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The PdII complex bis-{(S)-(-)-N-[(biphenyl-2-yl)methyl-idene]1-(4-meth-oxy-phen-yl)ethanamine-κN}di-chlorido-palladium(II), [PdCl2(C22H21NO)2], crystallizes in the monoclinic Sohncke space group P21 with a single mol-ecule in the asymmetric unit. The coordination environment around the palladium is slightly distorted square planar. The N-Pd-Cl bond angles are 91.85 (19), 88.10 (17), 89.96 (18), and 90.0 (2)°, while the Pd-Cl and Pd-N bond lengths are 2.310 (2) and 2.315 (2) Šand 2.015 (2) and 2.022 (6) Å, respectively. The crystal structure features inter-molecular N-H⋯Cl and intramolecular C-H⋯Pd inter-actions, which lead to the formation of a supramolecular framework structure.

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Janus-type nanoparticles are important because of their ability to combine distinct properties and functionalities in a single particle, making them extremely versatile and valuable in various scientific, technological, and industrial applications. In this work, bimetallic silver-palladium Janus nanoparticles were obtained for the first time using the inert gas condensation technique. In order to achieve this, an original synthesis equipment built by Mantis Ltd. was modified by the inclusion of an additional magnetron in a second chamber, which allowed us to use two monometallic targets to sputter the two metals independently. With this arrangement, we could find appropriate settings at room temperature to promote the synthesis of bimetallic Janus nanoparticles. The structural properties of the resulting nanoparticles were investigated by transmission electron microscopy (TEM), and the chemical composition was analyzed by TEM energy dispersive spectroscopy (TEM-EDS), which, together with structural analysis, confirmed the presence of Janus-type nanostructures. Results of molecular dynamics and TEM simulations show that the differences between the crystalline structures of the Pd and Ag regions observed in the TEM micrographs can be explained by small mismatches in the orientations of the two regions of the particle. A density functional theory structural aims to understand the atomic arrangement at the interface of the Janus particle.

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Escalating biodiesel production led to a surplus of glycerol, prompting its exploration as a valuable resource in industrial applications. Electrochemical systems have been studied, specifically employing noble metal catalysts like palladium for glycerol electrooxidation. Despite numerous studies on Pd-based catalysts for glycerol electrooxidation, a comprehensive analysis addressing critical questions related to the economic feasibility, global sourcing of Pd, and the thematic cohesion of publications in this field is lacking. Moreover, a standardized framework for comparing the results of various studies is absent, hindering progress on glycerol technologies. This critical overview navigates the evolution of Pd-based catalysts for glycerol electrooxidation, examining catalytic activity, stability, and potential applications. It critically addresses the geographical sources of Pd, the motivation behind glycerol technology exploration, thematic coherence in existing publications, and the meaningful comparison of results. It correlates the use of Pd-based catalysts with the natural source of Pd and the origin of glycerol derived from biodiesel. The proposed standardized approach for comparing electrochemical parameters and establishing experimental protocols provides a foundation for meaningful study comparisons. This critical overview underscores the need to address fundamental questions to accelerate the transition of glycerol technologies from laboratories to practical applications.

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We report herein an enantioselective palladium-catalyzed Heck-Matsuda reaction for the desymmetrization of N-protected 2,5-dihydro-1H-pyrroles with aryldiazonium salts, using the chiral N,N-ligand (S)-PyraBox. This strategy has allowed straightforward access to a diversity of 4-aryl-γ-lactams via Heck arylation followed by a sequential Jones oxidation. The overall method displays a broad scope and good enantioselectivity, favoring the (R) enantiomer. The applicability of the protocol is highlighted by the efficient enantioselective syntheses of the selective phosphodiesterase-4-inhibitor rolipram and the commercial drug baclofen as hydrochloride.

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CONTEXT: The activation of C-H bonds is a fundamental process in synthetic organic chemistry, which enables their replacement by highly reactive functional groups. Coordination compounds serve as effective catalysts for this purpose, as they facilitate chemical transformations by interacting with C-H bonds. A comprehensive understanding of the mechanism of activation of this type of bond lays the foundation for the development of efficient protocols for cross-coupling reactions. We explored the activation of C(sp2)-H bonds in 1-Phenyl-4-vinyl-1H-1,2,3-triazole derivatives with CH3, OCH3, and NO2 substituents in the para position of the phenyl ring, using palladium acetate as catalyst. The studied reaction is the first step for subsequent conjugation of the triazoles with naphthoquinones in a Heck-type reaction to create a C-C bond. The basic nitrogen atoms of the 1,2,3-triazole coordinate preferentially with the cationic palladium center to form an activated species. A concerted proton transfer from the terminal vinyl carbon to one of the acetate ligands with low activation energy is the main step for the C(sp2)-H activation. This study offers significant mechanistic insights for enhancing the effectiveness of C(sp2)-H activation protocols in organic synthesis. METHODS: All calculations were performed using the Gaussian 09 software package and density functional theory (DFT). The structures of all reaction path components were fully optimized using the CAM-B3LYP functional with the Def2-SVP basis set. The optimized geometries were analyzed by computing the second-order Hessian matrix to confirm that the corresponding minimum or transition state was located. To account for solvent effects, the Polarizable Continuum Model of the Integral Equation Formalism (IEFPCM) with water as the solvent was used.

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Palladium phthalocyanine (PdPc) nanowires (NWs) were developed to achieve the gas sensing of NO2 in the sub-parts-per-million (ppm) range. Non-substituted metal phthalocyanine are well known for their p-type semiconducting behavior, which is responsible for its gas-sensing capabilities. Nanofabrication of the PdPc NWs was performed by physical vapor deposition (PVD) on an interdigitated gold electrode (IDE). The coordination of palladium in the structure was confirmed with UV-Vis spectroscopy. Gas-sensing experiments for NO2 detection were undertaken at different sensed gas concentrations from 4 ppm to 0.5 ppm at room temperature. In this work, the responses at different gas concentrations are reported. In addition, structural studies of the PdPc NWs with scanning electron microscopy (SEM) and electron-dispersive X-ray diffraction (EDS) are shown.

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The (S)-(+)-1-(4-bromo-phen-yl)-N-[(4-methoxyphen-yl)methyl-idene]ethyl-amine ligand, C16H16BrNO, (I), was synthesized through the reaction of 4-meth-oxy-anisaldehyde with (S)-(-)-1-(4-bromo-phen-yl)ethyl-amine. It crystallizes in the ortho-rhom-bic space group P212121 belonging to the Sohncke group, featuring a single mol-ecule in the asymmetric unit. The refinement converged successfully, achieving an R factor of 0.0508. The PdII com-plex bis-{(S)-(+)-1-(4-bromo-phen-yl)-N-[(4-methoxyphen-yl)methyl-idene]ethyl-amine-κN}di-chlorido-pal-ladium(II), [PdCl2(C16H16BrNO)2], (II), crystallizes in the monoclinic space group P21 belonging to the Sohncke group, with two mol-ecules in the asymmetric unit. The central atom is tetra-coordinated by two N atoms and two Cl atoms, resulting in a square-planar configuration. The imine moieties exhibit a trans configuration around the PdII centre, with average Cl-Pd-N angles of approximately 89.95 and 90°. The average distances within the palladium com-plex for the two mol-ecules are ∼2.031 Šfor Pd-N and ∼2.309 Šfor Pd-Cl.

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The title complex, [PdCl2(C9H13N)2], comprises a single mol-ecule in the asymmetric unit. The PdII atom is tetra-coordinated by two N atoms from two trans-aligned organic ligands and two Cl ligands, forming a square-planar metal coordination environment. The distances from the ortho-H atoms on the phenyl ring to the central PdII atom fall within the range 4.70-5.30 Å, precluding any significant intra-molecular Pd⋯H inter-actions.

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Pt(II) and Pd(II) coordinating N-donor ligands have been extensively studied as anticancer agents after the success of cisplatin. In this work, a novel bidentate N-donor ligand, the N-[[4-(phenylmethoxy)phenyl]methyl]-2-pyridinemethanamine, was designed to explore the antiparasitic, antiviral and antitumor activity of its Pt(II) and Pd(II) complexes. Chemical and spectroscopic characterization confirm the formation of [MLCl2 ] complexes, where M=Pt(II) and Pd(II). Single crystal X-ray diffraction confirmed a square-planar geometry for the Pd(II) complex. Spectroscopic characterization of the Pt(II) complex suggests a similar structure. 1 H NMR, 195 Pt NMR and HR-ESI-MS(+) analysis of DMSO solution of complexes indicated that both compounds exchange the chloride trans to the pyridine for a solvent molecule with different reaction rates. The ligand and the two complexes were tested for in vitro antitumoral, antileishmanial, and antiviral activity. The Pt(II) complex resulted in a GI50 of 10.5 µM against the NCI/ADR-RES (multidrug-resistant ovarian carcinoma) cell line. The ligand and the Pd(II) complex showed good anti-SARS-CoV-2 activity with around 65 % reduction in viral replication at a concentration of 50 µM.

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The reaction of (2E)-N-phenyl-2-[(2E)-3-phenyl-2-propen-1-yl-idene]hydra-zine-carbo-thio-amide (common name: cinnamaldehyde-4-phenyl-thio-semi-carbazone) deprotonated with NaOH in ethanol with an ethano-lic suspension of PdII chloride in a 2:1 molar ratio yielded the title compound, [Pd(C16H14N3S)2]. The anionic ligands act as metal chelators, κ2 N 1 S-donors, forming five-membered rings with a trans-configuration. The PdII ion is fourfold coordinated in a slightly distorted square-planar geometry. For each ligand, one H⋯S and one H⋯N intra-molecular inter-actions are observed, with S(5) and S(6) graph-set motifs. Concerning the H⋯S inter-actions, the coordination sphere resembles a hydrogen-bonded macrocyclic environment-type. In the crystal, the complexes are linked via pairs of H⋯S inter-actions, with graph-set motif R 2 2(8), and building a mono-periodic hydrogen-bonded ribbon along [001]. The Hirshfeld surface analysis indicates that the major contributions for the crystal cohesion are: H⋯H (45.3%), H⋯C/C⋯H (28.0%), H⋯S/S⋯H (8.0%) and H⋯N/N⋯H (7.4%).

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Carbamazepine is a widely used antiepileptic drug to control and treat a variety of disorders that is frequently detected in surface water, and in municipal and urban wastewater. This recalcitrant pollutant could be removed by alternative advanced oxidation technology such as heterogeneous photocatalysis. Ce-modified ZnO and Pd-modified TiO2 were synthesized by a microwave-assisted sol-gel method. According to the characterizations (Raman spectroscopy, UV-Vis diffuse reflectance spectroscopy, scanning electron microscopy, and X-ray photoelectron spectroscopy), a mixture of oxides was determined in both materials: CeO2/ZnO and PdO/TiO2. Photocatalytic degradation of carbamazepine in pure water under visible light (3 h) was assayed. The degradation percentage obtained with each catalyst was 80%, 53%, 20%, and 9% for ZnO, Ce-modified ZnO, TiO2, and Pd-modified TiO2, respectively. The leaching of Zn as a possible source of water contamination was tested, finding the lowest value for Ce-modified ZnO by adjusting the initial pH up to neutrality. Later, an environmentally relevant concentration of carbamazepine (228 µg L-1) was assayed, using local surface water (pH = 8.3). Despite the presence of other compounds in the real water matrix, after 5 h of photocatalysis, a 56% of degradation of the pharmaceutical and low leaching of Zn were achieved. The use of Ce-modified ZnO activated by visible light is a promising strategy for the abatement of pharmaceutical active compounds.

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In this work, two analogous coumarin-thio and semicarbazone hybrid compounds were prepared and evaluated as a potential antichagasic agents. Furthermore, palladium and platinum complexes with the thiosemicarbazone derivative as ligand (L1) were obtained in order to establish the effect of metal complexation on the antiparasitic activity. All compounds were fully characterized both in solution and in solid state including the resolution of the crystal structure of the palladium complex by X-ray diffraction methods. Unexpectedly, all experimental and theoretical characterizations in the solid state, demonstrated that the obtained palladium and platinum complexes are structurally different: [PdCl(L1)] and [PtCl2(HL1)]. All the studied compounds lower the proliferation of the amastigote form of Trypanosoma cruzi while some of them also have an effect on the trypomastigote stage. Additionally, the compounds inhibit T. cruzi release from host cells in variable extents. The Pd compound presented a remarkable profile in all the in vitro experiments, and it showed no toxicity for mammalian cells in the assayed concentrations. In this sense, in vivo experiments were performed for this compound using an acute model of Chagas disease. Results showed that the complex significantly lowered the parasite count in the mice blood with no significant toxicity.

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This work describes the preparation, characterization and antimicrobial activity of four palladium(II) complexes, namely, [Pd(meg)(1,10-phen)] 1, [Pd(meg)(PPh3)2] 2, [Pd(og)(1,10-phen)] 3 and [Pd(og)(PPh3)2] 4, where meg = methyl gallate, og = octyl gallate, 1,10-phen = 1,10-phenanthroline and PPh3 = triphenylphosphine. As to the chemical structures, spectral and physicochemical studies of 1-4 indicated that methyl or octyl gallate coordinates a palladium(II) ion through two oxygen atoms upon deprotonation. A chelating bidentate phenanthroline or two triphenylphosphine molecules complete the coordination sphere of palladium(II) ion, depending on the complex. The metal complexes were tested against the Mycobacterium tuberculosis H37Rv strain and 2 exhibited high activity (MIC = 3.28 µg/mL). As to the tests with Campylobacter jejuni, complex 1 showed a significant effect in reducing bacterial population (greater than 7 log CFU) in planktonic forms, as well as in the biomass intensity (IBF: 0.87) when compared to peracetic acid (IBF: 1.11) at a concentration of 400 µg/mL. The effect provided by these complexes has specificity according to the target microorganism and represent a promising alternative for the control of microorganisms of public health importance.

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We report the synthesis and characterization of new tri-cationic corrole derivatives, containing Pt(II) or Pd(II) complexes attached at the peripheral position of thienyl moieties. Corrole derivatives were characterized through microanalysis, electrochemical, spectrometry and spectroscopy analysis. Singlet and triplet excited-states are investigated by photophysical/theoretical calculation methods and photobiological parameters were also evaluated spectroscopic techniques (UV-Vis and EPR). Also, the binding capacity of each corrole derivative with nucleic acids (DNA) and human serum albumin (HSA) was determined by UV-Vis, steady-state, and time-resolved fluorescence spectroscopy, combined with molecular docking analysis. Moreover, the new corroles containing peripheral complexes improve their interactions with biomacromolecules, generate reactive oxygen species under light source irradiation studied and has potential for application in photodynamic therapeutic processes.

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A novel, easily prepared and accessible water-soluble supramolecular catalyst for the Suzuki-Miyaura CC coupling reaction was synthesized and characterized by FTIR, NMR, XRD, SEM, and HR-TEM. An inexpensive Pd(II) source added to the resulting aqueous solution of thioglycolic ester ß-cyclodextrin (1-TGA-SH-ß-CD/PdCl2) showed Pd nanoclusters and efficient catalytic activity for Suzuki-Miyaura CC coupling reactions of aryl halides with aryl boronic acids, employing K2CO3 as base, in an environmentally benign aqueous solution prepared in open flasks. Organic aryl halides including chlorides can produce moderate to excellent yields with aryl boronic acids and a small catalytic amount (0.01 mol%) of 1-TGA-SH-ß-CD/PdCl2. This hydro-soluble catalyst stock solution was stable for long periods (more than three months) and could be reused in two runs until showing loss of catalytic activity. Some experiments to understand the mechanism were performed, with the results suggesting incorporation of aryl halide in the catalytic cavity.

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The production of sustainable catalytic supports for palladium nanoparticles is always desired, even more so through the recovery of biomass residues. In this sense, two different solids were investigated - chitosan/cellulose film and corn stem biochar - as catalytic supports of palladium nanoparticles. The solids were carefully characterized and tested in the Suzuki-Miyaura reaction, a typical cross-coupling reaction. The developed catalytic systems proved to be efficient and sustainable, promoted the formation of target products very well, and demanded green reactants under environmentally appropriate conditions. With the results shown in the manuscript, it is expected to contribute to the valorization of biomass and agro-industrial residues in the development of new catalysts for the chemical industry.

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Pure (TiO2) and 0.1 nominal atomic percent of palladium-modified TiO2 (Pd-TiO2) films were synthesized via a sol-gel method and compared through their physicochemical properties and photocatalytic activity in the degradation of an emerging contaminant, 17-α-ethinylestradiol (EE2). The activity of the films was studied using a continuous flow, planar microreactor under simulated sunlight. Catalysts characterization included X-ray diffraction, UV-Visible diffuse reflectance and transmittance spectroscopy, atomic force microscopy, transmission electron microscopy, Raman spectroscopy, N2 physisorption analysis, and X-ray photoelectron spectroscopy. The modification of TiO2 with palladium confined the size of anatase phase crystallites, increased the specific surface area and improved radiation absorption. PdO domains on TiO2 were observed. In all the tested conditions, higher conversion of EE2 was achieved with the Pd-TiO2 film compared with the TiO2 film, presenting an 80% increase in the reaction rate. The performance of the catalytic films was also assessed by the calculation of two efficiency parameters: radiation absorption efficiency and quantum efficiency of reaction. The Pd-TiO2 film showed a notable enhancement of the absorption of the incident radiation and a more efficient utilization of the absorbed photons to degrade the target pollutant.

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The reaction between the (R,S)-fixolide 4-methyl-thio-semicarbazone and PdII chloride yielded the title compound, [Pd(C20H30N3S)2]·C2H6O {common name: trans-bis-[(R,S)-fixolide 4-methyl-thio-semicarbazonato-κ2 N 2 S]palladium(II) ethanol monosolvate}. The asymmetric unit of the title compound consists of one bis-thio-semicarbazonato PdII complex and one ethanol solvent mol-ecule. The thio-semicarbazononato ligands act as metal chelators with a trans configuration in a distorted square-planar geometry. A C-H⋯S intra-molecular inter-action, with graph-set motif S(6), is observed and the coordination sphere resembles a hydrogen-bonded macrocyclic environment. Additionally, one C-H⋯Pd anagostic inter-action can be suggested. Each ligand is disordered over the aliphatic ring, which adopts a half-chair conformation, and two methyl groups [s.o.f. = 0.624 (2):0.376 (2)]. The disorder includes the chiral carbon atoms and, remarkably, one ligand has the (R)-isomer with the highest s.o.f. value atoms, while the other one shows the opposite, the atoms with the highest s.o.f. value are associated with the (S)-isomer. The N-N-C(=S)-N fragments of the ligands are approximately planar, with the maximum deviations from the mean plane through the selected atoms being 0.0567 (1) and -0.0307 (8) Š(r.m.s.d. = 0.0403 and 0.0269 Å) and the dihedral angle with the respective aromatic rings amount to 46.68 (5) and 50.66 (4)°. In the crystal, the complexes are linked via pairs of N-H⋯S inter-actions, with graph-set motif R 2 2(8), into centrosymmetric dimers. The dimers are further connected by centrosymmetric pairs of ethanol mol-ecules, building mono-periodic hydrogen-bonded ribbons along [011]. The Hirshfeld surface analysis indicates that the major contributions for the crystal cohesion are [atoms with highest/lowest s.o.f.s considered separately]: H⋯H (81.6/82.0%), H⋯C/C⋯H (6.5/6.4%), H⋯N/N⋯H (5.2/5.0%) and H⋯S/S⋯H (5.0/4.9%).

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A significant fraction of patients are affected by persistent fear and anxiety. Currently, there are several anxiolytic drug options, however their clinical outcomes do not fully manage the symptoms. Here, we evaluated the effects of a bromazepam­palladium derivative [2-{(7-bromo-2-oxo-1,3-dihydro-2H-1,4-benzodiazepin-5-il)pyridinyl-κ2-N,N}chloropalladium(II)], [(BMZ)PdCl2], on fear/anxiety and memory-related behavior in mice. For this, female Swiss mice were treated intraperitoneally (i.p.) with saline (NaCl 0.9%) or [(BMZ)PdCl2] (0.5, 5.0, or 50 µg/kg). After 30 min, different tests were performed to evaluate anxiety, locomotion, and memory. We also evaluated the acute toxicity of [(BMZ)PdCl2] using a cell viability assay (neutral red uptake assay), and whether the drugs mechanism of action involves the γ-aminobutyric acid type A (GABAA) receptor complex by pre-treating animals with flumazenil (1.0 mg/kg, i.p., a competitive antagonist of GABAA-binding site). Our results demonstrate that [(BMZ)PdCl2] induces an anxiolytic-like phenotype in the elevated plus-maze test and that this effect can be blocked by flumazenil. Furthermore, there were no behavioral alterations induced by [(BMZ)PdCl2], as evaluated in the light-dark box, open field, and step-down passive avoidance tests. In the acute toxicity assay, [(BMZ)PdCl2] presented IC50 and LD50 values of 218 ± 60 µg/mL and 780 ± 80 mg/kg, respectively, and GSH category 4. Taken together, our results show that the anxiolytic-like effect of acute treatment with [(BMZ)PdCl2] occurs through the modulation of the benzodiazepine site in the GABAA receptor complex. Moreover, we show indications that [(BMZ)PdCl2] does not promote sedation and amnesia and presents the same toxicity as the bromazepam prototype.

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This work aims to develop a photoelectrochemical (PEC) platform for detection of SARS-CoV-2 spike glyprotein S1. The PEC platform is based on the modification of a fluorine-doped tin oxide (FTO) coated glass slide with strontium titanate (SrTiO3 or ST), sulfur-doped carbon nitride (g-C3N4-S or CNS) and palladium nanoparticles entrapped in aluminum hydroxide matrix (PdAlO(OH) or PdNPs). The PEC platform was denoted as PdNPs/CNS/ST/FTO and it was characterized by SEM, TEM, FTIR, DRX, and EIS. The PEC response of the PdNPs/CNS/ST/FTO platform was optimized by evaluating the effects of the concentration of the donor molecule, the nature of the buffer, pH, antibody concentration, potential applied to the working electrode, and incubation time. The optimized PdNPs/CNS/ST/FTO PEC platform was modified with 5 µg mL-1 of antibody for determination of SARS-CoV-2 spike glycoprotein S1. A decrease in the photocurrent was observed with an increase in the concentration of SARS-CoV-2 from 1 fg mL-1 to 1000 pg mL-1 showing that the platform is a promising alternative for the detection of S1 protein from SARS-CoV-2. The designed PEC platform exhibited recovery percentages of 96.20% and 109.65% in artificial saliva samples.