Novel Coordination Polymer of Cadmium (II) with L-Tryptophan

A new cadmium (II) polymeric coordination compound with tryptophan (Trp) of general formula {[Cd(L-Trp)2(H2O)Cl]∙(Trp)∙(H2O)}n was synthesized. The monocrystals of the investigated complex were obtained using the method of slow evaporation. The crystal and molecular structure was determined. The compound was crystallized in the orthorhombic P212121 space group. The cadmium atom was seven coordinates by two oxygen atoms from one bidentate-chelating carboxylate group of bridging Trp, two oxygen atoms from one bidentate-chelating carboxylate group from a monodentate organic ligand, one oxygen atom of water molecule, one nitrogen atom of the amino group from bridging Trp and one chlorine atom, which means that every tridentate Trp substituent was bridging towards one cadmium atom and bidentate chelating towards one another. The monodentate Trp is a zwitterionic molecule. The coordination led to the formation of 1D supramolecular chains entrapping water and Trp molecules

Crystal structure of a one-dimensional coordination polymer of gadolinium dibromoacetate with 4,4'-bipyridine

A new gadolinium(III) complex with 4,4’-bipyridine (4-bpy) and dibromoacetate ligand of general formula [Gd(4-bpy)(CBr2HCOO)3(H2O)]n, has been synthesized, crystallized and characterized by a single-crystal X-ray diffraction analysis. The gadolinium atom has an unsymmetrical eight-coordinate geometry, being coordinated by six oxygen atoms of dibromoacetate anions, one nitrogen atom of 4-bpy and one water molecule. The complex is a one-dimensional polymer as a result of dibromoacetate ligand bridging with the repeating monomeric units. There are π...π stacking interactions between the 4-bpy rings as well as O–H...O and O–H...N hydrogen bonds. Crystal Data for C16H13Br6GdN2O7 (Mw = 981.99 g/mol): triclinic, space group P-1 (no. 2), a = 9.7368(4) Å, b = 11.5416(4) Å, c = 11.7634(4) Å, α = 104.2750(10)°, β = 94.060(2)°, γ = 92.6900(10)°, V = 1275.08(8) Å3, Z = 2, T = 90 K, μ(CuKα) = 28.190 mm-1, Dcalc = 2.558 g/cm3, 8399 reflections measured (7.782° ≤ 2Θ ≤ 133.18°), 4006 unique (Rint = 0.0409, Rsigma = 0.0639) which were used in all calculations. The final R1 was 0.0527 (I > 2σ(I)) and wR2 was 0.1396 (all data)

Struvite Grown in Gel, Its Crystal Structure at 90 K and Thermoanalytical Study

In this article, we report the crystallization of struvite in sodium metasilicate gel by single diffusion gel growth technique. The obtained crystals have a very rich morphology displaying 18 faces. In this study, the habit and morphology of the obtained struvite crystals are analyzed. The crystals were examined and identified as pure struvite by single X-ray diffraction (XRD). The orthorhombic polar noncentrosymmetric space group Pmn21 was identified. The structure of the crystal was determined at a temperature of 90 K. Our research indicates a lack of polymorphism, resulting from the temperature lowering to 90 K, which has not been previously reported. The determined unit cell parameters are as follows a = 6.9650(2) Å, b = 6.1165(2) Å, c = 11.2056(3) Å. The structure of struvite is presented here with a residual factor R1 = 1.2% at 0.80 Å resolution. We also present thermoanalytical study of struvite using thermal analysis techniques such as thermogravimetry (TG), derivative thermogravimetry (DTG) and differential thermal analysis (DTA)

Synthesis, Spectroscopic, Thermal, and Catalytic Properties of Eight New Complexes of Metal(II) Formates or Propionates with Imidazole; Relationship between the Carbon Chain Length and Catalytic Activity

In one of our previously published articles, we reported the synthesis, spectroscopic, thermal, and catalytic properties of four new M(II) acetate (where M = Co, Ni, Cu, Zn) complexes with imidazole. Presented compounds exhibited activity in the reaction on catalytic oxidation of styrene. In this study we have synthesized and investigated properties of analogous compounds, however using formates or propionates of mentioned metal cations instead of acetates. Such an approach allowed us to draw valuable conclusions concerning the relationship between the carbon chain length and catalytic activity, which is an important factor for catalyst modeling. Synthesized compounds have been thoroughly investigated using appropriate analytic techniques: AAS (Atomic Absorption Spectrometry), FTIR (Fourier-Transform Infrared Spectroscopy), and TGA (Thermogravimetric Analysis). Catalytic properties have been studied under the same previous conditions, using GC-FID (GC-chromatograph equipped with FID detector)

Horsetail (Equisetum Arvense) as a Functional Filler for Natural Rubber Biocomposites

Over the past decades, increased scientific and research activity has been observed in the development of new, innovative materials for various end uses. This is mainly due to the growing ecological, environmental, and material awareness of many industries and societies. Equisteum arvense-horsetail is a plant that has demonstrated its properties in pharmacological and clinical aspects as well as in vitro and in vivo biological activity. This article presents a new method of using horsetail as a natural, lignocellulosic filler for a natural rubber matrix. In-depth characteristics of the applied bio-additive were prepared based on several research techniques and methods such as ultraviolet-visible spectroscopy, Fourier-transform infrared spectroscopy, scanning electron microscopy with energy dispersive X-RAY spectroscopy, thermogravimetric analysis, and flame atomic absorption spectroscopy. Elastomer composites were prepared as a function of horsetail content. Then, an analysis of their main functional properties was performed, including mechanical properties and susceptibility to accelerated aging processes such as thermo-oxidative, ultraviolet radiation, and weathering. The research emphasizes the significant value of horsetail in its new role—as an active filler of elastomer biocomposites. The obtained results confirmed that horsetail is lignocellulosic material thermally stable up to 180 °C. Horsetail is an active filler to natural rubber, positively affecting mechanical strength. Due to the presence of flavonoids and phenolic acids in horsetail, it can be used as a polymer anti-aging agent

Structural, Spectroscopic, Thermal, and Magnetic Properties of a New Dinuclear Copper Coordination Compound with Tiglic Acid

The first coordination compound of copper and tiglic acid named tetrakis(μ-tiglato)bis(tiglic acid)dicopper(II) was synthesized and crystallized from water solution. Its structure was determined and analyzed based on X-ray diffraction measurement. The paddle-wheel coordination system of the investigated compound was compared with other similar copper structures known in the literature. The Hirshfeld analysis was used for the detailed analysis of intermolecular interaction. The new compound was also characterized in terms of infrared absorption, thermal, and magnetic properties. The antiferromagnetic coupling of copper ions was found

In Silico ADME and Toxicity Prediction of Benzimidazole Derivatives and Its Cobalt Coordination Compounds. Synthesis, Characterization and Crystal Structure

As a result of the synthesis, three new solids, cobalt (II) coordination compounds with benzimidazole derivatives, and chlorides were obtained. The ligands that were used in the synthesis were specially synthesized and were commercially unavailable. During the synthesis, a single crystal of the complex with the L1 ligand was obtained and the crystal structure was refined. All coordination compounds were characterized by elemental analysis, infrared spectroscopy, and thermogravimetric analysis. All the obtained data allowed one to determine the formulas of the new compounds, as well as to determine the method of metal–ligand coordination. Thermal analysis allowed to know the temperature stability of the compounds, solids intermediate and final products of pyrolysis. Additionally, volatile decomposition and fragmentation products have been identified. The toxicity of the compounds and their bioavailability were determined using in silico methods. By predicting activity on cell lines, the potential use of compounds as chemotherapeutic agents has been specified. The blood-brain barrier crossing and the gastrointestinal absorption were defined. Pharmaceutical biodistribution was also simulated

Crystal Structures, Hirshfeld Surfaces, and Thermal Study of Isostructural Polymeric Ladders of La(III) and Sm(III) Coordination Compounds with 4,4’-Bipyridine and Dibromoacetates

Two novel mixed ligand complexes with general formula [M2(4,4′-bpy)1.5(CBr2HCOO)6(H2O)2]n (where 4,4′-bpy = 4,4′-bipyridine) were synthesized. Thermal analysis was used to describe a solid intermediate and final products of thermolysis. A coupled TG-MS system was used to monitor principal volatile fragments evolved during pyrolysis. Crystal structures of the complexes were determined. Cationic dinuclear M2 (M(III) = La, Sm) coordination cores were obtained. Both crystal structures are isostructural. Single crystal X-ray diffraction analysis revealed that investigated structures of 1D coordination polymers assembled in ladder-like systems. The central atom replacement resulted in unit cell identity parameter П = 0.0091. Additionally, the isostructurality of the reported La(III) and Sm(III) complexes was revealed using Hirshfeld Surface analysis supported by Enrichment Ratio calculations

Synthesis, Spectral, Thermal and Biological Studies of 4-Cyclohexyl-3-(4-nitrophenyl)methyl-1,2,4-triazolin-5-thione and Its Copper(II) Coordination Compound, [CuCl2(H2O)2L2]

One of the strategies for seeking new biologically active substances is to modify compounds with potential biological activity. In this paper, 1,2,4-triazolin-5-thione derivative (3) was obtained in the cyclization reaction of appropriate thiosemicarbazide (2) as an organic ligand. The copper(II) complex, [CuCl2(H2O)2L2] (L=4-cyclohexyl-3-(nitrophenyl)methyl-1,2,4-triazolin-5-thione) (Cu-3) was prepared in a reaction of free ligand (3) with a CuCl2·2H2O solution in MeOH/EtOH mixture at room temperature. TGA data show that Cu-3 and free ligand are stable at room temperature. Both compounds were screened in vitro for antibacterial and antifungal activities using the broth microdilution method. The obtained complex (Cu-3) showed higher antibacterial effect, especially towards Gram-positive bacteria (with moderate activity and Minimal Inhibitory Concentration MIC = 250–500 µg/mL) than the free ligand (3) (with mild or no bioactivity and MIC ≥ 1000 µg/mL). In turn, yeasts, belonging to Candida albicans, exhibited similar sensitivity to both the copper(II) complex (Cu-3) and the organic ligand (3). The anticandidal activity of these compounds was moderate (MIC = 500 µg/mL), or, in the case of other Candida spp., lower (MIC ≥ 1000 µg/mL)

High Active and Selective Ni/CeO2–Al2O3 and Pd–Ni/CeO2–Al2O3 Catalysts for Oxy-Steam Reforming of Methanol

Herein, we report monometallic Ni and bimetallic Pd–Ni catalysts supported on CeO2–Al2O3 binary oxide which are highly active and selective in oxy-steam reforming of methanol (OSRM). Monometallic and bimetallic supported catalysts were prepared by an impregnation method. The physicochemical properties of the catalytic systems were investigated using a range of methods such as: Brunauer–Emmett–Teller (BET), X-ray Powder Diffraction (XRD), Temperature-programmed reduction (TPR–H2), Temperature-programmed desorption (TPD–NH3), X-ray photoelectron spectroscopy (XPS) and Scanning Electron Microscope equipped with an energy dispersive spectrometer (SEM–EDS). We demonstrate that the addition of palladium facilitates the reduction of nickel catalysts. The activity tests performed for all catalysts confirmed the promotion effect of palladium on the catalytic activity of nickel catalyst and their selectivity towards hydrogen production. Both nickel and bimetallic palladium–nickel supported catalysts showed excellent stability during the reaction. The reported catalytic systems are valuable to make advances in the field of fuel cell technology