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Journal ArticleDOI

From weak to strong interactions: A comprehensive analysis of the topological and energetic properties of the electron density distribution involving X–H⋯F–Y systems

04 Sep 2002-Journal of Chemical Physics (American Institute of Physics)-Vol. 117, Iss: 12, pp 5529-5542
TL;DR: In this paper, the topological and energetic properties of the electron density distribution ρ(r) of isolated pairwise H⋯F interaction have been theoretically calculated at several geometries and represented against the corresponding internuclear distances.
Abstract: The topological and energetic properties of the electron density distribution ρ(r) of the isolated pairwise H⋯F interaction have been theoretically calculated at several geometries (0.8
Citations
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Journal ArticleDOI
01 Sep 2015-IUCrJ
TL;DR: A combination of single-crystal X-ray and neutron diffraction experiments are used to determine the electron density distribution in orthorhombic rubrene and clearly demonstrate the presence of π⋯π stacking interactions in the crystalline state.

176 citations


Cites background from "From weak to strong interactions: A..."

  • ...The |V|/G ratio is smaller than 1 for closed shell interactions and larger than 2 for shared shell interactions (Espinosa et al., 2002)....

    [...]

Journal ArticleDOI
TL;DR: All methods of catalytic glycosylation with the focus on the development and application in oligosaccharide synthesis and an overview of the scope and limitations of these are provided.
Abstract: Catalytic glycosylation has been a central reaction in carbohydrate chemistry since its introduction by Fischer 125 years ago, but it is only in the past three to four decades that catalytic methods for synthesizing oligosaccharides have appeared. Despite the development of numerous elegant and ingenious catalytic glycosylation methods, only a few are in general use. This review covers all methods of catalytic glycosylation with the focus on the development and application in oligosaccharide synthesis and provide an overview of the scope and limitations of these. The review also includes relevant mechanistic studies of catalytic glycosylations. The future of catalytic glycosylation chemistry is discussed, including specific, upcoming methods and possible directions for the field of research in general.

175 citations

Journal ArticleDOI
TL;DR: Two minima complexes are found, one with an OH...N hydrogen bond and the other one with a X...N halogen bond, and the first one is more stable for the smallest halogen derivatives.
Abstract: A theoretical study of the complexes formed by hypohalous acids (HOX, X = F, Cl, Br, I, and At) with three nitrogenated bases (NH3, N2, and NCH) has been carried out by means of ab initio methods, up to MP2/aug-cc-pVTZ computational method. In general, two minima complexes are found, one with an OH···N hydrogen bond and the other one with a X···N halogen bond. While the first one is more stable for the smallest halogen derivatives, the two complexes present similar stabilities for the iodine case and the halogen-bonded structure is the most stable one for the hypoastatous acid complexes.

169 citations

Journal ArticleDOI
TL;DR: It was found that there are not any distinct differences between RAHBs and the other intramolecular hydrogen bonds, and the CVB index based on the ELF method as well as the total electron energy density at the bond critical point of the proton-acceptor distance may be treated as universal descriptors of the hydrogen bond strength.
Abstract: B3LYP/aug-cc-pVTZ calculations were performed on the species with intramolecular O–H···O hydrogen bonds. The Quantum Theory of Atoms in Molecules (QTAIM) and the Electron Localization Function (ELF) method were applied to analyze these interactions. Numerous relationships between ELF and QTAIM parameters were found. It is interesting that the CVB index based on the ELF method as well as the total electron energy density at the bond critical point of the proton–acceptor distance (Hbcp) may be treated as universal descriptors of the hydrogen bond strength, they are also useful to estimate the covalent character of this interaction. There are so-called resonance-assisted hydrogen bonds (RAHBs) among the species analyzed here. It was found that there are not any distinct differences between RAHBs and the other intramolecular hydrogen bonds.

163 citations

Journal ArticleDOI
TL;DR: The results indicate that HB pattern and electron density determine the strength of the interaction and that "parallel" HB interactions are more stable than the "bifurcated" ones.
Abstract: The nature of hydrogen bond interactions (HB) is still today the subject of many discussions. We present an overview of computational methods and parameters (interaction energy, HB distance and radii, electron density topological parameters or orbital energies) required for an accurate description of HB systems. As well, we present the different correlations that have been found between these descriptors providing a global view of HB interactions. A synopsis of the different HBs reported in terms of their strength was presented. Considering the definitions of covalent and ionic bonds, HB interactions could occur between these two extremes. Thus, we look into some of the very strong HBs (LBHB, CAHB, RAHB) and some of the weak HBs (weak donors: C–H or weak acceptors: π systems). Subsequently, aspects such as cooperativity or solvation are examined. Finally, we present a study on multiple “parallel” and “bifurcated” HB systems. Our results indicate that HB pattern and electron density determine the strength of the interaction and that “parallel” HB interactions are more stable than the “bifurcated” ones.

157 citations

References
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Journal ArticleDOI
TL;DR: A description of the ab initio quantum chemistry package GAMESS, which can be treated with wave functions ranging from the simplest closed‐shell case up to a general MCSCF case, permitting calculations at the necessary level of sophistication.
Abstract: A description of the ab initio quantum chemistry package GAMESS is presented. Chemical systems containing atoms through radon can be treated with wave functions ranging from the simplest closed-shell case up to a general MCSCF case, permitting calculations at the necessary level of sophistication. Emphasis is given to novel features of the program. The parallelization strategy used in the RHF, ROHF, UHF, and GVB sections of the program is described, and detailed speecup results are given. Parallel calculations can be run on ordinary workstations as well as dedicated parallel machines. © John Wiley & Sons, Inc.

18,546 citations

Journal ArticleDOI
TL;DR: In this article, a perturbation theory for treating a system of n electrons in which the Hartree-Fock solution appears as the zero-order approximation was developed, and it was shown by this development that the first order correction for the energy and the charge density of the system is zero.
Abstract: A perturbation theory is developed for treating a system of n electrons in which the Hartree-Fock solution appears as the zero-order approximation. It is shown by this development that the first order correction for the energy and the charge density of the system is zero. The expression for the second-order correction for the energy greatly simplifies because of the special property of the zero-order solution. It is pointed out that the development of the higher approximation involves only calculations based on a definite one-body problem.

12,067 citations

Book
01 Jan 1990
TL;DR: In this article, the quantum atom and the topology of the charge desnity of a quantum atom are discussed, as well as the mechanics of an atom in a molecule.
Abstract: List of symbols 1. Atoms in chemistry 2. Atoms and the topology of the charge desnity 3. Molecular structure and its change 4. Mathematical models of structural change 5. The quantum atom 6. The mechanics of an atom in a molecule 7. Chemical models and the Laplacian of the charge density 8. The action principle for a quantunm subsystem Appendix - Tables of data Index

11,853 citations

Journal ArticleDOI
TL;DR: In this paper, a modified basis set of supplementary diffuse s and p functions, multiple polarization functions (double and triple sets of d functions), and higher angular momentum polarization functions were defined for use with the 6.31G and 6.311G basis sets.
Abstract: Standard sets of supplementary diffuse s and p functions, multiple polarization functions (double and triple sets of d functions), and higher angular momentum polarization functions (f functions) are defined for use with the 6‐31G and 6‐311G basis sets. Preliminary applications of the modified basis sets to the calculation of the bond energy and hydrogenation energy of N2 illustrate that these functions can be very important in the accurate computation of reaction energies.

7,230 citations