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The dual descriptor potential (DDP) has appeared in several papers, It is proposed as a local reactivity descriptor within the framework of the Conceptual Density Functional Theory and as a complementary tool of the molecular electrostatic potential (MEP) rather than the dual descriptor (DD). DDP provides information concerning the most energetically favorable sites to undergo nucleophilic and electrophilic attacks. Unlike the dual descriptor, DDP is directly related with energy. Furthermore, the DDP seems to depure the scalar field, allowing us to unveil the predominance of nucleophilic and electrophilic regions on a molecule. This is in stark contrast to the dual descriptor, which tends to scatter around the molecule, hindering the interpretation of the local reactivity on regions that exceed the atomic volume. To the best of our knowledge, this is the first time that DDP is represented as a 3D picture. To assess its capability to describe interaction among molecules, DDP was tested on some molecular systems, along with MEP. Results show that the joint use of these tools helps in the understanding of certain experimental evidences, serving as an alternative to the molecular orbital theory. [ABSTRACT FROM AUTHOR]

The reason why the local softness (LS) and the local hyper-softness (LHS) allow comparisons of local reactivities among molecular systems of similar or different sizes is analyzed. We evidenced this scaling behavior on these functions by means of their working formulae. This feature bases on the scaling capacity of LS and LHS according to the molecular size. The Fukui function (FF), and the dual descriptor (DD) do not satisfy that property. [ABSTRACT FROM AUTHOR]

This document is a correction notice for an article titled "Why local softness and local hyper-softness are more appropriate local reactivity descriptors than dual descriptor and Fukui functions?" published in the Journal of Mathematical Chemistry. The correction addresses an error in the sequence of inequalities after Equation (23), specifically involving an extra 1/2 factor. It clarifies that the working formula for the Fukui function can be given by any of the three working equations defined in Equation (6), and that the 1/2 factor is already included in the definition of the variable η, as indicated in Equation (3). The correction does not invalidate the mathematical demonstration and involves replacing certain variables with others. The publisher maintains a neutral stance on jurisdictional claims and institutional affiliations. The text is authored by Jorge I. Martínez-Araya. [Extracted from the article]

This document is a correction notice for an article titled "The dual descriptor potential" published in the Journal of Mathematical Chemistry. The correction addresses an error in the unit used for the dual descriptor potential (DDP) in the first and second paragraphs on page 1103. The correct unit for DDP is "hartree·e^-3". The correction provides further analysis of the DDP and its implications for nucleophilic attacks in molecules. The correction notice is authored by Jorge I. Martínez-Araya and published by Springer Nature. [Extracted from the article]

This document is a correction notice for an article titled "Why local softness and local hyper-softness are more appropriate local reactivity descriptors than dual descriptor and Fukui functions?" published in the Journal of Mathematical Chemistry. The correction addresses an error in Equation (3) of the original article, where an extra minus sign was present. The correct expression for Equation (3) is provided in the correction notice. The document also includes a note from the publisher, Springer Nature, stating their neutrality regarding jurisdictional claims and institutional affiliations. The correction notice was reported by Jorge I. Martínez-Araya. [Extracted from the article]

This document is a correction notice for an article titled "Why are the local hyper-softness and the local softness more appropriate local reactivity descriptors than the dual descriptor and the Fukui function, respectively?" published in the Journal of Mathematical Chemistry. The correction addresses an error in equation numbering in section 2 of the article. The correction provides the correct equation number and states that the development for the dual descriptor should be written as Eq. (15) instead of Eq. (13). The correction notice also includes a statement from the publisher, Springer Nature, asserting their neutrality and impartiality. The correction was reported by the author, Jorge I. Martínez-Araya. [Extracted from the article]

In the current work, the authors analyzed and compared the chemical behavior of some (anti)aromatic compounds. The species selected are benzene and cyclobutadiene as the aromatic and antiaromatic classical examples, respectively. Next, the anion Al42−, which is the first all‐metal molecule catalogued as aromatic and its non‐metallic isoelectronic analog, B42− were also analyzed. The antiaromatic clusters Al44− and B44− were studied in form of lithium salts. And the end, the non‐planar B12 boron cluster and its isoelectronic analogs (B11Be− and B11C+) were considered for being analyzed under the same criterium. The analysis was realized employing the following descriptors: molecular electrostatic potential and local hyper‐softness to get insights concerning local reactivity when facing reagents leading to ionic or covalent interactions. The results show that all the molecules analyzed presented some specific variations in their respective local reactivity despite being labeled as aromatic compounds. This analysis provides a notion that the local reactivity is more based on the nature of the atoms and the molecular geometry than the aromatic character by itself. [ABSTRACT FROM AUTHOR]

Some Mo‐oxo complexes bearing pyridine rings have the capability for dihydrogen production from water. However, energy barrier and overall energy vary depending on the effect exerted by several substituent groups located at different positions around one or more pyridine rings which are ligands of these compounds. Based on the Karunadasa and coworkers investigation where the para‐position was experimentally tested in compounds derivatised from the 2,6‐bis[1,1‐bis(2‐pyridil)ethyl]‐pyridine oxo‐molybdenum complex synthesized (Karunadasa et al., Nature, 2010, 464, 1329), we tested the combined effect of electron‐withdrawing and electron‐donating groups simulated as perturbations represented by point‐charges. Then, we used the density polarization concept, δρ(r), a local reactivity descriptor corresponding to the partially integrated linear response function, χ(r, r′) (a non‐local reactivity descriptor), which is able to reveal different displacements of π‐electrons on molecular structures. We perturbed the para‐positions in the pentadentate ligand 2,6‐bis[1,1‐bis(2‐pyridil)ethyl]‐pyridine in the Mo‐based complex by means of point‐charges. They were located in three different configurations of the organic ligand (trans, geminal, and cis) which could help to explain energy barriers and overall energy of reactions catalyzed by this type of Mo‐complexes. Our results indicate that the trans configuration of point‐charges induces the most amount of fraction of electron shifted on the complex. A Mo‐based complex bearing the same trans configuration for electron‐withdrawing and electron‐donating substituent groups (cyano and amino, respectively), leads to a kinetically more favorable H2 release than the cis or geminal configuration of the substituent groups aforementioned. [ABSTRACT FROM AUTHOR]

A fundamental link between conceptual density functional theory and statistical thermodynamics is herein drawn, showing that intermolecular electrostatic interactions can be understood in terms of effective work and heat exchange. From a more detailed analysis of the heat exchange in a perturbation theory framework, an associated entropy can be subsequently derived, which appears to be a suitable descriptor for the local polarisability of the electron density. A general rule of thumb is evidenced: the more the perturbation can be spread, both through space and among the excited states, the larger the heat exchange and entropy. [ABSTRACT FROM AUTHOR]

Based on the experimental precedent discovered by Kuranadasa and coworkers [H. I. Karunadasa et al., Nature, 2010, 464, 1329] to produce dihydrogen from water electrocatalyzed by 2,6-bis[1,1-bis(2-pyridyl)ethyl]-pyridine oxo–molybdenum complexes, we performed an extensive analysis to study the substituent group effect of derivatised compounds coming from the before mentioned Mo-based metal–organic cations in terms of two kinds of substitutions: axial and equatorial at the para-position of pyridine rings; several conceptual tools were used to back up our conclusions. We found that each type of substituent group (electron-withdrawing and electron-donating ones) exerts an independent influence on energetic parameters (energy barrier and overall energy). This opens the chance to search for a synergistic effect by combining these opposite behaviours of these substituents located in the equatorial and axial para-positions of pyridine rings to computationally modulate the aforementioned energetic parameters. This procedure will make easier the proposal of new catalysts to favour either kinetically or thermodynamically or in both ways the production of dihydrogen from water. Additionally, we encompassed a key point: the number of solvent molecules, so that including their presence in further investigations is mandatory. [ABSTRACT FROM AUTHOR]

In this paper, we assess the performance of 24 density functional theory (DFT) based methods classified into 5 categories (GGA, MGGA, HGGA, HMGGA and DHGGA) in predicting reaction energetics, transition state geometries, and the degree of synchronicity/nonsynchronicity in the formation of two new C–C single-bonds in three Diels–Alder reactions between symmetrically and unsymmetrically substituted cyanoethylenes and cyclopentadiene, which gradually proceed from fully synchronous to highly asynchronous concerted mechanisms. This important concept in reaction mechanisms is revealed by the fine structure of the reaction force constant κ(ξ) along the transition region. Some wave function theory (WFT) based methods are also assessed against the CCSD(T) and CCSD benchmarks for the energy and geometry, respectively. The results and the statistical analysis of the errors confirm the robustness of SCS-MP2 (a WFT-based method) as one of the most reliable computational approaches. Regarding DFT-based methods, hybrid exchange–correlation functionals combined with medium-range electron correlation effects or long-range corrected exchange appear as the best performing methods, highlighting both M11 and M06-2X, since a certain percentage of exact Hartree–Fock exchange could counterbalance the delocalization errors that affect pure functionals. Thus, they reliably describe energetics, geometries and the degree of synchronicity in the formation of new C–C single bonds in Diels–Alder reactions. Noticeably, moderate performance for double hybrid functionals and poor performance for the most popular B3LYP method were found as well. [ABSTRACT FROM AUTHOR]

By means of the conceptual density functional theory, the socalled dual descriptor (DD) has been adapted to be used in any closed-shell molecule that presents degeneracy in its frontier molecular orbitals. The latter is of paramount importance because a correct description of local reactivity will allow to predict the most favorable sites on a molecule to undergo nucleophilic or electrophilic attacks; on the contrary, an incomplete description of local reactivity might have serious consequences, particularly for those experimental chemists that have the need of getting an insight about reactivity of chemical reagents before using them in synthesis to obtain a new compound. In the present work, the old approach based only on electronic densities of frontier molecular orbitals is replaced by the most accurate procedure that implies the use of total electronic densities thus keeping consistency with the essential principle of the DFT in which the electronic density is the fundamental variable and not the molecular orbitals. As a result of the present work, the DD will be able to properly describe local reactivities only in terms of total electronic densities. To test the proposed operational formula, 12 very common molecules were selected as the original definition of the DD was not able to describe their local reactivities properly. The ethylene molecule was additionally used to test the capability of the proposed operational formula to reveal a correct local reactivity even in absence of degeneracy in frontier molecular orbitals. [ABSTRACT FROM AUTHOR]

Searching for adequate and effective compounds displaying antimicrobial activities, especially against Gram-positive bacteria, is an important research area due to the high hospitalization and mortality rates of these bacterial infections in both the human and veterinary fields. In this work, we explored (E)-4-amino-3-((3,5-di-tert-butyl-2-hydroxybenzylidene)amino) benzoic acid (SB-1, harboring an intramolecular hydrogen bond) and (E)-2-((4-nitrobenzilidene)amino)aniline (SB-2), two Schiff bases derivatives. Results demonstrated that SB-1 showed an antibacterial activity determined by the minimal inhibitory concentration (MIC) against Staphylococcus aureus, Enterococcus faecalis, and Bacillus cereus (Gram-positive bacteria involved in human and animal diseases such as skin infections, pneumonia, diarrheal syndrome, and urinary tract infections, among others), which was similar to that shown by the classical antibiotic chloramphenicol. By contrast, this compound showed no effect against Gram-negative bacteria (Klebsiella pneumoniae, Escherichia coli, and Salmonella enterica). Furthermore, we provide a comprehensive physicochemical and theoretical characterization of SB-1 (as well as several analyses for SB-2), including elemental analysis, ESMS, 1H and 13C NMR (assigned by 1D and 2D techniques), DEPT, UV-Vis, FTIR, and cyclic voltammetry. We also performed a computational study through the DFT theory level, including geometry optimization, TD-DFT, NBO, and global and local reactivity analyses. [ABSTRACT FROM AUTHOR]

Ten functionals were used to assess their capability to compute a local reactivity descriptor coming from the Conceptual Density Functional Theory on a group of iron-based organometallic compounds that have been synthesized by Zohuri, G.H. et al. in 2010; these compounds bear the following substituent groups: H-, O2N- and CH3O- at the para position of the pyridine ring and their catalytic activities were experimentally measured by these authors. The present work involved a theoretical analysis applied on the aforementioned iron-based compounds thus leading to suggest a new 2,6-bis(imino)pyridine catalyst based on iron(II) bearing a fluorine atom whose possible catalytic activity is suggested to be near the catalytic activity of the complex bearing a hydrogen atom as a substituent group by means of the so called local hyper-softness (LHS) thus opening a chance to estimate a possible value of catalytic activity for a new catalyst that has not been synthesized yet without simulating the entire process of ethylene polymerization. Since Conceptual DFT is not a predictive theory, but rather interpretative, an analysis of the used reactivity descriptor and its dependence upon the level of theory was carried in the present work, thus revealing that care should be taken when DFT calculations are used for these purposes. [ABSTRACT FROM AUTHOR]