Search results for "interactions."

Titelbild: Achieving Strong Positive Cooperativity through Activating Weak Non‐Covalent Interactions (Angew. Chem. 3/2018)

2017

Cover Picture: Achieving Strong Positive Cooperativity through Activating Weak Non‐Covalent Interactions (Angew. Chem. Int. Ed. 3/2018)

2018

Single-Crystal X-ray Diffraction and Solution Studies of Anion-π Interactions inN-(Pentafluorobenzyl)pyridinium Salts

2014

A solid-state structural study on anion–π interaction in various N-(pentafluorobenzyl)pyridinium salts accompanied by NMR spectroscopic investigations is presented. The crystal structures of 1a–1d reveal different kinds of contacts with anions, including anion–π interactions. In particular, the solid-state structure of 1b-I3 shows distinct evidence of anion–π interactions. Attempts to study anion–π interactions in solution were not successful, but their presence in solution could not be ruled out.

Advanced descriptors for long-range noncovalent interactions between SARS-CoV-2 spikes and polymer surfaces.

2021

The recent pandemic triggered numerous societal efforts aimed to control and limit the spread of SARS-CoV-2. One of these aspects is related on how the virion interacts with inanimate surfaces, which might be the source of secondary infection. Although recent works address the adsorption of the spike protein on surfaces, there is no information concerning the long-range interactions between spike and surfaces, experimented by the virion when is dispersed in the droplet before its possible adsorption. Some descriptors, namely the interaction potentials per single protein and global potentials, were calculated in this work. These descriptors, evaluated for the closed and open states of the sp…

Coordination complexes of chromium(0) with a series of 1,3-diphenyl-6-arylfulvenes

2018

The synthesis and structural properties of a series of chromium tricarbonyl `piano-stool' complexes bearing substituted pentafulvene ligands were studied. The complexes, tricarbonyl(1,3,6-triphenylfulvene)chromium(0) benzene hemisolvate, [Cr(C24H18)(CO)3]·0.5C6H6 (I), tricarbonyl[1,3-diphenyl-6-(3-vinylphenyl)fulvene]chromium(0), [Cr(C26H20)(CO)3] (II), and tricarbonyl[1,3-diphenyl-6-(pyren-1-yl)fulvene]chromium(0), [Cr(C34H22)(CO)3] (III), each have a distorted octahedral geometry, with the fulvene coordinated in a π–η2:π–η2:π–η2 fashion. Significant deviation of the exocyclic fulvene double bond from the cyclopentadiene plane accompanies coordination. Evidence of non-covalent π–π interact…

Crystal structures of isomeric 3,5-dichloro-N-(2,3-dimethylphenyl)benzenesulfonamide, 3,5-dichloro-N-(2,6-dimethylphenyl)benzenesulfonamide and 3,5-d…

2017

The crystal structures of three isomeric compounds of formula C14H13Cl2NO2S, namely 3,5-dichloro-N-(2,3-dimethylphenyl)-benzenesulfonamide (I), 3,5-dichloro-N-(2,6-dimethylphenyl)benzenesulfonamide (II) and 3,5-dichloro-N-(3,5-dimethylphenyl)benzenesulfonamide (III) are described. The molecules of all the three compounds are U-shaped with the two aromatic rings inclined at 41.3 (6)° in (I), 42.1 (2)° in (II) and 54.4 (3)° in (III). The molecular conformation of (II) is stabilized by intramolecular C—H...O hydrogen bonds and C—H...π interactions. The crystal structure of (I) features N—H...O hydrogen-bonded R 2 2(8) loops interconnected via C(7) chains of C—H...O interactions, forming a thre…

Studies of Nature of Uncommon Bifurcated I–I···(I–M) Metal-Involving Noncovalent Interaction in Palladium(II) and Platinum(II) Isocyanide Cocrystals

2021

Two isostructural trans-[MI2(CNXyl)2]·I2 (M = Pd or Pt; CNXyl = 2,6-dimethylphenyl isocyanide) metallopolymeric cocrystals containing uncommon bifurcated iodine···(metal–iodide) contact were obtained. In addition to classical halogen bonding, single-crystal X-ray diffraction analysis revealed a rare type of metal-involved stabilizing contact in both cocrystals. The nature of the noncovalent contact was studied computationally (via DFT, electrostatic surface potential, electron localization function, quantum theory of atoms in molecules, and noncovalent interactions plot methods). Studies confirmed that the I···I halogen bond is the strongest noncovalent interaction in the systems, followed …

The Nonlocal Correlation Density Functional VV10

2015

Abstract In this chapter, we review the most relevant attempts to merge the Vydrov and van Voorhis nonlocal density-dependent functional kernel (VV10) with modern density functionals to accurately describe van der Waals interactions with a reasonable computational cost. The chapter is organized by providing first an introduction of the relevance of van der Waals interactions and the difficulties of common density functionals to describe these forces. Second, the historical developments that eventually give rise to the most modern formulation of the nonlocal density functional VV10 are briefly addressed. Then, an overview of its technical formulation, adjustable parameters, and implementatio…

Photochemistry of the H2O/CO System Revisited : The HXeOH···CO Complex in a Xenon Matrix

2017

We report on the complex of a noble-gas hydride HXeOH with carbon monoxide. This species is prepared via the annealing-induced H + Xe + OH···CO reaction in a xenon matrix, the OH···CO complexes being produced by VUV photolysis of the H2O···CO complexes. The H–Xe stretching mode of the HXeOH···CO complex absorbs at 1590.3 cm–1 and it is blue-shifted by 12.7 cm–1 from the H–Xe stretching band of HXeOH monomer. The observed blue shift indicates the stabilization of the H–Xe bond upon complexation, which is characteristic of complexes of noble-gas hydrides. The HXeOH···CO species is the first complex of a noble-gas hydride with carbon monoxide and the second observed complex of HXeOH. On the ba…

The hedgehog receptor patched is involved in cholesterol transport.

2011

International audience; BACKGROUND: Sonic hedgehog (Shh) signaling plays a crucial role in growth and patterning during embryonic development, and also in stem cell maintenance and tissue regeneration in adults. Aberrant Shh pathway activation is involved in the development of many tumors, and one of the most affected Shh signaling steps found in these tumors is the regulation of the signaling receptor Smoothened by the Shh receptor Patched. In the present work, we investigated Patched activity and the mechanism by which Patched inhibits Smoothened. METHODOLOGY/PRINCIPAL FINDINGS: Using the well-known Shh-responding cell line of mouse fibroblasts NIH 3T3, we first observed that enhancement …