Radicals can be regarded as electrophilic/nucleophilic, depending on their tendency to attack sites of relatively higher/lower electron density. In this paper, an electrophilicity scale, global well local, and a nucleophilicity scale for 35 radicals is reported. The correlates with the suggesting that these concepts are inversely related.

The chalcogen bond has been acknowledged as an influential noncovalent interaction (NCI) between electron‐deficient (donor) and a Lewis base (acceptor). This work explores the main features of bonding through large‐scale computational study on series donors acceptors spanning wide range in strength character this type bond: (benzo)chalcogenadiazoles (with Ch = Te/Se/S) versus halides neutral bases with O, N, C donor atoms. We start from Pearson's hard soft acids (HSAB) principle, where...

In this work a complete and consistent set of 95 Benson group additive values (GAVs) for standard entropies S(o) heat capacities C(p)(o) hydrocarbons hydrocarbon radicals is presented. These GAVs include 46 groups, among which 25 radical which, to the best our knowledge, have not been reported before. The determined from B3LYP/6-311G(d,p) ideal gas statistical thermodynamics 265 species, consistently with previously enthalpies formation. One-dimensional hindered rotor corrections all...

Functionalized diamondoids show great potential as building blocks for various new optoelectronic applications. However, until now, only simple mono and double substitutions were investigated. In this work, we considered up to 10 6 sites functionalization of the two smallest diamondoids, adamantane diamantane, respectively, in search diamondoid derivatives with a minimal maximal HOMO–LUMO energy gap. To end, gap was optimized systematically using an inverse molecular design methodology based...

The halogen bond complexes CF3X⋯Y and C2F3X⋯Y, with Y = furan, thiophene, selenophene X Cl, Br, I, have been studied by using DFT CCSD(T) in order to understand which factors govern the interaction between atom aromatic ring. We found that PBE0-dDsC/QZ4P gives an adequate description of energies these complexes, compared experimental results. π-bonds perpendicular orientation is stronger than in-plane lone pairs heteroatom cycle. strength follows trend Cl < Br I; chalcogenide ring nor...

Abstract Using a set of state-of-the-art quantum chemical techniques we scrutinized the characteristically different reactivity frustrated and classical Lewis pairs towards molecular hydrogen. The mechanisms reaction profiles computed for H 2 splitting various are in good agreement with experimentally observed feasibility activation. More importantly, analysis activation parameters unambiguously revealed existence two pathways through low-energy high-energy transition state. An exhaustive...

Bond dissociation enthalpies (BDEs) of a large series molecules the type A−B, where radicals A ranging from strongly electrophilic to nucleophilic are coupled with 8 (CH2OH, CH3, NF2, H, OCH3, OH, SH, and F) also nucleophilic, computed analyzed using chemical concepts emerging density functional theory, more specifically electrophilicities individual radical fragments B. It is shown that, when introducing concept relative electrophilicity, an (approximately) intrinsic stability scale can be...

An efficient metal-free cascade reaction between 1-dibromovinyl-2-nitro-substituted arenes and secondary amines results in the formation of polycyclic pseudoindoxyls a single step. The mechanism leading to these fused ring systems was investigated, is believed involve initial nitroarylated ynamines/ynamides. These intermediates cycloisomerize towards N-alkenyl-tethered 2-aminoisatogens via carbene intermediate as demonstrated by QTAIM (quantum theory atoms molecules) ELF (electron...

The contributions of covalent and noncovalent interactions to the formation classical adducts bulky Lewis acids bases frustrated pairs (FLPs) were scrutinized by using various conceptual quantum chemical techniques. Significantly negative complexation energies calculated for fourteen investigated containing with substituents sizes. A Ziegler-Rauk-type energy decomposition analysis confirmed that two types can be distinguished on basis nature primary between reactants; dative-bond concomitant...

Abstract Spectroscopic properties are commonly used in the experimental evaluation of ground‐ and excited‐state aromaticity expanded porphyrins. Herein, we investigate if defining photophysical still hold for a diverse set hexaphyrins with varying redox states, topologies, peripheral substitutions, core‐modifications. By combining TD‐DFT calculations several descriptors chemical compound space maps, intricate interplay between structural planarity, aromaticity, absorption spectra is...

Explainable machine learning can aid in deriving chemical rules which combination with inverse molecular design methods support humans to optimise classes of molecules such as pesticides. This study demonstrates that pesticide vapour pressures be predicted (77.1% within one order magnitude) using kernel ridge regression on quantum properties but the model lacks interpretability. However, insights (via Shapley additive explanations) gained when a framework functional groups is employed...

The regioselectivity in the cyclopolymerization of diallyl monomers is investigated using DFT-based reactivity indices. In first part, experimentally observed mode cyclization (exo versus endo) 11 selected radicals involved this process reproduced by computation activation energies, entropies, enthalpies, and Gibb's free energies for 5- 6-membered reactions. application a recently proposed energy partitioning barriers shows that cannot be explained steric effect alone. Next, number relevant...

The photocycloaddition reaction of benzene with ethylene has been studied at the CASSCF level, including characterization an extended conical intersection seam. We show that chemical selectivity is, in part, controlled by this seam and shape can be understood terms simple VB arguments. Further, energetics asynchronous segment suggest 1,2 (ortho) 1,3 (meta) will preferred products similar weight. 1,4 (para) point on is higher energy corresponds to a local maximum analysis shows pairs...

Diels-Alder (DA) cycloadditions in reversible polymer networks are important for designing sustainable materials with self-healing properties. In this study, the DA kinetics of hydroxyl-substituted bis- and tetrafunctional furans tris-functional maleimides, both containing ether-functionalized spacers, is investigated by modelling two equilibria representing endo exo cycloadduct formation. Concretely, potential catalysis reaction through hydrogen bonding between hydroxyl carbonyl maleimides...

Heteroaryl sulfonamides are important structural motifs in the medicinal and agrochemical industries. However, their synthesis often relies on use of heteroaryl sulfonyl chlorides, which unstable toxic reagents. Herein, we report a protocol that allows direct oxidative coupling thiols primary amines, readily available inexpensive commodity chemicals. The transformation proceeds under mild reaction conditions yields desired N-alkylated good yields. N-alkyl can be further transformed using...

Combining meso -substitutions and core-modifications in the 28R → 30R hexaphyrin-based switch can synergistically improve contrast between nonlinear optical responses of ON OFF states by 10-fold compared to unsubstituted switch.

The design of molecules with optimal properties is an important challenge in chemistry because the astronomically large number possible stable structures that accessible chemical space. This obstacle can be overcome through inverse molecular design. In design, one uses computation certain indices to target property. this study, for first time, was used optimize reactivity molecules. Specifically, we optimized acidity substituted 2-naphthols, both ground and excited state. Substituted...

In this study, for the first time inverse design was applied to search intrinsically most stable radical system in a predefined chemical space of enormous size by scanning rational way that entire space. The focus predominantly on thermodynamic stabilization effects, such as through resonance. Two different properties were optimized: newly introduced descriptor called delocalization value and intrinsic stability via previously established bond dissociation enthalpy model. thiadiazinyl chosen...

Abstract In the last decade, halogen bonds, noncovalent interactions formed between positive regions in electrostatic potential on atoms, often referred to as σ‐holes, and electron‐rich sites, have gained a lot of interest. Recently, this interest has been expanded towards with Group V VI elements, giving rise pnicogen chalcogen bonds. Although bonds already shown some promising results for applications crystallography catalysis, experimental characterising these remain scarce. combined...

Radical additions to substituted alkenes are among the most important reactions in radical chemistry. Nonetheless, there is still some controversy literature about factors that affect rate and regioselectivity these addition reactions. In this paper, orientation of (nucleophilic) electron-rich, -neutral, -poor monosubstituted substrates (11 total) investigated through use chemical concepts reactivity descriptors. The nucleophilic radicals on electron-rich -neutral thermodynamically...

Herein, the effects of an electric field on radicals are investigated for a set model with varying complexity. An impacts intrinsic philicity radical, as quantified by global electrophilicity index, ω. The extent change in depends directionality and strength applied dipole moment polarizability radical.

The unexpected nucleophilic reactivity of free-radicals generated from α-iodoketones is reported; two different procedures, either employing tin or the more environmentally acceptable ethylsulfone-based coupling reagent 5c have been developed.

Abstract Theoretical design can be an important aid in the discovery of valuable stable radical systems. In this study, inverse molecular was applied to thiadiazinyl radicals maximize two fundamental electronic properties chemistry, namely electrophilicity and nucleophilicity. We discovered that structure made moderately nucleophilic or highly electrophilic, depending on character its substituents. The most electrophilic displays highest encountered so far for uncharged accumulated data...

There is an increasing interest in applying quantum chemistry to rationally design novel compounds with some desired characteristics. Furthermore, many applications require more than one property be optimal. In this Concept, several inverse strategies, based on the discrete best first search scheme, are introduced that allow for simultaneous optimization of multiple properties or most vital target constraints secondary properties. A detailed assessment different techniques carried out, and...