Hydrogen bonding. Part 2.—Equilibrium constants and enthalpies of complexation for 72 monomeric hydrogen-bond acids with N-methylpyrrolidinone in 1,1,1-trichloroethane

1987 ◽  
Vol 83 (9) ◽  
pp. 2867 ◽  
Author(s):  
Michael H. Abraham ◽  
Philip P. Duce ◽  
Jeffrey J. Morris ◽  
Peter J. Taylor
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Equilibrium Constants

Stabilities in the gas phase of the hydrogen bonded complexes, YC6H4OH-X−, of substituted phenols, YC6E4OH, with the halide anions X− (Cl−, Br−, I−)

1990 ◽  
Vol 68 (11) ◽  
pp. 2070-2077 ◽  
Author(s):  
Gary J. C. Paul ◽  
Paul Kebarle
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Proton Transfer ◽  
Gas Phase ◽  
Equilibrium Constants ◽  
Substituent Effects ◽  
Closed Shell ◽  
Bond Energies ◽  
Substituted Phenols ◽  
Hydrogen Bonded

The equilibria, YPhOH + Br− = YPhOH-Br−, involving 26 differently substituted phenols, were determined with a pulsed high pressure mass spectrometer. The −ΔG0 evaluated from the equilibrium constants represent the hydrogen bond free energies in YPhOH-Br−. These data and data for X− = Cl− and I−, determined previously in this laboratory, are used to examine the substituent effects on the hydrogen bonding. It was found that the hydrogen bond energies in YPhOH-X− increase approximately linearly with the gas phase acidities of the phenols, YPhOH. This is in agreement with earlier observations that showed the bond energies in AH-B−, where AH were oxygen and nitrogen acids and B− closed shell anions, increase with increasing acidity of AH.A detailed analysis of the substituent effects, which is possible for YPhOH-X−, shows that the relationship with the acidity of AH can be divided into two parts. One is the increasing extent of actual proton transfer from AH on formation of the hydrogen bonded complex. Such proton transfer occurs in YPhOH-X− only for the series X− = Cl−. The second effect, which occurs for Cl− and is dominant for Br− and I−, is not directly related to the acidity of the phenols (or AH in general) but depends on a similarity of the substituent effects on the acidity and the stabilization of YPhOH-X− (or AH-B− in general). The dominant contribution to YPhOH-X− stabilization in this case is due to the field effects of the substituents, i.e., π delocalization plays only a small part. Therefore, the correlation with the acidity of YPhOH, where π delocalization is important, is not very close. Keywords: hydrogen bonding, substituent effects, ion–molecule equilibria, stability constants, thermochemistry.

Hydrogen bonding between phenols and cyanides

1966 ◽  
Vol 291 (1427) ◽  
pp. 460-468 ◽  
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Carbon Tetrachloride ◽  
Equilibrium Constants ◽  
Lone Pair ◽  
Frequency Shifts ◽  
Tertiary Butyl ◽  
Group Frequency ◽  
Steric Factors ◽  
Lone Pair Electrons

The association between phenols and cyanides, dissolved in carbon tetrachloride, has been measured. The shifts of the bonded OH group frequency have been determined for a range of cyanides, and correlated with the Taft inductive factors of the groups concerned. Equilibrium constants for the formation of the complexes have been determined and correlated with the frequency shifts. The influence of steric factors has been studied, and it has been found that tertiary butyl groups in the ortho positions of phenol restrict the formation of the hydrogen bond. In most cases, the C≡N group frequency is displaced to higher frequency when bonded to a phenol. This effect is unusual, and suggests that the bonding occurs through the lone pair electrons on the nitrogen atom. Some data on the widths of the association bands have been given.

Hydrogen bonding of O—H and C—H hydrogen donors to Cl−. Results from mass spectrometric measurements of the ion–molecule equilibria RH + Cl− = RHCl−

1982 ◽  
Vol 60 (15) ◽  
pp. 1907-1918 ◽  
Author(s):  
M. A. French ◽  
S. Ikuta ◽  
P. Kebarle
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Gas Phase ◽  
Positive Charge ◽  
Equilibrium Constants ◽  
Basis Set ◽  
Molecular Orbital Calculations ◽  
Simple Relationship ◽  
Gas Phase Acidity ◽  
Carbon Acids

Equilibrium constants K1 for reaction [1] RH + Cl− = RHCl− in the gas phase were measured with a high pressure mass spectrometer under chemical ionization conditions. Data for some 40 compounds RH are presented. It is found that the binding free energies [Formula: see text] for RH = oxygen acids increase with the gas phase acidity of RH. The strongest bonds are formed with strong acids like HCO2H, CH3CO2H, and phenol. Water and alkyl alcohols give much weaker interactions. A simple relationship between gas phase acidity and binding free energy does not occur for RH = carbon acids. Carbon acids like cyclopentadiene, whose high gas phase acidity is largely due to charge derealization by conjugation in the completed anion, do not give Cl− adducts with stability commensurate with the acidity. A relationship between gas phase acidity and binding energy is found for carbon acids with carbonyl groups and for the substituted toluenes. Molecular orbital calculations with the STO-3G basis set provide insights to the bonding occurring in RHCl−. For all cases investigated, hydrogen bonding to Cl− provides the most stable structure. Generally the hydrogen bond occurs through the hydrogen which has the highest net positive charge. The hydrogen bond strength is found approximately proportional to this positive charge. Another proportionality is found between the charge transferred from Cl− to RH, on formation of RHCl−, and the strength of the hydrogen bond.

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.

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