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Knapkiewicz M, Jankowska I, Swiergiel J, Tritt-Goc J. Evidence for NMR Relaxation Enhancement in a Protic Ionic Liquid by the Movement of Protons Independent of the Translational Diffusion of Cations. J Phys Chem B 2024; 128:6876-6884. [PMID: 38968545 PMCID: PMC11264263 DOI: 10.1021/acs.jpcb.4c02497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2024] [Revised: 06/10/2024] [Accepted: 06/28/2024] [Indexed: 07/07/2024]
Abstract
The molecular dynamics, thermal stability, and ionic conductivity were studied in the protic ionic liquid 1-methylimidazolium bis(trifluoromethylsulfonyl)imide ([MIm][TFSI]). The relaxation of the 1H spin-lattice of cations in the measured frequency range (10 kHz to 20 MHz) and temperature (298 to 343 K) is sensitive mainly to slow processes occurring in the molecular dynamics of protic ionic liquid and dominated by the contribution of intermolecular translational diffusion. Molecular rotations give only a constant contribution and become significant in the higher frequency range. An interesting feature is the observed enhancement of the 1H spin-lattice relaxation below 0.03 MHz attributed to the exchange of protons (order of 10-5 s) between imidazolium cations. The measurements of the self-diffusion coefficient of hydrogen atoms of cation from 298 to 343 K additionally confirm the observed phenomenon. The coefficient for exchangeable protons -NH is higher than for the cation. The nuclear magnetic resonance (NMR) experiments provide unambiguous evidence for proton transport decoupled from molecular diffusion of ions and support the conclusion that the charge transport mechanism in the studied PIL includes contributions from both the vehicular and Grotthus mechanisms. The protic ionic liquid is thermally stable to about 573 K as shown by thermogravimetric analysis and its electrical conductivity is 5 × 10-2 S/cm at 423 K.
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Affiliation(s)
- Magdalena Knapkiewicz
- Institute of Molecular Physics, Polish Academy of Sciences, M. Smoluchowskiego 17, Poznań 60-179, Poland
| | - Iga Jankowska
- Institute of Molecular Physics, Polish Academy of Sciences, M. Smoluchowskiego 17, Poznań 60-179, Poland
| | - Jolanta Swiergiel
- Institute of Molecular Physics, Polish Academy of Sciences, M. Smoluchowskiego 17, Poznań 60-179, Poland
| | - Jadwiga Tritt-Goc
- Institute of Molecular Physics, Polish Academy of Sciences, M. Smoluchowskiego 17, Poznań 60-179, Poland
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2
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Wang M, Wang Y. Advances for Triangular and Sandwich-Shaped All-Metal Aromatics. Molecules 2024; 29:763. [PMID: 38398515 PMCID: PMC10892378 DOI: 10.3390/molecules29040763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2023] [Revised: 01/19/2024] [Accepted: 01/26/2024] [Indexed: 02/25/2024] Open
Abstract
Much experimental work has been contributed to all-metal σ, π and δ-aromaticity among transition metals, semimetallics and other metals in the past two decades. Before our focused investigations on the properties of triangular and sandwich-shaped all-metal aromatics, A. I. Boldyrev presented general discussions on the concepts of all-metal σ-aromaticity and σ-antiaromaticity for metallo-clusters. Schleyer illustrated that Nucleus-Independent Chemical Shifts (NICS) were among the most authoritative criteria for aromaticity. Ugalde discussed the earlier developments of all-metal aromatic compounds with all possible shapes. Besides the theoretical predictions, many stable all-metal aromatic trinuclear clusters have been isolated as the metallic analogues of either the σ-aromatic molecule's [H3]+ ion or the π-aromatic molecule's [C3H3]+ ion. Different from Hoffman's opinion on all-metal aromaticity, triangular all-metal aromatics were found to hold great potential in applications in coordination chemistry, catalysis, and material science. Triangular all-metal aromatics, which were theoretically proved to conform to the Hückel (4n + 2) rule and possess the smallest aromatic ring, could also play roles as stable ligands during the formation of all-metal sandwiches. The triangular and sandwich-shaped all-metal aromatics have not yet been specifically summarized despite their diversity of existence, puissant developments and various interesting applications. These findings are different from the public opinion that all-metal aromatics would be limited to further applications due to their overstated difficulties in synthesis and uncertain stabilities. Our review will specifically focus on the summarization of theoretical predictions, feasible syntheses and isolations, and multiple applications of triangular and sandwich shaped all-metal aromatics. The appropriateness and necessities of this review will emphasize and disseminate their importance and applications forcefully and in a timely manner.
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Affiliation(s)
| | - Yanlan Wang
- Department of Chemistry and Chemical Engineering, Shandong Provincial Key Laboratory of Chemical Energy Storage and Novel Cell Technology, Liaocheng University, Liaocheng 252059, China;
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3
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Naz A, Asif S, Alwutayd KM, Sarfaraz S, Abbasi SW, Abbasi A, Alenazi AM, Hasan ME. Repurposing FIASMAs against Acid Sphingomyelinase for COVID-19: A Computational Molecular Docking and Dynamic Simulation Approach. Molecules 2023; 28:molecules28072989. [PMID: 37049752 PMCID: PMC10096053 DOI: 10.3390/molecules28072989] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 03/16/2023] [Accepted: 03/24/2023] [Indexed: 03/30/2023] Open
Abstract
Over the past few years, COVID-19 has caused widespread suffering worldwide. There is great research potential in this domain and it is also necessary. The main objective of this study was to identify potential inhibitors against acid sphingomyelinase (ASM) in order to prevent coronavirus infection. Experimental studies revealed that SARS-CoV-2 causes activation of the acid sphingomyelinase/ceramide pathway, which in turn facilitates the viral entry into the cells. The objective was to inhibit acid sphingomyelinase activity in order to prevent the cells from SARS-CoV-2 infection. Previous studies have reported functional inhibitors against ASM (FIASMAs). These inhibitors can be exploited to block the entry of SARS-CoV-2 into the cells. To achieve our objective, a drug library containing 257 functional inhibitors of ASM was constructed. Computational molecular docking was applied to dock the library against the target protein (PDB: 5I81). The potential binding site of the target protein was identified through structural alignment with the known binding pocket of a protein with a similar function. AutoDock Vina was used to carry out the docking steps. The docking results were analyzed and the inhibitors were screened based on their binding affinity scores and ADME properties. Among the 257 functional inhibitors, Dutasteride, Cepharanthine, and Zafirlukast presented the lowest binding affinity scores of −9.7, −9.6, and −9.5 kcal/mol, respectively. Furthermore, computational ADME analysis of these results revealed Cepharanthine and Zafirlukast to have non-toxic properties. To further validate these findings, the top two inhibitors in complex with the target protein were subjected to molecular dynamic simulations at 100 ns. The molecular interactions and stability of these compounds revealed that these inhibitors could be a promising tool for inhibiting SARS-CoV-2 infection.
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Affiliation(s)
- Aliza Naz
- National Center for Bioinformatics, Quaid-i-Azam University, Islamabad 45320, Pakistan
- Department of Bioinformatics and Biotechnology, International Islamic University, Islamabad 44000, Pakistan
| | - Sumbul Asif
- Department of Bioinformatics and Biotechnology, International Islamic University, Islamabad 44000, Pakistan
- School of Interdisciplinary Engineering and Sciences, National University of Sciences and Technology, Islamabad 44000, Pakistan
| | - Khairiah Mubarak Alwutayd
- Department of Biology, College of Science, Princess Nourah bint Abdulrahman University, P.O. Box 84428, Riyadh 11671, Saudi Arabia
| | - Sara Sarfaraz
- Department of Bioinformatics, Kohsar University Murree, Murree 47150, Pakistan
- Correspondence:
| | - Sumra Wajid Abbasi
- Department of Biological Sciences, National University of Medical Sciences, Rawalpindi 46000, Pakistan
| | - Asim Abbasi
- Department of Environmental Sciences, Kohsar University Murree, Murree 47150, Pakistan
| | - Abdulkareem M. Alenazi
- Pediatric Senior Registrar, King Salman Armed Forces Hospital in Northwestern Region (KSAFH), Tabuk 47512, Saudi Arabia
| | - Mohamed E. Hasan
- Bioinformatic Department, Genetic Engineering and Biotechnology Research Institute, University of Sadat City, Sadat City 32897, Egypt
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Al-Sheakh L, Fritsch S, Appelhagen A, Villinger A, Ludwig R. Thermodynamically Stable Cationic Dimers in Carboxyl-Functionalized Ionic Liquids: The Paradoxical Case of "Anti-Electrostatic" Hydrogen Bonding. Molecules 2022; 27:molecules27020366. [PMID: 35056680 PMCID: PMC8778807 DOI: 10.3390/molecules27020366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 12/28/2021] [Accepted: 01/03/2022] [Indexed: 11/18/2022] Open
Abstract
We show that carboxyl-functionalized ionic liquids (ILs) form doubly hydrogen-bonded cationic dimers (c+=c+) despite the repulsive forces between ions of like charge and competing hydrogen bonds between cation and anion (c+–a−). This structural motif as known for formic acid, the archetype of double hydrogen bridges, is present in the solid state of the IL 1−(carboxymethyl)pyridinium bis(trifluoromethylsulfonyl)imide [HOOC−CH2−py][NTf2]. By means of quantum chemical calculations, we explored different hydrogen-bonded isomers of neutral (HOOC–(CH2)n–py+)2(NTf2−)2, single-charged (HOOC–(CH2)n–py+)2(NTf2−), and double-charged (HOOC– (CH2)n−py+)2 complexes for demonstrating the paradoxical case of “anti-electrostatic” hydrogen bonding (AEHB) between ions of like charge. For the pure doubly hydrogen-bonded cationic dimers (HOOC– (CH2)n−py+)2, we report robust kinetic stability for n = 1–4. At n = 5, hydrogen bonding and dispersion fully compensate for the repulsive Coulomb forces between the cations, allowing for the quantification of the two equivalent hydrogen bonds and dispersion interaction in the order of 58.5 and 11 kJmol−1, respectively. For n = 6–8, we calculated negative free energies for temperatures below 47, 80, and 114 K, respectively. Quantum cluster equilibrium (QCE) theory predicts the equilibria between cationic monomers and dimers by considering the intermolecular interaction between the species, leading to thermodynamic stability at even higher temperatures. We rationalize the H-bond characteristics of the cationic dimers by the natural bond orbital (NBO) approach, emphasizing the strong correlation between NBO-based and spectroscopic descriptors, such as NMR chemical shifts and vibrational frequencies.
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Affiliation(s)
- Loai Al-Sheakh
- Institut für Chemie, Abteilung für Physikalische Chemie, Universität Rostock, Dr.-Lorenz-Weg 2, 18059 Rostock, Germany; (L.A.-S.); (S.F.); (A.A.)
| | - Sebastian Fritsch
- Institut für Chemie, Abteilung für Physikalische Chemie, Universität Rostock, Dr.-Lorenz-Weg 2, 18059 Rostock, Germany; (L.A.-S.); (S.F.); (A.A.)
| | - Andreas Appelhagen
- Institut für Chemie, Abteilung für Physikalische Chemie, Universität Rostock, Dr.-Lorenz-Weg 2, 18059 Rostock, Germany; (L.A.-S.); (S.F.); (A.A.)
| | - Alexander Villinger
- Institut für Chemie, Abteilung für Anorganische Chemie, Universität Rostock, Albert-Einstein-Str. 3a, 18059 Rostock, Germany;
| | - Ralf Ludwig
- Institut für Chemie, Abteilung für Physikalische Chemie, Universität Rostock, Dr.-Lorenz-Weg 2, 18059 Rostock, Germany; (L.A.-S.); (S.F.); (A.A.)
- Department LL&M, University of Rostock, Albert-Einstein−Str. 25, 18059 Rostock, Germany
- Leibniz−Institut für Katalyse an der Universität Rostock e.V., Albert-Einstein−Str. 29a, 18059 Rostock, Germany
- Correspondence:
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Chen L, Feng Q, Wang C, Yin S, Mo Y. Classical Electrostatics Remains the Driving Force for Interanion Hydrogen and Halogen Bonding. J Phys Chem A 2021; 125:10428-10438. [PMID: 34818021 DOI: 10.1021/acs.jpca.1c09250] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Interanion hydrogen bonding (IAHB) and halogen bonding (IAXB) have emerged as a counterintuitive linker in a range of fascinating applications. Despite the overall repulsive (positive) binding energy, anions are trapped in a local minimum with its corresponding transition state (TS) preventing dissociation. In other words, the adduct of anions is metastable. Seemingly, the electrostatic paradigm and force field description of hydrogen/halogen bonding (HB/XB) are challenged, because of the preconceived Coulombic repulsion. Aiming at an insightful understanding of these interanion phenomena, we employed the energy decomposition approach based on the block-localized wavefunction method (BLW-ED) to investigate a series of exemplary interanion complexes. As expected, the key distinction from the conventional HB/XB lies in the electrostatic interaction, which is not increasingly repulsive as anions gradually approach to each other. Rather, there is a Coulombic barrier at a certain point. After this point, the electrostatic repulsion diminishes with the decreasing distance between anions. Differently, other energy components vary monotonically just like in conventional cases. The nonmonotonic characteristic of the electrostatic interaction in interanion complexes was reproduced using the multipole expansion in AMOEBA polarizable force field in which the state-specified atomic multipoles were adopted. This suggests that the nonmonotonicity can be well interpreted by classical electrostatic theory and there is no conceptual difference between conventional HB/XB and IAHB/IAXB. The stability of IAHB/IAXB depends on the competition between the local attractive HB/XB and the global Coulombic repulsion of net charges, though there is cooperativity between these two contrasting forces. This concise model was supported by the attractive IAHB/IAXB in modified molecular capsules, which exhibit strong quadruple HB/XBs and a considerable distance between charged substituents.
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Affiliation(s)
- Li Chen
- Key Laboratory for Macromolecular Science of Shaanxi Province, School of Chemistry & Chemical Engineering, Shaanxi Normal University, Xi'an 710119, China
| | - Qiuyan Feng
- Key Laboratory for Macromolecular Science of Shaanxi Province, School of Chemistry & Chemical Engineering, Shaanxi Normal University, Xi'an 710119, China
| | - Changwei Wang
- Key Laboratory for Macromolecular Science of Shaanxi Province, School of Chemistry & Chemical Engineering, Shaanxi Normal University, Xi'an 710119, China
| | - Shiwei Yin
- Key Laboratory for Macromolecular Science of Shaanxi Province, School of Chemistry & Chemical Engineering, Shaanxi Normal University, Xi'an 710119, China
| | - Yirong Mo
- Department of Nanoscience, Joint School of Nanoscience and Nanoengineering, University of North Carolina at Greensboro, Greensboro, North Carolina 27401, United States
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6
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Ludwig R. Towards thermodynamically stable anionic dimers with “anti-electrostatic” hydrogen bonds overcoming like-charge repulsion. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2021.116882] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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7
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Canbulat Özdemir M, Aktan E, Şahin O. The association of like-charged ions in tunable protic pyrazolium salts. J Mol Struct 2021. [DOI: 10.1016/j.molstruc.2021.130684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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8
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Jenepha Mary SJ, Pradhan S, James C. Molecular structure, NBO analysis of the hydrogen-bonded interactions, spectroscopic (FT-IR, FT-Raman), drug likeness and molecular docking of the novel anti COVID-2 molecule (2E)-N-methyl-2-[(4-oxo-4H-chromen-3-yl)methylidene]-hydrazinecarbothioamide (Dimer) - quantum chemical approach. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2021; 251:119388. [PMID: 33503560 PMCID: PMC7834302 DOI: 10.1016/j.saa.2020.119388] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2020] [Revised: 12/04/2020] [Accepted: 12/24/2020] [Indexed: 05/14/2023]
Abstract
Prospective antiviral molecule (2E)-N-methyl-2-[(4-oxo-4H-chromen-3-yl)methylidene]-hydrazinecarbothioamide has been probed using Fourier transform infrared (FTIR), FT-Raman and quantum chemical computations. The geometry equilibrium and natural bond orbital analysis have been carried out with density functional theory employing Becke, 3-parameter, Lee-Yang-Parr method with the 6-311G++(d,p) basis set. The vibrational assignments pertaining to different modes of vibrations have been augmented by normal coordinate analysis, force constant and potential energy distributions. Drug likeness and oral activity have been carried out based on Lipinski's rule of five. The inhibiting potency of 2(2E)-methyl-2-[(4-oxo-4H-chromen-3-yl)methylidene]-hydrazinecarbothioamide has been investigated by docking simulation against SARS-CoV-2 protein. The optimized geometry shows a planar structure between the chromone and the side chain. Differences in the geometries due to the substitution of the electronegative atom and intermolecular contacts due to the chromone and hydrazinecarbothioamide were analyzed. NBO analysis confirms the presence of two strong stable hydrogen bonded NH⋯O intermolecular interactions and two weak hydrogen bonded CH⋯O interactions. The red shift in NH stretching frequency exposed from IR substantiates the formation of NH⋯O intermolecular hydrogen bond and the blue shift in CH stretching frequency substantiates the formation of CH⋯O intermolecular hydrogen bond. Drug likeness, absorption, distribution, metabolism, excretion and toxicity property gives an idea about the pharmacokinetic properties of the title molecule. The binding energy of the nonbonding interaction with Histidine 41 and Cysteine 145, present a clear view that 2(2E)-methyl-2-[(4-oxo-4H-chromen-3-yl)methylidene]-hydrazinecarbothioamide can irreversibly interact with SARS-CoV-2 protease.
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Affiliation(s)
- S J Jenepha Mary
- Department of Physics and Research Centre, Scott Christian College (Autonomous), Nagercoil 629003, Tamil Nadu, Affiliated to Manonmaniam Sundarnar University, Abishekapatti, Tirunelveli 627012, India
| | - Sayantan Pradhan
- Department of Chemistry, Jadavpur University, Kolkata 700 032, West Bengal, India
| | - C James
- Department of Physics and Research Centre, Scott Christian College (Autonomous), Nagercoil 629003, Tamil Nadu, Affiliated to Manonmaniam Sundarnar University, Abishekapatti, Tirunelveli 627012, India.
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9
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Chen J, Dong K, Liu L, Zhang X, Zhang S. Anti-electrostatic hydrogen bonding between anions of ionic liquids: a density functional theory study. Phys Chem Chem Phys 2021; 23:7426-7433. [PMID: 33876102 DOI: 10.1039/d0cp06718k] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Hydrogen bonds (HBs) play a crucial role in the physicochemical properties of ionic liquids (ILs). To date, HBs between cations and anions (Ca-An) or between cations (Ca-Ca) in ILs have been reported extensively. Here, we provided DFT evidence for the existence of HBs between anions (An-An) in the IL 1-(2-hydroxyethyl)-3-methylimidazolium 4-(2-hydroxyethyl)imidazolide [HEMIm][HEIm]. The thermodynamic stabilities of anionic, cationic, and H2O dimers together with ionic pairs were studied using potential energy scans. The results show that the cation-anion pair is the most stable one, while the HB in the anionic dimer possesses similar thermodynamic stability to the water dimer. The further geometric, spectral and electronic structure analyses demonstrate that the inter-anionic HB meets the general theoretical criteria of traditional HBs. The strength order of four HBs in complexes is cation-anion pair > H2O dimer ≈ cationic dimer > anionic dimer. The energy decomposition analysis indicates that induction and dispersion interactions are the crucial factors to overcome strong Coulomb repulsions, forming inter-anionic HBs. Finally, the presence of inter-anionic HBs in the ionic cluster has been confirmed by a global minimum search for a system containing two ionic pairs. Even though hydroxyl-functionalized cations are more likely to form HBs with anions, there are still inter-anionic HBs between hydroxyl groups in the low-lying structures. Our studies broaden the understanding of HBs in ionic liquids and support the recently proposed concept of anti-electrostatic HBs.
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Affiliation(s)
- Junwu Chen
- Beijing Key Laboratory of Ionic Liquids Clean Process, CAS Key Laboratory of Green Process and Engineering, State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, P. R. China.
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10
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Itoh Y, Kurohara T, Suzuki T. N<sup>+</sup>-C-H…O Hydrogen Bonds in Protein-Ligand Complexes and their Application to Drug Design. J SYN ORG CHEM JPN 2020. [DOI: 10.5059/yukigoseikyokaishi.78.1151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
| | | | - Takayoshi Suzuki
- The Institute of Scientific and Industrial Research, Osaka University
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11
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Quiñonero D, Alkorta I, Elguero J. Metastable Dianions and Dications. Chemphyschem 2020; 21:1597-1607. [PMID: 32314864 DOI: 10.1002/cphc.202000172] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2020] [Revised: 04/13/2020] [Indexed: 12/17/2022]
Abstract
A theoretical study of metastable dianions and dications has been carried out at the CCSD(T)//MP2 level. MX3 2- and LX4 2- (M=Li and Na, L=Be and Mg, X=F and Cl) have been considered as dianions, M3 X2+ (M=Li and Na, X=F and Cl), YH3 2+ and ZH4 2+ (Y=F and Cl and Z=O, S) as dications. Minima structures are found in all cases, but they are less stable than the corresponding dissociated pair of mono-ions. The dissociation profile of the molecules in two mono-ions has been explored showing in all cases a maximum that prevent their spontaneous dissociation. The strength and nature of the chemical bond in the dianions and dications have been analyzed with the QTAIM, NBO and LMOEDA method and compared to the corresponding monoanions and monocations.
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Affiliation(s)
- David Quiñonero
- Departament de Química, Universitat de les Illes Balears, Crta. de Valldemossa km 7.5, 07122, Palma de Mallorca, Spain
| | - Ibon Alkorta
- Instituto de Química Médica (CSIC), Juan de la Cierva, 3. 28006, Madrid, Spain
| | - Jose Elguero
- Instituto de Química Médica (CSIC), Juan de la Cierva, 3. 28006, Madrid, Spain
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12
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Intermolecular Interactions in Ionic Crystals of Nucleobase Chlorides—Combining Topological Analysis of Electron Densities with Energies of Electrostatic Interactions. CRYSTALS 2019. [DOI: 10.3390/cryst9120668] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Understanding intermolecular interactions in crystals of molecular ions continues to be difficult. On the one hand, the analysis of interactions from the point of view of formal charges of molecules, similarly as it is commonly done for inorganic ionic crystals, should be performed. On the other hand, when various functional groups are present in the crystal, it becomes natural to look at the interactions from the point of view of hydrogen bonding, π…π stacking and many other kinds of non-covalent atom–atom bonding. Often, these two approaches seem to lead to conflicting conclusions. On the basis of experimental charge densities of cytosinium chloride, adeninium chloride hemihydrate, and guanine dichloride crystals, with the help of theoretical simulations, we have deeply analysed intermolecular interactions among protonated nucleobases, chloride anions and water molecules. Here, in the second paper of the series of the two (Kumar et al., 2018, IUCrJ 5, 449–469), we focus on applying the above two approaches to the large set of dimers identified in analysed crystals. To understand electrostatic interactions, we analysed electrostatic interaction energies (Ees) computed directly from molecular charge densities and contrasted them with energies computed only from net molecular charges, or from a sum of electric multipolar moments, to find the charge penetration contribution to Ees. To characterize non-covalent interactions we performed topological analyses of crystal electron densities and estimated their interaction energies (EEML) from properties of intermolecular bond critical points. We show that the overall crystal architecture of the studied compounds is governed by the tight packing principle and strong electrostatic attractions and repulsions between ions. Many ions are oriented to each other in a way to strengthen attractive electrostatic interactions or weaken strong repulsion, but not all of them. Numerous bond critical points and bond paths were found between ions, including nucleobase cations despite their overall repulsive interactions. It is clear there is no correlation between EEML and Ees. However, strong relation between EEML and the charge penetration component of Ees is observed. The relation holds regardless of interaction types or whether or not interacting molecules bear the same or opposite charges. Thus, a charge density-based approach for computing intermolecular interaction energies and the atom–atom approach to analyse non-covalent interactions do complement each other, even in ionic systems.
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13
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Grabowski SJ, Casanova D, Formoso E, Ugalde JM. Tetravalent Oxygen and Sulphur Centres Mediated by Carborane Superacid: Theoretical Analysis. Chemphyschem 2019; 20:2443-2450. [PMID: 31411374 DOI: 10.1002/cphc.201900687] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 08/09/2019] [Indexed: 11/09/2022]
Abstract
The tetravalent oxygen or sulphur centres, especially in H4 O2+ and H4 S2+ dications, were analysed experimentally and theoretically in various studies. Herein, we discuss stabilities of such centres in related H(CH3 )3 O2+ and H(CH3 )3 S2+ dications mediated by carborane superacid. The ωB97X-D/6-311++G(d,p) calculations were performed for a gas phase and for different solvents characterized by a wide range of dielectric constants for complexes of these dications with the conjugated base of H(CHB11 F11 ) carborane superacid, CHB11 F11 - , which indicate that these complexes are linked by hydrogen bonds. The Quantum Theory of 'Atoms in Molecules' (QTAIM) approach is applied to characterize these interactions. DFT results show that tetravalent oxygen and sulphur structures are additionally stabilized by polar solvents.
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Affiliation(s)
- Sławomir J Grabowski
- Kimika Fakultatea, Euskal Herriko Unibertsitatea (UPV/EHU), P.K. 1072, 20080, Donostia, Euskadi, Spain.,Donostia International Physics Center (DIPC), 20018, Donostia, Euskadi, Spain.,IKERBASQUE, Basque Foundation for Science, 48011, Bilbo, Euskadi, Spain
| | - David Casanova
- Donostia International Physics Center (DIPC), 20018, Donostia, Euskadi, Spain.,IKERBASQUE, Basque Foundation for Science, 48011, Bilbo, Euskadi, Spain
| | - Elena Formoso
- Donostia International Physics Center (DIPC), 20018, Donostia, Euskadi, Spain.,Farmazia Fakultatea, Euskal Herriko Unibertsitatea (UPV/EHU), 01006, Vitoria-Gasteiz, Euskaldi, Spain
| | - Jesus M Ugalde
- Kimika Fakultatea, Euskal Herriko Unibertsitatea (UPV/EHU), P.K. 1072, 20080, Donostia, Euskadi, Spain.,Donostia International Physics Center (DIPC), 20018, Donostia, Euskadi, Spain
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14
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Pike SJ, Lavagnini E, Varley LM, Cook JL, Hunter CA. H-Bond donor parameters for cations. Chem Sci 2019; 10:5943-5951. [PMID: 31360400 PMCID: PMC6566073 DOI: 10.1039/c9sc00721k] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Accepted: 05/01/2019] [Indexed: 11/21/2022] Open
Abstract
UV/Vis absorption and NMR spectroscopy titrations have been used to investigate the formation of complexes between cations and neutral H-bond acceptors in organic solvents. Complexes formed by two different H-bond acceptors with fifteen different cations were studied in acetone and in acetonitrile. The effects of water and ion pairing with the counter-anion were found to be negligible in the two polar solvents employed for this study. The data were used to determine self-consistent H-bond donor parameters (α) for a series of organic and inorganic cations; guanidinium, primary, tertiary and quaternary ammonium, imidazolium, methylpyridinium, lithium, sodium, potassium, rubidium and caesium. The results demonstrate the transferability of α parameters for cations between different solvents and different H-bond acceptor partners, allowing reliable prediction of cation recognition properties in different environments. Lithium and protonated nitrogen cations form the most stable complexes, but the α parameter is only 5.0, which is similar to the neutral H-bond donor 3-trifluoromethyl,4-nitrophenol (α = 5.1). Quaternary ammonium is the weakest H-bond donor investigated with an α value of 2.7, which is comparable to an alcohol. The α parameters for alkali metal cations decrease down the group from 5.0 (Li+) to 3.5 (Cs+).
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Affiliation(s)
- Sarah J Pike
- Department of Chemistry , University of Cambridge , Lensfield Road , Cambridge , CB2 1EW , UK .
| | - Ennio Lavagnini
- Department of Chemistry , University of Cambridge , Lensfield Road , Cambridge , CB2 1EW , UK .
| | - Lisa M Varley
- Department of Chemistry , University of Sheffield , Sheffield , S3 7HF , UK
| | - Joanne L Cook
- Unilever R&D Port Sunlight , Quarry Road East , Bebington , Wirral CH63 3JW , UK
| | - Christopher A Hunter
- Department of Chemistry , University of Cambridge , Lensfield Road , Cambridge , CB2 1EW , UK .
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15
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Itoh Y, Nakashima Y, Tsukamoto S, Kurohara T, Suzuki M, Sakae Y, Oda M, Okamoto Y, Suzuki T. N +-C-H···O Hydrogen bonds in protein-ligand complexes. Sci Rep 2019; 9:767. [PMID: 30683882 PMCID: PMC6347603 DOI: 10.1038/s41598-018-36987-9] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Accepted: 11/28/2018] [Indexed: 12/03/2022] Open
Abstract
In the context of drug design, C-H···O hydrogen bonds have received little attention so far, mostly because they are considered weak relative to other noncovalent interactions such as O-H···O hydrogen bonds, π/π interactions, and van der Waals interactions. Herein, we demonstrate the significance of hydrogen bonds between C-H groups adjacent to an ammonium cation and an oxygen atom (N+-C-H···O hydrogen bonds) in protein-ligand complexes. Quantum chemical calculations revealed details on the strength and geometrical requirements of these N+-C-H···O hydrogen bonds, and a subsequent survey of the Protein Data Bank (PDB) based on these criteria suggested that numerous protein-ligand complexes contain such N+-C-H···O hydrogen bonds. An ensuing experimental investigation into the G9a-like protein (GLP)-inhibitor complex demonstrated that N+-C-H···O hydrogen bonds affect the activity of the inhibitors against the target enzyme. These results should provide the basis for the use of N+-C-H···O hydrogen bonds in drug discovery.
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Affiliation(s)
- Yukihiro Itoh
- Department of Chemistry, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 1-5 Shimogamohangi-cho, Sakyo-ku, Kyoto, 606-0823, Japan
| | - Yusuke Nakashima
- Department of Chemistry, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 1-5 Shimogamohangi-cho, Sakyo-ku, Kyoto, 606-0823, Japan
| | - Shuichiro Tsukamoto
- Department of Physics, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi, 464-8602, Japan
| | - Takashi Kurohara
- Department of Chemistry, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 1-5 Shimogamohangi-cho, Sakyo-ku, Kyoto, 606-0823, Japan
| | - Miki Suzuki
- Department of Chemistry, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 1-5 Shimogamohangi-cho, Sakyo-ku, Kyoto, 606-0823, Japan
| | - Yoshitake Sakae
- Department of Physics, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi, 464-8602, Japan
| | - Masayuki Oda
- Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, Kyoto, 1-5 Shimogamohangi-cho, Sakyo-ku, Kyoto, 606-8522, Japan
| | - Yuko Okamoto
- Department of Physics, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi, 464-8602, Japan.,CREST, Japan Science and Technology Agency (JST), 4-1-8 Honcho, Kawaguchi, Saitama, 332-0012, Japan
| | - Takayoshi Suzuki
- Department of Chemistry, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 1-5 Shimogamohangi-cho, Sakyo-ku, Kyoto, 606-0823, Japan. .,CREST, Japan Science and Technology Agency (JST), 4-1-8 Honcho, Kawaguchi, Saitama, 332-0012, Japan.
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16
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Niemann T, Stange P, Strate A, Ludwig R. When hydrogen bonding overcomes Coulomb repulsion: from kinetic to thermodynamic stability of cationic dimers. Phys Chem Chem Phys 2019; 21:8215-8220. [PMID: 30672530 DOI: 10.1039/c8cp06417b] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Quantum chemical calculations have been employed to study the kinetic and thermodynamic stability of hydroxy-functionalized 1-(3-hydroxyalkyl)pyridinium cationic dimers. For [Py-(CH2)n-OH+]2 structures with n = 2-17 we have calculated the robust local minima with clear dissociation barriers preventing their "Coulomb explosion" into separated cations. For n = 15 hydrogen bonding and dispersion forces fully compensate for the repulsive Coulomb forces between the cations allowing for the quantification of the pure hydrogen bond in the order of 20 kJ mol-1. The increasing kinetic stability even turns to thermodynamic stability with further elongated hydroxyalkyl chains. Now, quantum-type short-range attraction wins over classical long-range electrostatic repulsion resulting in negative binding energies and providing the first thermodynamically stable cationic dimers. The electronic, structural and spectroscopic signatures of the cationic dimers could be correlated to NBO parameters, supporting the existence of anti-electrostatic hydrogen bonds (AEHB) as recently suggested by Weinhold. In principle, these pure cationic dimers should be detectable in gas-phase experiments at low temperatures without the need of mediating molecules or counteranions.
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Affiliation(s)
- T Niemann
- Universität Rostock, Institut für Chemie, Abteilung für Physikalische Chemie, Dr.-Lorenz-Weg 2, 18059, Rostock, Germany.
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17
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Dash SG, Thakur TS. Cation⋯cation hydrogen bonds in synephrine salts: a typical interaction in an unusual environment. Phys Chem Chem Phys 2019; 21:20647-20660. [DOI: 10.1039/c9cp03164b] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Computational studies of hydrogen-bonded cationic species observed in the synephrine salts point towards the stabilizing nature of hydrogen bonds and highlights their contribution in reducing destabilization caused by coulombic repulsion.
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Affiliation(s)
- Sibananda G. Dash
- Academy of Scientific and Innovative Research (AcSIR)
- CSIR-Central Drug Research Institute (CSIR-CDRI) campus
- Lucknow 226 031
- India
- Molecular and Structural Biology Division
| | - Tejender S. Thakur
- Academy of Scientific and Innovative Research (AcSIR)
- CSIR-Central Drug Research Institute (CSIR-CDRI) campus
- Lucknow 226 031
- India
- Molecular and Structural Biology Division
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18
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Niemann T, Stange P, Strate A, Ludwig R. Like-likes-Like: Cooperative Hydrogen Bonding Overcomes Coulomb Repulsion in Cationic Clusters with Net Charges up to Q=+6e. Chemphyschem 2018; 19:1691-1695. [PMID: 29633456 PMCID: PMC6099258 DOI: 10.1002/cphc.201800293] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Indexed: 01/30/2023]
Abstract
Quantum chemical calculations have been employed to study kinetically stable cationic clusters, wherein the monovalent cations are trapped by hydrogen bonding despite strongly repulsive electrostatic forces. We calculated linear and cyclic clusters of the hydroxy-functionalized cation N-(3-hydroxypropyl) pyridinium, commonly used as cation in ionic liquids. The largest kinetically stable cluster was a cyclic hexamer that very much resembles the structural motifs of molecular clusters, as known for water and alcohols. Surprisingly, strong cooperative hydrogen bonds overcome electrostatic repulsion and result in cationic clusters with a high net charge up to Q=+6e. The structural, spectroscopic, and electronic signatures of the cationic and related molecular clusters of 3-phenyl-1-propanol could be correlated to NBO parameters, supporting the existence of "anti-electrostatic" hydrogen bonds (AEHB), as recently suggested by Weinhold. We also showed that dispersion forces enhance the cationic cluster formation and compensate the electrostatic repulsion of one additional positive charge.
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Affiliation(s)
- Thomas Niemann
- Universität Rostock, Institut für ChemieAbteilung für Physikalische und Theoretische ChemieDr.-Lorenz-Weg 218059RostockGermany
| | - Peter Stange
- Universität Rostock, Institut für ChemieAbteilung für Physikalische und Theoretische ChemieDr.-Lorenz-Weg 218059RostockGermany
| | - Anne Strate
- Universität Rostock, Institut für ChemieAbteilung für Physikalische und Theoretische ChemieDr.-Lorenz-Weg 218059RostockGermany
| | - Ralf Ludwig
- Universität Rostock, Institut für ChemieAbteilung für Physikalische und Theoretische ChemieDr.-Lorenz-Weg 218059RostockGermany
- Leibniz-Institut für Katalyse an der Universität Rostock e.V.Albert-Einstein-Str. 29a18059RostockGermany
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19
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Kumar P, Cabaj MK, Pazio A, Dominiak PM. Protonated nucleobases are not fully ionized in their chloride salt crystals and form metastable base pairs further stabilized by the surrounding anions. IUCRJ 2018; 5:449-469. [PMID: 30002846 PMCID: PMC6038959 DOI: 10.1107/s2052252518006346] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Accepted: 04/25/2018] [Indexed: 06/08/2023]
Abstract
This paper presents experimental charge-density studies of cytosinium chloride, adeninium chloride hemihydrate and guaninium dichloride crystals based on ultra-high-resolution X-ray diffraction data and extensive theoretical calculations. The results confirm that the cohesive energies of the studied systems are dominated by contributions from intermolecular electrostatic interactions, as expected for ionic crystals. Electrostatic interaction energies (Ees) usually constitute 95% of the total interaction energy. The Ees energies in this study were several times larger in absolute value when compared, for example, with dimers of neutral nucleobases. However, they were not as large as some theoretical calculations have predicted. This was because the molecules appeared not to be fully ionized in the studied crystals. Apart from charge transfer from chlorine to the protonated nucleobases, small but visible charge redistribution within the nucleobase cations was observed. Some dimers of singly protonated bases in the studied crystals, namely a cytosinium-cytosinium trans sugar/sugar edge pair and an adeninium-adeninium trans Hoogsteen/Hoogsteen edge pair, exhibited attractive interactions (negative values of Ees) or unusually low repulsion despite identical molecular charges. The pairs are metastable as a result of strong hydrogen bonding between bases which overcompensates the overall cation-cation repulsion, the latter being weakened due to charge transfer and molecular charge-density polarization.
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Affiliation(s)
- Prashant Kumar
- Biological and Chemical Research Center, Department of Chemistry, University of Warsaw, ul. Żwirki i Wigury 101, Warszawa 02-089, Poland
| | - Malgorzata Katarzyna Cabaj
- Biological and Chemical Research Center, Department of Chemistry, University of Warsaw, ul. Żwirki i Wigury 101, Warszawa 02-089, Poland
| | - Aleksandra Pazio
- Biological and Chemical Research Center, Department of Chemistry, University of Warsaw, ul. Żwirki i Wigury 101, Warszawa 02-089, Poland
| | - Paulina Maria Dominiak
- Biological and Chemical Research Center, Department of Chemistry, University of Warsaw, ul. Żwirki i Wigury 101, Warszawa 02-089, Poland
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20
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Weinhold F. Theoretical Prediction of Robust Second-Row Oxyanion Clusters in the Metastable Domain of Antielectrostatic Hydrogen Bonding. Inorg Chem 2018; 57:2035-2044. [PMID: 29381336 DOI: 10.1021/acs.inorgchem.7b02943] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We provide ab initio and density functional theory evidence for a family of surprisingly robust like-charged clusters of common HSO4- and H2PO4- oxyanions, ranging up to tetramers of net charge 4-. Our results support other recent theoretical and experimental evidence for "antielectrostatic" hydrogen-bonded (AEHB) species that challenge conventional electrostatic conceptions and force-field modeling of closed-shell ion interactions. We provide structural and energetic descriptors of the predicted kinetic well-depths (in the range 3-10 kcal/mol) and barrier widths (in the range 2-4 Å) for simple AEHB dimers, including evidence of extremely strong hydrogen bonding in the fluoride-bisulfate dianion. For more complex polyanionic species, we employ natural-bond-orbital-based descriptors to characterize the electronic features of the cooperative hydrogen-bonding network that are able to successfully defy Coulomb explosion. The computational results suggest a variety of kinetically stable AEHB species that may be suitable for experimental detection as long-lived gas-phase species or structural units of condensed phases, despite the imposing electrostatic barriers that oppose their formation under ambient conditions.
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Affiliation(s)
- Frank Weinhold
- Theoretical Chemistry Institute and Department of Chemistry, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States
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21
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Horn PR, Mao Y, Head-Gordon M. Probing non-covalent interactions with a second generation energy decomposition analysis using absolutely localized molecular orbitals. Phys Chem Chem Phys 2018; 18:23067-79. [PMID: 27492057 DOI: 10.1039/c6cp03784d] [Citation(s) in RCA: 233] [Impact Index Per Article: 38.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
An energy decomposition analysis (EDA) separates a calculated interaction energy into as many interpretable contributions as possible; for instance, permanent and induced electrostatics, Pauli repulsions, dispersion and charge transfer. The challenge is to construct satisfactory definitions of all terms in the chemically relevant regime where fragment densities overlap, rendering unique definitions impossible. Towards this goal, we present an improved EDA for Kohn-Sham density functional theory (DFT) with properties that have previously not been simultaneously attained. Building on the absolutely localized molecular orbital (ALMO)-EDA, this second generation ALMO-EDA is variational and employs valid antisymmetric electronic wavefunctions to produce all five contributions listed above. These contributions moreover all have non-trivial complete basis set limits. We apply the EDA to the water dimer, the T-shaped and parallel-displaced benzene dimer, the p-biphthalate dimer "anti-electrostatic" hydrogen bonding complex, the biologically relevant binding of adenine and thymine in stacked and hydrogen-bonded configurations, the triply hydrogen-bonded guanine-cytosine complex, the interaction of Cl(-) with s-triazine and with the 1,3-dimethyl imidazolium cation, which is relevant to the study of ionic liquids, and the water-formaldehyde-vinyl alcohol ter-molecular radical cationic complex formed in the dissociative photoionization of glycerol.
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Affiliation(s)
- Paul R Horn
- Kenneth S. Pitzer Center for Theoretical Chemistry, Department of Chemistry, University of California, Berkeley, CA 94720, USA.
| | - Yuezhi Mao
- Kenneth S. Pitzer Center for Theoretical Chemistry, Department of Chemistry, University of California, Berkeley, CA 94720, USA.
| | - Martin Head-Gordon
- Kenneth S. Pitzer Center for Theoretical Chemistry, Department of Chemistry, University of California, Berkeley, CA 94720, USA. and Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
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22
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Strate A, Overbeck V, Lehde V, Neumann J, Bonsa AM, Niemann T, Paschek D, Michalik D, Ludwig R. The influence of like-charge attraction on the structure and dynamics of ionic liquids: NMR chemical shifts, quadrupole coupling constants, rotational correlation times and failure of Stokes–Einstein–Debye. Phys Chem Chem Phys 2018; 20:5617-5625. [DOI: 10.1039/c7cp06454c] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The formation of clusters of like-charge influences the structure and dynamics of ionic liquids.
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Affiliation(s)
- Anne Strate
- University of Rostock
- Institute for Chemistry
- Physical and Theoretical Chemistry
- Rostock
- Germany
| | - Viviane Overbeck
- University of Rostock
- Institute for Chemistry
- Physical and Theoretical Chemistry
- Rostock
- Germany
| | - Viktoria Lehde
- University of Rostock
- Institute for Chemistry
- Physical and Theoretical Chemistry
- Rostock
- Germany
| | - Jan Neumann
- University of Rostock
- Institute for Chemistry
- Physical and Theoretical Chemistry
- Rostock
- Germany
| | - Anne-Marie Bonsa
- University of Rostock
- Institute for Chemistry
- Physical and Theoretical Chemistry
- Rostock
- Germany
| | - Thomas Niemann
- University of Rostock
- Institute for Chemistry
- Physical and Theoretical Chemistry
- Rostock
- Germany
| | - Dietmar Paschek
- University of Rostock
- Institute for Chemistry
- Physical and Theoretical Chemistry
- Rostock
- Germany
| | - Dirk Michalik
- University of Rostock
- Institute for Chemistry
- Physical and Theoretical Chemistry
- Rostock
- Germany
| | - Ralf Ludwig
- University of Rostock
- Institute for Chemistry
- Physical and Theoretical Chemistry
- Rostock
- Germany
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23
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Wang C, Fu Y, Zhang L, Danovich D, Shaik S, Mo Y. Hydrogen- and Halogen-Bonds between Ions of like Charges: Are They Anti-Electrostatic in Nature? J Comput Chem 2017; 39:481-487. [DOI: 10.1002/jcc.25068] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2017] [Revised: 08/28/2017] [Accepted: 09/05/2017] [Indexed: 01/16/2023]
Affiliation(s)
- Changwei Wang
- Department of Chemistry, College of Science; China University of Petroleum (East China), Changjiangxi Road 66; 266580 Tsingtao China
| | - Yuzhuang Fu
- Department of Chemistry, College of Science; China University of Petroleum (East China), Changjiangxi Road 66; 266580 Tsingtao China
| | - Lina Zhang
- Department of Chemistry, College of Science; China University of Petroleum (East China), Changjiangxi Road 66; 266580 Tsingtao China
| | - David Danovich
- Institute of Chemistry; The Hebrew University; Jerusalem 91904 Israel
| | - Sason Shaik
- Institute of Chemistry; The Hebrew University; Jerusalem 91904 Israel
| | - Yirong Mo
- Department of Chemistry; Western Michigan University; Kalamazoo Michigan 49008
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24
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Strate A, Niemann T, Ludwig R. Controlling the kinetic and thermodynamic stability of cationic clusters by the addition of molecules or counterions. Phys Chem Chem Phys 2017; 19:18854-18862. [DOI: 10.1039/c7cp02227a] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
We discuss the stability of cationic clusters when adding molecules or counterions, and predict their occurrence in gas phase experiments.
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Affiliation(s)
- Anne Strate
- Universität Rostock
- Institut für Chemie
- Abteilung für Physikalische Chemie
- Rostock
- Germany
| | - Thomas Niemann
- Universität Rostock
- Institut für Chemie
- Abteilung für Physikalische Chemie
- Rostock
- Germany
| | - Ralf Ludwig
- Universität Rostock
- Institut für Chemie
- Abteilung für Physikalische Chemie
- Rostock
- Germany
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25
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2,2,6,6-Tetramethylpiperidinium triflate (TMPT): a highly selective and self-separated catalyst for esterification. Tetrahedron Lett 2016. [DOI: 10.1016/j.tetlet.2016.09.061] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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26
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Pollak D, Goddard R, Pörschke KR. Cs[H2NB2(C6F5)6] Featuring an Unequivocal 16-Coordinate Cation. J Am Chem Soc 2016; 138:9444-51. [DOI: 10.1021/jacs.6b02590] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- David Pollak
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz
1, 45470 Mülheim
an der Ruhr, Germany
| | - Richard Goddard
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz
1, 45470 Mülheim
an der Ruhr, Germany
| | - Klaus-Richard Pörschke
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz
1, 45470 Mülheim
an der Ruhr, Germany
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27
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Xu W, Xu X, Wu J, Fu M, Chen L, Wang N, Xiao H, Chen X, Ye D. Removal of toluene in adsorption–discharge plasma systems over a nickel modified SBA-15 catalyst. RSC Adv 2016. [DOI: 10.1039/c6ra21704d] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
In situ FT-IR spectra show the toluene adsorption process of SBA and Ni–SBA catalysts.
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Affiliation(s)
- Weicheng Xu
- School of Environment and Energy
- South China University of Technology
- Guangzhou 510006
- China
| | - Xiaoxin Xu
- School of Environment and Energy
- South China University of Technology
- Guangzhou 510006
- China
| | - Junliang Wu
- School of Environment and Energy
- South China University of Technology
- Guangzhou 510006
- China
- Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control
| | - Mingli Fu
- School of Environment and Energy
- South China University of Technology
- Guangzhou 510006
- China
- Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control
| | - Limin Chen
- School of Environment and Energy
- South China University of Technology
- Guangzhou 510006
- China
- Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control
| | - Ni Wang
- School of Environment and Energy
- South China University of Technology
- Guangzhou 510006
- China
| | - Hailin Xiao
- School of Environment and Energy
- South China University of Technology
- Guangzhou 510006
- China
| | - Xiaofang Chen
- School of Environment and Energy
- South China University of Technology
- Guangzhou 510006
- China
| | - Daiqi Ye
- School of Environment and Energy
- South China University of Technology
- Guangzhou 510006
- China
- Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control
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28
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Knorr A, Ludwig R. Cation-cation clusters in ionic liquids: Cooperative hydrogen bonding overcomes like-charge repulsion. Sci Rep 2015; 5:17505. [PMID: 26626928 PMCID: PMC4667241 DOI: 10.1038/srep17505] [Citation(s) in RCA: 88] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Accepted: 10/28/2015] [Indexed: 12/27/2022] Open
Abstract
Direct spectroscopic evidence for H-bonding between like-charged ions is reported for the ionic liquid, 1-(2-hydroxyethyl)-3-methylimidazolium tetrafluoroborate. New infrared bands in the OH frequency range appear at low temperatures indicating the formation of H-bonded cation-cation clusters similar to those known for water and alcohols. Supported by DFT calculations, these vibrational bands can be assigned to attractive interaction between the hydroxyl groups of the cations. The repulsive Coulomb interaction is overcome by cooperative hydrogen bonding between ions of like charge. The transition energy from purely cation-anion interacting configurations to those including cation-cation H-bonds is determined to be 3-4 kJmol(-1). The experimental findings and DFT calculations strongly support the concept of anti-electrostatic hydrogen bonds (AEHBs) as recently suggested by Weinhold and Klein. The like-charge configurations are kinetically stabilized with decreasing temperatures.
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Affiliation(s)
- Anne Knorr
- Universität Rostock, Institut für Chemie, Abteilung für Physikalische Chemie, Dr.-Lorenz-Weg 1, 18059, Rostock (Germany)
| | - Ralf Ludwig
- Universität Rostock, Institut für Chemie, Abteilung für Physikalische Chemie, Dr.-Lorenz-Weg 1, 18059, Rostock (Germany)
- Leibniz-Institut für Katalyse an der Universität Rostock e.V., Albert-Einstein-Str. 29a, 18059 Rostock (Germany)
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29
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Cebollada A, Vellé A, Iglesias M, Fullmer LB, Goberna-Ferrón S, Nyman M, Sanz Miguel PJ. Direct X-Ray Scattering Evidence for Metal-Metal Interactions in Solution at the Molecular Level. Angew Chem Int Ed Engl 2015; 54:12762-6. [DOI: 10.1002/anie.201505736] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Revised: 07/20/2015] [Indexed: 11/05/2022]
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30
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Cebollada A, Vellé A, Iglesias M, Fullmer LB, Goberna-Ferrón S, Nyman M, Sanz Miguel PJ. Direct X-Ray Scattering Evidence for Metal-Metal Interactions in Solution at the Molecular Level. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201505736] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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