Intermolecular Covalent Interactions: Nature and Directionality

Chemistry - A European Journal, Год журнала: 2022, Номер 29(14)

Опубликована: Дек. 7, 2022

Quantum chemical methods were employed to analyze the nature and origin of directionality pnictogen (PnB), chalcogen (ChB), halogen bonds (XB) in archetypal Fm Z⋅⋅⋅F- complexes (Z=Pn, Ch, X), using relativistic density functional theory (DFT) at ZORA-M06/QZ4P. Quantitative Kohn-Sham MO energy decomposition analyses (EDA) show that all these intermolecular interactions have common covalence, is, HOMO-LUMO interactions, provide a crucial contribution bond energy, besides electrostatic attraction. Strikingly, are directional (i.e., F-Z⋅⋅⋅F- is approximately linear) despite, not because of, which, fact, favor bending. This constitutes breakdown σ-hole model. It was shown how model fails by neglecting both, essential physics behind interaction electron-rich interactions. Our findings general extend neutral, weaker ClI⋅⋅⋅NH3 , HClTe⋅⋅⋅NH3 H2 ClSb⋅⋅⋅NH3 complexes.

Язык: Английский

---

Factors contributing to halogen bond strength and stretch or contraction of internal covalent bond

Physical Chemistry Chemical Physics, Год журнала: 2023, Номер 25(4), С. 2907 - 2915

Опубликована: Янв. 1, 2023

The halogen bond formed by a series of Lewis acids TF3X (T = C, Si, Ge, Sn, Pb; X Cl, Br, I) with NH3 is studied quantum chemical calculations. interaction energy closely mimicked the depth σ-hole on atom as well full electrostatic energy. There first trend which hole deepened if T to attached becomes more electron-withdrawing: C > Si Ge Sn Pb. On other hand, larger polarizable atoms are better able transmit electron-withdrawing power F substituents. combination these two opposing factors leaves PbF3X forming strongest XBs, followed CF3X, SiF3X engaging in weakest bonds. charge transfer from lone pair into σ*(TX) antibonding orbital tends elongate covalent TX bond, and this force largest for heavier atoms. contraction deepens at atom, would enhance both component This bond-shortening effect greatest lighter forces T-X contracting Cl but lengthening I.

Язык: Английский

---

On the strength of hydrogen bonding within water clusters on the coordination limit

Journal of Computational Chemistry, Год журнала: 2020, Номер 41(26), С. 2266 - 2277

Опубликована: Авг. 6, 2020

Hydrogen bonds (HB) are arguably the most important noncovalent interactions in chemistry. We study herein how differences connectivity alter strength of HBs within water clusters different sizes. used for this purpose interacting quantum atoms energy partition, which allows quantification HB formation energies a molecular cluster. could expand our previously reported hierarchy these systems (Phys. Chem. Phys., 2016, 18, 19557) to include tetracoordinated monomers. Surprisingly, between molecules not strongest despite widespread occurrence motifs (e.g., ice Ih ). The H2 O involve tricoordinated Nonetheless, tetracoordination is preferred large because (a) it reduces anticooperativity associated with double donors and acceptors (b) results larger number favorable system. Finally, we also discuss importance exchange-correlation discriminate among examined types clusters, use above-mentioned scale quickly assess relative stability isomers given cluster, (c) findings research can be exploited indagate about polymorphs crystallography. Overall, expect that investigation will provide valuable insights into subtle interplay tri- as well ensuing interaction clusters.

Язык: Английский

---

Challenging the electrostatic σ‐hole picture of halogen bonding using minimal models and the interacting quantum atoms approach

Journal of Computational Chemistry, Год журнала: 2021, Номер 42(10), С. 676 - 687

Опубликована: Фев. 10, 2021

Abstract Among the different noncovalent interactions, halogen bonds have captured wide attention in last years. Their stability has been rationalized electrostatic terms by appealing to σ ‐hole concept, a charge‐depleted region that is able interact favorably with electron rich moieties. This interpretation questioned, and this work set of anionic model systems are used shed some light on issue. We use interacting quantum atoms method, which provides an orbital invariant energy decomposition pure well isolated, we complement our insights analysis potentials (ESPs) as traditional descriptors charge accumulation like Laplacian density. The total interaction between species surprisingly destabilizing many examined, demonstrating although ‐holes might be qualitatively helpful, much care taken ascribing these electrostatics. It clearly shown delocalization essential understand complexes. evolution atomic charges aggregates forms reveals transfer picture central, bearing acts mere spectator. These may then not far from engaging classical 3c‐4e interaction. Since presence characterized ESP mapped suitable molecular envelope isosurface does guarantee attractive encourage employ wider perspective takes into account full distribution.

Язык: Английский

---

Decorated crown ethers as selective ion traps: Solvent’s role in crown’s preference towards a specific ion

Journal of Molecular Liquids, Год журнала: 2023, Номер 381, С. 121791 - 121791

Опубликована: Апрель 6, 2023

Язык: Английский

---

Electrophilicity Indices and Halogen Bonds: Some New Alternatives to the Molecular Electrostatic Potential

The Journal of Physical Chemistry A, Год журнала: 2020, Номер 124(10), С. 2090 - 2101

Опубликована: Март 2, 2020

We assess the ability of various atomic and molecular electrophilicity descriptors to predict strength halogen bonds. To this aim, several physicochemical quantities rooted within framework conceptual density functional theory were derived using second third order Taylor expansions electronic energy, their correlation binding energies compared with those obtained for more usual descriptors. This benchmark was performed a large representative database noncovalent complexes involving fluorine, chlorine, bromine atoms, showed that some these new quantities, in particular cubic index, exhibited transferability broadness application than did common such as electrostatic potential.

Язык: Английский

---

Capture of CO₂ by Melamine Derivatives: A DFT Study Combining the Relative Energy Gradient Method with an Interaction Energy Partitioning Scheme

The Journal of Physical Chemistry A, Год журнала: 2024, Номер 128(7), С. 1288 - 1296

Опубликована: Фев. 13, 2024

A theoretical study of the interaction between melamine and CO2 was carried out using density functional theory (DFT) with B3LYP-D3(BJ)/aug-cc-pVTZ level theory. The presence anions interacting transforms weakly bonded tetrel complexes into adducts. Thus, acts as an FLP (frustrated Lewis pair) acid groups (NHs hydrogen bond donors) a base group (N triazine ring). application relative energy gradient formalism (REG) along reaction coordinate has demonstrated that ability melamine-anion systems to capture is linked its capacity polarize molecule. These results have been confirmed by placing melamine:CO2 complex in uniform electric field different strengths.

Язык: Английский

---

Cooperativity and Anticooperativity in Ion‐Water Interactions: Implications for the Aqueous Solvation of Ions

ChemPhysChem, Год журнала: 2021, Номер 22(12), С. 1269 - 1285

Опубликована: Фев. 26, 2021

Non-additive effects in hydrogen bonds (HB) take place as a consequence of electronic charge transfers. Therefore, it is natural to expect cooperativity and anticooperativity ion-water interactions. Nevertheless, investigations on this matter are scarce. This paper addresses the interactions (i) cations Li+ , Na+ K+ Be2+ Mg2+ Ca2+ together with (ii) anions F- Cl- Br- NO3- SO42- water clusters (H2 O)n n=1-8, these ions HBs within complete molecular adducts. We used quantum chemical topology tools, specifically theory atoms molecules interacting energy partition investigate non-additive among studied herein. Our results show decrease interaction between first neighbouring an increment coordination number. also found strong cooperative interplay ion-dipole systems. Such affects considerably their second solvation shells aqueous environments. Overall, we believe article provides valuable information about how contacts interact each other they relate interactions, such HBs, framework media.

Язык: Английский

---

An Interacting Quantum Atoms (IQA) and Relative Energy Gradient (REG) Study of the Halogen Bond with Explicit Analysis of Electron Correlation

Molecules, Год журнала: 2020, Номер 25(11), С. 2674 - 2674

Опубликована: Июнь 9, 2020

Energy profiles of seven halogen-bonded complexes were analysed with the topological energy partitioning called Interacting Quantum Atoms (IQA) at MP4(SDQ)/6–31 + G(2d,2p) level theory. Explicit interatomic electron correlation energies are included in analysis. Four combine X2 (X = Cl or F) HCN NH3, while remaining three ClF HCN, NH3 N2. Each complex was systematically deformed by translating constituent molecules along its central axis linking X and N, reoptimising geometry. The Relative Gradient (REG) method (Theor. Chem. Acc. 2017, 136, 86) then computes which IQA most correlate total during process formation further compression beyond respective equilibrium geometries. It turns out that covalent (i.e., exchange) halogen bond, X…N, itself drives formation. When compressed from their to shorter X…N distance intra-atomic N is charge. REG analysis restricted between again formation, best described destabilisation through-space “outer” halogen.

Язык: Английский

---

New insights in chemical reactivity from quantum chemical topology

Journal of Computational Chemistry, Год журнала: 2021, Номер 42(12), С. 840 - 854

Опубликована: Март 3, 2021

Abstract Based on the quantum chemical topology of modified electron localization function ELF x , an efficient and robust mechanistic methodology designed to identify favorable reaction pathway between two reactants is proposed. We first recall reshape how supermolecular interaction energy can be evaluated from only three distinct terms, namely intermolecular coulomb energy, exchange‐correlation intramolecular energies reactants. Thereafter, we show that reactivity driven by first‐order variation in defined terms response changes number electrons. Illustrative examples with formation dative bond B‐N involved BH 3 NH molecule typical hydrogen canonical water dimer are presented. For these selected systems, our approach unveils a noticeable mimicking E dual onto DFT surface calculated both An automated reaction‐path algorithm aimed determine most relative orientations when molecules each other also outlined.

Язык: Английский

---