scholarly journals The Effect of Intramolecular Hydrogen Bond Type on the Gas-Phase Deprotonation of ortho-Substituted Benzenesulfonic Acids. A Density Functional Theory Study

Molecules ◽  
2020 ◽  
Vol 25 (24) ◽  
pp. 5806
Author(s):  
Nina I. Giricheva ◽  
Sergey N. Ivanov ◽  
Anastasiya V. Ignatova ◽  
Mikhail S. Fedorov ◽  
Georgiy V. Girichev
Keyword(s):  
Hydrogen Bond ◽  
Gas Phase ◽  
Density Functional ◽  
Structural Features ◽  
Proton Donor ◽  
Comparative Characteristic ◽  
Structural Factors ◽  
Sulfonic Group ◽  
Intramolecular Hydrogen ◽  
Benzenesulfonic Acids

Structural factors have been identified that determine the gas-phase acidity of ortho-substituted benzenesulfonic acid, 2-XC6H4–SO3H, (X = –SO3H, –COOH, –NO2, –SO2F, –C≡N, –NH2, –CH3, –OCH3, –N(CH3)2, –OH). The DFT/B3LYP/cc-pVTZ method was used to perform conformational analysis and study the structural features of the molecular and deprotonated forms of these compounds. It has been shown that many of the conformers may contain anintramolecular hydrogen bond (IHB) between the sulfonic group and the substituent, and the sulfonic group can be an IHB donor or an acceptor. The Gibbs energies of gas-phase deprotonation ΔrG0298 (kJ mol–1) were calculated for all compounds. It has been set that in ortho-substituted benzenesulfonic acids, the formation of various types of IHB is possible, having a significant effect on the ΔrG0298 values of gas-phase deprotonation. If the –SO3H group is the IHB donor, then an ion without an IHB is formed upon deprotonation, and the deprotonation energy increases. If this group is an IHB acceptor, then a significant decrease in ΔrG0298 of gas-phase deprotonation is observed due to an increase in IHB strength and the A− anion additional stabilization. A proton donor ability comparative characteristic of the –SO3H group in the studied ortho-substituted benzenesulfonic acids is given, and the ΔrG0298 energies are compared with the corresponding values of ortho-substituted benzoic acids.

Theoretical calculations of intramolecular hydrogen bond of the 2-Amino-2, 4, 6-cycloheptatrien-1-one in the gas phase and solution: Substituent effects and their positions

2016 ◽  
Vol 15 (07) ◽  
pp. 1650063 ◽  
Author(s):  
Narges Khatoon Attaran Toosy ◽  
Heidar Raissi ◽  
Maryam Zaboli
Keyword(s):  
Hydrogen Bond ◽  
Gas Phase ◽  
Intramolecular Hydrogen Bond ◽  
Density Functional ◽  
Theoretical Calculations ◽  
Substituent Effects ◽  
Dft Method ◽  
Basis Set ◽  
Parent Molecule ◽  
Intramolecular Hydrogen

The density functional theory (DFT) method with 6-311[Formula: see text]G[Formula: see text] basis set has been used to calculate the intramolecular hydrogen bond, molecular structure, vibrational frequencies, nuclear quadrupole resonance (NQR) parameters, 1HNMR, and resonance parameters of 2-Amino-2, 4, 6-cycloheptatrien-1-one (2-amino tropone) and its 18 derivatives in 5 positions. The natural bonding orbital (NBO) and quantum theory of atoms in molecules (QTAIM) analyses have been studied. The strongest and weakest hydrogen bonds exist for NO2 substituent in R3 position and OH in R7 position, respectively. In general, the substituted systems in position 3 indicate the stronger hydrogen bond in comparison with the parent molecule (R[Formula: see text]H), while, it is comparatively weaker for position 5. The energy of the N-H[Formula: see text]O interaction is found to be medium in strength ([Formula: see text][Formula: see text]kJ mol[Formula: see text] to [Formula: see text][Formula: see text]kJ mol[Formula: see text]). The low [Formula: see text], positive [Formula: see text] values and [Formula: see text] show that the nature of O [Formula: see text] H bonding is electrostatic. Also, our theoretical results show that the hydrogen bond strength in solution phase and the first singlet excited state is weaker in comparison with the gas phase ground state.

Crystal structure of osimertinib mesylate Form B (Tagrisso), (C28H34N7O2)(CH3O3S)

2021 ◽  
pp. 1-9
Author(s):  
James A. Kaduk ◽  
Nicholas C. Boaz ◽  
Emma L. Markun ◽  
Amy M. Gindhart ◽  
Thomas N. Blanton
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Powder Diffraction ◽  
Density Functional ◽  
Amino Nitrogen ◽  
Strong Hydrogen Bond ◽  
Powder Diffraction File ◽  
Dimethylamino Group ◽  
Intramolecular Hydrogen

The crystal structure of osimertinib mesylate Form B has been solved and refined using synchrotron X-ray powder diffraction data and optimized using density functional techniques. Osimertinib mesylate Form B crystallizes in space group P-1 (#2) with a = 11.42912(17), b = 11.72274(24), c = 13.32213(22) Å, α = 69.0265(5), β = 74.5914(4), γ = 66.4007(4)°, V = 1511.557(12) Å3, and Z = 2. The crystal structure is characterized by alternating layers of cation–anion and parallel stacking interactions parallel to the ab-planes. The cation is protonated at the nitrogen atom of the dimethylamino group, which forms a strong hydrogen bond between the cation and the anion. That hydrogen atom also participates in a weaker intramolecular hydrogen bond to an amino nitrogen. There are two additional N–H⋅⋅⋅O hydrogen bonds between the cation and the anion. Several C–H⋅⋅⋅O hydrogen bonds also link the cations and anions. The powder pattern has been submitted to ICDD® for inclusion in the Powder Diffraction File™.

scholarly journals Does the Intramolecular Hydrogen Bond Affect the Spectroscopic Properties of Bicyclic Diazole Heterocycles?

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Paweł Misiak ◽  
Alina T. Dubis ◽  
Andrzej Łapiński
Keyword(s):  
Hydrogen Bond ◽  
Quantum Theory ◽  
Intramolecular Hydrogen Bond ◽  
Natural Bond Orbital ◽  
Spectroscopic Properties ◽  
Proton Donor ◽  
Proton Acceptor ◽  
Nbo Method ◽  
Acceptor Group ◽  
Intramolecular Hydrogen

The formation of an intramolecular hydrogen bond in pyrrolo[1,2-a]pyrazin-1(2H)-one bicyclic diazoles was analyzed, and the influence of N-substitution on HB formation is discussed in this study. B3LYP/aug-cc-pVDZ calculations were performed for the diazole, and the quantum theory of atoms in molecules (QTAIM) approach as well as the natural bond orbital (NBO) method was applied to analyze the strength of this interaction. It was found that the intramolecular hydrogen bond that closes an extra ring between the C=O proton acceptor group and the CH proton donor, that is, C=O⋯H–C, influences the spectroscopic properties of pyrrolopyrazine bicyclic diazoles, particularly the carbonyl frequencies. The influence of N-substitution on the aromaticity of heterocyclic rings is also discussed in this report.

scholarly journals Salicylaldehyde Hydrazones: Buttressing of Outer-Sphere Hydrogen-Bonding and Copper Extraction Properties

2017 ◽  
Vol 70 (5) ◽  
pp. 556 ◽  
Author(s):  
Benjamin D. Roach ◽  
Tai Lin ◽  
Heiko Bauer ◽  
Ross S. Forgan ◽  
Simon Parsons ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Outer Sphere ◽  
Copper Extraction ◽  
Hydrogen Bond Acceptor ◽  
Hydrogen Bond Formation ◽  
Oxime Derivatives ◽  
Intramolecular Hydrogen

Salicylaldehyde hydrazones are weaker copper extractants than their oxime derivatives, which are used in hydrometallurgical processes to recover ~20 % of the world’s copper. Their strength, based on the extraction equilibrium constant Ke, can be increased by nearly three orders of magnitude by incorporating electron-withdrawing or hydrogen-bond acceptor groups (X) ortho to the phenolic OH group of the salicylaldehyde unit. Density functional theory calculations suggest that the effects of the 3-X substituents arise from a combination of their influence on the acidity of the phenol in the pH-dependent equilibrium, Cu2+ + 2Lorg ⇌ [Cu(L–H)2]org + 2H+, and on their ability to ‘buttress’ interligand hydrogen bonding by interacting with the hydrazone N–H donor group. X-ray crystal structure determination and computed structures indicate that in both the solid state and the gas phase, coordinated hydrazone groups are less planar than coordinated oximes and this has an adverse effect on intramolecular hydrogen-bond formation to the neighbouring phenolate oxygen atoms.

Intramolecular hydrogen bonds and the orientation of amino groupsin o-phenylenediamines

1967 ◽  
Vol 45 (19) ◽  
pp. 2135-2141 ◽  
Author(s):  
P. J. Krueger
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Infrared Absorption ◽  
Substituent Effect ◽  
Proton Donor ◽  
Proton Acceptor ◽  
Amino Groups ◽  
Intramolecular Hydrogen Bonds ◽  
Infrared Absorption Spectra ◽  
Intramolecular Hydrogen

The infrared absorption spectra of partially deuterated o-phenylenediamine and 4,5-di-methyl-, 4-methyl-, and 4-chloro-o-phenylenediamine in dilute CCl4 solution show double intramolecular [Formula: see text] hydrogen bonds in which the two NHD groups are equivalent and each group acts as both a proton donor and a proton acceptor. The ring substituent effect on this interaction in these compounds is small. In 4-methoxy-o-phenylenediamine, the amino groups are not equivalent, but double intramolecular hydrogen bonds are still present. In 4-nitro-o-phenylenediamine, only one intramolecular [Formula: see text] hydrogen bond appears to exist. The effect of N-substitution on some of these observations is discussed.

scholarly journals HIGH-RESOLUTION GAS PHASE THz SPECTROSCOPY OF THE CATECHOL LOW FREQUENCY MODES INVOLVING AN INTRAMOLECULAR HYDROGEN BOND

2021 ◽  
Author(s):  
Jonas Bruckhuisen ◽  
Arnaud Cuisset ◽  
Marie-Aline Martin-Drumel ◽  
Manuel Goubet ◽  
Thi Tran ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
High Resolution ◽  
Gas Phase ◽  
Intramolecular Hydrogen Bond ◽  
Low Frequency ◽  
Thz Spectroscopy ◽  
Intramolecular Hydrogen

scholarly journals Crystal structure of trirubidium citrate monohydrate from laboratory X-ray powder diffraction data and DFT comparison

2017 ◽  
Vol 73 (2) ◽  
pp. 227-230 ◽  
Author(s):  
Alagappa Rammohan ◽  
James A. Kaduk
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Density Functional ◽  
Three Dimensional ◽  
Powder Diffraction Data ◽  
Hydrogen Bond Donor ◽  
X Ray ◽  
Intramolecular Hydrogen

The crystal structure of the title compound, 3Rb+·C6H5O73−·H2O, has been solved and refined using laboratory X-ray powder diffraction data, and optimized using density functional techniques. The hydroxy group participates in an intramolecular hydrogen bond to the deprotonated central carboxylate group with graph-set motifS(5). The water molecule acts as a hydrogen-bond donor to both terminal and central carboxylate O atoms. The three independent rubidium cations are seven-, six- and six-coordinate, with bond-valence sums of 0.84, 1.02, and 0.95, respectively. In the extended structure, their polyhedra share edges and corners to form a three-dimensional network. The hydrophobic methylene groups occupy channels along thebaxis.

scholarly journals Influence of catecholic ring torsion on hydroxyflavones

2020 ◽  
Vol 13 (1) ◽  
pp. 49-55
Author(s):  
Martin Michalík ◽  
Monika Biela ◽  
Denisa Cagardová ◽  
Vladimír Lukeš
Keyword(s):  
Gas Phase ◽  
Phenyl Ring ◽  
Density Functional ◽  
Hydroxyl Group ◽  
Torsional Deformation ◽  
Functional Theory ◽  
Electron Transitions ◽  
The Density Functional Theory ◽  
Intramolecular Hydrogen ◽  
Theoretical Results

AbstractSystematic quantum chemical investigation of quercetin and selected eight mono- and bihydroxyflavonols is presented. Structural analysis based on the Density Functional Theory showed that the energetically preferred conformation of flavonols substituted at the C5 and C3 atoms by a hydroxyl group is stabilised via intramolecular hydrogen bonds occurring between the (C4)O···HO(3 or 5) atomic pairs. Depending on the hydroxyl group positions, energetically preferred torsional orientation of the phenyl ring with respect to the planar benzo-γ-pyrone moiety changed from 0 to 180 degrees. Gas-phase electron transitions were investigated using the time-dependent DFT treatment. The dependence of maximal wavelengths on the torsional deformation of the phenyl ring is of a similar shape, i.e. minima observed for the perpendicular orientation and maxima for the planar one. Shape and energies of the Highest Occupied (HOMO) and Lowest Unoccupied (LUMO) Molecular Orbitals were compared. The obtained theoretical results were compared with available experimental data.

Torsional isomers in methylated aminoethanols - A jet-FT-IR study

2004 ◽  
Vol 82 (6) ◽  
pp. 1006-1012 ◽  
Author(s):  
Yaqian Liu ◽  
Corey A Rice ◽  
Martin A Suhm
Keyword(s):  
Hydrogen Bond ◽  
Gas Phase ◽  
Quantum Chemical ◽  
Supersonic Jet ◽  
Energy Difference ◽  
Ft Ir ◽  
Ir Study ◽  
Intramolecular Hydrogen ◽  
Quantum Chemical Data ◽  
Torsional Isomers

Jet-FT-IR spectra of aminoethanol (AE), N-methylaminoethanol (MAE), and N,N-dimethylaminoethanol (DMAE) are presented and compared to gas-phase and matrix isolation IR, microwave, and quantum chemical data. The intramolecular O-H···N hydrogen bond gives rise to characteristically shifted O-H stretching bands and torsional difference bands in the monomer spectra. It stabilizes one out of 14 diastereomeric monomer conformations of AE and DMAE and two out of 27 diastereomeric MAE conformations. The latter two correspond to torsional or N-inversional isomers, the interconversion of which is hindered by the intramolecular hydrogen bond. Their energy difference is found to be <1.2 kJ/mol. The intermolecular aggregation patterns of the three aminoethanols are quite distinct and non-monotonic, as suggested by their O-H stretching fingerprints.Key words: aminoethanol, IR spectroscopy, conformation, hydrogen bond, supersonic jet.

Sign in / Sign up

Export Citation Format

Share Document