نتایج جستجو برای: type ii halogenhalogen contacts are halogen bonds
تعداد نتایج: 6157948 فیلتر نتایج به سال:
Short oxygen-halogen interactions have been known in organic chemistry since the 1950s and recently have been exploited in the design of supramolecular assemblies. The present survey of protein and nucleic acid structures reveals similar halogen bonds as potentially stabilizing inter- and intramolecular interactions that can affect ligand binding and molecular folding. A halogen bond in biomole...
The crystal contacts of several families of hydrocarbon compounds substituted with one or several types of oxygenated chemical groups were analyzed statistically using the Hirshfeld surface methodology. The propensity of contacts to occur between two chemical types is described with the contact enrichment descriptor. The systematic large enrichment ratios of some interactions like the O-H⋯O hyd...
In recent years, several specific imidazolium-based ionic liquids with halogen substituents on the imidazole ring as well as on the alkyl chains have been reported. In this work, noncovalent interactions in four halogenated ionic liquids, i.e. 2-bromo-/iodo- and 4,5-dibromo-/diiodo-1,3-dimethylimidazolium trifluoromethanesulfonates, were systematically investigated using density functional theo...
A fragment of Histidine rich protein II (HRP II 215-236) was investigated by 14N and 17O electric field gradient, EFG, tensor calculations using DFT. This study is intended to explore the differences between 310-helix and α-helix of HRPII both in the gas phase and in solution. To achieve the aims, the 17O and 14N NQR parameters of a fragment of HRPII (215-236) for both structures are calculated...
The role of halogen bonds in self-assembled networks for systems with Br and I ligands has recently been studied with scanning tunneling microscopy (STM), which provides physical insight at the atomic scale. Here, we study the supramolecular interactions of 1,5-dichloroanthraquinone molecules on Au(111), including Cl ligands, by using STM. Two different molecular structures of chevron and squar...
In the title compound, C10H4BrFO3, a brominated and fluorinated 3-formyl-chromone derivative, all atoms are essentially coplanar (r.m.s. deviation of 0.025 Å for the non-H atoms), with the largest deviation from the least-squares plane [0.050 (6) Å] being for a benzene-ring C atom. In the crystal, mol-ecules are linked through stacking inter-actions [centroid-centroid distance between the benze...
In the title compound, C10H4ClFO3, a chlorinated and fluorinated 3-formyl-chromone derivative, all atoms are essentially coplanar (r.m.s. = 0.0336 Å for the non-H atoms), with the largest deviation from the least-squares plane [0.062 (2) Å] being for a benzene-ring C atom. In the crystal, mol-ecules are linked through stacking inter-actions [centroid-centroid distance between the benzene and py...
In this paper, the effect of halogen compounds on tetrahedrozoline with nanosized fullerene was investigated. First, the structures of Tetrahydrozoline on a fully vectorized nanoclay were optimized with halogen compounds on carbon 69 (R-X: X = F, Cl, Br; R = C60-Tetrahydrozoline-C69-). Then orbital calculations were performed using NBO technique, and structural parameters and bipolar moments of...
Halogen bonding (XB) is being extensively explored for its potential use in advanced materials and drug design. Despite significant progress in describing this interaction by theoretical and experimental methods, the chemical nature remains somewhat elusive, and it seems to vary with the selected system. In this work we present a detailed DFT analysis of three-center asymmetric halogen bond (XB...
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