The Synthesis and Characterization of a Novel One-Dimensional Bismuth (III) Coordination Polymer as a Precursor for the Production of Bismuth (III) Oxide Nanorods

A novel Bi (III) coordination compound, [Bi(HQ)(Cl)4]n ((Q = pyridine-4-carbaldehyde thiosemicarbazone), was prepared in this research using a sonochemical technique. SEM, infrared spectroscopy (IR), XRD, and single-crystal X-ray analysis were utilized to analyze the Bi(III) coordination compound. The structure determined using single-crystal X-ray crystallography indicates that the coordination compound is a 1D polymer in solid state and that the coordination number of bismuth (III) ions is six, (BiSCl5), with one S donor from the organic ligand and five Cl donors from anions. It is equipped with a hemidirectional coordination sphere. It is interesting that the ligand has been protonated in the course of the reaction with a Cl- ion balancing the charge. This compound’s supramolecular properties are directed and regulated by weak directional intermolecular interactions. Through π–π stacking interactions, the chains interact with one another, forming a 3D framework. Thermolysis of the compound at 170 °C with oleic acid resulted in the formation of pure phase nanosized Bi (III) oxide. SEM technique was used to examine the morphology and size of the bismuth (III) oxide product produced.

Thermoinduced Structural-transformation and Luminescent Conversion in Hybrid Manganese Halides

We report here the synthesis of hybrid manganese halide crystals, (C4H7N2)MnCl3·H2O and (C4H7N2)2MnCl4, by using the same organic ligand 2-methylimidazole. Upon heating treatment, the red-emissive (C4H7N2)MnCl3·H2O crystal is structurally transformed into green-emissive (C4H7N2)2MnCl4 crystal in situ. The crystal structural analysis reveals that the [MnCl5·H2O]3- octahedra chains decompose into mono [MnCl4]2- tetrahedra, accompanied by the departure of H2O molecules. Upon cooling in air or water vapor, the crystal structure and luminescence of (C4H7N2)2MnCl4 are transformed to those of (C4H7N2)MnCl3·H2O. The in situ conversion of luminescence between (C4H7N2)MnCl3·H2O and (C4H7N2)2MnCl4 provides new insight into the potential application of hybrid manganese halides.

Facing Diseases Caused by Trypanosomatid Parasites: Rational Design of Pd and Pt Complexes With Bioactive Ligands

Human African Trypanosomiasis (HAT), Chagas disease or American Trypanosomiasis (CD), and leishmaniases are protozoan infections produced by trypanosomatid parasites belonging to the kinetoplastid order and they constitute an urgent global health problem. In fact, there is an urgent need of more efficient and less toxic chemotherapy for these diseases. Medicinal inorganic chemistry currently offers an attractive option for the rational design of new drugs and, in particular, antiparasitic ones. In this sense, one of the main strategies for the design of metal-based antiparasitic compounds has been the coordination of an organic ligand with known or potential biological activity, to a metal centre or an organometallic core. Classical metal coordination complexes or organometallic compounds could be designed as multifunctional agents joining, in a single molecule, different chemical species that could affect different parasitic targets. This review is focused on the rational design of palladium(II) and platinum(II) compounds with bioactive ligands as prospective drugs against trypanosomatid parasites that has been conducted by our group during the last 20 years.

Investigating the effect of nickel concentration on phytoplankton growth to inform the assessment of ocean alkalinity enhancement

Ocean alkalinity enhancement (OAE) is a proposed method for removing carbon dioxide (CO2) from the atmosphere by the accelerated weathering of (ultra-) basic minerals to increase alkalinity – the chemical capacity of seawater to store CO2. During the weathering of OAE-relevant minerals relatively large amounts of trace metals will be released and may perturb pelagic ecosystems. Nickel (Ni) is of particular concern as it is abundant in olivine, one of the most widely considered minerals for OAE. However, so far there is limited knowledge about the impact of Ni on marine biota including phytoplankton. To fill this knowledge gap, this study tested the growth and photo-physiological response of 11 marine phytoplankton species to a wide range of dissolved Ni concentrations (from 0 nmol/L to 50,000 nmol/L). We found that the phytoplankton species were not very sensitive to Ni concentrations under the culturing conditions established in our experiments, but the responses were species-specific. The growth rates of 6 of the 11 tested species showed small but significant responses to changing Ni concentrations. Photosynthetic performance, assessed by measuring the maximum quantum yield (Fv/Fm) and the functional absorption cross-section (σPSII) of photosystem II, was also only mildly sensitive to changing Ni in 3 out of 11 species and 4 out of 11 species, respectively. The limited effect of Ni may be partly due to the provision of nitrate as the nitrogen source for growth, as previous studies suggest higher sensitivities when urea is the nitrogen source. Furthermore, limited influence may be due to the relatively high concentrations of organic ligands in the growth media in our experiments. These ligands reduced bioavailable Ni (i.e., “free Ni2+”) concentrations by binding the majority of the dissolved Ni. Our data suggest that dissolved Ni does not have a strong effect on phytoplankton under our experimental conditions, but we emphasize that a deeper understanding of nitrogen sources, ligand concentrations and phytoplankton composition is needed when assessing the influence of Ni release associated with OAE. We discuss if applications of OAE with Ni-rich minerals may be safer in regions with high organic ligand concentrations and low concentrations of urea as such boundary conditions may lead to less impact of Ni on phytoplankton communities.

Theoretical investigation on the effect of the ligand on bis-silylation of C(sp)–C(sp) by Ni complexes

Density functional theory (DFT) is used to study the bis-silylation of alkynes catalyzed by a transition metal nickel–organic complex; the active catalyst, the organic ligand, the reaction mechanism, and rate-determining step are discussed in this paper.

Bis(η5-cyclopentadienyl)(2-{[(2-methoxyphenyl)imino]methyl}phenolato-κ3 O,N,O′)terbium

The air- and moisture-sensitive title compound, [Tb(C5H5)2(C14H12NO2)], was synthesized from tris(cyclopentadienyl)(tetrahydrofuran)terbium and 2-{[(2-methoxyphenyl)imino]methyl}phenol. Each Tb atom is coordinated by two cyclopentadienyl ligands in an η5-coordination mode and by one N and two O atoms of the organic ligand in a tridentate κ3 O,N,O′-mode.

Homochiral porous coordination polymer of EuIII for metal ion sensing and enantioselective adsorption

A novel three-dimensional homochiral porous coordination polymer was obtained by combining luminescent component Eu(III) with enantiomerically pure semirigid triangular organic ligand derived from (L)-α-leucine. Remarkably, it not only exhibited photoluminescence...

Atmospheric Iron and Aluminium Deposition and Sea-Surface Dissolved Iron and Aluminium Concentrations in the South China Sea off Malaysia Borneo (Sarawak Waters)

South China Sea (SCS) is an oligotrophic sea which usually receives low nutrients supply. However, massive atmospheric dust input was occurred during the haze event in Southeast Asia for almost every year. The input of dissolved iron (DFe) and dissolved aluminium (DAl) from dust and nearby land into SCS off Sarawak Borneo region during the worst haze event in 2015 of the Southeast Asia were investigated. The estimation dust deposition during this study was 0.162 mg/m2/yr. The atmospheric fluxes of total Fe and total Al at the offshore Sarawak waters were 0.611 µmol/m2/yr and 2.03 µmol/m2/yr, respectively, where the readily available dissolved Fe and Al from the dust were 0.11 µmol/m2/yr (DFe) and 0.31 µmol/m2/yr (DAl). Fe has higher solubility (17.78%) than Al (15.21%). The lateral fluxes (e.g. from the nearby land) were 37.08 nmol/m2/yr (DFe) and 125 nmol/m2/yr (DAl), with strong Fe organic ligand class L1 (log K:22.43 – 24.33). High concentrations of DFe and DAl at the surface water of the offshore region, coincided with high concentration of macronutrients due to the prevailing south-westerly winds originated from the west Kalimantan. Low residence times, ~0.92 (DFe) and ~1.31 (DAl) years, corresponded well with DAlexcess in surface seawater due to biological utilization of DFe. Future works emphasize on natural organic Fe(III) ligands and phytoplankton study are needed for better understanding on biogeochemistry of Fe and Al at SCS off Malaysia Borneo.

Translational imaging of the fibroblast activation protein (FAP) using the new ligand [68Ga]Ga-OncoFAP-DOTAGA

Purpose The fibroblast activation protein (FAP) is an emerging target for molecular imaging and therapy in cancer. OncoFAP is a novel small organic ligand for FAP with very high affinity. In this translational study, we establish [68Ga]Ga-OncoFAP-DOTAGA (68Ga-OncoFAP) radiolabeling, benchmark its properties in preclinical imaging, and evaluate its application in clinical PET scanning. Methods 68Ga-OncoFAP was synthesized in a cassette-based fully automated labeling module. Lipophilicity, affinity, and serum stability of 68Ga-OncoFAP were assessed by determining logD7.4, IC50 values, and radiochemical purity. 68Ga-OncoFAP tumor uptake and imaging properties were assessed in preclinical dynamic PET/MRI in murine subcutaneous tumor models. Finally, biodistribution and uptake in a variety of tumor types were analyzed in 12 patients based on individual clinical indications that received 163 ± 50 MBq 68Ga-OncoFAP combined with PET/CT and PET/MRI. Results 68Ga-OncoFAP radiosynthesis was accomplished with high radiochemical yields. Affinity for FAP, lipophilicity, and stability of 68Ga-OncoFAP measured are ideally suited for PET imaging. PET and gamma counting–based biodistribution demonstrated beneficial tracer kinetics and high uptake in murine FAP-expressing tumor models with high tumor-to-blood ratios of 8.6 ± 5.1 at 1 h and 38.1 ± 33.1 at 3 h p.i. Clinical 68Ga-OncoFAP-PET/CT and PET/MRI demonstrated favorable biodistribution and kinetics with high and reliable uptake in primary cancers (SUVmax 12.3 ± 2.3), lymph nodes (SUVmax 9.7 ± 8.3), and distant metastases (SUVmax up to 20.0). Conclusion Favorable radiochemical properties, rapid clearance from organs and soft tissues, and intense tumor uptake validate 68Ga-OncoFAP as a powerful alternative to currently available FAP tracers.