A non-classical hydrogen bond in the molybdenum arene complex [η6-C6H5C6H3(Ph)OH]Mo(PMe3)3: evidence that hydrogen bonding facilitates oxidative addition of the O–H bond

2002 ◽  
pp. 2644-2645 ◽  
Author(s):  
Tony Hascall ◽  
Mu-Hyun Baik ◽  
Brian M. Bridgewater ◽  
Jun Ho Shin ◽  
David G. Churchill ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Oxidative Addition ◽  
Arene Complex ◽  
Classical Hydrogen Bond

scholarly journals Influence of steric crowding on hydrogen bonding in anti-cancer quinols

2014 ◽  
Vol 70 (a1) ◽  
pp. C561-C561
Author(s):  
Carl Schwalbe ◽  
Geoffrey Wells ◽  
Malcolm Stevens
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Antitumor Activity ◽  
Donor Group ◽  
Anti Cancer ◽  
Cell Dimensions ◽  
Steric Crowding ◽  
Michael Acceptor ◽  
Classical Hydrogen Bond ◽  
Unit Cell Dimensions

The quinol 4-(1-benzenesulfonyl-1H-6-fluoroindol-2-yl)-4-hydroxycyclohexa-2,5-dienone (1) is strongly active against cancer cells [1]. Two "Michael acceptor" electrophilic β-carbons on the quinol ring are believed necessary for optimal antitumor activity, and disruption of thioredoxin signaling is a possible mechanism of action. As a model for the possible product, the adduct (2) with two molecules of ethanethiol was prepared. These molecules have just one classical hydrogen bond (HB) donor group, the quinol OH, but a surfeit of acceptors, namely one C=O and two SO2oxygen atoms (designated O15, O17 and O18) as well as O14, the OH itself. In (1) paired molecules form a R22(14) ring by O14-H...O17 HB with H...O distance 2.15 Å and O-H...O angle 156°. In (2) the two EtS groups on the same side of the quinol ring as O14 interfere with this motif. Instead, a C(7) chain is formed by less optimal O14-H...O17 HB (2.34 Å and 134°). In apparent compensation, an intramolecular C-H...O HB to O17 is shorter and straighter in (2). In both structures all O atoms accept C-H...O HB. The unit cell dimensions are dissimilar, but a motif persists: one phenyl CH and one indole CH group bite onto the same O atom, O15 in (1) but O18 in (2).

Interaction of Gold Atom with Clusters of Water: Few Computational Mise-En-Scènes with Hydrogen Bonding Motif

2008 ◽  
Vol 73 (11) ◽  
pp. 1457-1474 ◽  
Author(s):  
Eugene S. Kryachko
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Computational Model ◽  
Photoelectron Spectroscopy ◽  
Water Clusters ◽  
Gold Atom ◽  
Proton Acceptor ◽  
Anion Photoelectron Spectroscopy ◽  
Relationship Of ◽  
First Time

The present work outlines the fair relationship of the computational model with the experiments on anion photoelectron spectroscopy for the gold-water complexes [Au(H2O)1≤n≤2]- that is established between the auride anion Au- and water monomer and dimer thanks to the nonconventional hydrogen bond where Au- casts as the nonconventional proton acceptor. This work also extends the computational model to the larger complexes [Au(H2O)3≤n≤5]- where gold considerably thwarts the shape of water clusters and even particularly breaks their conventional hydrogen bonding patterns. The fascinating phenomenon of the lavish proton acceptor character of Au- to form at least six hydrogen bonds with molecules of water is computationally unveiled in the present work for the first time.

Rietveld refinement of the cocrystal 2,4-dihydroxybenzoic acid–N′-(propan-2-ylidene)nicotinohydrazide (1/1)

2012 ◽  
Vol 68 (9) ◽  
pp. o335-o337 ◽  
Author(s):  
Saul H. Lapidus ◽  
Andreas Lemmerer ◽  
Joel Bernstein ◽  
Peter W. Stephens
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Powder Diffraction ◽  
Supramolecular Assembly ◽  
Covalent Bond ◽  
Analytical Tool ◽  
Powder Diffraction Data ◽  
Dihydroxybenzoic Acid ◽  
Bond Forming ◽  
Hydrogen Bond Interactions

A further example of using a covalent-bond-forming reaction to alter supramolecular assembly by modification of hydrogen-bonding possibilities is presented. This concept was introduced by Lemmerer, Bernstein & Kahlenberg [CrystEngComm(2011),13, 55–59]. The title structure, C9H11N3O·C7H6O4, which consists of a reacted niazid molecule,viz.N′-(propan-2-ylidene)nicotinohydrazide, and 2,4-dihydroxybenzoic acid, was solved from powder diffraction data using simulated annealing. The results further demonstrate the relevance and utility of powder diffraction as an analytical tool in the study of cocrystals and their hydrogen-bond interactions.

Supramolecular assembling using synthons with NH—CO(S)—CS—NH and NH—CO—CO—NH functionalities: crystal structures of (S,S)-N,N′-monothiooxalyldileucine methyl ester and its dithio analogue

2004 ◽  
Vol 60 (1) ◽  
pp. 90-96 ◽  
Author(s):  
Biserka Kojić-Prodić ◽  
Berislav Perić ◽  
Zoran Štefanić ◽  
Anton Meden ◽  
Janja Makarević ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Methyl Ester ◽  
Crystal Structures ◽  
Hydrogen Bond Network ◽  
Asymmetric Unit ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
Bond Network ◽  
Bonding Systems

To compare the structural properties of oxalamide and thiooxalamide groups in the formation of hydrogen bonds suitable for supramolecular assemblies a series of retropeptides was studied. Some of them, having oxalamide bridges, are gelators of organic solvents and water. However, retropeptides with oxygen replaced by the sp 2 sulfur have not exhibited such properties. The crystal structures of the two title compounds are homostructural, i.e. they have similar packing arrangements. The monothio compound crystallizes in the orthorhombic space group P212121 with two molecules in the asymmetric unit arranged in a hydrogen-bond network with an approximate 41 axis along the crystallographic b axis. However, the dithio and dioxo analogues crystallize in the tetragonal space group P41 with similar packing patterns and hydrogen-bonding systems arranged in agreement with a crystallographic 41 axis. Thus, these two analogues are isostructural having closely related hydrogen-bonding patterns in spite of the different size and polarity of oxygen and sulfur which serve as the proton acceptors.

Solvent, coordination and hydrogen-bond effects on the chromic luminescence of the cationic complex [(phen)(H2O)Re(CO)3]+

2016 ◽  
Vol 40 (7) ◽  
pp. 6451-6459 ◽  
Author(s):  
Pablo Mella ◽  
Karina Cabezas ◽  
Carla Cerda ◽  
Marjorie Cepeda-Plaza ◽  
German Günther ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Solvent Polarity ◽  
Cationic Complex ◽  
Unusual Behavior ◽  
Luminescence Emission

The unusual behavior of the solution luminescence emission of [(phen)(H2O)Re(CO)3]+(CF3SO3)− depends on the solvent polarity, and coordinating and hydrogen bonding ability.

scholarly journals Conformational analysis and intramolecular interactions in monosubstituted phenylboranes and phenylboronic acids

2013 ◽  
Vol 9 ◽  
pp. 1127-1134 ◽  
Author(s):  
Josué M Silla ◽  
Rodrigo A Cormanich ◽  
Roberto Rittner ◽  
Matheus P Freitas
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Conformational Analysis ◽  
Conformational Equilibrium ◽  
Intramolecular Hydrogen Bonding ◽  
Intramolecular Interactions ◽  
Coupling Constant ◽  
Intramolecular Hydrogen ◽  
Phenylboronic Acids ◽  
Electron Donation

A 1 TS J F,H(O) coupling pathway, dictated by a hydrogen bond, in some 2-fluorobenzoic acids has been observed, while such an interaction does not occur in 2-fluorophenol. Thus, this work reports the conformational analysis of 2-fluorophenylboronic acid (1), in order to evaluate a possible intramolecular OH∙∙∙F hydrogen bond in comparison to an nF→pB interaction, which mimics the quantum nF→σ*OH hydrogen bond that would be expected in 2-fluorophenol. 2-Fluorophenylborane (3), which does not experience hydrogen bonding, was used to verify whether nF→pB interaction governs the conformational equilibrium in 1 due to a predominant OH∙∙∙F hydrogen bond or to other effects. A series of 2-X-phenylboranes (X = Cl, Br, NH2, PH2, OH and SH) were further computationally analyzed to search for electron donors to boron, capable of influencing the conformational equilibrium. Overall, the intramolecular OH∙∙∙F hydrogen bond in 1 is quite stabilizing and dictates the 1 h J F,H(O) coupling constant. Moreover, electron donation to the empty p orbital of boron (for noncoplanar BH2 moiety relative to the phenyl ring) is also significantly stabilizing for the NH2 and PH2 derivatives, but not enough to make the corresponding conformers appreciably populated, because of steric effects and the loss of πCC→pB resonance. Thus, the results found earlier for 2-fluorophenol about the lack of intramolecular hydrogen bonding are now corroborated.

scholarly journals Doubly ionic hydrogen bond interactions within the choline chloride–urea deep eutectic solvent

2016 ◽  
Vol 18 (27) ◽  
pp. 18145-18160 ◽  
Author(s):  
Claire R. Ashworth ◽  
Richard P. Matthews ◽  
Tom Welton ◽  
Patricia A. Hunt
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Computational Analysis ◽  
Choline Chloride ◽  
Deep Eutectic Solvent ◽  
Hydrogen Bond Interactions

Computational analysis indicates flexibility and diversity in the hydrogen bonding, but limited charge delocalisation, within the choline chloride–urea eutectic.

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