxide, di(2-ethylhexyl)phosphoric acid, and menthol, which is effective for separating Ti(IV), Co(II), Mn(II), Ni(II), and Li⁺ ions from hydrochloric acid leachates of NMC (LiNi_xMn_yCo_1−x−yO₂) batteries with LTO (Li₄Ti₅O₁₂) anodes. By optimising the molar composition of the trioctylphosphine oxide/di(2-ethylhexyl)phosphoric acid/menthol mixture to a 4:1:5 ratio, high extraction efficiency was achieved. The solvent demonstrated stability over 10 cycles, and conditions for its regeneration were successfully established. At room temperature, the DES exhibited a density of 0.89 g/mL and a viscosity of 56 mPa·s, which are suitable for laboratory-scale extraction processes. Experimental results from a laboratory setup with mixer-settlers confirmed the efficiency of separating Ti(IV) and Co(II) ions in the context of their extraction kinetics. Full article

One method for the colorimetric detection of hydrogen peroxide vapor is based on a titanium–hydrogen peroxide complex. A color changing material based on a titania hydroxypropyl cellulose thin film was initially developed. However, as this material dries, the sensitivity of the material is significantly reduced. Thus, an alternative sensing material, based on titanium(IV) oxysulfate, an ionic liquid, and in some cases, triflouromethanesulfonic acid adsorbed onto low-cost silicon thin-layer chromatography (TLC) plates, was developed. TiO₂ was heated with concentrated sulfuric acid in a controlled environment, usually at temperatures ranging from 100 °C to 250 °C. These sensors are disposable and single-use and are simple and inexpensive. When the resulting thin-film sensors are exposed to ppm levels of hydrogen peroxide vapor, they turn from a white reflective material to an intense yellow or orange. Ti(IV) oxysulfate combined with an acid catalyst and an ionic-liquid-based material provides an opportunity to enhance the sensor activity towards the peroxide vapor and decreases the detection limit. Kinetic measurements were made by the quantification of the intensity of the reflected light as a function of the exposure time from the sensor in a special cell using a low-cost web camera and a tungsten lamp. The measured rate of the color change indicates high sensitivity and first-order kinetics over a hydrogen peroxide concentration range of approximately 2 to 31 ppm. These new materials are a starting point for the preparation of more active sensor materials for hydrogen peroxide and organic peroxide vapor detection. Full article

The efficient adsorption and removal of As(III), which is highly toxic, remains difficult. TiO₂ shows promise in this field, though the process needs improvement. Herein, how doping regulates As(OH)₃ adsorption over TiO₂ surfaces is comprehensively investigated by means of the DFT + D3 approach. Doping creates the bidentate mononuclear (Ce doping at the Ti_5c site), tridentate (N, S doping at the O_2c site), and other new adsorption structures. The extent of structural perturbation correlates with the atomic radius when doping the Ti site (Ce >> Fe, Mn, V >> B), while it correlates with the likelihood of forming more bonds when doping the O site (N > S > F). Doping the O_2c, O_3c rather than the Ti_5c site is more effective in enhancing As(OH)₃ adsorption and also causes more structural perturbation and diversity. Similar to the scenario of pristine surfaces, the bidentate binuclear complexes with two Ti-O_As bonds are often the most preferred, except for B doping at the Ti_5c site, S doping at the O_2c site, and B doping at the O_3c site of rutile (110) and Ce, B doping at the Ti_5c site, N, S doping at the O_2c site, and N, S, B doping at the O_3c site of anatase (101). Doping significantly regulates the As(OH)₃ adsorption efficacy, and the adsorption energies reach −4.17, −4.13, and −4.67 eV for Mn doping at the Ti_5c site and N doping at the O_2c and O_3c sites of rutile (110) and −1.99, −2.29, and −2.24 eV for Ce doping at the Ti_5c site and N doping at the O_2c and O_3c sites of anatase (101), respectively. As(OH)₃ adsorption and removal are crystal-dependent and become apparently more efficient for rutile vs. anatase, whether doped at the Ti_5c, O_2c, or O_3c site. The auto-oxidation of As(III) occurs when the As centers interact directly with the TiO₂ surface, and this occurs more frequently for rutile rather than anatase. The multidentate adsorption of As(OH)₃ causes electron back-donation and As(V) re-reduction to As(IV). The regulatory effects of doping during As(III) adsorption and the critical roles played by crystal control are further unraveled at the molecular level. Significant insights are provided for As(III) pollution management via the adsorption and rational design of efficient scavengers. Full article

The use of endosseous dental implants may become unfeasible in the presence of significant maxillary bone atrophy; thus, surgical techniques have been proposed to promote bone regeneration in such cases. However, such techniques are complex and may expose the patient to complications. Subperiosteal implants, being placed between the periosteum and the residual alveolar bone, are largely independent of bone thickness. Such devices had been abandoned due to the complexity of positioning and adaptation to the recipient bone site, but are nowadays witnessing an era of revival following the introduction of new acquisition procedures, new materials, and innovative manufacturing methods. We have analyzed the changes induced in gene and protein expression in C-12720 human osteoblasts by differently surface-modified TiO₂ materials to verify their ability to promote bone formation. The TiO₂ materials tested were (i) raw machined, (ii) electropolished with acid mixture, (iii) sand-blasted + acid-etched, (iv) AlTiColorTM surface, and (v) anodized. All five surfaces efficiently stimulated the expression of markers of osteoblastic differentiation, adhesion, and osteogenesis, such as RUNX2, osteocalcin, osterix, N-cadherin, β-catenin, and osteoprotegerin, while cell viability/proliferation was unaffected. Collectively, our observations document that presently available TiO₂ materials are well suited for the manufacturing of modern subperiosteal implants. Full article

Research on titanium-oxo complexes (TOCs) is usually focused on their structure and photocatalytic properties. Findings from these investigations further sparked our interest in exploring their potential biological activities. In this study, we focused on the synthesis and structure of a compound with the general formula [Ti₈O₂(OⁱPr)₂₀(man)₄] (1), which was isolated from the reaction mixture of titanium(IV) isopropoxide with mandelic acid (Hman) in a molar ratio of 4:1. The structure (1) was determined using single-crystal X-ray diffraction, while spectroscopic studies provided insights into its physicochemical properties. To assess the potential practical applications of (1), its microcrystals were incorporated into a polymethyl methacrylate (PMMA) matrix, yielding composite materials of the type PMMA + (1) (2 wt.%, 5 wt.%, 10 wt.%, and 20 wt.%). The next stage of our research involved the evaluation of the antimicrobial activity of the obtained materials. The investigations performed demonstrated the antimicrobial activity of pure (1) and its composites (PMMA + (1)) against both Gram-positive and Gram-negative strains. Furthermore, MTT tests conducted on the L929 murine fibroblast cell line confirmed the lack of cytotoxicity of these composites. Our study identified (1) as a promising antimicrobial agent, which is also may be use for producing composite coatings. Full article

Cancer is one of the leading causes of human death among all major diseases. Metal-based complexes are considered as the most promising vital part in the existing arsenal of cytotoxic candidates used in cancer therapy and diagnostics. The efforts of many scientific groups resulted in the development of numerous metal-based compounds featuring different biologically active organic ligands in order to modulate their bioactivity. Along with the main representatives as potential therapeutic agents, such as the complexes Pt(II)/Pt(IV), Pd(II), Ru(II)/Ru(III), Ag(I), Au(I)/Au(III), Ti(IV), V(IV) and Ga(III), many other transition metal and lanthanide complexes possessing antiproliferative activity are widely discussed in the literature. However, such drugs remain outside the scope of this review. The main purpose of the current study is to review the potential activity of main group metal- and metalloid-based complexes against the most common cancer cell types, such as carcinomas (lung, liver, breast, kidney, gastric, colorectal, bladder, ovarian, cervical, prostate, etc.); sarcomas; blastomas; lymphomas; multiple myeloma; and melanoma. Overcoming the long disregard of organometallic compounds of metals and metalloids from the main groups, a growing number of emerging anticancer agents remarkably prove this field offers an extensive variety of new options for the design of innovative unexplored chemopharmaceutics. Moreover, some of the metal complexes and organometallic compounds from these elements can exhibit entirely different, specific modes of action and biological targets. Obviously, exploitation of their distinct properties deserves more attention. Full article

Wastewater discharge from the textile industry poses significant health problems for humans. As a result, the effluent waters are often rich in dyes, whose low natural decomposition capacity makes their treatment complex, thus contributing to environmental degradation. It becomes imperative to implement effective solutions for treating these contaminated waters, with a primary goal: to make them fit for human consumption. The present study focuses on the development of green TiO₂ nanoparticles (TiO₂-NP) using titanium (IV) isopropoxide as a precursor, along with the extract of Astragalus boeticus (A.B). These green TiO₂ nanoparticles have been developed for use as highly efficient photocatalysts for the degradation of two types of dyes: Reactive Yellow 161 (RY161), an anionic dye, and Crystal Violet (CV), a cationic dye. The structural, microstructural, and optical properties of the synthesized material were characterized using XRD, FTIR, SEM, EDX, and UV-Vis methods. The results of these analyses revealed that the nanoparticles have a size of approximately 68 nm, possess an anatase structure, exhibit a spherical surface morphology, and have a band gap of 3.22 eV. The photocatalytic activity of the synthesized material demonstrated a 94.06% degradation of CV dye in a basic environment (pH = 10) within 30 min, with an initial CV concentration of 10 mg/L and a catalyst mass of 1 g/L. Additionally, it achieved a 100% degradation of RY161 dye in an acidic environment (pH = 4) within 90 min, with an initial RY161 concentration of 30 mg/L and a catalyst mass of 1 g/L. Furthermore, the recycling study indicated that the green TiO₂ NPs catalyst could be effectively reused for up to five cycles. These experimental findings suggest that the developed TiO₂ catalyst holds significant potential as an eco-friendly solution for remediating aqueous media polluted by both anionic and cationic dyes. Full article

Sol compositions for transparent TiO₂ and ZnO photocatalytic thin film deposition are of interest for the wet-chemical fabrication of self-cleaning coatings. The choice of stabilizing agent is crucial for the sol film-forming properties, with acetylacetone and monoethanolamine conventionally employed for TiO₂ and ZnO deposition sols, respectively. Salicylic acid (SA), capable of chelating both Ti(IV) and Zn(II) precursors, remains underexplored. This study presents novel SA-based sol formulations for the deposition of both TiO₂ and ZnO films, based on titanium tetraisopropoxide (TTIP) and zinc acetate dihydrate (ZAD) precursors, in a fixed 1:3 (TTIP:SA) and 1:2 (ZAD:SA) ratio, and isopropanol solvent, varied across the 1:10 to 1:20 precursor-to-solvent ratio range. Fourier-Transform Infrared Spectroscopy analysis and Density Functional Theory computations confirmed the formation of H₂Ti[SA]₃ and Zn[SA]₂·2H₂O complexes. Scanning Electron Microscopy, X-ray diffraction, and Ultraviolet-Visible spectroscopy were employed to study the structural and optical properties of the dip-coated films, revealing dense TiO₂ (86–205 nm) and ZnO (35–90 nm) layers of thickness proportional to the salicylate concentration and transmittance in the 70–90% range. Liquid-phase Methylene blue (MB) photooxidation experiments revealed that all films exhibit photocatalytic activity, with ZnO films being superior to TiO₂, with 2.288 vs. 0.366 nm h⁻¹ cm⁻² MB removal rates. Full article

A visible-light-active photocatalyst, SnP/AA@TiO₂, was fabricated by utilizing the coordination chemistry between the axial hydroxo-ligand in the (trans-dihydroxo)(5,10,15,20-tetraphenylporphyrinato)Sn(IV) complex (SnP) and adipic acid (AA) on the surface of TiO₂ nanoparticles. The SnP center was strongly bonded to the surface of the TiO₂ nanoparticles via the adipic acid linkage in SnP/AA@TiO₂, as confirmed by various instrumental techniques. SnP/AA@TiO₂ exhibited remarkably enhanced photocatalytic activity toward the degradation of rhodamine B dye (RhB) in aqueous solution under visible-light irradiation. The RhB degradation efficiency of SnP/AA@TiO₂ was 95% within 80 min, with a rate constant of 0.0366 min⁻¹. The high degradation efficiency, low catalyst loading and high reusability make SnP-anchored photocatalysts more efficient than other photocatalysts, such as TiO₂ and SnP@TiO₂. Full article

The prospect of developing soluble and bioavailable Ti(IV) complex forms with physiological substrates, capable of influencing (patho)physiological aberrations, emerges as a challenge in the case of metabolism-related pathologies (e.g., diabetes mellitus 1 and 2). To that end, pH-specific synthetic efforts on binary Ti(IV)-(α-hydroxycarboxylic acid) systems, involving natural physiological chelator ligands (α-hydroxy isobutyric acid, D-quinic acid, 2-ethyl-2-hydroxybutyric acid) in aqueous media, led to the successful isolation of binary crystalline Ti(IV)-containing products. The new materials were physicochemically characterized by elemental analysis, FT-IR, TGA, and X-ray crystallography, revealing in all cases the presence of mononuclear Ti(IV) complexes bearing a TiO₆ core, with three bound ligands of variable deprotonation state. Solution studies through electrospray ionization mass spectrometry (ESI-MS) revealed the nature of species arising upon dissolution of the title compounds in water, thereby formulating a solid-state–solution correlation profile necessary for further employment in biological experiments. The ensuing cytotoxicity profile (pre-adipocytes and osteoblasts) of the new materials supported their use in cell differentiation experiments, thereby unraveling their structure-specific favorable effect toward adipogenesis and mineralization through an arsenal of in vitro biological assays. Collectively, well-defined atoxic binary Ti(IV)-hydroxycaboxylato complexes, bearing bound physiological substrates, emerge as competent inducers of cell differentiation, intimately associated with cell maturation, thereby (a) associating the adipogenic (insulin mimetic properties) and osteogenic potential (mineralization) of titanium and (b) justifying further investigation into the development of a new class of multipotent titanodrugs. Full article