Dissecting intermolecular interactions in the condensed phase of ibuprofen and related compounds: the specific role and quantification of hydrogen bonding and dispersion forces

Emel′yanenko, Vladimir N.; Stange, Peter; Feder‐Kubis, Joanna; Verevkin, Sergey P.; Ludwig, Ralf

doi:10.1039/c9cp06641a

Cited by 18 publications

(24 citation statements)

References 76 publications

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“…The estimated values of the energies calculated for the dimers of 3 and 4 correlated well with the energies reported for similar systems. For example, according to the experimental temperature-dependent attenuated total reflection (ATR) IR studies of ibuprofen by Ludwig et al [ 76 ], the enthalpy of the transition between doubly H-bonded cyclic dimers to singly H-bonded linear dimers is equal to −5.07 kcal/mol. The binding energy of a p -biphthalate dimer obtained at the B3LYP/6-31+G* approximation is about 12.4 kcal/mol (6.2 kcal/mol per one hydrogen bond) [ 77 ].…”

Section: Resultsmentioning

confidence: 99%

Inter- vs. Intramolecular Hydrogen Bond Patterns and Proton Dynamics in Nitrophthalic Acid Associates

et al. 2020

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Noncovalent interactions are among the main tools of molecular engineering. Rational molecular design requires knowledge about a result of interplay between given structural moieties within a given phase state. We herein report a study of intra- and intermolecular interactions of 3-nitrophthalic and 4-nitrophthalic acids in the gas, liquid, and solid phases. A combination of the Infrared, Raman, Nuclear Magnetic Resonance, and Incoherent Inelastic Neutron Scattering spectroscopies and the Car–Parrinello Molecular Dynamics and Density Functional Theory calculations was used. This integrated approach made it possible to assess the balance of repulsive and attractive intramolecular interactions between adjacent carboxyl groups as well as to study the dependence of this balance on steric confinement and the effect of this balance on intermolecular interactions of the carboxyl groups.

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Section: Resultsmentioning

confidence: 99%

Inter- vs. Intramolecular Hydrogen Bond Patterns and Proton Dynamics in Nitrophthalic Acid Associates

et al. 2020

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“…Intermolecular hydrogen bonds (H‐bonds) are of paramount importance in supramolecular chemistry, 1,2 crystal engineering 3 and biochemistry 4 . These noncovalent interactions have been intensively studied by various theoretical and experimental techniques 5–8 : ab initio calculations, 9,10 molecular dynamic modeling, 11 quantum mechanics/molecular mechanics calculations, 12 NMR and IR spectroscopy, 13–15 X‐Ray and neutron diffraction 16–18 and thermochemical experiments 19 . Among theoretical approaches, the electron density 7,20–23 and energy decomposition analyses 7,24 are gaining considerable popularity in the studies of H‐bonds in the isolated state, 25,26 solution 27 and solid state 28,29 .…”

Section: Introductionmentioning

confidence: 99%

The explicit role of electron exchange in the hydrogen bonded molecular complexes

2021

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We applied a set of advanced bonding descriptors to establish the hidden electron density features and binding energy characteristics of intermolecular D HÁÁÁA hydrogen bonds (O HÁÁÁO, N HÁÁÁO and S HÁÁÁO) in 150 isolated and solvated molecular complexes. The exchange-correlation and Pauli potentials as well as corresponding local one-electron forces allowed us to explicitly ascertain how electron exchange defines the bonding picture in the proximity of the H-bond critical point. The electron density features of D HÁÁÁA interaction are governed by alterations in the electron localization in the H-bond region displaying itself in the exchange hole. At that, they do not depend on the variations in the exchange hole mobility. The electrostatic interaction mainly defines the energy of H-bonds of different types, whereas the strengthening/weakening of H-bonds in complexes with varying substituents depends on the barrier height of the exchange potential near the bond critical point. Energy variations between H-bonds in isolated and solvated systems are also caused the electron exchange peculiarities as follows from the corresponding potential and the interacting quantum atom analyses complemented by electron delocalization index calculations. Our approach is based on the bonding descriptors associated with the characteristics of the observable electron density and can be recommended for in-depth studies of non-covalent bonding. K E Y W O R D S electron density, hydrogen bond, IQA, potential acting on an electron in a molecule, QM/MM, QTAIM, source function 1 | INTRODUCTION Intermolecular hydrogen bonds (H-bonds) are of paramount importance in supramolecular chemistry, 1,2 crystal engineering 3 and biochemistry. 4 These noncovalent interactions have been intensively studied by various theoretical and experimental techniques 5-8 : ab initio calculations, 9,10 molecular dynamic modeling, 11 quantum mechanics/molecular mechanics calculations, 12 NMR and IR spectroscopy, 13-15 X-Ray and neutron diffraction 16-18 and thermochemical experiments. 19 Among theoretical approaches, the electron density 7,20-23 and energy decomposition analyses 7,24 are gaining considerable popularity in the studies of H-bonds in the isolated state, 25,26 solution 27 and solid state. 28,29 Lest us consider some of them shortly. The non-local density-based descriptors 30-36 carry information about the mutual influence of electrons in spatially remote regions and detect subtle effects in chemical bonding. The source function (SF) 30,31 reveals the role of atoms, defined in terms of QTAIM, 37 in formation of H-bonds. 30 It is successfully used for classification of the H-bonds and other noncovalent interactions 38,39 as well as for identification of molecular parts having the greatest impact on the electron density along the H-bonds. 40 The electron delocalization indices (DI) characterize the extent of electron-pair sharing between atoms 41 and measure the H-bond covalency. 7,42-45

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“…Recent studies explain dimerization and liquid/gas phase transition of ibuprofen and related compounds on the basis of hydrogen bonding and dispersion forces. 35 On the other hand, in the positive ion mode, water adducts were observed for the tested NSAIDs (m/z 224.5 for ibuprofen, m/z 272.5 for ketoprofen), as it has been recently described in a different plasma source (FAPA ionization). 36 Additionally, fragmentation is observed for ibuprofen and ketoprofen (m/z 161.4, m/z 463.6).…”

Section: ■ Results and Discussionmentioning

confidence: 69%

“…At the same concentration level, in the positive ion mode, protonated quasi-molecules ( m / z 207.5) are the most abundant species, whereas in the negative ion mode, dimers ( m / z 411.6) are preferably detected. Recent studies explain dimerization and liquid/gas phase transition of ibuprofen and related compounds on the basis of hydrogen bonding and dispersion forces …”

Section: Resultsmentioning

confidence: 99%

Detection and Evaluation of Lipid Classes and Other Hydrophobic Compounds Using a Laser Desorption/Plasma Ionization Interface

et al. 2020

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Ionization mechanisms of different lipid classes and other hydrophobic compounds have been evaluated in an ambient air laser-desorption flexible microtube plasma ionization (LD-FμTPi) setup, without sample manipulation. Lipids require a minimum laser fluency of 27 W/mm2 for efficient desorption and detection, providing the possibility for temperature-programmed laser desorption of different lipid classes. The flexible microtube plasma (FμTP) produces oxygen addition to double bonds, even to polyunsaturated molecules. The characteristic fragmentation pattern of phospholipids consisting of the neutral loss of the phosphocholine head group was verified. The formation of dimers due to hydrogen bonding and dispersion forces was observed as well. In this sense, soft ionization capabilities of the FμTP were proven in both ion modes. Ambient air mass spectrometry methods often suffer from decreased reproducibility, for instance, due to changing atmospheric conditions or sensitive positioning of the ion source. It was shown that neutrals become increasingly unstable above a distance of 7 ± 1 mm to the spectrometer’s inlet, providing estimates for the free volume in LD-FμTPi MS. In this sense, no guided transport is required. The ion plume ejected from the plasma can be altered by applying a bias voltage to the copper substrate. Ions can be detected at −950 V, 300 V (negative ion mode) and −400 V, 900 V (positive ion mode), respectively. The ions are guided through an internal electric field gradient of the FμTP that arises from charged capillary walls, ideal for ion detection. In conclusion, this makes the method fast, robust, and flexible.

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Dissecting intermolecular interactions in the condensed phase of ibuprofen and related compounds: the specific role and quantification of hydrogen bonding and dispersion forces

Abstract: Hydrogen bonding and dispersion interaction in liquid ibuprofen is analyzed by thermodynamic methods, infrared spectroscopy and quantum chemistry.

Cited by 18 publications

References 76 publications

Inter- vs. Intramolecular Hydrogen Bond Patterns and Proton Dynamics in Nitrophthalic Acid Associates

Inter- vs. Intramolecular Hydrogen Bond Patterns and Proton Dynamics in Nitrophthalic Acid Associates

The explicit role of electron exchange in the hydrogen bonded molecular complexes

Detection and Evaluation of Lipid Classes and Other Hydrophobic Compounds Using a Laser Desorption/Plasma Ionization Interface

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