We present that halogen-substituted and air-stable Thiele-type diradicaloids with folded (1) and planar (2, 3) structures can be obtained by switching the positions of fluorine and chlorine substituents. The strongly distorted p-quinodimethane 1 demonstrates emission in the UV-visible/near-infrared (UV-vis/NIR) range with a photoluminescence quantum yield (PLQY) of 100%, an exceedingly large Stokes shift of up to 2.0 eV, an excited state lifetime of 81 ns, and pronounced solvatochromic emission (from 1.81 eV in n-pentane to approximately 2.0 eV in dichloromethane). Dual emission in pentane, transient absorption spectroscopy, quantum chemical calculations, as well as the comparison with compounds 2 and 3 reveal that the exceptional photophysical properties of closed-shell 1 are thanks to interconversion with its planar conformer 1flat. The key here is that the conformer 1flat, which is generated upon photoexcitation, excels with a pronounced singlet diradical character (y0 = 0.78) and a dark doubly excited (DE) S1 state. Our findings delineate how to leverage conformational equilibria to design bright luminescent materials based on hidden and thus air-stable organic diradicals.

A family of gold(I) complexes bearing N-heterocyclic carbene (NHC) ligands functionalized with a selenoether moiety is reported herein. By combining selenium-containing groups with gold NHC scaffolds, we aimed to develop multifunctional anticancer agents with enhanced efficacy through the simultaneous modulation of multiple biological pathways. All new compounds were subjected to comprehensive spectroscopic characterization, with X-ray crystallographic analysis performed on representative samples. The gold(I) complexes exhibited antiproliferative activity against a wide panel of human cancer cell lines, in both 2D and 3D models, with IC50 values comparable to those displayed by cisplatin. However, the complexes bearing the selenoether moiety showed anticancer activity comparable to that of their non-functionalized counterparts. Mechanistic investigations suggest that the antiproliferative effects are primarily associated with thioredoxin reductase inhibition.

Stable fluorine and chlorine decorated Thiele-like diradicaloids were synthesized and studied in solution and in thin films. Femtosecond transient absorption measurements showed, for both molecules, charge-separated states in solution, but only short-lived singlets in thin films, with no evidence of twisted or charge-separated intermediates. This suppression of excited-state dynamics reflects the strong intermolecular interactions in the solid state and limits their singlet fission potential, highlighting key design challenges for implementing diradicaloids in solid-state optoelectronic and photovoltaic devices.

The effectiveness of a hydrophobic coating based on TEOS/PDMS in protecting Carparo stone, a biocalcarenite characterized by high porosity and poor resistance to atmospheric agents and erosion, was evaluated. The hydrophobic treatment was applied over a pretreatment based on PMMA/ZrO2/SiO2 to promote a uniform distribution on the surface. Micro-tomography analyses demonstrate that pretreatment forms a homogeneous coating on the surface. Scanning electron microscopy investigation shows that the hydrophobic treatment based on TEOS/PDMS spreads across the entire surface. The coating is effective in reducing capillary water absorption, and the coated stones exhibit hydrophobicity, achieving contact angles > 140°. The coating has proven esthetically acceptable based on colorimetric tests. The durability of the treatments was evaluated through artificial aging consisting of rain cycles alternating with UV irradiation cycles. The contact angle tests carried out at the end of each cycle demonstrate that the protective coating is not leached and is still very effective. The new sustainable hydrophobic treatment can be successfully proposed for the protection of porous stones.

Organic It-conjugated materials have revolutionized the landscape of optoelectronics and are now widely used in key technologies such as organic light-emitting diodes (OLEDs), organic photovoltaic cells (OPVs), organic fields transistors (OFETs) and sensors. Today, there is a growing interest in pushing the frontier of organic optoelectronics towards the near infrared (NIR) region, unlocking new applications. In this work, we introduce a novel NIR photoresponsive material active in the 700-1500 nm range, based on inorganic-organic heterojunction architecture. This system pairs molybdenum oxide (MoO3) with a newly developed large band-gap donor molecule featuring a benzodithiophene core and triarylamine unit. The ease of synthesis, good thermal stability and optimal film forming properties of the new donor material make this approach extremely appealing. We show the processing of the heterostructure by vacuum-evaporation, realizing an interfacial charge transfer complex with impressive NIR absorption properties, whose main features have been studied by photoemission and optical absorption techniques. We demonstrated that the hybrid material can be effectively employed in NIR photodetectors.

Catalyst design, variable-temperature experiments and theoretical modelling rationalize SABRE of [1- 13 C]pyruvate, leading to a temperature-jump experimental protocol that selectively enhances the free pyruvate signal.

Supramolecular chemistry enables molecules to dynamically adapt and reorganize in response to their environment, providing a key route to achieving high levels of structural and functional complexity. This work explores a particular strategy for the dynamic and programmable self-assembly of luminescent platinum(II) complexes via sequential coordination-driven and hierarchical processes. The aggregation behavior and optical properties of square-planar Pt(II) complexes bearing a chromophoric terdentate N̂N̂N ligand and exchangeable monodentate ligands are highly dependent on the nature of the ancillary ligand, resulting in morphologically and photophysically distinct supramolecular structures. We demonstrate that these preassembled aggregates undergo dynamic ligand exchange reactions in solution, leading to metastable supramolecular states, including emissive gels, that are accessible exclusively through in situ exchange. Real-time fluorescence microscopy and NMR spectroscopy reveal both homogeneous and heterogeneous exchange pathways, governed by the identity of the initial complex and the incoming ligand. Remarkably, the system exhibits a degree of reversibility and structural memory. These findings establish a framework for stepwise self-assembly that bridges coordination chemistry with noncovalent interactions, offering a versatile platform for designing responsive nanostructures with tailored properties and a step toward adaptive, life-like materials with potential applications in sensing and optoelectronics.

The possibility of pairing the α-emitter 223Ra for targeted α therapy with the γ-emitter 131Ba for SPECT imaging could unlock novel theranostic options in cancer management. However, the lack of stable in vivo chelation for Ra2+/Ba2+ remains a key barrier to clinical use. Four macrocyclic chelators were herein developed by functionalizing 1,10-diaza-18-crown-6 (Kryptofix 22) with donor groups tailored to Ra2+/Ba2+: 2-pyridylphosphonic acid (macrophospho), malonic acid (macromal), catechol (macrocat), and 1,2-HOPO (macroHOPO). The thermodynamic and structural properties of their Ba2+ and Ra2+ complexes were explored in aqueous solution through potentiometry, NMR spectroscopy, X-ray crystallography and DFT calculations. Macromal gave the highest stability constant known so far for a 1:1 Ba2+-to-ligand fully deprotonated complex (logβ = 16.6), even higher than that of Ba2+-macropa, the current state-of-the-art chelator for 223Ra/131Ba. The experimental complex stability followed the order macromal > macropa ≫ macrophospho ∼ macroHOPO > macrocat. Concentration-, temperature-, pH-, and time-dependent radiolabeling were carried out using 223Ra derived from Xofigo residues and cyclotron-produced 131Ba. Although quantitative 223Ra/131Ba incorporation was not achieved, this work expands the scarce coordination chemistry and radiochemistry of the two heaviest alkaline earth (radio)metals.

Gypsum has been largely used since ancient times both as a building material and for create sculptural decorations. In recent years, interest in the use of gypsum as one of the most sustainable mineral binders has grown. However, due to its strong water absorption and poor mechanical properties, it is subject to several physical, chemical and biological degradation processes. To improve the durability and water resistance of gypsum-based plaster artifacts, a new hydrophobic nanocomposite treatment for gypsum is proposed, based on a mixture of Mg (OH)2nanoparticles with size of about 15 nm and TEOS/PDMS solution (commonly referred to as OrMoSil). The reinforcing and protective properties of the treatment were investigated. The treatment was distributed homogeneously inside and on the surface of the samples. Thermal stability is slightly improved by the treatments. The new hydrophobic coating is very effective as a protective agent against water penetration with a capillary water absorption reduced by 40 %. The super-hydrophobic properties are evidenced by a static contact angle greater than 150 degrees with a wettability behaviour similar to the petal effect. Colorimetric measurements show no colour changes even after repeated artificial aging cycles. When embedded into the plaster, the treatment improves the mechanical resistance with respect to reference gypsum: flexural and compressive strength increase of 59 % and 72 %, respectively, and the dynamic elastic modulus of about 35 %. The new hydrophobic nanocomposite can be proposed for the protection and the improvement of mechanical properties of gypsum artifacts both for restoration of cultural heritage artefacts and for building interest.

This study investigates Hispano-Muslim plasterworks, exemplified by the Cuarto Real de Santo Domingo, the Madraza, and the Alhambra in Granada, focusing on cleaning methods to remove oil-based repaintings without damaging the original polychromies. To this end, samples replicating traditional materials (gypsum coating, pigments, and binders) and techniques (tempera painting) were prepared and subjected to an artificial ageing protocol (AAP). Subsequently, cleaning tests aimed at removing the oil repaintings were performed to recover the original polychromies. Analytical techniques, including Fourier Transform Infrared Spectroscopy (FTIR), Gas Chromatography–Mass Spectrometry (GC–MS), and colorimetry, were employed to evaluate ageing effects and cleaning efficacy. Results revealed significant chromatic alterations in vermilion and azurite bound with animal glue, while ochre remained comparatively stable. Chemical analyses indicated marked binder deterioration, including protein denaturation in animal glue and oxidation/polymerization in linseed oil. Cleaning tests demonstrated that both a heptane–acetone gel and a novel polyamidoamine–glycine (PAAGLY) treatment effectively removed oil-based repaintings while preserving the original layers. These findings highlight the critical role of pigment–binder interactions in conservation strategies and advocate for selective, minimally invasive restoration methods.

Hyperpolarized pyruvate is a key molecular probe for biomedical imaging but achieving efficient 13C signal amplification by reversible exchange (SABRE) enhancement remains elusive. Here, we report a comprehensive study integrating catalyst design, systematic experimentation, and advanced theoretical modelling. We synthesized and tested seven Ir-NHC catalysts, spanning the main families of carbene ligands, including previously unexplored variants for pyruvate SABRE. IMes remains the benchmark, delivering ∼3% 13C polarization at 50% parahydrogen enrichment (extrapolated to ∼10% at 100% parahydrogen), but structurally distinct alternatives such as IPr and SIPr achieve only ∼20% lower performance, allowing detection of natural abundance 13C signals in one scan at 1.4 T. DFT calculations indicate that J-couplings between hydrides and 13C nuclei are similar across binding geometries and catalysts, indicating that exchange dynamics-rather than coupling strength-govern polarization efficiency. To clarify this, we performed variable-temperature experiments on both free and catalyst-bound pyruvate. To interpret the observed trends, we developed a detailed mechanistic model that incorporates species concentrations, parahydrogen fraction, exchange kinetics, spin couplings, and relaxation. By leveraging molecular symmetry to reduce Liouville space dimensionality, the model serves as an efficient and predictive tool for SABRE systems. Finally, we apply this framework to devise a SABRE protocol based on a temperature jump designed to selectively enhance the free pyruvate signal. This approach yields an ∼30% increase in free pyruvate polarization at the expense of Ir catalyst-bound forms, with potential for further optimization. Altogether, our work bridges molecular design, theoretical modelling, and protocol development, offering a blueprint for the rational optimization of SABRE hyperpolarization of pyruvate and beyond.

In October 2021, a mural painting was discovered in the crypt of Parma Cathedral (Italy). It was covered by a wall, erasing it form historical memory. The painting, presumably from the 15th–16th century, depicts the Madonna and Child enthroned in the center, between Saints Peter and John. Before the restoration project, investigations were conducted with different techniques to identify the pigments and binders used, the nature of the surface finish and the efflorescence. Micro-Raman spectroscopy detected numerous pigments compatible with the presumed age. An interesting result concerns the presence of crocoite (lead chromate), an unusual and rare pigment for this period. These pigments were confirmed through investigation by means of Scanning Electron Microscopy coupled to Energy-Dispersive X-ray Spectroscopy (SEM-EDS). Fourier Transform Infrared Spectroscopy (FT–IR) and Gas Chromatography/Mass Spectroscopy (GC/MS) were used to identify the binder and the type of wax used in the finish layer. The rather widespread presence of egg, used to spread the paint, allows us to affirm that this mural painting was created as a fresco, with substantial parts a secco.

The need to reduce greenhouse gas emissions has promoted the development of sustainable materials for the building industry to replace ordinary Portland cement (OPC). This work focuses on the development of one-part geopolymer-like binders using calcium-based solid alkaline activators and metakaolin. The alkaline activator was prepared by mixing Ca(OH)2 or CaO and Na-silicate or Ksilicate, all in powders form. XRD, FTIR, TGA/DTG and solid-state NMR analyses show the coexistence of both geopolymer gel and hydrated aluminosilicates. Microscopical investigations show that the morphology of the binders is heterogeneous with micrometric agglomerates. TEM reveals that the binders are characterized by agglomerates of nanoparticles, with abundant amorphous material and rare crystalline phases. The mechanical properties demonstrate the potential of this product as an eco-friendly alternative to OPC. The use of powdered alkaline activators and the production process followed make the product suitable for the building industry to be used on construction sites.

To address the global plastic crisis, recycled plastics from food packaging were used as road materials by the dry method for practical application research. First, the main components of the recycled plastics were identified based on FTIR, and their thermal stability was evaluated through DSC, TG, and microscopic analysis. Then, the workability of the plastic-asphalt mixture was evaluated using the gyratory compaction indicator, void content, and compaction energy index (CEI). Finally, the effect of reused plastics on the cracking resistance of bituminous mixtures was examined with the Superpave IDT test. The results indicate that recycled plastics from food packaging are polyolefin composite materials, primarily consisting of Low-Density Polyethylene (LDPE), Linear Low-Density Polyethylene (LLDPE), High-Density Polyethylene (HDPE), and Polypropylene (PP), and that their thermal stability meets production requirements. Good compaction performance was observed with plastic content below 2% of the aggregate weight, while higher contents reduced void content due to the space occupied by plastics. When the plastic content increased from 0.5% to 2.0%, creep compliance decreased from 68.4% to 77.87%, while the m-value, tensile strength, and elastic energy maximum decreased by 30.77%, 5.6%, and 7%, respectively. In contrast, the failure strain, fracture energy, and maximum DSCE increased by 25.86%, 87.43%, and 133.05%, respectively. The recycled plastic enhanced the toughness of the asphalt mixture, increasing the dissipated energy during crack propagation and improving its resistance to permanent deformation. Moreover, the plastics hindered crack propagation through a bridging effect, leading to fewer cracks within plastic zones compared with surrounding areas. This study provides actionable guidance for the application of composite plastics in asphalt pavements and supports their sustainable development.

Self-assembly via non-covalent interactions is key to constructing complex architectures with advanced functionalities. A noncovalent synthetic chemistry approach, akin to organic chemistry, allows stepwise construction with enhanced control. Here, we explore this by coupling Pt(II) complex self-assembly with a redox reaction. Oxidation to Pt(IV) creates a non-emissive monomer that, upon reduction to Pt(II), forms luminescent gels with unique kinetic and thermodynamic pathways. UV irradiation induces Pt(IV) reduction, generating supramolecular fibers with Pt∙∙∙Pt interactions, enhancing photophysical properties and enabling visible light absorption up to 550 nm. This allows photoselective growth, where fibers convert surrounding Pt(IV) to Pt(II), promoting growth over nucleation, as observed via real-time fluorescence microscopy.

N-Methylation of amines is of great interest in the synthesis of pharmaceuticals and valuable compounds, and the possibility to perform this reaction with an inexpensive and non-toxic substrate like CO2 and its derivatives is quite appealing. Herein, the synthesis of four novel homoleptic Cu(ii) complexes with hybrid NHC-phenolate (NHC = N-Heterocyclic Carbene) ligands is reported, and their use in the catalytic N-methylation of amines with CO2 in the presence of hydrosilanes is explored. Both bidentate or tetradentate ligands can be used in the preparation of the complexes provided that the structural requirement that the two NHC and the two phenolate donors in the metal coordination sphere are mutually in trans is fulfilled. A new reaction protocol to perform the N-methylation of secondary aromatic amines and dibenzylamine in high yield under mild reaction conditions is developed, using the ionic liquid [BMMIM][NTf2] (1-butyl-2,3-dimethylimidazolium bis(trifluoromethylsulfonyl)imide) as solvent and the catalyst precursor [Cu(L2)2]. Reactivity studies indicate that the reaction follows two different pathways with different hydrosilanes, and that the starting Cu(ii) complexes are reduced under the catalytic conditions.

Self-cleaning and hydrophobic treatments based on TiO2 and SiO2 nanoparticles are widely applied for the preservation of cultural heritage materials, to improve their resilience in polluted environments. Excellent results have been obtained on stone materials, but experiments on painted stone surfaces, such as wall paintings and polychrome plasters used in historic buildings, are still limited. In this work, we present a study on the use of water dispersions of TiO2 nanoparticles obtained via sol-gel and organically modified silica (OrMoSil) for cleaning and protective purposes on Lecce stone, a carbonate stone, widely used for its excellent workability but easily attacked by atmospheric agents and pollutants. First, we evaluated the harmlessness of the treatment on Lecce stone through colorimetric tests, water absorption by capillarity and permeability to water vapor. The photocatalytic activity of the TiO2 nanoparticles was assessed by photo-degradation of methyl orange and methylene blue dyes. The dispersion was then applied on painted samples prepared according to ancient recipes to confirm the effectiveness of the cleaning. The proposed TiO2/OrMoSil-based coating can act as a self-cleaning and protective treatment on lithic surfaces to prevent degradation phenomena and preserve the original appearance of the monument.