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Based on the relationship between average local ionization energy I ̄ (r) and average local electron affinity A ̄ (r) with the electronic Fukui functions, i.e., f−(r) and f+(r), respectively, in this paper, we establish a connection between nuclear and electronic Fukui functions beyond frontier molecular orbitals. As a consequence of this connection, we obtain expressions of average nuclear Fukui functions interpreted as a variation of average nucleophilicity or electrophilicity (weighted by the electronic orbital Fukui functions) with respect to nuclear displacements, which goes beyond the highest occupied molecular orbital/or lowest unoccupied molecular orbital consideration. Furthermore, from this connection and considering the frontier molecular orbital approximation, we derive expressions of nuclear Fukui functions in terms of the atom-condensed electronic Fukui functions, which imply a locality in the chemical reactivity and could be used to study the variation of local nucleophilicity or electrophilicity with respect to nuclear displacements. Finally, this new way to interpret the nuclear Fukui function could be useful in the future to study the chemical reactivity related to molecular vibrations, internal rotations, bond dissociation, chemical reaction along the model of reaction coordinate, and so on. [ABSTRACT FROM AUTHOR]

The role of the degree of synchronicity in the formation of the new single-bonds in a large set of 1,3-dipolar cycloadditions and its relation in the fulfilment of the classical Bell–Evans–Polanyi principle and Hammond–Leffler postulate are deeply investigated. Our results confirm that asynchronicity is an important path-dependent factor to be taken into account: (i) the Bell–Evans–Polanyi is fulfilled as the degree of (a)synchronicity is quite the same, and a linear relationship between reorganisation energy and asynchronicity is found; (ii) the asynchronicity is the origin of deviations of this classical principle of chemical reactivity since any decrease of the energy barrier is due to an increase of asynchronicity at the same exothermicity; and (iii) the less exothermic the reaction is, the more asynchronous the mechanism is, at the same energy barrier. Thus, this implies that TS imbalance decreases the reorganisation energy, consequently affecting the reaction exothermicity as well. [ABSTRACT FROM AUTHOR]

Five new heteroleptic copper(I) complexes (C1‐5) of the type [Cu(dpa)(P,P)]BF4 based on dipyridylamine (dpa) as N,N ligand and commercial diphosphines as P,P ancillary ligands have been synthesised through a simple methodology with high yields. All complexes were thoroughly characterised by spectroscopic and spectrometric techniques, as well by theoretical calculations. These showed Metal to Ligand Charge Transfer (MLCT) absorptions in the 300–370 nm region, and emission in the 450–520 nm region with quantum yields and lifetimes that depend on the nature of the P,P ligand. The photocatalytic performance of copper(I) complexes C1‐5 was evaluated for their use as photoredox catalysts in ATRA reactions, decarboxylative coupling and an Appel‐type reaction. The use of readily available dpa as N,N ligand constitutes an attractive alternative to the well‐established phenanthroline ligands typically used in photocatalysis. [ABSTRACT FROM AUTHOR]

To analyze the evolution of a chemical property along the reaction path, it is necessary to extract all the information from a set of electronic structure computations. However, this process is time‐consuming and prone to human error. Here we introduce intrinsic reaction coordinate (IRC)‐Analysis, a new extension in Eyringpy, to monitor the evolution of chemical properties along the intrinsic reaction coordinate, including the complete reaction force analysis. IRC‐Analysis collects the entire data set for each snapshot of the reaction coordinate, avoiding human error in data capture, and allowing the study of several chemical reactions in seconds. Eyringpy is written in Python, has a simple input format, and no programming skills are required. Python's Matplotlib library is used for plotting the evolution of the properties along the reaction coordinate. This version can analyze the evolution of bond distances, angles, Wiberg bond indices, natural charges, dipole moments, and orbital energies (and related properties). [ABSTRACT FROM AUTHOR]

Five new heteroleptic copper(I) complexes (C1‐5) of the type [Cu(dpa)(P,P)]BF4 based on dipyridylamine (dpa) as N,N ligand and commercial diphosphines as P,P ancillary ligands have been synthesised through a simple methodology with high yields. All complexes were thoroughly characterised by spectroscopic and spectrometric techniques, as well by theoretical calculations. These showed Metal to Ligand Charge Transfer (MLCT) absorptions in the 300–370 nm region, and emission in the 450–520 nm region with quantum yields and lifetimes that depend on the nature of the P,P ligand. The photocatalytic performance of copper(I) complexes C1‐5 was evaluated for their use as photoredox catalysts in ATRA reactions, decarboxylative coupling and an Appel‐type reaction. The use of readily available dpa as N,N ligand constitutes an attractive alternative to the well‐established phenanthroline ligands typically used in photocatalysis. [ABSTRACT FROM AUTHOR]

A large set of intramolecular aminoborane-based FLPs was studied employing density functional theory in the H 2 activation process to analyze how the acidity and basicity of boron and nitrogen atoms, respectively, affect the reversibility of the process. Three different linkers were employed, keeping the C-C nature in the connection between both Lewis centers: -CH 2 -CH 2 -, -CH[double bond, length as m-dash]CH-, and -C 6 H 4 -. The results show that significant differences in the Gibbs free energy of the process are found by considering all the combinations of substituents. Of the 75 systems studied, only 9 showed the ability to carry out the process reversibly (Δ G H 2 in the range of -3.5 to 2.0 kcal mol -1 ), where combinations of alkyl/aryl or aryl/alkyl in boron/nitrogen generate systems capable of reaching reversibility. If the alkyl/alkyl or aryl/aryl combination is employed, highly exergonic (non-reversible H 2 activation) and endergonic (unfeasible H 2 activation) reactions are found, respectively. No appreciable differences in the linker were found, allowing us to continue the analysis with the most entropically favorable linker, the -C 6 H 4 - linker. From this, 25 different FLP systems of type 2-[bis(X)boryl]-(Y)aniline (X: H, CF 3 , C 6 F 5 , PF t B, FMes and Y: H, CH 3 , t -but, Ph, Mes) can be formed. By analyzing the electronic properties of each system, we have found that the condensed-to-boron electrophilicity index ω B + is inversely related to the Δ G H 2 . Interestingly, two relationships were found; the first is for alkyl groups (Y: CH 3 and t -but) and the second for aryl groups (Y: H, Ph, and Mes), which is intimately related to the proton affinity of each aniline. In addition, it is quite interesting when the frustration degree, given by B⋯N distance d B-N , is brought together with ω B + , since the quotient has unit energy/length corresponding to unit force; concomitantly, a measure of the FLP strength in H-H bond activation can be defined. With this finding, a rational design of this kind of FLP can be performed by analyzing the acidity of boron through condensed-to-boron electrophilicity and knowing the nature of the substituent of nitrogen according to whether the Y is alkyl or aryl, optimizing the H 2 reversible activation in a rational way, which is crucial to improve the catalytic performance., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

A new selective fluorogenic chemosensor for Hg 2+ , which combines a calixarene derivative with a BODIPY core as a fluorescent reporter, is described. The remarkable change in its fluorogenic properties in DMSO and CHCl 3 has been analyzed. A study of its spectral properties on dilution, along with molecular modeling studies, allowed us to explain that this behavior involves the formation of a J-dimer, as well as how the sensing mechanism of Hg 2+ proceeds., Competing Interests: The authors declare no competing financial interest., (© 2022 The Authors. Published by American Chemical Society.)

The binding of C-4-halogenated 1-(4-X-2,5-dimethoxyphenyl)-2-aminopropane (DOX) serotonin agonist psychedelics at all three 5-HT 2 receptor subtypes is up to two orders of magnitude stronger for X = Cl, Br, or I (but not F) than when C-4 bears a hydrogen atom and more than expected from their hydrophobicities. Our docking and molecular dynamics simulations agree with the fact that increasing the polarizability of halogens results in halogen-oxygen distances to specific backbone C═O groups, and C-X···O angles, in ranges expected for halogen bonds (XBs), which could contribute to the high affinities observed. Good linear correlations are found for each receptor type, indicating that the binding pocket-ligand affinity is enhanced as the XB interaction becomes stronger (i.e., I ≈ Br > Cl > F). It is also striking to note how the linear equations unveil that the receptor's response on the strength of the XB interaction is quite similar among 5-HT 2A and 5-HT 2C , whereas the 5-HT 2B 's sensitivity is less. The calculated dipole polarizabilities in the binding pocket of the receptors reflect the experimental affinity values, indicating that less-polarizable and harder binding sites are more prone to XB formation.