Lanthanide Oxalates: From Single Crystals to 2D Functional Honeycomb Nanosheets.

Oxalates are simple, low-cost but crucial compounds in the technology of lanthanides, actinides, and transition metals. Apart from using oxalate as a versatile ligand in coordination chemistry, simple oxalate salts are still under a scientific focus, linked with ion batteries, optical and magnetic materials, and, most importantly, industrial-technological mining and separation loops. The typically low solubility of oxalate salts is advantageous from the viewpoint of a convenient and affordable synthesis requiring only green solvents.

Preparation, Structure, Reactivity, Lewis Acidic and Fluorescence Properties of Arylpyridine Based Boron C,N-Chelates Featuring Weakly Coordinating Anions.

Herein, we present the preparation of a series of electronically and/or sterically distinct borenium-type species based on a simple 2-arylpyridine scaffold. Corresponding arylpyridine was firstly subjected to electrophilic borylation (BBr/i-PrNEt) and formed BBr chelate was reduced with LiAlH to yield arylpyridine boron dihydride. Elimination of one hydride led to Lewis acidic borenium-like products.

Expanding Luminescence Horizons in Macropolyhedral Heteroboranes.

Luminescence is observed in three novel macropolyhedral nineteen- and eighteen-vertex chalcogenaboranes: SeBH (1), SeBH (3) and SeBH (4). This led us to the recognition that previously published macropolyhedral heteroborane species might also exhibit luminescence. Thus, the known nineteen- and eighteen-vertex dithiaboranes SBH (2), n-SBH (5) and i-SBH (6) were synthesised and also found to exhibit a range of luminescent properties.

PEGylated Molybdenum-Iodine Nanocluster as a Promising Radiodynamic Agent against Prostatic Adenocarcinoma.

The combination of photodynamic therapy and radiotherapy has given rise to a modality called radiodynamic therapy (RDT), based on reactive oxygen species-producing radiosensitizers. The production of singlet oxygen, O(Δ), by octahedral molybdenum (Mo) clusters upon X-ray irradiation allows for simplification of the architecture of radiosensitizing systems. In this context, we prepared a radiosensitizing system using copper-free click chemistry between a Mo cluster bearing azido ligands and the homo-bifunctional linker bis-dPEG-DBCO.

Subphthalocyanines as fluorescence sensors for metal cations.

Subphthalocyanines (SubPcs) and their aza-analogues (SubTPyzPzs) are fluorophores with strong orange fluorescence emission; however, their sensing ability towards metal cations remains uncharted. To fill this gap, we have developed an efficient method for introducing aza-crown moieties at the axial position of SubPcs and SubTPyzPzs to investigate the structure-activity relationship for sensing alkali (Li, Na, K) and alkaline earth metal (Ca, Mg, Ba) cations. SubPcs showed better photostability than SubTPyzPzs and even a commonly utilized dye, 6-carboxyfluorescein.

"Activated Borane": A Porous Borane Cluster Polymer as an Efficient Lewis Acid-Based Catalyst.

Borane cluster-based porous covalent networks, named activated borane (), were prepared by cothermolysis of decaborane(14) (-BH) and selected hydrocarbons (toluene, cyclohexane, ; and -hexane, ) under anaerobic conditions. These amorphous solid powders exhibit different textural and Lewis acid (LA) properties that vary depending on the nature of the constituent organic linker. For , its LA strength even approaches that of the commonly used molecular LA, B(CF).

Graphene Oxide Sheets Decorated with Octahedral Molybdenum Cluster Complexes for Enhanced Photoinactivation of .

The emergence of multidrug-resistant microbial pathogens poses a significant threat, severely limiting the options for effective antibiotic therapy. This challenge can be overcome through the photoinactivation of pathogenic bacteria using materials generating reactive oxygen species upon exposure to visible light. These species target vital components of living cells, significantly reducing the likelihood of resistance development by the targeted pathogens.

Multifunctional Oxidized Dextran as a Matrix for Stabilization of Octahedral Molybdenum and Tungsten Iodide Clusters in Aqueous Media.

Due to their high abundance, polymeric character, and chemical tunability, polysaccharides are perfect candidates for the stabilization of photoactive nanoscale objects, which are of great interest in modern science but can be unstable in aqueous media. In this work, we have demonstrated the relevance of oxidized dextran polysaccharide, obtained via a simple reaction with HO, towards the stabilization of photoactive octahedral molybdenum and tungsten iodide cluster complexes [MI}(DMSO)](NO) in aqueous and culture media. The cluster-containing materials were obtained by co-precipitation of the starting reagents in DMSO solution.

A Window into the Workings of -BH Luminescence-Blue-Fluorescent Isomeric Pair 3,3'-Cl-BH and 3,4'-Cl-BH (and Others).

The action of AlCl on room-temperature tetrachloromethane solutions of -BH () results in a mixture of fluorescent isomers, 3,3'-Cl-BH () and 3,4'-Cl-BH (), together isolated in a 76% yield. Compounds and are capable of the stable emission of blue light under UV-excitation. In addition, small amounts of other dichlorinated isomers, 4,4'-Cl-BH (), 3,1'-Cl-BH (), and 7,3'-Cl-BH () were isolated, along with blue-fluorescent monochlorinated derivatives, 3-Cl-BH () and 4-Cl-BH (), and trichlorinated species 3,4,3'-Cl-BH () and 3,4,4'-Cl-BH ().

Carborane-thiol protected copper nanoclusters: stimuli-responsive materials with tunable phosphorescence.

Atomically precise nanomaterials with tunable solid-state luminescence attract global interest. In this work, we present a new class of thermally stable isostructural tetranuclear copper nanoclusters (NCs), shortly Cu@oCBT, Cu@mCBT and Cu@ICBT, protected by nearly isomeric carborane thiols: -carborane-9-thiol, -carborane-9-thiol and -carborane 12-iodo 9-thiol, respectively. They have a square planar Cu core and a butterfly-shaped CuS staple, which is appended with four respective carboranes.

Octahedral Molybdenum Cluster-Based Nanomaterials for Potential Photodynamic Therapy.

Photo/radiosensitizers, such as octahedral molybdenum clusters (Mo), have been intensively studied for photodynamic applications to treat various diseases. However, their delivery to the desired target can be hampered by its limited solubility, low stability in physiological conditions, and inappropriate biodistribution, thus limiting the therapeutic effect and increasing the side effects of the therapy. To overcome such obstacles and to prepare photofunctional nanomaterials, we employed biocompatible and water-soluble copolymers based on -(2-hydroxypropyl)methacrylamide (pHPMA) as carriers of Mo clusters.

"Activated Borane" - A Porous Borane Cluster Network as an Effective Adsorbent for Removing Organic Pollutants.

The unprecedented co-thermolysis of decaborane(14) (nido-B H ) and toluene results in a novel porous material (that we have named "activated borane") containing micropores between 1.0 and 1.5 nm in diameter and a specific surface area of 774 m  g (Ar, 87 K) that is thermally stable up to 1000 °C.

Avenue to X-ray-induced photodynamic therapy of prostatic carcinoma with octahedral molybdenum cluster nanoparticles.

X-Ray-induced photodynamic therapy represents a suitable modality for the treatment of various malignancies. It is based on the production of reactive oxygen species by radiosensitizing nanoparticles activated by X-rays. Hence, it allows overcoming the depth-penetration limitations of conventional photodynamic therapy and, at the same time, reducing the dose needed to eradicate cancer in the frame of radiotherapy treatment.

A Cell Membrane Targeting Molybdenum-Iodine Nanocluster: Rational Ligand Design toward Enhanced Photodynamic Activity.

The development of singlet oxygen photosensitizers, which target specific cellular organelles, constitutes a pertinent endeavor to optimize the efficiency of photodynamic therapy. Targeting of the cell membrane eliminates the need for endocytosis of drugs that can lead to toxicity, intracellular degradation, or drug resistance. In this context, we utilized copper-free click chemistry to prepare a singlet oxygen photosensitizing complex, made of a molybdenum-iodine nanocluster stabilized by triazolate apical ligands.

Heterogeneous photoactive antimicrobial coatings based on a fluoroplastic doped with an octahedral molybdenum cluster compound.

Despite the wide variety of strategies developed to combat pathogenic microorganisms, the infectious diseases they cause remain a worldwide health issue. Hence, the search for new disinfectants, which prevent infection spread, constitutes an extremely urgent task. One of the most promising methods is the use of photoactive compounds - photosensitizers, capable of generating reactive oxygen species, in particular, singlet oxygen (O2(1Δg)), which causes rapid and effective death of microorganisms of all types.

Luminescent Cationic Group 4 Metallocene Complexes Stabilized by Pendant N-Donor Groups.

Cationic group 4 metallocene complexes with pendant imine and pyridine donor groups were prepared as stable crystalline [B(CF)] salts either by protonation of the intramolecularly bound ketimide moiety in neutral complexes [(η-CMe){η-CHCMeCMeC(R)═N-κ}MCl] (M = Ti, Zr, Hf; R = -Bu, Ph) by PhNMeH[B(CF)] to give [(η-CMe){η-CHCMeCMeC(R)═NH-κ}MCl][B(CF)] or by chloride ligand abstraction from the complexes [(η-CMe)(η-CHCMeCHCHN)MCl] (M = Ti, Zr) by Li[B(CF)]·2.5EtO to give [(η-CMe)(η-CHCMeCHCHN-κ)MCl][B(CF)]. Solid state structures of the new compounds were established by X-ray diffraction analysis, and their electrochemical behavior was studied by cyclic voltammetry.

A water-soluble octahedral molybdenum cluster complex as a potential agent for X-ray induced photodynamic therapy.

X-ray-induced photodynamic therapy (X-PDT) has recently evolved into a suitable modality to fight cancer. This technique, which exploits radiosensitizers producing reactive oxygen species, allows for a reduction of the radiation dose needed to eradicate cancer in the frame of the radiotherapy treatment of deep tumors. The use of transition metal complexes able to directly produce singlet oxygen, O(Δ), upon X-ray irradiation constitutes a promising route towards the optimization of the radiosensitizer's architecture.

Electrophoretically Deposited Layers of Octahedral Molybdenum Cluster Complexes: A Promising Coating for Mitigation of Pathogenic Bacterial Biofilms under Blue Light.

The fight against infective microorganisms is becoming a worldwide priority due to serious concerns about the rising numbers of drug-resistant pathogenic bacteria. In this context, the inactivation of pathogens by singlet oxygen, O(Δ), produced by photosensitizers upon light irradiation has become an attractive strategy to combat drug-resistant microbes. To achieve this goal, we electrophoretically deposited O(Δ)-photosensitizing octahedral molybdenum cluster complexes on indium-tin oxide-coated glass plates.

A Series of Ultra-Efficient Blue Borane Fluorophores.

We present the first examples of alkylated derivatives of the macropolyhedral boron hydride, -BH, which is the gain medium in the first borane laser. This new series of ten highly stable and colorless organic-inorganic hybrid clusters are capable of the conversion of UVA irradiation to blue light with fluorescence quantum yields of unity. This study gives a comprehensive description of their synthesis, isolation, and structural characterization together with a delineation of their photophysical properties using a combined theoretical and experimental approach.

Octahedral Molybdenum Cluster Complexes with Optimized Properties for Photodynamic Applications.

Two new octahedral molybdenum cluster complexes act as an efficient singlet oxygen supplier in the context of the photodynamic therapy of cancer cells under blue-light irradiation. These complexes integrate the {MoI} core with 4'-carboxybenzo-15-crown-5 or cholate apical ligands and were characterized by H NMR, HR ESI-MS, and CHN elemental analysis. Both complexes display high quantum yields of luminescence and singlet oxygen formation in aqueous media associated with a suitable stability against hydrolysis.

Robust Aluminum and Iron Phosphinate Metal-Organic Frameworks for Efficient Removal of Bisphenol A.

Porous metal-organic frameworks (MOFs) have excellent characteristics for the adsorptive removal of environmental pollutants. Herein, we introduce a new series of highly stable MOFs constructed using Fe and Al metal ions and bisphosphinate linkers. The isoreticular design leads to ICR-2, ICR-6, and ICR-7 MOFs with a honeycomb arrangement of linear pores, surface areas up to 1360 m g, and high solvothermal stabilities.

Swollen Polyhedral Volume of the -BH Cluster via Extensive Methylation: -BHClMe.

Methylation of -BH () affords the first example of alkyl substitution of terminal hydrogen atoms on the fluorescent octadecaborane-22 molecule to give highly methylated 2,2'-Cl-1,1',3,3',4,4',7,7',8,8',10,10'-Me--BH (). This extensive chemical substitution leads to a swelling in the polyhedral volume of the 18-vertex boron atomic skeleton of the molecule and an enhancement of the absorption and solubility characteristics of this highly fluorescent molecule. We propose this "swollen polyhedral volume" to be the result of a marked increase in the relative positivity of the "cluster-only total charge" of the boron atomic skeleton caused by the combined electron-withdrawing capacity of the 12 methyl groups.

Phosphinate Apical Ligands: A Route to a Water-Stable Octahedral Molybdenum Cluster Complex.

Recent studies have unraveled the potential of octahedral molybdenum cluster complexes (Mo) as relevant red phosphors and photosensitizers of singlet oxygen, O(Δ), for photobiological applications. However, these complexes tend to hydrolyze in an aqueous environment, which deteriorates their properties and limits their applications. To address this issue, we show that phenylphosphinates are extraordinary apical ligands for the construction of Mo complexes.

Photochromic System among Boron Hydrides: The Hawthorne Rearrangement.

Photoswitchable molecules have attracted wide interest for many applications in chemistry, physics, and materials science. In this work, we revisit the reversible photochemical and thermal rearrangements of the two BH isomers reported by Hawthorne and Pilling in 1966, whose mechanism had not been understood so far. We investigate the rearrangements by means of a joint experimental and computational study with the outcome that BH represents the first boron-based photochromic system ever reported.