Electrophilic aromatic substitution (EAS) is one of the most widely researched transforms in synthetic organic chemistry. Numerous studies have been carried out to provide an understanding of the nature of its reactivity pattern. There is now a need for a concise and general, but detailed and up-to-date, overview. The basic principles behind EAS are essential to our understanding of what the mechanisms underlying EAS are. To date, textbook overviews of EAS have provided little information about the mechanistic pathways and chemical species involved. In this review, the aim is to gather and present the up-to-date information relating to reactivity in EAS, with the implication that some of the key concepts will be discussed in a scientifically concise manner. In addition, the information presented herein suggests certain new possibilities to advance EAS theory, with particular emphasis on the role of modern instrumental and theoretical techniques in EAS reactivity monitoring.The stepped surfaces in nanoscale zero-valent iron (nZVI) play an essential role for environmental application. However, there is still currently a deficiency in the atomic understanding of stepped surface properties due to the limitation of the computational methodology. In this study, stepped Fe(210) and (211) surfaces were theoretically investigated using density functional theory (DFT) computations in terms of the flat Fe(110) surface. Our results suggest that the consideration of van der Waals (vdW) interaction correction is beneficial for the DFT study on Fe-based systems. The DF-cx method is found to be the most promising vdW correction method. The DF-cx results reveal that the stepped Fe(210) and Fe(211) surfaces experience significant surface relaxation and abnormal trends in their work function. Their electronic properties and reactivities of the surface atoms are strongly affected by the Fe coordination numbers and the strong adsorption strengths of oxygen on the surfaces are dependent on both the coordination number of the adsorbed atoms and the geometry of the adsorption sites.The synthesis, photophysical characterization, and quantum chemical calculations of a series of benzotriazinyl radicals and their styryl radical trapping products are presented.  https://www.selleckchem.com/products/bms-1166.html  The benzotriazinyl radicals are non-luminescent but surprisingly the corresponding styryl radical trapping products exhibit high fluorescence quantum yields (up to 60% in some cases), making them highly valuable probes or labels. Additionally, the influence of the substitution pattern on the optical properties of the radical trapping products was observed experimentally and interpreted by means of quantum chemical calculations. Specific substitution patterns showed a bathochromic shift compared to the unsubstituted compound. Computationally, it was shown that this substitution pattern leads to a stronger energetic stabilization of the lowest unoccupied molecular orbital than the highest occupied molecular orbital. Analysis of the influence of the substitution pattern on the optical properties showed a bathochromic shift in several examples, which was interpreted by means of quantum chemical calculations.High-entropy alloy (HEA) nanoparticles (NPs) hold great promise in electrocatalysis because of their nearly unlimited compositions, tailorable active sites, and high durability. However, the synthesis of these compositionally complex structures as monodisperse NPs remains a challenge by colloidal routes because the different rates of metal precursor reduction lead to phase separation. Here, we report the conversion of core@shell NPs into HEA NPs through annealing, with conservation of sample monodispersity. This potentially general route for high-quality HEA NPs was demonstrated by preparing PdCu@PtNiCo NPs via seed-mediated co-reduction, wherein Pt, Ni, and Co were co-deposited on PdCu seeds in solution. These multimetallic NPs were then converted to single-crystalline and single-phase PdCuPtNiCo NPs through annealing. On account of their small particle size, highly dispersed Pt/Pd content, and low elemental diffusivity, these HEA NPs were found to be a highly efficient and durable catalyst for the oxygen reduction reaction. They were also highly selective for the four-electron transfer pathway. We expect that this new synthetic strategy will facilitate the synthesis of new HEA NPs for catalysis and other applications.Volatile organic compounds (VOCs) have been identified as highly toxic and carcinogenic pollutants threatening both human health and the living environment. Their recognition and removal are important issues. Carbon nanotubes (CNTs) have been proposed as a promising agent for the adsorption of detrimental VOC molecules. Due to the intrinsic nanoscale nature of such processes, details of molecular interactions and the adsorption mechanism remain to be clarified. This paper aims to provide a molecular perspective on the adsorption behavior of VOC molecules on both neutral and electrically charged CNTs by the means of molecular dynamics simulations. Simulation results indicate a strong correlation between the adsorption affinity and hydrophobicity of acetone, ether, methanol and toluene molecules. VOCs possessing a higher hydrophobicity demonstrate greater adsorption affinity. The adsorption of toluene and ether molecules is quite stable around the CNT surface. In contrast, hydrophilic molecules such as acetone and methanol can only be unstably adsorbed. For neutral CNTs, the van der Waals interaction is responsible for the adsorption affinity. For electrically charged CNTs, however, electrostatic attraction or repulsion with the charged groups in VOC molecules significantly affects the adsorption behavior. As a result, the introduction of charges on the CNT surface can help to optimize the adsorption process of VOC molecules. Calculations on the potentials of mean forces support the same reasonings. Simulation results about acetone, ether, methanol and toluene clearly indicate that customized strategies are needed for precisely controlling the adsorption of different VOC molecules on CNTs. The results reported in this work should be helpful for the better development of sensing and removal systems of detrimental VOC molecules.