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Three recently synthesized neutral dinuclear carbonyl manganese complexes with the pyridazine bridging ligand, of general formula [Mn[sub.2](μ-ER)[sub.2](CO)[sub.6](μ-pydz)] (pydz = pyridazine; E = O or S; R = methyl or phenyl), have been investigated by cyclic voltammetry in dimethylformamide and acetonitrile both under an inert argon atmosphere and in the presence of carbon dioxide. This family of Mn(I) compounds behaves interestingly at negative potentials in the presence of CO[sub.2]. Based on this behavior, which is herein discussed, a rather efficient catalytic mechanism for the CO[sub.2] reduction reaction toward the generation of CO has been hypothesized.

The coordination behavior of tris(2-pyridyl)arsine (Py[sub.3]As) has been studied for the first time on the example of the reactions with CuI, CuBr and AgClO[sub.4]. When treated with CuI in CH[sub.2]Cl[sub.2] medium, Py[sub.3]As unexpectedly affords the scorpionate complex [Cu(Py[sub.3]As)I]∙CH[sub.2]Cl[sub.2] only, while this reaction in MeCN selectively leads to the dimer [Cu[sub.2](Py[sub.3]As)[sub.2]I[sub.2]]. At the same time, the interaction of CuBr with Py[sub.3]As exclusively gives the dimer [Cu[sub.2](Py[sub.3]As)[sub.2]Br[sub.2]]. It is interesting to note that the scorpionate [Cu(Py[sub.3]As)I]∙CH[sub.2]Cl[sub.2], upon fuming with a MeCN vapor (r.t., 1 h), undergoes quantitative dimerization into the dimer [Cu[sub.2](Py[sub.3]As)[sub.2]I[sub.2]]. The reaction of Py[sub.3]As with AgClO[sub.4] produces complex [Ag@Ag[sub.4](Py[sub.3]As)[sub.4]](CIO[sub.4])[sub.5] featuring a Ag-centered Ag[sub.4] tetrahedral kernel. At ambient temperature, the obtained Cu(I) complexes exhibit an unusually short-lived photoluminescence, which can be tentatively assigned to the thermally activated delayed fluorescence of (M + X) LCT type (M = Cu, L = Py[sub.3]As; X = halogen). For the title Ag(I) complexes, QTAIM calculations reveal the pronounced argentophilic interactions for all short Ag∙∙∙Ag contacts (3.209–3.313 Å).

Numerous compounds that are scavengers of hydroxyl radicals (•OH) in Fenton systems have low solubility in water. Therefore, they are dissolved in organic solvents to reach suitable concentrations in the reaction milieu of the Fenton system. However, these solvents may react with •OH and iron, leading to significant errors in the results. We evaluated 11 solvents (4 alcohols, acetone, 4 esters, dimethyl-sulfoxide, and acetonitrile) at concentrations ranging from 0.105 µmol/L to 0.42 µmol/L to assess their effects on light emission, a recognized measure of •OH radical activity, in the Fe[sup.2+]-EGTA-H[sub.2]O[sub.2] system. Six solvents inhibited and four solvents enhanced light emission at all tested concentrations. Acetonitrile, which initially suppressed light emission, lost this effect at a concentration of 0.105 µmol/L, (−1 ± 13 (2; 0) %, p > 0.05). Methanol, at the lowest tested concentration, inhibited light emission by 62 ± 4% (p < 0.05), while butyl butyrate enhanced it by 93 ± 16% (p < 0.05). These effects may be explained by solvent-driven •OH-scavenging, inhibition or acceleration of Fe2+ regeneration, or photon emission from excited solvent molecules. Our findings suggest that acetonitrile seems suitable for preparing stock solutions to evaluate antioxidant activity in the Fe[sup.2+]-EGTA-H[sub.2]O[sub.2] system, provided that the final concentration of this solvent in the reaction milieu is kept below 0.105 µmol/L.

Copper is well-known to be selective to primary amines via electrocatalytic nitriles hydrogenation. However, the correlation between the local fine structure and catalytic selectivity is still illusive. Herein, we find that residual lattice oxygen in oxide-derived Cu nanowires (OD-Cu NWs) plays vital roles in boosting the acetonitrile electroreduction efficiency. Especially at high current densities of more than 1.0 A cm −2 , OD-Cu NWs exhibit relatively high Faradic efficiency. Meanwhile, a series of advanced in situ characterizations and theoretical calculations uncover that oxygen residues, in the form of Cu 4 -O configuration, act as electron acceptors to confine the free electron flow on the Cu surface, consequently improving the kinetics of nitriles hydrogenation catalysis. This work could provide new opportunities to further improve the hydrogenation performance of nitriles and beyond, by employing lattice oxygen-mediated electron tuning engineering. While copper is active for electrocatalytic nitriles hydrogenation, the correlation between the local structures and catalytic activity is still illusive. Here, the authors report that residual lattice oxygen in oxide-derived copper nanowires plays vital roles in boosting the hydrogenation activity.

Due to the emergence of drug resistance, many antimicrobial medications are becoming less effective, complicating the treatment of infections. Therefore, it is crucial to develop new active agents. This article aims to explore the ruthenium(IV) complexes with the following formulas: (Hdma)2(HL)2[RuIVCl6]·2Cl·2H2O (1), where Hdma is protonated dimethylamine and L is 2-hydroxymethylbenzimidazole, and [RuIVCl4(AN)2]·H2O (2), where AN is acetonitrile. This paper delves into the physicochemical characteristics and crystal structures of these complexes, employing various techniques such as spectroscopy (IR, UV–Vis), electrochemistry (CV, DPV), and X-ray crystallography. Hirshfeld surface analysis was also performed to visualize intermolecular interactions. Furthermore, the potential antibiofilm activity of the complexes against Pseudomonas aeruginosa PAO1 was investigated and the effect of the compounds on the production of pyoverdine, one of the virulence factors of the Pseudomonas strain, was assessed. The results show that particularly complex 1 reduces biofilm formation and pyoverdine production. Additionally, the bioavailability of these complexes in biological systems (by fluorescence quenching of human serum albumin (HSA) and molecular docking studies) is discussed, assessing how their chemical properties influence their interactions with biological molecules and their potential therapeutic applications.

The Quick Easy Cheap Effective Rugged and Safe multiresidue method (QuEChERS) has been validated for the extraction of 80 pesticides belonging to various chemical classes from various types of representative commodities with low lipid contents. A mixture of 38 pesticides amenable to gas chromatography (GC) were quantitatively recovered from spiked lemon, raisins, wheat flour and cucumber, and determined using gas chromatography-tandem mass spectrometry (GC-MS/MS). An additional mixture of 42 pesticides were recovered from oranges, red wine, red grapes, raisins and wheat flour, using liquid chromatography-tandem mass spectrometry (LC-MS/MS) for determination. The pesticides chosen for this study included many of the most frequently detected ones and/or those that are most often found to violate the maximum residue limit (MRL) in food samples, some compounds that have only recently been introduced, as well as a few other miscellaneous compounds. The method employed involved initial extraction in a water/acetonitrile system, an extraction/partitioning step after the addition of salt, and a cleanup step utilizing dispersive solid-phase extraction (D-SPE); this combination ensured that it was a rapid, simple and cost-effective procedure. The spiking levels for the recovery experiments were 0.005, 0.01, 0.02 and 0.2 mg kg(-1) for GC-MS/MS analyses, and 0.01 and 0.1 mg kg(-1) for LC-MS/MS analyses. Adequate pesticide quantification and identity confirmation were attained, even at the lowest concentration levels, considering the high signal-to-noise ratios, the very good accuracies and precisions, as well as the good matches between the observed ion ratios. Mean recoveries mostly ranged between 70 and 110% (98% on average), and relative standard deviations (RSD) were generally below 10% (4.3% on average). The use of analyte protectants during GC analysis was demonstrated to provide a good alternative to the use of matrix-matched standards to minimize matrix-effect-related errors. Based on these results, the methodology has been proven to be highly efficient and robust and thus suitable for monitoring the MRL compliance of a wide range of commodity/pesticide combinations.

Over 10% of pheochromocytoma and paraganglioma (PPGL) patients have malignant disease at their first presentation in the clinic. Development of malignancy and the underlying molecular pathways in PPGLs are poorly understood and efficient treatment strategies are missing. Marine sponges provide a natural source of promising anti-tumorigenic and anti-metastatic agents. We evaluate the anti-tumorigenic and anti-metastatic potential of Aeroplysinin-1 and Isofistularin-3, two secondary metabolites isolated from the marine sponge Aplysina aerophoba, on pheochromocytoma cells. Aeroplysinin-1 diminished the number of proliferating cells and reduced spheroid growth significantly. Beside these anti-tumorigenic activity, Aeroplysinin-1 decreased the migration ability of the cells significantly (p = 0.01), whereas, the invasion capacity was not affected. Aeroplysinin-1 diminished the high adhesion capacity of the MTT cells to collagen (p < 0.001) and, furthermore, reduced the ability to form spheroids significantly. Western Blot and qRT-PCR analysis showed a downregulation of integrin β1 that might explain the lower adhesion and migration capacity after Aeroplysinin-1 treatment. Isofistularin-3 showed only a negligible influence on proliferative and pro-metastatic cell properties. These in vitro investigations show promise for the application of the sponge-derived marine drug, Aeroplysinin-1 as anti-tumorigenic and anti-metastatic agent against PPGLs for the first time.

Electrochemical reduction of acetonitrile to ethylamine with a high selectivity is a novel approach to manufacture valuable primary amines which are important raw material in organic chemical industry. However, the poor ethylamine Faradic efficiency (FE ethylamine ) and catalyst stability at the high current density prohibit this method from being practically used. Herein, CuNi alloy ultrafine-nano-particles based on the d -orbital coupling modulation were synthesized through the electrodeposition and their catalytic performance towards acetonitrile reduction reaction (ACNRR) has been systematically studied. The highest FE ethylamine (97%) is achieved with the current density of −114 mA cm −2 . For practical application, the current density can reach −602.8 mA cm −2 with 82.8% FE ethylamine maintained. With the appearance of other organics which co-exist with acetonitrile in the SOHIO process, CuNi can also hydrogenate acetonitrile in it with more than 80% FE ethylamine . Our in-situ spectroscopy analysis and DFT calculations towards the acetonitrile hydrogenation behavior reveal that the evenly dispersed Ni in Cu modulates the d -band so as to endow CuNi with the better acetonitrile adsorption, milder binding energy with the reaction intermediates, smaller barrier for *CH 3 CH 2 NH 2 desorption and higher ability for H 2 O dissociation to provide *H.

An efficient, green and practical approach to synthesize alkenyl nitriles using new supported Cu(II) catalyst via aromatic aldehydes and acetonitrile was developed. The novel catalyst was characterized by FT-IR, XRD, SEM/EDX, TEM, TGA and VSM. Interestingly, the catalyst was found to be active for synthesis of alkenyl nitriles, which were readily obtained in good yields under mild conditions. But most importantly, the original catalyst could be conveniently recovered and recycled from the reaction system by applying an external magnet and reused in four cycles without significant loss in catalytic activity.

Asymmetric catalysis is a powerful approach for the synthesis of optically active compounds, and visible light constitutes an abundant source of energy to enable chemical transformations, which are often triggered by photoinduced electron transfer (photoredox chemistry). Recently, bis-cyclometalated iridium(III) and rhodium(III) complexes were introduced as a novel class of catalysts for combining asymmetric catalysis with visible-light-induced photoredox chemistry. These catalysts are attractive because of their unusual feature of chirality originating exclusively from a stereogenic metal center, which offers the prospect of an especially effective asymmetric induction upon direct coordination of the substrate to the metal center. As these chiral catalysts contain only achiral ligands, special strategies are required for their synthesis. In this protocol, we describe strategies for preparing two types of chiral-at-metal catalysts, namely the Î>- and Î\"-enantiomers (left- and right-handed propellers, respectively) of the iridium complex IrS and the rhodium complex RhS. Both contain two cyclometalating 5-tert-butyl-2-phenylbenzothiazoles in addition to two acetonitrile ligands and a hexafluorophosphate counterion. The two cyclometalated ligands set the propeller-shaped chiral geometry, but the acetonitriles are labile and can be replaced by substrate molecules. The synthesis protocol consists of three stages: first, preparation of the ligand 5-tert-butyl-2-phenylbenzothiazole; second, preparation of salicylthiazoline (used for iridium) and salicyloxazoline (used for rhodium) chiral auxiliaries; and third, the auxiliary-mediated synthesis of the individual enantiopure Î>- and Î\"-configured catalysts. This class of stereogenic-only-at-metal complexes is of substantial value in the field of asymmetric catalysis, offering stereocontrolled radical reactions based on visible-light-activated photoredox chemistry. Representative examples of visible-light-induced asymmetric catalysis are provided.