Inorganics

Cancer remains one of the leading causes of death worldwide. The interest in organometallic complexes as anticancer drug candidates continues to be pivotal for many researchers. Initially underestimated for their therapeutic potentials, rhenium complexes are now slowly gaining momentum. While tricarbonyl complexes of rhenium are widely investigated, dicarbonyl derivatives of the cis-[Re(CO)₂]⁺ core remain largely unexplored. In this study, we tested in vitro a variety of rhenium dicarbonyl complexes for their activity towards three cancer cell lines (A549, MCF-7 and HCT116) and one healthy cell line (HEK293). The most lipophilic compounds showed, like the tricarbonyl species, good activity against specific cancer lines (IC₅₀ = 1.5–2.5 µM); however, the same were also toxic towards healthy cells. In order to understand these differences, we performed a reactivity study of cis-[Re(CO)₂(NN)]⁺ species (where NN = diimine) with biologically relevant functional groups (-COOH, -NH₂, -SH and aromatic nitrogen-based ligands) and compared the chemistry to what is known for the fac-[Re(CO)₃]⁺ core. Overall, we found that the rhenium dicarbonyl complexes only show good reactivity with aromatic nitrogen-based ligands. The reaction of cis-[Re(CO)₂(NN)]⁺ species with common bio-functional groups leads, rather, to the formation of bis-diimine dicarbonyl complexes (cis-[Re(CO)₂(NN)₂]⁺) as the major by-product. Full article

Vanadium-substituted Keggin-type heteropolyanions have been studied for a wide variety of applications, ranging from catalysis to antiviral/antimicrobial agents. While the V-substituted phosphomolybdates [PV_xMo_12−xO₄₀]^(3+x)− have been well investigated in this context, comparatively little is known about the corresponding phosphotungstates [PV_xW_12-xO₄₀]^(3+x)−. We have succeeded in synthesizing the sodium salts of the whole series [PV_xW_12−xO₄₀]^(3+x)−, for x = 1 to 6, and characterised them spectroscopically (FT-IR, UV-Vis, ³¹P-, and ⁵¹V-NMR) and electrochemically (CV and SWV). Thereby, direct comparisons between the vanadium-substituted phosphomolybdates and -tungstates, with substitution degrees from 1 to 6, can be established, which provides a solid basis for further investigations of potential applications. Full article

A series of dibromo-N-acyclic (NAC) carbene complexes of platinum(II) were synthesized, starting from trans-[Pt(μ-Br)Br(PPh₃)]₂ and according to a protocol previously optimized for the preparation of analogous chlorinated compounds. In the first step of the synthesis, the ring opening of the dinuclear precursor was carried out using suitable isonitrile ligands, while the following step consisted of the addition of N,N-diethylamine to the products obtained in the first step. The two reactions were separately investigated, and attention was given to the differences between brominated and chlorinated systems. Full article

Excitation–emission matrix (EEM) fluorescence spectroscopy of unmodified (pristine) fullerenes C₆₀ and C₇₀ in benzene, toluene, and n-hexane at room temperature was used for their quantification by their solvent-dependent EEM bands specific to each fullerene. The intensity and parameters of fluorescence depend on both the fullerene and solvent and provide the conditions for the quantification of both fullerenes in their mixtures without separation. The detection limits for C₆₀ in n-hexane and C₇₀ in benzene under the selected conditions are 7 and 2 nmol/L, respectively. The approach was tested for model and real mixtures of fullerenes C₆₀ and C₇₀. Full article

A new 1D Ni(II) coordination polymer was synthesized by the reaction of NiSO₄·6H₂O with 2,4-bis(3,5-dimethyl-1H-pyrazol-1-yl)-6-methoxy-1,3,5-triazine (BPT) and SCN⁻ as a linker in an acidic medium by heating under reflux conditions. Unusually, the BPT ligand underwent acid-mediated hydrolysis by losing one of the pyrazolyl arms afforded the polymeric [Ni(MPT)(H₂O)(SCN)₂]_n complex (MPT: 4-(3,5-dimethyl-1H-pyrazol-1-yl)-6-methoxy-1,3,5-triazin-2-ol. The Ni(II) center is coordinated with one MPT as a bidentate NN-chelate, one water molecule, and two thiocyanate groups in cis positions to one another. One of the thiocyanate groups acts as a bridging ligand between metal centers, leading to a one-dimensional polymeric structure that extends along the c-direction. The other thiocyanate group is terminally N-coordinated. The [Ni(MPT)(H₂O)(SCN)₂]_n complex has been screened in vitro against two pathogenic fungal strains: A. fumigatus, C. albican, and four pathogenic bacterial strains: S. aureus, B. subtilis as gram-positive bacteria, E. coli, P. vulgaris as gram-negative bacteria. The results showed that the complex has the potential to be used as both an antibacterial and an antifungal agent. Also, the [Ni(MPT)(H₂O)(SCN)₂]_n complex showed cytotoxic activities against hepatocellular (HepG-2) and lung (A-549) cell lines, with IC₅₀ values of 132.67 ± 5.14 and 146.97 ± 7.34 μM, respectively. Full article

Cd-doped BiFeO₃ powders, with varying doping concentrations of Cd (Bi_(1−x)Cd_xFeO₃, where x = 0–0.3), were prepared through a facile chemical co-precipitation method and calcinated at 550 °C in the air. The BiFeO₃ has a rhombohedral crystal structure, which changes to an orthorhombic crystal structure with an increase in Cd doping. The presence of dopant has also altered the bandgap of material suppressing it from 2.95 eV to 2.51 eV, improving the visible light absorption. Vibrating sample magnetometry (VSM) confirmed stronger ferromagnetic character for Bi_0.7Cd_0.3FeO₃ with a coercivity of 250 Oe, and remnant magnetization was 0.15 emu/g, which is because of the misalignment of the two sublattices of perovskite structure after doping resulting in the imbalanced magnetic moment giving rise to net nonzero magnetic behavior. The particle size reduction is observed with an increase in the doping concentration of Cd. Full article

Water treatment through photocatalysts has become an important topic regarding environmental protection. In the present study, silver and TiO₂ (Ag/TiO₂) composites for photocatalysts were effectively synthesized by adopting the template induced method. The prepared samples were characterized using XRD, FTIR spectroscopy, SEM, and EDX. The constructed samples’ particle size and shape were evaluated using a SEM, and the XRD patterns showed anatase crystalline phases. Their morphologies were controllable with changing concentration of reactants and calcination temperature. The synthesized composites act as catalyst in the degradation of methylene blue (MB) and reduction of Cr(VI) to Cr(III) under solar irradiation. In both of these activities, the best result has been shown by the 0.01 Ag/TiO₂ composite. Methanol is used as the hole scavenger in the reduction of Cr(VI) to Cr(III). While the pH factor is important in the photocatalytic reduction of Cr(VI) to Cr(III). According to observations, S. macrospora and S. maydis were each subject to 0.01 Ag/TiO₂ nanocomposites maximum antifungal activity, which was 38.4 mm and 34.3 mm, respectively. The outcomes demonstrate that both photocatalytic and antifungal properties are effectively displayed by the constructed material. Full article

Herein, the synthesis, structural characterization and in vitro biological evaluation of a novel Cu(II) complex with the 2-(4-aminophenyl)benzothiazole pharmacophore conjugated with the (2-pyridinyl)methylamino chelating moiety is reported for the first time. A full characterization of the Cu(II) complex was conducted by X-ray crystallography, EPR, IR, elemental and MS analysis, and its binding to CT-DNA was investigated by UV-vis spectroscopy, ethidium bromide competition studies, circular dichroism, viscometry and thermal denaturation. The data clearly indicate that the Cu(II) complex interacts with CT-DNA via intercalation, registering a difference compared to previously reported Pt(II) and Pd(II) analogues. To evaluate the anticancer activity of the complex, a series of in vitro experiments against breast, glioblastoma, prostate and lung cancer cell lines along with healthy fibroblasts were implemented. Cytotoxicity, cellular uptake, intracellular ROS production, cell cycle and apoptosis analysis revealed an increased anticancer activity towards breast cancer cells that is accompanied by an induction in intracellular ROS levels and a significant G2/M arrest followed by apoptosis. Full article

Supported nano zero-valent iron is receiving great attention nowadays due to its effectiveness in treating heavy metal pollutants. Therefore, this study aimed to investigate the effectiveness of granitic residual soil-supported nano zero-valent iron (Gr-nZVI) for the removal of the heavy metals Pb²⁺, Cu²⁺, Co²⁺, Cd²⁺ Ni²⁺ and Zn²⁺ in mixture solutions under different experimental conditions of batch equilibrium tests. In this study, Gr-nZVI was successfully synthesized by using the chemical reduction of Ferric Chloride Hexahydrate (FeCl₃.6H₂O) and Sodium Borohydride (NaBH₄)_. The physical and chemical properties, morphology and mineralogy of all adsorbents were characterized by the Braeuer–Emmett–Teller (BET) method, cation exchange capacity (CEC), X-ray fluorescence (XRF), scanning electron microscopy (SEM), field-emission scanning electron microscopy (FESEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). Isotherm, kinetic and diffusion model analyses were conducted to fit the experimental data. The results show rapid adsorption within 5 min in the initial adsorption stage for Pb²⁺ on nZVI (q_e.Pb = 17.89 mg/g) and Gr-nZVI (q_e.Pb = 15.29 mg/g). nZVI and Gr-nZVI also showed no significant effects on pH and temperature, serving as a good example of an energy-efficient process. The isotherm data fitted better to the Langmuir model and the pseudo-second-order kinetic model for the adsorption of all of the heavy metals. The diffusion models revealed that adsorption was not the only rate-limiting step. In this study, nZVI compared to Gr-nZVI and Gr demonstrated superior adsorption capacity for the heavy metal adsorption selectivity. Hence, these materials can be utilized as alternative energy-efficient adsorbents for the adsorption of metal ions from wastewater. Full article

Inorganic nanostructured (metal) oxides are a large class of inorganic materials extensively investigated for their unique and outstanding properties that allow for their use within a multitude of technological fields of emerging interest, such as (photo)catalysis, environmental remediation processes, energy storage, controlled transport and/or release of drugs and chemicals, biomedicine, sensing, development of smart materials, stimuli-responsive materials, and nanocomposites [...] Full article

We report a broad theoretical study on [(PMe₃)₃MER]⁺ complexes, with M = Ni, Pd, Pt, E = C, Si, Ge, Sn, Pb, and R = Ar^Mes, Tbb, (Ar^Mes = 2,6-dimesitylphenyl; Tbb = C₆H₂-2,6-[CH(SiMe₃)₂]₂-4-^tBu). A few years ago, our group succeeded in obtaining heavier homologues of cationic group 10 carbyne complexes via halide abstraction of the tetrylidene complexes [(PMe₃)₃M=E(X)R] (X = Cl, Br) using a halide scavenger. The electronic structure and the M-E bonds of the [(PMe₃)₃MER]⁺ complexes were analyzed utilizing quantum-chemical tools, such as the Pipek–Mezey orbital localization method, the energy decomposition analysis (EDA), and the extended-transition state method with natural orbitals of chemical valence (ETS-NOCV). The carbyne, silylidyne complexes, and the germylidyne complex [(PMe₃)₃NiGeAr^Mes]⁺ are suggested to be tetrylidyne complexes featuring donor–acceptor metal tetrel triple bonds, which are composed of two strong π(M→E) and one weaker σ(E→M) interaction. In comparison, the complexes with M = Pd, Pt; E = Sn, Pb; and R = Ar^Mes are best described as metallotetrylenes and exhibit considerable M−E−C bending, a strong σ(M→E) bond, weakened M−E π-components, and lone pair density at the tetrel atoms. Furthermore, bond cleavage energy (BCE) and bond dissociation energy (BDE) reveal preferred splitting into [M(PMe₃)₃]⁺ and [ER] fragments for most complex cations in the range of 293.3–618.3 kJ·mol⁻¹ and 230.4–461.6 kJ·mol⁻¹, respectively. Finally, an extensive study of the potential energy hypersurface varying the M−E−C angle indicates the presence of isomers with M−E−C bond angles of around 95°. Interestingly, these isomers are energetically favored for M = Pd, Pt; E = Sn, Pb; and R = Ar^Mes over the less-bent structures by 13–29 kJ·mol⁻¹. Full article

Both LiBH₄ and NaBH₄ are well known for having high hydrogen contents, but also high decomposition temperatures and slow hydrogen absorption–desorption kinetics, preventing their use for hydrogen storage applications. The low melting temperature (219 °C) of their eutectic mixture 0.71 LiBH₄–0.29 NaBH₄ allowed the synthesis of a new composite material through the melt infiltration of the hydrides into the ~5 nm diameter pores of a CMK-3 type carbon. A composite of 0.71 LiBH₄–0.29 NaBH₄ and non-porous graphitic carbon discs was also prepared by similar methods for comparison. Both composites showed improved kinetics and a partial reversibility of the dehydrogenation/rehydrogenation reactions. However, the best results were observed for the CMK-3 nanoconfined hydrides; a consistent uptake of about 3.5 wt.% H₂ was recorded after five hydrogenation/dehydrogenation cycles for an otherwise non-reversible system. The improved hydrogen release kinetics are attributed to carbon–hydride surface interactions rather than nanoconfinement, while enhanced heat transfer due to the carbon support may also play a role. Likewise, the carbon–hydride contact proved beneficial in terms of reversibility, without, however, ruling out the potential positive effect of pore confinement. Full article

New carboranyl thioethers 1-MeO(CH₂)_nS-1,2-C₂B₁₀H₁₁ (n = 2, 3) were prepared by the alkylation of the trimethylammonium salt of 1-mercapto-ortho-carborane with 1-bromo- 2-methoxyethane and 1-bromo-3-methoxypropane, respectively. Their deboronation with cesium fluoride in ethanol gave the corresponding nido-carboranes Cs[7-MeO(CH₂)_nS-7,8-C₂B₉H₁₁] (n = 2, 3). The reactions of Cs[7-MeO(CH₂)₂S-7,8-C₂B₉H₁₁] with various nickel(II) phosphine complexes [(dppe)NiCl₂] and [(R’R₂P)₂NiCl₂] (R = R’ = Ph, Bu; R = Me, R’ = Ph; R = Ph, R’ = Me, Et) were studied and a series of nickelacarboranes 3,3-dppe-1-MeO(CH₂)₂S-closo-3,1,2-NiC₂B₉H₁₀ and 3,3- (R’R₂P)₂-1-MeO(CH₂)₂S-closo-3,1,2-NiC₂B₉H₁₀ (R = R’ = Bu; R = Me, R’ = Ph; R = Ph, R’ = Me, Et) was prepared. The molecular crystal structure of 3,3-dppe-1-MeO(CH₂)₂S-closo-3,1,2-NiC₂B₉H₁₀ was determined by single-crystal X-ray diffraction. Full article

The article presents the distribution coefficient (K_d) values of ¹³⁷Cs and ⁹⁰Sr tracer radionuclides in solutions of sodium and calcium salts for a wide range of commercially available inorganic sorbents: natural and synthetic aluminosilicates, manganese, titanium and zirconium oxyhydrates, titanium and zirconium phosphates, titanosilicates of alkali metals, and ferrocyanides of transition metals. The results were obtained using a standard technique developed by the authors for evaluating the efficiency of various sorption materials towards cesium and strontium radionuclides. It was shown that bentonite clays and natural and synthetic zeolites are the best for decontaminating low-salt natural water from cesium radionuclides, and ferrocyanide sorbents are the choice for decontaminating high-salt-bearing solutions. The manganese (III, IV) oxyhydrate-based MDM sorbent is the most effective for removing strontium from natural water; for seawater, the barium silicate-based SRM-Sr sorbent is the first-in-class. Results of the study provide a possibility of making a reasonable choice of sorbents for the most effective treatment of natural water and technogenic aqueous waste contaminated with cesium and strontium radionuclides. Full article

The reaction between [PtCl₂(L-L)] (L-L = dppe, dppp, dppb, dppf, Phen and Bipy) or [PtCl₂(PPh₃)₂] with 1-benzyl-3-phenylthiourea (H₂BPT) in a basic medium (CHCl₃/EtOH) created new coordinated square planner Pt(II) complexes with [Pt(BPT)(L-L)] (1–4,6,7) and [Pt(BPT)(PPh₃)₂] (5) types. These complexes were fully characterized by analytical and spectroscopic techniques (i.e., IR, UV. Vis., ¹H, and ³¹P NMR). The results indicated that the thiourea derivative ligand act as a dianion ligand bonded through both S and N atoms in a chelating mode or as a mono-anion ligand coordinated through a sulfur atom with Pt(II) ion. Cytotoxicity activity was performed by the MTT assay to determine anti-cancer activities against MCF-7 breast cancer cells. The study indicated that IC₅₀ values for MCF-7 cells were 10.96–78.90 µM. Additionally, the complexes [Pt(BPT)(dppe)] (1), [Pt(BPT)(PPh₃)₂] (5), and [Pt(BPT)₂(Bipy)] (7) were investigated theoretically, where their quantum parameters were evaluated using the Gaussian 09 program using the theory of B3LYP/Def2TZVP//B3LYP/Lanl2dz. The calculation results confirmed the optimized structures of the complexes square planar geometry. However, the calculated bond lengths and angles showed a slightly distorted square planar geometry due to the trans influence of the sulfur atom. Additionally, complexes of [Pt(BPT)(dppe)] (1) and [Pt(BPT)(PPh₃)₂] (5) showed higher stability compared to [Pt(BPT)₂(Bipy)] (7), which can be attributed to the higher back-donation of (1) and (5) complexes. Furthermore, among the three complexes, the [Pt(BPT)₂(Bipy)] (7) complex possessed the lowest HOMO–LUMO gap, which may be a good candidate as the photo-catalyst material. Full article

New organometallic iridium compounds with phosphorus modified glucose ligands containing isopropylidene protection group or bearing uracil, thymine, and 5-fluorouracil (3,5,6-bicyclophosphite-1,2-O-isopropylidene-α-d-glucofuranoside, 3,5,6-bicyclophosphite-1-β-D-glucofuranosyluracil, 3,5,6-bicyclophosphite-1-β-D-glucofuranosylthymine, 3,5,6-bicyclophosphite-1-β-D-glucofuranosyl-5-flurouracil) were prepared. The structure of the new complexes was confirmed by the spectroscopic technique (¹H, ³¹P{¹H} NMR) and mass spectrometry, and purity by elemental analysis. The molecular structure of the complex with the isopropylidene protection group was established by the X-ray analysis. The antiproliferative activity of the new iridium compounds was evaluated against several cancer cell lines of human origin, and all compounds showed low toxicity independent of the pyrimidine base nature, attached to the sugar unit. Full article

This report deals with the quantum-chemical evaluation of the energetics and thermodynamics of the simultaneous encapsulation of HF and H${}_2$O by the IPR (isolated pentagon rule) C${}_{70}$ fullerene cage, yielding ${\mathrm{H}}_2\mathrm{O}·\mathrm{HF}@{\mathrm{C}}_{70}$ species which were synthesized and characterized recently, thus further expanding the family of fullerene endohedrals with non-metallic encapsulates. The structures were optimized at the DFT (density functional theory) M06-2X/6-31++G** level. The encapsulation energetics were further refined by the advanced B2PLYPD/6-31++G** and B2PLYPD/6-311++G** methods. After enhancement of the B2PLYPD/6-311++G** encapsulation energy for the BSSE and steric corrections, the encapsulation energy gain was obtained, as 26 kcal/mol. The equilibrium encapsulation thermodynamics were described using the M06-2X/6-31++G** partition functions. The results correspond to our previous evaluations for the water dimer encapsulation by C${}_{84}$ cages. Full article

Energy-relevant small molecule activations and related processes are often multi-electron in nature. Ferrocene is iconic for its well-behaved one-electron chemistry, and it is often used to impart redox activity to self-assembled architectures. When multiple ferrocenes are present as pendant groups in a single structure, they often behave as isolated sites with no separation of their redox events. Herein, we study a suite of molecules culminating in a self-assembled palladium(II) truncated tetrahedron (TT) with six pendant ferrocene moieties using the iron(III/II) couple to inform about the electronic structure and, in some cases, subsequent reactivity. Notably, although known ferrocene-containing metallacycles and cages show simple reversible redox chemistry, this TT undergoes a complex multi-step electrochemical mechanism upon oxidation. The electrochemical behavior was observed by voltammetric and spectroelectrochemical techniques and suggests that the initial Fc-centered oxidation is coupled to a subsequent change in species solubility and deposition of a film onto the working electrode, which is followed by a second separable electrochemical oxidation event. The complicated electrochemical behavior of this self-assembly reveals emergent properties resulting from organizing multiple ferrocene subunits into a discrete structure. We anticipate that such structures may provide the basis for multiple charge separation events to drive important processes related to energy capture, storage, and use, especially as the electronic communication between sites is further tuned. Full article

Layered double hydroxides (LDHs), a type of synthetic clay with assorted potential applications, are deliberated upon in view of their specific properties, such as adsorbent-specific behavior, biocompatibility, fire-retardant capacity, and catalytic and anion exchange properties, among others. LDHs are materials with two-dimensional morphology, high porosity, and exceptionally tunable and exchangeable anionic particles with sensible interlayer spaces. The remarkable feature of LDHs is their flexibility in maintaining the interlayer spaces endowing them with the capacity to accommodate a variety of ionic species, suitable for many applications. Herein, some synthetic methodologies, general characterizations, and applications of LDHs are summarized, encompassing their broader appliances as a remarkable material to serve society and address several problems viz. removal of pollutants and fabrication of sensors and materials with multifaceted useful applications in the medical, electrochemical, catalytic, and agricultural fields, among others. Full article