Kamil Lang

Institute of Inorganic Chemistry of the Czech Academy of Sciences, Řež, Czech Republic · Department of Material Chemistry

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 (BBr3/i‐Pr2NEt) and formed BBr2 chelate was reduced with LiAlH4 to yield arylpyridine boron dihydride. Elimination o...

Luminescence is observed in three novel macropolyhedral nineteen‐ and eighteen‐vertex chalcogenaboranes: Se2B17H17 (1), SeB17H19 (3) and SeB18H20 (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 S2B17H17 (2)...

Luminescence is observed in three novel macropolyhedral nineteen‐ and eighteen‐vertex chalcogenaboranes: Se2B17H17 (1), SeB17H19 (3) and SeB18H20 (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 S2B17H17 (2)...

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, O2(¹Δg), by octahedral molybdenum (Mo6) clusters upon X-ray irradiation allows for simplification of the architecture of radiosensitiz...

Subphthalocyanines (SubPcs) and their aza-analogues (SubTPyzPz) are fluorophores with strong orange fluorescence emission, however, their sensing ability towards metal cations remains uncharted. To fill this gap, we have developed an...

Metal-organic frameworks (MOFs) are studied for many applications, however, there are only a few examples of commercialization. One of the reasons is that the stability of MOFs is still unknown....

Radiodynamic therapy treats deep-seated tumors by exploiting radiosensitizers (RSs) that are delivered to tumors and produce reactive oxygen species upon X-ray irradiation. Octahedral molybdenum clusters (Mo6) have shown promise as RSs, but their direct administration is hampered by their limited stability and low solubility in the biological mediu...

Borane cluster-based porous covalent networks, named activated borane (ActB), were prepared by cothermolysis of decaborane(14) (nido-B10H14) and selected hydrocarbons (toluene, ActB-Tol; cyclohexane, ActB-cyHx; and n-hexane, ActB-nHx) under anaerobic conditions. These amorphous solid powders exhibit different textural and Lewis acid (LA) properties...

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 compone...

Borane cluster based porous covalent networks, named activated borane (ActB), were prepared by co-thermolysis of decaborane(14) (nido-B10H14) and selected hydrocarbons (toluene – ActB-Tol, cyclohexane – ActB-cyHx, and n-hexane – ActB-nHx) under anaerobic conditions. These amorphous solid powders exhibit different textural and Lewis acid (LA) proper...

Design of self-sterilizing materials for protecting surfaces from pathogenic microorganisms is of profound interest in the medical community. In this study, we have prepared textile materials composed of cotton fabrics and octahedral molybdenum cluster complex, [{Mo6I8}(DMSO)6](NO3)4 (DMSO – dimethyl sulfoxide), with photoactivated antibacterial, a...

Photodynamic applications requires efficient intracellular uptake of the photosensitizer that can be achieved through the development of nanoscaled delivery system. Herein, we prepared PEGylated poly(lactic-co-glycolic acid) nanoparticles doped with an octahedral molybdenum cluster complex bearing iodine inner ligands and o-carborane carboxylate ap...

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 vi...

The action of AlCl3 on room-temperature tetrachloromethane solutions of anti-B18H22 (1) results in a mixture of fluorescent isomers, 3,3′-Cl2-B18H20 (2) and 3,4′-Cl2-B18H20 (3), together isolated in a 76% yield. Compounds 2 and 3 are capable of the stable emission of blue light under UV-excitation. In addition, small amounts of other dichlorinated...

The luminescent octahedral molybdenum, tungsten, and rhenium cluster complexes have attracted a broad interest in the past decades for the design of photofunctional materials. These complexes, with the general formula [{M6Li8}La6] n , display red phosphorescence with high quantum yields, quenching of their emission by oxygen, and robust production...

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 4 @oCBT, Cu 4 @mCBT and Cu 4 @ICBT, protected by nearly isomeric carborane thiols: ortho-carborane-9-thiol, meta-carborane-9-thiol a...

The unprecedented co‐thermolysis of decaborane(14) (nido‐B10H14) 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 m² g⁻¹ (Ar, 87 K) that is thermally stable up to 1000 °C. Solid state ¹H, ¹¹B and ¹³C MAS NMR, UV‐vis and...

Photo/radiosensitizers, such as octahedral molybdenum clusters (Mo6), 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 therapeu...

As a preliminary step toward its condensation into the porous polymer Activated Borane, the thermolysis of nido-B10H14 (1) in benzene at 200 °C results in the generation of a number of phenylated borane molecular species. The principal product is the new monophenylated compound 5-Ph-nido-B10H13 (2), isolated in 48% yield (based on consumption of 1)...

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, reducin...

The unprecedented co-thermolysis of nido-decaborane (B10H14) and toluene results in a novel porous material (that we have named “Activated Borane”) containing micropores of 1.0 and 1.5 nm in diameter and a specific surface area of 774 m2 g-1 (Ar, 87 K) that is thermally stable up to 1000 oC. Solid-state 1H, 11B and 13C MAS NMR, UV-vis and IR spectr...

Photosensitizers, which produce singlet oxygen O2(¹Δg) under light irradiation, have attracted much attention due to their application potential in medicine and material science. In this respect, we recently reported on cationic metallocene complexes with pendant N-donor moieties, which exhibited enhanced luminescence in the solid-state originating...

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 - photosensitiz...

Diaryl and dialkyl phosphinic acids are diverse groups of ligands capable of bonding to a wide variety of metal ions. This review provides a brief overview of their synthesis methods, and summarizes various functions and binding motifs phosphinic acids can have in the area of materials chemistry. The combination of these characteristics allows for...

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 co...

UiO-66 is a zirconium-based metal-organic framework (MOF) that has numerous applications. Our group recently determined that UiO-66 is not as inert in aqueous dispersions as previously reported in the literature. The present work therefore assessed the behaviour of UiO-66 in buffers: 2-amino-2-(hydroxymethyl)-1,3-propanediol (TRIS), 4-(2-hydroxyeth...

We present the first examples of alkylated derivatives of the macropolyhedral boron hydride, anti-B18H22, 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. T...

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, O2(1Δg), produced by photosensitizers upon light irradiation has become an attractive strategy to combat drug-resistant...

div> UiO-66 is a zirconium-based metal-organic framework (MOF) that has numerous applications. Our group recently determined that UiO-66 is not as inert in aqueous dispersions as previously reported in the literature. The present work therefore assessed the behaviour of UiO-66 in buffers: 2-amino-2-(hydroxymethyl)-1,3-propanediol (TRIS), 4-(2-hydro...

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 {Mo6I8}4+ core with 4'-carboxybenzo-15-crown-5 or cholate apical ligands and were characterized by 1H NMR, HR ESI-MS, and CHN elemental ana...

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 Fe3+ and Al3+ metal ions and bisphosphinate linkers. The isoreticular design leads to ICR-2, ICR-6, and ICR-7 MOFs with a honeycomb arrangement of lin...

Methylation of anti-B18H22 (1) affords the first example of alkyl substitution of terminal hydrogen atoms on the fluorescent octadecaborane-22 molecule to give highly methylated 2,2'-Cl2-1,1',3,3',4,4',7,7',8,8',10,10'-Me12-anti-B18H8 (2). This extensive chemical substitution leads to a swelling in the polyhedral volume of the 18-vertex boron atomi...

Herein, we introduce a new series of highly stable MOFs, constructed using Fe³⁺ and Al³⁺ metal ions and bisphosphinate linkers. The isoreticular design leads to ICR-2, ICR-4, ICR-6, and ICR-7 MOFs with a honeycomb arrangement of linear pores, surface areas up to 1360 m² g^-1, and high solvothermal stabilit...

Recent studies have unraveled the potential of octahedral molybdenum cluster complexes (Mo6) as relevant red phosphors and photosensitizers of singlet oxygen, O2(1Δg), for photobiological applications. However, these complexes tend to hydrolyze in an aqueous environment, which deteriorates their properties and limits their applications. To address...

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 B20H18²⁻ isomers reported by Hawthorne and Pilling in 1966, whose mechanism had not been understood so far. We investigate the rearrang...

Treatment of the laser borane anti-B18H22 (compound 1) with iodine in ethanol gives the monoiodinated derivative 7-I-anti-B18H21 (compound 2) in 67% yield, or, by reaction with iodine or ICl in the presence of AlCl3 in dichloromethane, the diiodinated derivative 4,4'-I2-anti-B18H20 (compound 3) in 85% yield. On excitation with 360 nm light, both co...

The first Ce(III)-based coordination polymer ICR-9 (ICR stands for Inorganic Chemistry Řež), with the formula Ce2(C8H10P2O4)3, containing ditopic phenylene-1,4-bis(methylphosphinic acid) linker, was synthetized under solvothermal conditions. The crystal structure, solved using electron diffraction tomography (EDT), revealed 2D layers of octahedrall...

The spatiotemporal sensing of specific cationic and anionic species is crucial for understanding the processes occurring in living systems. Herein, we developed new fluorescence sensors derived from tetrapyrazinoporphyrazines (TPyzPzs) with a recognition moiety that consists of an aza-crown and supporting substituents. Their sensitivity and selecti...

The development of water-soluble hexanuclear cluster complexes of low toxicity is a promising task due to their potential in biomedical applications such as bioimaging and photodynamic therapy. Herein, we present the syntheses of two new water-soluble hexarhenium cluster complexes with terminal amphiphilic phosphine ligands, and delineate their pho...

Octahedral molybdenum cluster complexes have recently come forth as pertinent singlet oxygen photosensitizers towards biological applications. Still, their phototoxic efficiency in the absence of nanocarrier remains limited in reason of poor cellular uptake. Here, two cationic octahedral molybdenum cluster complexes, bearing carboxylate ligands wit...

Despite the apparent diversity of the protocols developed for the synthesis of helicenes, they essentially follow the same strategy: the closure of one, or several, internal rings in a key step. Herein, we report the synthesis of a new family of the heterohelicenes consisting of fused silacyclopentadiene rings formed via a facile and novel process....

Despite the apparent diversity of the protocols developed for the synthesis of helicenes, they essentially follow the same strategy: the closure of one, or several, internal rings in a key step. Herein, we report the synthesis of a new family of the heterohelicenes consisting of fused silacyclopentadiene rings formed via a facile and novel process....

Nanosized porphyrin-containing metal-organic frameworks (MOFs) attract considerable attention as solid-state photosensitizers for biological applications. In this study, we have for the first time synthesised and characterised phosphinate-based MOF nanoparticles, nanoICR-2 (Inorganic Chemistry Rez). We demonstrate that nanoICR-2 can be decorated wi...

Zirconium-based metal−organic frameworks were recently investigated as catalysts for degradation of organophosphate toxic compounds, such as pesticides or chemical warfare agents. The most utilized UiO-66 is considered as a stable material for these applications in an aqueous environment. However, the presented results indicate that the properties...

The development of effective photosensitizers is particularly attractive for photodynamic therapy of cancer. Three novel porphyrin photosensitizers functionalized with phosphinic groups were synthesized and their physicochemical, photophysical, and photobiological properties were collected. Phosphinic acid groups (R1R2POOH) attached to the porphyri...

Invited for the cover of this issue is Anton A. Ivanov, Mohamed Haouas, Stéphane Cordier, Pavel Abramov, Emmanuel Cadot, and co‐workers involved within the CLUSPOM‐CNRS International Laboratory, including the Nikolaev Institute of Inorganic Chemistry (Novosibirsk, Russia) University of Versailles Saint Quentin and University of Rennes 1 (France). T...

Rhenium‐containing octahedral clusters [Re6Q8(CN)6]4− with Q=S, Se or Te exhibit high propensity to interact with γ‐cyclodextrin in aqueous solutions, leading to host–guest supramolecular assemblies, driven by the chaotropic nature of these ions. Encapsulation processes give rise to significant alterations of the intrinsic physical–chemical propert...

Water‐soluble salts of anionic [Re6Q8(CN)6]4‐ (Q = S, Se, Te) chalcogenide octahedral rhenium clusters react with γ‐cyclodextrin (γ‐CD) producing a new type of inclusion compounds. Crystal structures determined through single‐crystal X‐ray diffraction analysis revealed supramolecular host‐guest assemblies resulting from close encapsulations of the...

The use of radiosensitizers recently emerged as a promising approach to circumvent the depth penetration limitations of photodynamic therapy of cancer and to enhance radiotherapeutical effects. A widely explored current strategy is based on complex nanoarchitectures that facilitate the transfer of energy harvested from X-ray radiation by scintillat...

Microbial colonization of biomedical devices is a recognized complication contributing to healthcare-associated infections. One of the possible approaches to prevent surfaces from the biofilm formation is antimicrobial photodynamic inactivation, based on the cytotoxic effect of singlet oxygen, O2(¹Δg), a short-lived, highly oxidative species, produ...

Reaction of anti -B 18 H 221 with pyridine in neutral solvents gives sparingly soluble B 16 H 18 -3′,8′-Py 23a as the major product (ca. 53 %) and B 18 H 20 -6′,9′-Py 22 (ca. 15 %) as the minor...

The singlet oxygen photogeneration, cellular uptake kinetics, subcellular localization and in vitro photoinduced oxidative stress, and the dark and photodynamic cytotoxicity of octahedral rhenium cluster complexes [{Re6Q8}(CN)6]⁴⁻, where Q = S, Se, Te, were investigated. The results have demonstrated that the complexes penetrate through cell membra...

We report the synthesis and characterization of sulfonated polystyrene nanoparticles (average diameter 30 ± 14 nm) with encapsulated 5,10,15,20-tetraphenylporphyrin or ionically entangled tetracationic 5,10,15,20-tetrakis(N-methylpyridinium-4-yl)porphyrin, their photooxidation properties and the application of singlet oxygen-sensitized delayed fluo...

We report intensive visible light radioluminescence upon X-ray irradiation of archetypal tetranuclear copper(I) iodide complexes containing triphenylphosphine or pyridine ligands in the solid state. These properties, attractive for the design of X-ray responsive materials, can be attributed to the heavy {Cu4I4} cubane-like core, the absence of oxyg...

The photocytotoxic activity of porphyrin-containing materials including metal-organic frameworks (MOFs) has attracted ever increasing interest. We have developed a simple synthesis of hexagonal PCN-222/MOF-545 nanoparticles, which are powerful in inducing reactive oxygen species-mediated apoptosis of cancer cells upon visible light irradiation. The...

Highly luminescent anisotropic materials are promising for light harvesting systems, sensors, solid lasers and optical devices. To achieve this, polyethylene glycol (PEG) was derivatized with a reactive rhodamine B (RhB) fluorophore to produce a luminescent, water-soluble and positively-charged polymer (RhPEG) that can be intercalated between layer...

This paper reports the synthesis, characterization, and electrochemical performance of nickel-cobalt hydroxide nanosheets. The hydroxide nanosheets of approximately 0.7 nm thickness were prepared by delamination of layered nickel-cobalt hydroxide lactate in water and formed transparent colloids that were stable for months. The nanosheets were depos...

B18H20(NC5H5)2 is a rare example of two conjoined boron hydride subclusters of nido and arachno geometrical character. At room temperature, solutions of B18H20(NC5H5)2 emit a 690 nm fluorescence. In the solid state, this emission is shifted to 620 nm and intensifies due to restriction of the rotation of the pyridine ligands. In addition, there is a...

The design and preparation of highly active heterogeneous palladium catalysts is attracting ever-increasing attention. In this paper, we report on the self-assembly of palladium centers and an octahedral molybdenum cluster complex bearing phosphine terminal ligands. This leads to a coordination polymer exhibiting high catalytic activity in the Suzu...

Novel non-toxic materials with antimicrobial surfaces are needed for medicinal applications. Potential alternatives for bacterial inactivation include materials that produce singlet oxygen, O2(1Δg), a short-lived, highly oxidative, and cytotoxic species. We synthesized a promising group of materials, porphyrin-based conjugated microporous polymers...

A series of zinc azaphthalocyanines with two azacrowns in a rigid tweezer arrangement were prepared and the fluorescence sensing properties were investigated. The size-driven recognition of alkali and alkaline earth metal cations was significantly enhanced by the close cooperation of the two azacrown units, in which both donor nitrogen atoms need t...

Newly synthesized octahedral molybdenum cluster compound (n-Bu4N)2[Mo6I8(OOC-1-adamantane)6] revealed uncharted features applicable for the development of X-ray inducible luminescent materials and sensitizers of singlet oxygen, O2((1)Δg). The compound exhibits a red-NIR luminescence in the solid state and in solution (e.g., quantum yield of 0.76 in...

This review aims to summarize the current status of photoactivatable nanostructured film and polymeric nanofiber surfaces used in biomedical applications with emphasis on their photoantimicrobial activity, oxygen-sensing in biological media, light-triggered release of drugs, and physical or structural transformations. Many light-responsive function...

This work describes the multistep Förster resonance energy transfer (FRET) among laser dyes adsorbed onto the nanoparticles of a layered silicate, saponite (Sap). Six cationic laser dyes with appropriate spectral properties to fit the resonance conditions were selected. Fluorescence spectroscopy proved cascade FRET in the experiments based on hybri...