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Ash and biochar mixed biomixtures to degrade co-applied atrazine and fipronil in bio-augmented biobeds
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Optical Resonances of Chiral Metastructures in the Mid‐infrared Spectral Range
Abstract
Metamaterials with localized surface plasmon resonances have been the subject of intense research for a wealth of applications ranging from active photonic devices to analytical sensing units that utilizes the local field enhancement to improve sensitivity and decrease acquisition time. Herein, we focus on the modelled properties of a series of spiral metastructures that present multiple chiral plasmon modes in the 1–10 μm mid-IR spectral range and that could be utilized to enhance vibrational circular dichroism measurements to further identify molecular, supramolecular and structural chirality centres. Finite-difference time-domain electromagnetic modelling was conducted to calculate the infrared spectra of the metastructures in response to a circularly polarized excitation. Several geometric parameters were altered to further tune the position of the resonances. In addition, the near-field distribution of the optical resonances was calculated providing a spatial snapshot of the chiral modes. Preliminary spiral structures were fabricated using electron beam lithography and their vibrational circular response was measured.
New cobalt(III) complex with triethylenetetramine and 2,2′-bipyridine: synthesis, crystal structure, DNA interaction, hirshfeld surface, DFT analysis, and cytotoxicity
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Temperature and pH influence on Diuron adsorption by Algerian Mont-Na Clay
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Can van der Waals constants be used in the chemical reactivity analysis? A new approach as a support to minimum magnetizability principle
A new equation to calculate the magnetic susceptibility of molecular systems is derived. It is proved that van der Waals constants are minimized in stable states Van der Waals constants are measures of the reactivity.
Abstract
One of the most important purposes of theoretical chemists is to derive new, useful, and reliable equations to compute the well-known parameters like hardness, polarizability, magnetizability, and electrophilicity providing enough hints for the reactivity analysis of the chemical systems. In the derivation of such equations, our research team widely considers the popular electronic structure rules like electronegativity equalization, maximum hardness, minimum polarizability, minimum magnetizability, and minimum electrophilicity principles. Recently, in the light of maximum entropy and minimum magnetizability principles, Kaya and Chattaraj (2021) presented a simple way to calculate their standard absolute entropies (S 0 298) based on molar diamagnetic susceptibilities (χ m ) of inorganic ionic systems. In the present paper, a new and useful molar diamagnetic susceptibility calculation method including the use of van der Waals constants (a and b) is introduced. Here, we named this method as Kaya–Şimşek approach. Through the relations between molar diamagnetic susceptibility and van der Waals constants, we can easily predict the magnetic susceptibility of molecules that their magnetic susceptibilities are unknown. The results of the equations derived are quite close to experimentally reported data. The analyses made proved that van der Waals constants can be considered as chemical reactivity descriptors. We propose that in stable states, van der Waals constants are minimized. The validity of minimum magnetizability principle is supported with solid evidences.
Organic contaminants: photocatalytic degradation using HHP/CuONPs (2D/3D) composite as a heterogeneous catalyst
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Ecological Impacts of Coral Reefs, Egyptian Red Sea Coast: Elemental Characterization and Spatial Distribution with INAA
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The synergetic and multifaceted nature of carbon–carbon rotation reveals the origin of conformational barrier heights with bulky alkane groups
This work examines the nature of the rotation barrier of exceedingly long carbon–carbon bonds for nine dimeric models with bulky alkane groups using density-based energy partition and information-theoretic approach. Many factors come into play and the generation of rotation barrier heights is synergetic and multifaceted. Our results invalidate that their stability comes from dispersion forces and confirm that the dominant factor is the electrostatic interaction but contributions from steric and exchange-correlation effects are minor yet indispensable.
Abstract
Designing compounds with as long carbon–carbon bond distances as possible to challenge conventional chemical wisdom is of current interest in the literature. These compounds with exceedingly long bond lengths are commonly believed to be stabilized by dispersion interactions. In this work, we build nine dimeric models with varying sizes of alkyl groups, let the carbon–carbon bond flexibly rotate, and then analyze rotation barriers with energy decomposition and information-theoretic approaches in density functional theory. Our results show that these rotations lead to extraordinarily elongated carbon–carbon bond distances and rotation barriers are synergetic and multifaceted in nature. The dominant factor contributing to the relative stability of the dimers with bulky alkane groups is not the dispersion force but the electrostatic interaction with steric and exchange-correlation effects playing minor yet indispensable roles.
Investigation and mapping of natural and artificial radioactivity in sediment samples from Borçka Black Lake, Artvin-Turkey
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