The formation of gaseous chlorine within chlor-alkali electrolysis is accompanied by a selectivity problem, as the evolution of gaseous oxygen constitutes a detrimental side reaction in the same potential range. As such, the development of electrode materials with high selectivity toward the chlorine evolution reaction is of particular importance to the chemical industry. Insight into the elementary reaction steps is ultimately required to comprehend chlorine selectivity on a molecular level. Commonly, linear scaling relationships are analyzed by the construction of a volcano plot, using the binding energy of oxygen, ΔEO, as a descriptor in the analysis. The present article reinvestigates the selectivity problem of the competing chlorine and oxygen evolution reactions by applying a different strategy compared to previous literature studies. On the one hand, a unifying material-screening framework that, besides binding energies, also includes the applied overpotential, kinetics, and the electrochemical-step symmetry index is used to comprehend trends in this selectivity issue for transition-metal oxide-based electrodes. On the other hand, the free-energy difference between the adsorbed oxygen and adsorbed hydroxide, ΔG2, rather than ΔEO is used as a descriptor in the analysis. It is demonstrated that the formation of the OCl adsorbate within the chlorine evolution reaction inherently limits chlorine selectivity, whereas, in the optimum case, the formation of the Cl intermediate can result in significantly higher chlorine selectivity. This finding is used to derive the design criteria for highly selective chlorine evolution electrocatalysts, which can be used in the future to search for potential electrode compositions by material-screening techniques.ZrB2 is first explored as an earth-abundant metal diboride catalyst for highly efficient nitrogen reduction reaction (NRR). The synthesized ZrB2 nanocubes exhibited a highly attractive NRR performance with an NH3 yield of 37.7 μg h-1 mg-1 and a Faradaic efficiency 18.2% at -0.3 V (RHE). Theoretical calculations unraveled that active Zr centers enabled the effective activation of the N2 molecule via a unique tetranuclear side-on mode and concurrently impeded hydrogen evolution by restricting H+ adsorption.Here, we discuss that unlike bond dissociation energy (BDE) that is a state function quantity, the energy components of the energy decomposition analysis (EDA), i.e. electrostatic interaction, Pauli repulsion, and orbital interaction, are path (process) function quantities. Being a path function means that EDA energy components are not uniquely defined, i.e. the relative magnitudes of the orbital interaction, Pauli repulsion, and electrostatic components may vary depending on the selected pathway for EDA. Therefore, at best, EDA can define whether closely related chemical bonds are more or less ionic/covalent compared with each other. https://www.selleckchem.com/products/kn-93.html However, a precise assessment of the nature of a certain type of chemical bond using EDA is a questionable task. Besides, we briefly discuss that the widely used EDA pathway, which is merely an arbitrary choice among infinite possible paths, comes to conclusions not consistent with our widely accepted knowledge of bond formation even for the simplest molecules.Methanol (CH3OH) is the simplest alcohol and carbon tetrachloride (CCl4) is widely used as a solvent in the chemical industry. CH3OH and CCl4 are both important volatile substances in the atmosphere and CCl4 is an important precursor for atmospheric ozone depletion. Moreover, mixtures of CH3OH and CCl4 are an important class of non-aqueous mixtures as they exhibit a large deviation from Raoult's law. The specific interaction between CH3OH and CCl4 is not yet investigated experimentally. The interaction between CH3OH and CCl4 at the molecular level can be twofold hydrogen bond (O-HCl) and halogen bond (C-ClO) interaction. One halogen bonded minimum and two hydrogen bonded minima are identified in the dimer potential energy surface. Herein, the 1  1 complex of [CH3OH-CCl4] has been characterised using matrix-isolation infrared spectroscopy and electronic structure calculations to investigate the competition between hydrogen bonded and halogen bonded complexes. Vibrational spectra have been monitored in the C-Cl, C-O, and O-H stretching regions. The exclusive formation of halogen bonded 1  1 complexes in argon and nitrogen matrices is confirmed by a combination of experimental and simulated vibrational frequency, stabilisation energy, energy decomposition analysis, and natural bond orbital and atoms-in-molecules analyses. This investigation helps to understand the specific interactions in the [CH3OH-CCl4] mixture and also the possibilities of formation of halogen bonded atmospheric complexes that may influence the atmospheric chemical activities, and enhance aerosol formation and deposition of CCl4.Herein we report a diaminocyclopentadienone iron tricarbonyl complex catalyzed synthesis of substituted cyclopentane, cyclohexane and cycloheptane compounds using the borrowing hydrogen strategy in the presence of various substituted primary and secondary 1,n diols as alkylating reagents. Deuterium labeling experiments confirm that the diols were the hydride source in this cascade process.A new efficient strategy to access benzylic carbamates through C-H activation is reported. The use of a catalytic amount of a Cu(i)/diimine ligand in combination with NFSI ((PhSO2)2NF) or F-TEDA-PF6 as oxidants and H2NCO2R as an amine source directly leads to the C-N bond formation at the benzylic position. The mild reaction conditions and the broad substrate scope make this transformation a useful method for the late-stage incorporation of a ubiquitous carbamate fragment onto hydrocarbons.In this paper, we report on the demonstration of a portable immunoassay system consisting of a small centrifugal microfluidic device driver (bento box) and a centrifugal microfluidic device made of polypropylene and fabricated by injection molding. The bento box consists of a cheap DC motor and an Arduino microcontroller. It has a simple structure and is the size of a bento box, that is, 150 × 150 × 100 (W × D × H) mm3. The developed device can automatically execute an enzyme-linked immunosorbent assay (ELISA) process under a steady rotating condition because it was designed based on the principle of CLOCK, which we previously presented. Here, we first executed an ELISA using a system consisting of the bento box and a device made of polydimethylsiloxane (PDMS) and compared it with a servo-controlled device driver. It was confirmed that the results of the bento box were consistent with those of the servo-controlled device driver. The limit of detection (LOD) using the bento box was 0.759 ng ml-1. Therefore, the controllability of the bento box was demonstrated.
The formation of gaseous chlorine within chlor-alkali electrolysis is accompanied by a selectivity problem, as the evolution of gaseous oxygen constitutes a detrimental side reaction in the same potential range. As such, the development of electrode materials with high selectivity toward the chlorine evolution reaction is of particular importance to the chemical industry. Insight into the elementary reaction steps is ultimately required to comprehend chlorine selectivity on a molecular level. Commonly, linear scaling relationships are analyzed by the construction of a volcano plot, using the binding energy of oxygen, ΔEO, as a descriptor in the analysis. The present article reinvestigates the selectivity problem of the competing chlorine and oxygen evolution reactions by applying a different strategy compared to previous literature studies. On the one hand, a unifying material-screening framework that, besides binding energies, also includes the applied overpotential, kinetics, and the electrochemical-step symmetry index is used to comprehend trends in this selectivity issue for transition-metal oxide-based electrodes. On the other hand, the free-energy difference between the adsorbed oxygen and adsorbed hydroxide, ΔG2, rather than ΔEO is used as a descriptor in the analysis. It is demonstrated that the formation of the OCl adsorbate within the chlorine evolution reaction inherently limits chlorine selectivity, whereas, in the optimum case, the formation of the Cl intermediate can result in significantly higher chlorine selectivity. This finding is used to derive the design criteria for highly selective chlorine evolution electrocatalysts, which can be used in the future to search for potential electrode compositions by material-screening techniques.ZrB2 is first explored as an earth-abundant metal diboride catalyst for highly efficient nitrogen reduction reaction (NRR). The synthesized ZrB2 nanocubes exhibited a highly attractive NRR performance with an NH3 yield of 37.7 μg h-1 mg-1 and a Faradaic efficiency 18.2% at -0.3 V (RHE). Theoretical calculations unraveled that active Zr centers enabled the effective activation of the N2 molecule via a unique tetranuclear side-on mode and concurrently impeded hydrogen evolution by restricting H+ adsorption.Here, we discuss that unlike bond dissociation energy (BDE) that is a state function quantity, the energy components of the energy decomposition analysis (EDA), i.e. electrostatic interaction, Pauli repulsion, and orbital interaction, are path (process) function quantities. Being a path function means that EDA energy components are not uniquely defined, i.e. the relative magnitudes of the orbital interaction, Pauli repulsion, and electrostatic components may vary depending on the selected pathway for EDA. Therefore, at best, EDA can define whether closely related chemical bonds are more or less ionic/covalent compared with each other. https://www.selleckchem.com/products/kn-93.html However, a precise assessment of the nature of a certain type of chemical bond using EDA is a questionable task. Besides, we briefly discuss that the widely used EDA pathway, which is merely an arbitrary choice among infinite possible paths, comes to conclusions not consistent with our widely accepted knowledge of bond formation even for the simplest molecules.Methanol (CH3OH) is the simplest alcohol and carbon tetrachloride (CCl4) is widely used as a solvent in the chemical industry. CH3OH and CCl4 are both important volatile substances in the atmosphere and CCl4 is an important precursor for atmospheric ozone depletion. Moreover, mixtures of CH3OH and CCl4 are an important class of non-aqueous mixtures as they exhibit a large deviation from Raoult's law. The specific interaction between CH3OH and CCl4 is not yet investigated experimentally. The interaction between CH3OH and CCl4 at the molecular level can be twofold hydrogen bond (O-HCl) and halogen bond (C-ClO) interaction. One halogen bonded minimum and two hydrogen bonded minima are identified in the dimer potential energy surface. Herein, the 1  1 complex of [CH3OH-CCl4] has been characterised using matrix-isolation infrared spectroscopy and electronic structure calculations to investigate the competition between hydrogen bonded and halogen bonded complexes. Vibrational spectra have been monitored in the C-Cl, C-O, and O-H stretching regions. The exclusive formation of halogen bonded 1  1 complexes in argon and nitrogen matrices is confirmed by a combination of experimental and simulated vibrational frequency, stabilisation energy, energy decomposition analysis, and natural bond orbital and atoms-in-molecules analyses. This investigation helps to understand the specific interactions in the [CH3OH-CCl4] mixture and also the possibilities of formation of halogen bonded atmospheric complexes that may influence the atmospheric chemical activities, and enhance aerosol formation and deposition of CCl4.Herein we report a diaminocyclopentadienone iron tricarbonyl complex catalyzed synthesis of substituted cyclopentane, cyclohexane and cycloheptane compounds using the borrowing hydrogen strategy in the presence of various substituted primary and secondary 1,n diols as alkylating reagents. Deuterium labeling experiments confirm that the diols were the hydride source in this cascade process.A new efficient strategy to access benzylic carbamates through C-H activation is reported. The use of a catalytic amount of a Cu(i)/diimine ligand in combination with NFSI ((PhSO2)2NF) or F-TEDA-PF6 as oxidants and H2NCO2R as an amine source directly leads to the C-N bond formation at the benzylic position. The mild reaction conditions and the broad substrate scope make this transformation a useful method for the late-stage incorporation of a ubiquitous carbamate fragment onto hydrocarbons.In this paper, we report on the demonstration of a portable immunoassay system consisting of a small centrifugal microfluidic device driver (bento box) and a centrifugal microfluidic device made of polypropylene and fabricated by injection molding. The bento box consists of a cheap DC motor and an Arduino microcontroller. It has a simple structure and is the size of a bento box, that is, 150 × 150 × 100 (W × D × H) mm3. The developed device can automatically execute an enzyme-linked immunosorbent assay (ELISA) process under a steady rotating condition because it was designed based on the principle of CLOCK, which we previously presented. Here, we first executed an ELISA using a system consisting of the bento box and a device made of polydimethylsiloxane (PDMS) and compared it with a servo-controlled device driver. It was confirmed that the results of the bento box were consistent with those of the servo-controlled device driver. The limit of detection (LOD) using the bento box was 0.759 ng ml-1. Therefore, the controllability of the bento box was demonstrated.
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