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Sławomir J. Grabowski

Bio: Sławomir J. Grabowski is an academic researcher from Ikerbasque. The author has contributed to research in topics: Hydrogen bond & Atoms in molecules. The author has an hindex of 21, co-authored 38 publications receiving 1567 citations. Previous affiliations of Sławomir J. Grabowski include University of the Basque Country & Donostia International Physics Center.

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Journal ArticleDOI
TL;DR: Calculations were carried out on complexes of ZH4, ZFH3 and ZF4 (Z = C, Si and Ge) molecules with HCN, LiCN and Cl(-) species acting as Lewis bases through nitrogen centre or chlorine ion, finding the electron charge redistribution is the same as that of the SN2 reaction.
Abstract: MP2/aug-cc-pVTZ calculations were carried out on complexes of ZH4, ZFH3 and ZF4 (Z = C, Si and Ge) molecules with HCN, LiCN and Cl− species acting as Lewis bases through nitrogen centre or chlorine ion. Z-Atoms in these complexes usually act as Lewis acid centres forming σ-hole bonds with Lewis bases. Such noncovalent interactions may adopt a name of tetrel bonds since they concern the elements of the group IV. There are exceptions for complexes of CH4 and CF4, as well as for the F4Si⋯NCH complex where the tetrel bond is not formed. The energetic and geometrical parameters of the complexes were analyzed and numerous correlations between them were found. The Quantum Theory of ‘Atoms in Molecules’ and Natural Bonds Orbital (NBO) method used here should deepen the understanding of the nature of the tetrel bond. An analysis of the electrostatic potential surfaces of the interacting species is performed. The electron charge redistribution, being the result of the tetrel bond formation, is the same as that of the SN2 reaction. The energetic and geometrical parameters of the complexes analyzed here correspond to different stages of the SN2 process.

387 citations

Journal ArticleDOI
TL;DR: Different types of noncovalent interactions such as halogen bond, hydrogen bond, and dihalogen bond are analyzed and it was found that the mechanism of the formation of complexes linked through various interactions is generally the same as that known for the hydrogen bond formation.
Abstract: Different types of noncovalent interactions such as, for example, halogen bond, hydrogen bond, and dihalogen bond are analyzed. The analysis is based on ab initio calculations which were performed on complexes of the F3CCl molecule. This choice is connected with the features of the Cl atom which may act as the Lewis acid and also as the Lewis base center. Such a dual role is a consequence of the existence of negative and positive regions of the electrostatic potential of the Cl center. Hence, the F3CCl molecule forms complexes linked by various interactions. The formation of the complexes leads to the electron charge redistribution which is reflected in the quantum theory of atoms in molecules (QTAIM) characteristics. Numerous correlations and tendencies were found here between QTAIM, geometrical and energetic parameters. It was found that the mechanism of the formation of complexes linked through various interactions is generally the same as that known for the hydrogen bond formation. The dependencies an...

166 citations

Journal ArticleDOI
TL;DR: Hydrogen and halogen bonds are compared on the basis of ab initio calculations performed for complexes linked through these interactions and the Quantum Theory of Atoms in Molecules and the Natural Bond Orbitals method are applied for a deeper understanding of the nature of interactions.
Abstract: Hydrogen and halogen bonds are compared on the basis of ab initio calculations performed for complexes linked through these interactions. The Quantum Theory of Atoms in Molecules (QTAIM) and the Natural Bond Orbitals (NBO) method are applied for a deeper understanding of the nature of interactions. Both interactions are ruled by the same effects of hyperconjugation and rehybridization. In general for both kinds of interactions the same processes of the electron charge redistribution being the result of complexation are observed. As a consequence similar characteristics are also observed for the hydrogen and halogen bonds for example the increase of the positive charge of the atom being in contact with the Lewis base (hydrogen and chlorine or bromine for complexes analyzed here) and the decrease of its volume as a result of the complex formation. The halogen bond is enhanced by the charge assistance, similarly to the hydrogen bond.

132 citations

Journal ArticleDOI
TL;DR: The calculations were carried out at the MP2(full)/aug-cc-pVTZ level of approximation, the analyses were performed with the use of the Natural Bond Orbital method, the Quantum Theory of 'Atoms in Molecules' (QTAIM) and the Electron Localization Function (ELF) approach and the results obtained are in agreement giving the consistent picture of the complexes' configurations and their electron charge distribution.
Abstract: The analysis of interactions in complexes of S(CN)2, Se(CN)2, SFCl and SeFCl with F− and Cl− anions is performed here. The sulphur and selenium atoms act in these complexes as Lewis acid centres interacting with fluorine and chlorine anions. The arrangement of sub-units in complexes is in agreement with the σ-hole concept; particularly it is a result of contacts between positive and negative electrostatic potential sites. The interactions in complexes analyzed may be classified as very strong charge assisted chalcogen bonds and they possess numerous characteristics typical for covalent bonds. Even in the case of complexes of SFCl and SeFCl, i.e. SFCl2− and SeFCl2−, the trivalency of the chalcogen atom is observed. The calculations were carried out at the MP2(full)/aug-cc-pVTZ level of approximation, the analyses were performed with the use of the Natural Bond Orbital (NBO) method, the Quantum Theory of ‘Atoms in Molecules’ (QTAIM) and the Electron Localization Function (ELF) approach. The results obtained by these methods are in agreement giving the consistent picture of the complexes' configurations and their electron charge distribution. The QTAIM and ELF approaches allow us to predict for S(CN)2, Se(CN)2, SFCl and SeFCl molecules the directions of nucleophilic attack. They are in line with the prediction based on the σ-hole concept. The Symmetry Adapted Perturbation Theory (SAPT) approach was also applied.

89 citations

Journal ArticleDOI
TL;DR: It was found that Lewis acid-Lewis base interactions lead to the electron charge redistribution being in agreement with Bent's rule, which explains the formation of nonbonding interactions.
Abstract: Ab Initio calculations were carried out on complexes of F3CCl. The Cl center may act as the Lewis acid as well as the Lewis base. Hence various interactions are analyzed for several complexes of F3CCl: halogen bond, dihalogen bond, halogen–hydride bond, hydrogen bond, and others. It was found that Lewis acid–Lewis base interactions lead to the electron charge redistribution being in agreement with Bent’s rule. This rule explains the formation of nonbonding interactions. For example, if the C–Cl bond acts as the Lewis acid thus the increase of the s-character in C-orbital of C–Cl is observed as a result of complexation. However, if the C–Cl bond acts as the Lewis base thus the mentioned above s-character decreases. Numerous analogies between the halogen bond and the hydrogen bond are analyzed and various relationships between energetic, geometrical and the natural bond orbitals method (NBO) parameters are shown.

79 citations


Cited by
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01 Feb 1995
TL;DR: In this paper, the unpolarized absorption and circular dichroism spectra of the fundamental vibrational transitions of the chiral molecule, 4-methyl-2-oxetanone, are calculated ab initio using DFT, MP2, and SCF methodologies and a 5S4P2D/3S2P (TZ2P) basis set.
Abstract: : The unpolarized absorption and circular dichroism spectra of the fundamental vibrational transitions of the chiral molecule, 4-methyl-2-oxetanone, are calculated ab initio. Harmonic force fields are obtained using Density Functional Theory (DFT), MP2, and SCF methodologies and a 5S4P2D/3S2P (TZ2P) basis set. DFT calculations use the Local Spin Density Approximation (LSDA), BLYP, and Becke3LYP (B3LYP) density functionals. Mid-IR spectra predicted using LSDA, BLYP, and B3LYP force fields are of significantly different quality, the B3LYP force field yielding spectra in clearly superior, and overall excellent, agreement with experiment. The MP2 force field yields spectra in slightly worse agreement with experiment than the B3LYP force field. The SCF force field yields spectra in poor agreement with experiment.The basis set dependence of B3LYP force fields is also explored: the 6-31G* and TZ2P basis sets give very similar results while the 3-21G basis set yields spectra in substantially worse agreements with experiment. jg

1,652 citations

Journal ArticleDOI
TL;DR: This work received funding from the European Union's Seventh Framework Programme (FP7/2007-2013) under grant agreement no.
Abstract: This work received funding from the European Union's Seventh Framework Programme (FP7/2007-2013) under grant agreement no. REGPOT-CT2012-316331-POLARIS. The work was also funded by FEDER through the Competitive Factors Operational Program (COMPETE) and by National funds through the Portuguese Foundation for Science and Technology (FCT) in the scope of the projects PTDC/FIS/115048/2009 and PTDC/CTM-BIO/1814/2012. The authors gratefully acknowledge Dr. Luca Gasperini (3B's Research Group, University of Minho, Portugal) for his help with the figures.

673 citations

Journal ArticleDOI
TL;DR: Using the applicability and extension of these parameters to describe and quantify the doubly ionic H-bond has been explored, and it is clear that doubly ionsicH-bonds cover the full range of weak through to very strong H- bonds.
Abstract: Ionic liquids (IL) and hydrogen bonding (H-bonding) are two diverse fields for which there is a developing recognition of significant overlap. Doubly ionic H-bonds occur when a H-bond forms between a cation and anion, and are a key feature of ILs. Doubly ionic H-bonds represent a wide area of H-bonding which has yet to be fully recognised, characterised or explored. H-bonds in ILs (both protic and aprotic) are bifurcated and chelating, and unlike many molecular liquids a significant variety of distinct H-bonds are formed between different types and numbers of donor and acceptor sites within a given IL. Traditional more neutral H-bonds can also be formed in functionalised ILs, adding a further level of complexity. Ab initio computed parameters; association energies, partial charges, density descriptors as encompassed by the QTAIM methodology (ρBCP), qualitative molecular orbital theory and NBO analysis provide established and robust mechanisms for understanding and interpreting traditional neutral and ionic H-bonds. In this review the applicability and extension of these parameters to describe and quantify the doubly ionic H-bond has been explored. Estimating the H-bonding energy is difficult because at a fundamental level the H-bond and ionic interaction are coupled. The NBO and QTAIM methodologies, unlike the total energy, are local descriptors and therefore can be used to directly compare neutral, ionic and doubly ionic H-bonds. The charged nature of the ions influences the ionic characteristics of the H-bond and vice versa, in addition the close association of the ions leads to enhanced orbital overlap and covalent contributions. The charge on the ions raises the energy of the Ylp and lowers the energy of the X–H σ* NBOs resulting in greater charge transfer, strengthening the H-bond. Using this range of parameters and comparing doubly ionic H-bonds to more traditional neutral and ionic H-bonds it is clear that doubly ionic H-bonds cover the full range of weak through to very strong H-bonds.

572 citations

Journal ArticleDOI
TL;DR: Advances from about the last 10 years in understanding those interactions related to σ-hole are summarized, with particular attention to theoretical and computational techniques, which play a crucial role in the field.
Abstract: In the field of noncovalent interactions a new paradigm has recently become popular. It stems from the analysis of molecular electrostatic potentials and introduces a label, which has recently attracted enormous attention. The label is σ-hole, and it was first used in connection with halogens. It initiated a renaissance of interest in halogenated compounds, and later on, when found also on other groups of atoms (chalcogens, pnicogens, tetrels and aerogens), it resulted in a new direction of research of intermolecular interactions. In this review, we summarize advances from about the last 10 years in understanding those interactions related to σ-hole. We pay particular attention to theoretical and computational techniques, which play a crucial role in the field.

503 citations