Hydration of diazoles in water solution: pyrazole. A theoretical and X-ray diffraction study

Ramondo, Fabio; Tanzi, Luana; Campetella, Marco; Gontrani, Lorenzo; Mancini, Giordano; Pieretti, Andrea; Sadun, Claudia

doi:10.1039/b909388e

Cited by 8 publications

(21 citation statements)

References 38 publications

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“…These observations about the positions of hydrate molecules are in line with previous studies combining molecular dynamics modelling with neutron and X-ray scattering results, including neutral and protonated imidazole, 58 and the related solutes pyrazole 59 and pyridine 60 in aqueous solutions. Recent MD simulation studies of aqueous solutions of imidazole at different concentrations came to similar conclusions.…”

Section: Imidazole-water Interactionssupporting

confidence: 91%

Hydrophilic and hydrophobic interactions in concentrated aqueous imidazole solutions: a neutron diffraction and total X-ray scattering study

Al-Madhagi

Callear

Schroeder

2020

Phys. Chem. Chem. Phys.

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The intermolecular interactions in concentrated (5 M) aqueous imidazole solutions have been investigated by combining neutron diffraction with isotopic substitution, total X-ray scattering and empirical potential structure refinement (EPSR) simulations using a box containing 5530 water and 500 imidazole molecules. The structural model with the best fit was used to generate radial distribution functions and spatial density functions. The local volume surrounding imidazole molecules is dominated by water, due to strong hydrogen-bonding between the nitrogen moieties of imidazole and water molecules; within a radius of 6.4 Å from the central imidazole molecule there are, on average, 17 water and only 3 imidazole molecules. Even though imidazole interacts with water it appears to disrupt hydrogen bonding in the surrounding water network only minimally. Hydrogen-bonding between imidazole molecules is negligible. The most probable positions of imidazole nearest-neighbours are above and below the plane of the aromatic ring. At low distances (up to B3.5-3.8 Å) these nearest neighbours were found to prefer parallel orientation of the molecular planes, indicating hydrophobic (p-p) stacking. At longer distances (up to B5 Å), imidazole neighbours assume both parallel and edgeto-face orientations. Overall, hydrated imidazole molecules are the most probable structural motif in aqueous solutions, with very few direct imidazole-imidazole interactions.

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Section: Imidazole-water Interactionssupporting

confidence: 91%

Hydrophilic and hydrophobic interactions in concentrated aqueous imidazole solutions: a neutron diffraction and total X-ray scattering study

Al-Madhagi

Callear

Schroeder

2020

Phys. Chem. Chem. Phys.

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“…1 In agreement with the MD previous study, pyrrolic nitrogen is a single and strong hydrogen bond donor (Figure 5a), with a maximum N· · · O distance distribution at 2.82 Å. Pyridinic group has a hydrogen bond distance distribution more intense around a maximum again at 2.82 Å whereas bond angle distribution is broader (Figure 5b). 1 In agreement with the MD previous study, pyrrolic nitrogen is a single and strong hydrogen bond donor (Figure 5a), with a maximum N· · · O distance distribution at 2.82 Å. Pyridinic group has a hydrogen bond distance distribution more intense around a maximum again at 2.82 Å whereas bond angle distribution is broader (Figure 5b).…”

Section: Acs Paragon Plus Environmentsupporting

confidence: 91%

“…It means that vibrational motions are not critical in determining the mean geometry of the molecule and this is expected for a rigid system like pyrazole. 1 Next we analyse PYR(20 K) and PYR(300 K) frequencies (Tables 2 and 3). On the other hand, mean geometry is not significantly changed also at room temperature, PYR (300 K), although the estimated errors on bond distances are higher.…”

Section: Ab Initio Molecular Dynamics Resultsmentioning

confidence: 99%

“…Such a comparative approach results particularly useful for molecules with vibrational modes quite easy to observe and assign in the different phases, as for example carbonyl stretching. 1 We expect therefore that also its vibrational properties could be sensitive to the solvent. Theoretical and computational approaches can be a valuable help for the understanding and the rationalization of these effects since they provide a direct correlation between structural and spectroscopic properties.…”

Section: Introductionmentioning

confidence: 99%

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Vibrational Spectra of Water Solutions of Azoles from QM/MM Calculations: Effects of Solvation

2012

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Using microsolvation models and mixed quantum/classical ab initio molecular dynamics simulations, we investigate the vibrational properties of two azoles in water solution: pyrazole and oxazole. The effects of the water-azole hydrogen bonding are rationalized by an extensive comparison between structural parameters and harmonic frequencies obtained by microsolvation models. Following the effective normal-mode analysis introduced by Martinez et al. [Martinez et al., J. Chem. Phys. 2006, 125, 144106], we identify the vibrational frequencies of the solutes using the decomposition of the vibrational density of states of the gas phase and solution dynamics. The calculated shifts from gas phase to solution are fairly in agreement with the available experimental data.

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“…Recent findings suggest that the biological effects of hydrogen peroxide (HP) are actually mediated by hydrogen-bonded complexes of HP and molecules of biological interest. In the last decade, several studies − had been conducted to describe the energetic and structural properties of hydrogen-bonded complexes of azoles.…”

Section: Introductionmentioning

confidence: 99%

Nature and Hierarchy of Hydrogen-Bonding Interactions in Binary Complexes of Azoles with Water and Hydrogen Peroxide

2018

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In the present study, the hydrogen-bonded complexes of azole with water and hydrogen peroxide are systematically investigated by second-order Møller–Plesset perturbation theory and density functional theory with dispersion function calculations. This study suggests that the ability of pyrrolic nitrogen (NH) atom to function as hydrogen-bond donor increases with the introduction of nitrogen atoms in the ring, whereas the ability of pyridinic nitrogen (N) atom to act as hydrogen-bond acceptor reduces with successive aza substitution in the ring. With introduction of nitrogen atoms in the ring, the vibrational frequency, stabilization energy, and electron density in the σ antibonding orbitals of the X–H (X = N, C of azole) bond of the complexes all increase or decrease systematically. Decomposition analysis of total stabilization energy showed that the electrostatic energy term is a dominant attractive contribution in comparison to induction and dispersion terms in all of the complexes under study.

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Hydration of diazoles in water solution: pyrazole. A theoretical and X-ray diffraction study

Cited by 8 publications

References 38 publications

Hydrophilic and hydrophobic interactions in concentrated aqueous imidazole solutions: a neutron diffraction and total X-ray scattering study

Hydrophilic and hydrophobic interactions in concentrated aqueous imidazole solutions: a neutron diffraction and total X-ray scattering study

Vibrational Spectra of Water Solutions of Azoles from QM/MM Calculations: Effects of Solvation

Nature and Hierarchy of Hydrogen-Bonding Interactions in Binary Complexes of Azoles with Water and Hydrogen Peroxide

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