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Unraveling the Nature of Hydrogen Bonds of "Proton Sponges" Based on Car-Parrinello and Metadynamics Approaches. Int J Mol Sci 2023; 24:ijms24021542. [PMID: 36675059 PMCID: PMC9860969 DOI: 10.3390/ijms24021542] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2022] [Revised: 12/26/2022] [Accepted: 01/05/2023] [Indexed: 01/14/2023] Open
Abstract
The nature of intra- and intermolecular non-covalent interactions was studied in four naphthalene derivatives commonly referred to as "proton sponges". Special attention was paid to an intramolecular hydrogen bond present in the protonated form of the compounds. The unsubstituted "proton sponge" served as a reference structure to study the substituent influence on the hydrogen bond (HB) properties. We selected three compounds substituted by methoxy, amino, and nitro groups. The presence of the substituents either retained the parent symmetry or rendered the compounds asymmetric. In order to reveal the non-covalent interaction properties, the Hirshfeld surface (HS) was computed for the crystal structures of the studied compounds. Next, quantum-chemical simulations were performed in vacuo and in the crystalline phase. Car-Parrinello molecular dynamics (CPMD), Path Integral Molecular Dynamics (PIMD), and metadynamics were employed to investigate the time-evolution changes of metric parameters and free energy profile in both phases. Additionally, for selected snapshots obtained from the CPMD trajectories, non-covalent interactions and electronic structure were studied. Quantum theory of atoms in molecules (QTAIM) and the Density Overlap Regions Indicator (DORI) were applied for this purpose. It was found based on Hirshfeld surfaces that, besides intramolecular hydrogen bonds, other non-covalent interactions are present and have a strong impact on the crystal structure organization. The CPMD results obtained in both phases showed frequent proton transfer phenomena. The proton was strongly delocalized in the applied time-scale and temperature, especially in the PIMD framework. The use of metadynamics allowed for tracing the free energy profiles and confirming that the hydrogen bonds present in "proton sponges" are Low-Barrier Hydrogen Bonds (LBHBs). The electronic and topological analysis quantitatively described the temperature dependence and time-evolution changes of the electronic structure. The covalency of the hydrogen bonds was estimated based on QTAIM analysis. It was found that strong hydrogen bonds show greater covalency, which is additionally determined by the proton position in the hydrogen bridge.
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Symmetry/Asymmetry of the NHN Hydrogen Bond in Protonated 1,8-Bis(dimethylamino)naphthalene. Symmetry (Basel) 2020. [DOI: 10.3390/sym12111924] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Experimental and theoretical results are presented based on vibrational spectra and motional dynamics of 1,8-bis(dimethylamino)naphthalene (DMAN) and its protonated forms (DMANH+ and the DMANH+ HSO4− complex). The studies of these compounds have been performed in the gas phase and solid-state. Spectroscopic investigations were carried out by infrared spectroscopy (IR), Raman, and incoherent inelastic neutron scattering (IINS) experimental methods. Density functional theory (DFT) and Car–Parrinello molecular dynamics (CPMD) methods were applied to support our experimental findings. The fundamental investigations of hydrogen bridge vibrations were accomplished on the basis of isotopic substitutions (NH → ND). Special attention was paid to the bridged proton dynamics in the DMANH+ complex, which was found to be affected by interactions with the HSO4− anion.
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Malkin VG, Malkina OL, Zhidomirov GM. Visualization of Electron Paramagnetic Resonance Hyperfine Structure Coupling Pathways. J Phys Chem A 2017; 121:3580-3587. [PMID: 28410441 DOI: 10.1021/acs.jpca.7b01833] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The close relation between the EPR hyperfine coupling constant and NMR indirect spin-spin coupling constant is well-known. For example, the Karplus-type dependence of hyperfine constants on the dihedral angle, originally proposed for NMR spin-spin coupling, is widely used in pNMR studies. In the present work we propose a new tool for visualization of hyperfine coupling pathways based on our experience with visualization of NMR indirect spin-spin couplings. The plotted 3D-function is the difference between the total electron densities when the magnetic moment of the nucleus of interest changes its sign and as such is an observable from the physical point of view. It has been shown that it is proportional to the linear response of the spin density to the nuclear spin (i.e., magnetic moment). In contrast to the widely used visualization of spin density, our new approach depicts only the part of the electron cloud of a molecule that is affected by the interaction of the unpaired electron(s) with the desired nuclear magnetic moment. Because visualization of NMR spin-spin couplings and hyperfine interaction is based on the same ideas and done using similar techniques, it allows a direct comparison of the corresponding pathways for the two phenomena so as to analyze their resemblance and/or dissimilarity.
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Affiliation(s)
- Vladimir G Malkin
- Institute of Inorganic Chemistry, Slovak Academy of Sciences , Dúbravská cesta 9, SK-84536 Bratislava, Slovakia
| | - Olga L Malkina
- Institute of Inorganic Chemistry, Slovak Academy of Sciences , Dúbravská cesta 9, SK-84536 Bratislava, Slovakia.,Department of Inorganic Chemistry, Comenius University , SK-84215 Bratislava, Slovakia
| | - Georgy M Zhidomirov
- G. K. Boreskov Institute of Catalysis, Siberian Branch of the Russian Academy of Sciences , Prospect Lavrentieva 5, 630090 Novosibirsk, Russia
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Sobczyk L, Chudoba D, Tolstoy PM, Filarowski A. Some Brief Notes on Theoretical and Experimental Investigations of Intramolecular Hydrogen Bonding. Molecules 2016; 21:E1657. [PMID: 27918442 PMCID: PMC6273268 DOI: 10.3390/molecules21121657] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2016] [Revised: 11/18/2016] [Accepted: 11/28/2016] [Indexed: 11/16/2022] Open
Abstract
A review of selected literature data related to intramolecular hydrogen bonding in ortho-hydroxyaryl Schiff bases, ortho-hydroxyaryl ketones, ortho-hydroxyaryl amides, proton sponges and ortho-hydroxyaryl Mannich bases is presented. The paper reports on the application of experimental spectroscopic measurements (IR and NMR) and quantum-mechanical calculations for investigations of the proton transfer processes, the potential energy curves, tautomeric equilibrium, aromaticity etc. Finally, the equilibrium between the intra- and inter-molecular hydrogen bonds in amides is discussed.
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Affiliation(s)
- Lucjan Sobczyk
- Faculty of Chemistry, University of Wrocław, 14 F. Joliot-Curie Str., 50-383 Wrocław, Poland.
| | - Dorota Chudoba
- Faculty of Physics, A. Mickiewicz University, Umultowska 85, 61-614 Poznan, Poland.
- Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, 141980 Dubna, Russia.
| | - Peter M Tolstoy
- Center for Magnetic Resonance, St. Petersburg State University, St. Petersburg 198504, Russia.
| | - Aleksander Filarowski
- Faculty of Chemistry, University of Wrocław, 14 F. Joliot-Curie Str., 50-383 Wrocław, Poland.
- Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, 141980 Dubna, Russia.
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Sánchez-Sanz G, Trujillo C, Alkorta I, Elguero J. Modulating intramolecular P⋯N pnictogen interactions. Phys Chem Chem Phys 2016; 18:9148-60. [DOI: 10.1039/c6cp00227g] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The strength of P⋯N intramolecular pnictogen interactions can be modulated, enhanced or diminished upon substitution of different electron withdrawing or donor groups.
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Affiliation(s)
| | - Cristina Trujillo
- School of Chemistry
- Trinity Biomedical Sciences Institute
- Trinity College Dublin
- Dublin 2
- Ireland
| | - Ibon Alkorta
- Instituto de Química Médica
- CSIC
- E-28006 Madrid
- Spain
| | - José Elguero
- Instituto de Química Médica
- CSIC
- E-28006 Madrid
- Spain
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6
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Sánchez-Sanz G, Trujillo C, Alkorta I, Elguero J. Intramolecular pnicogen interactions in phosphorus and arsenic analogues of proton sponges. Phys Chem Chem Phys 2014; 16:15900-9. [DOI: 10.1039/c4cp01072h] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A computational study of the intramolecular pnicogen bond in 1,8-bis-substituted naphthalene derivatives (ZXH and ZX2 with Z = P, As and X = H, F, Cl, and Br), structurally related to proton sponges, has been carried out.
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Affiliation(s)
- Goar Sánchez-Sanz
- School of Physics & Complex and Adaptive Systems Laboratory
- University College Dublin
- Dublin 4, Ireland
| | - Cristina Trujillo
- Institute of Organic Chemistry and Biochemistry
- Gilead Sciences Research Center & IOCB
- Academy of Sciences of the Czech Republic
- 166 10 Praha 6, Czech Republic
| | - Ibon Alkorta
- Instituto de Química Médica (CSIC)
- 28006-Madrid, Spain
| | - José Elguero
- Instituto de Química Médica (CSIC)
- 28006-Madrid, Spain
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Masuda Y, Mori Y, Sakurai K. Effects of Counterion and Solvent on Proton Location and Proton Transfer Dynamics of N–H···N Hydrogen Bond of Monoprotonated 1,8-Bis(dimethylamino)naphthalene. J Phys Chem A 2013; 117:10576-87. [DOI: 10.1021/jp4061297] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Yuichi Masuda
- Department of Chemistry,
Faculty of Science, Ochanomizu University, Otsuka, Bunkyo-ku, Tokyo 112-8610, Japan
| | - Yukie Mori
- Department of Chemistry,
Faculty of Science, Ochanomizu University, Otsuka, Bunkyo-ku, Tokyo 112-8610, Japan
| | - Kazumi Sakurai
- Department of Chemistry,
Faculty of Science, Ochanomizu University, Otsuka, Bunkyo-ku, Tokyo 112-8610, Japan
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Sanz D, Claramunt RM, Mathey F, Alkorta I, Sánchez-Sanz G, Elguero J. Intermolecular spin–spin coupling constants between 31P atoms. CR CHIM 2013. [DOI: 10.1016/j.crci.2013.05.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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9
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Elguero J, Alkorta I, Del Bene JE. Ramsey terms for two-, three-, and four-bond coupling involving15N and17O in hydrogen-bonded and nonhydrogen-bonded systems: are coupling constants sensitive to RAHBs? Mol Phys 2013. [DOI: 10.1080/00268976.2013.802820] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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10
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Pozharskii AF, Ozeryanskii VA. Proton Sponges and Hydrogen Transfer Phenomena. MENDELEEV COMMUNICATIONS 2012. [DOI: 10.1016/j.mencom.2012.05.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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11
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Povalyakhina MA, Antonov AS, Dyablo OV, Ozeryanskii VA, Pozharskii AF. H-Bond-Assisted Intramolecular Nucleophilic Displacement of the 1-NMe2 Group in 1,8-Bis(dimethylamino)naphthalenes as a Route to Multinuclear Heterocyclic Compounds and Strained Naphthalene Derivatives. J Org Chem 2011; 76:7157-66. [DOI: 10.1021/jo201171z] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Maria A. Povalyakhina
- Department of Organic Chemistry, Southern Federal University, Zorge 7, 344090 Rostov-on-Don, Russian Federation
| | - Alexander S. Antonov
- Department of Organic Chemistry, Southern Federal University, Zorge 7, 344090 Rostov-on-Don, Russian Federation
| | - Olga V. Dyablo
- Department of Organic Chemistry, Southern Federal University, Zorge 7, 344090 Rostov-on-Don, Russian Federation
| | - Valery A. Ozeryanskii
- Department of Organic Chemistry, Southern Federal University, Zorge 7, 344090 Rostov-on-Don, Russian Federation
| | - Alexander F. Pozharskii
- Department of Organic Chemistry, Southern Federal University, Zorge 7, 344090 Rostov-on-Don, Russian Federation
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12
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Lorand JP. CH hydrogen bonding: 3. Hammett correlations for phenylacetonitriles and tetrafluorobenzenes with HMPA. J PHYS ORG CHEM 2011. [DOI: 10.1002/poc.1740] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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13
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Afonin AV, Vashchenko AV. Theoretical study of bifurcated hydrogen bonding effects on the 1J(N,H), 1hJ(N,H), 2hJ(N,N) couplings and 1H, 15N shieldings in model pyrroles. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2010; 48:309-317. [PMID: 20198609 DOI: 10.1002/mrc.2579] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
According to the density functional theory calculations, the X...H...N (X=N, O) intramolecular bifurcated (three-centered) hydrogen bond with one hydrogen donor and two hydrogen acceptors causes a significant decrease of the (1h)J(N,H) and (2h)J(N,N) coupling constants across the N-H...N hydrogen bond and an increase of the (1)J(N,H) coupling constant across the N-H covalent bond in the 2,5-disubstituted pyrroles. This occurs due to a weakening of the N-H...N hydrogen bridge resulting in a lengthening of the N...H distance and a decrease of the hydrogen bond angle at the bifurcated hydrogen bond formation. The gauge-independent atomic orbital calculations of the shielding constants suggest that a weakening of the N-H...N hydrogen bridge in case of the three-centered hydrogen bond yields a shielding of the bridge proton and deshielding of the acceptor nitrogen atom. The atoms-in-molecules analysis shows that an attenuation of the (1h)J(N,H) and (2h)J(N,N) couplings in the compounds with bifurcated hydrogen bond is connected with a decrease of the electron density rho(H...N) at the hydrogen bond critical point and Laplacian of this electron density nabla(2)rho(H...N). The natural bond orbital analysis suggests that the additional N-H...X interaction partly inhibits the charge transfer from the nitrogen lone pair to the sigma*(N-H) antibonding orbital across hydrogen bond weakening of the (1h)J(N,H) and (2h)J(N,N) trans-hydrogen bond couplings through Fermi-contact mechanism. An increase of the nitrogen s-character percentage of the N-H bond in consequence of the bifurcated hydrogen bonding leads to an increase of the (1)J(N,H) coupling constant across the N-H covalent bond and deshielding of the hydrogen donor nitrogen atom.
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Affiliation(s)
- Andrei V Afonin
- Institute of Chemistry, Siberian Branch of the Russian Academy of Science, Favorski St. 1, 664033 Irkutsk, Russia.
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14
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Pietrzak M, Wehling J, Kong S, Tolstoy P, Shenderovich I, López C, Claramunt RM, Elguero J, Denisov G, Limbach HH. Symmetrization of Cationic Hydrogen Bridges of Protonated Sponges Induced by Solvent and Counteranion Interactions as Revealed by NMR Spectroscopy. Chemistry 2010; 16:1679-90. [DOI: 10.1002/chem.200902259] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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15
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Durlak P, Latajka Z. Car–Parrinello and path integral molecular dynamics study of the intramolecular hydrogen bond in the novel class of anionic H-chelates: 6-Nitro-2,3-dipyrrol-2-ylquinoxaline anion. Chem Phys Lett 2009. [DOI: 10.1016/j.cplett.2009.09.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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16
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Donghi D, Maggioni D, Beringhelli T, D'Alfonso G. 19
F NMR Spectroscopic Investigation of the Reaction of Bis(pentafluorophenyl)borinic Acid with a “Proton Sponge”: Deprotonation, Trimerization and Stepwise Dearylation. Eur J Inorg Chem 2008. [DOI: 10.1002/ejic.200800280] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Daniela Donghi
- Dipartimento di Chimica Inorganica, Metallorganica e Analitica, Facoltà di Farmacia, Università degli Studi di Milano, Via Venezian 21, 20133 Milano, Italy, Fax: +39‐02‐50314405
| | - Daniela Maggioni
- Dipartimento di Chimica Inorganica, Metallorganica e Analitica, Facoltà di Farmacia, Università degli Studi di Milano, Via Venezian 21, 20133 Milano, Italy, Fax: +39‐02‐50314405
| | - Tiziana Beringhelli
- Dipartimento di Chimica Inorganica, Metallorganica e Analitica, Facoltà di Farmacia, Università degli Studi di Milano, Via Venezian 21, 20133 Milano, Italy, Fax: +39‐02‐50314405
| | - Giuseppe D'Alfonso
- Dipartimento di Chimica Inorganica, Metallorganica e Analitica, Facoltà di Farmacia, Università degli Studi di Milano, Via Venezian 21, 20133 Milano, Italy, Fax: +39‐02‐50314405
- Istituto di Scienze e Tecnologie Molecolari, CNR, Via Golgi 19, 20133 Milano, Italy
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Alkorta I, Elguero J, Denisov GS. A review with comprehensive data on experimental indirect scalar NMR spin-spin coupling constants across hydrogen bonds. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2008; 46:599-624. [PMID: 18357569 DOI: 10.1002/mrc.2209] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Scalar NMR spin-spin coupling constants across hydrogen bonds are fundamental in structural studies and as test grounds for theoretical calculations. Since they are scattered among many articles of different kinds, it seems useful to collect them in the most comprehensive way.
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Affiliation(s)
- Ibon Alkorta
- Instituto de Química Médica (CSIC), Juan de la Cierva, 3, E-28006 Madrid, Spain.
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18
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2,7-Disubstituted proton sponges as borderline systems for investigating barrier-free intramolecular hydrogen bonds. Protonated 2,7-bis(trimethylsilyl)- and 2,7-di(hydroxymethyl)-1,8-bis(dimethylamino)naphthalenes. Tetrahedron 2008. [DOI: 10.1016/j.tet.2008.05.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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19
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Del Bene JE, Alkorta I, Elguero J. Spin-spin coupling across intramolecular N-H(+)-N hydrogen bonds in models for proton sponges: an ab initio investigation. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2008; 46:457-463. [PMID: 18297741 DOI: 10.1002/mrc.2199] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Ab initio calculations have been performed to obtain structures and coupling constants (1)J(N-H), (1h)J(H-N), and (2h)J(N-N) for models of proton sponges with symmetric and asymmetric N-H(+)-N intramolecular hydrogen bonds (IMHBs). For a given model, the asymmetric structure has a lower energy, a longer N-N distance, and a hydrogen bond which has a greater deviation from linearity. The computed values of (2h)J(N-N) for the models are significantly less than predicted values based on the distance dependence of (2h)J(N-N) for complexes with intermolecular N-H(+)-N hydrogen bonds. However, the reduced values of (2h)J(N-N) cannot be attributed solely to the distortion of the hydrogen bond in the models, but also reflect differences in s electron populations at the nitrogens in both the ground state and the excited states which couple to it through the Fermi-contact (FC) operator. Values of (2h)J(N-N) for IMHBs can be related quadratically to the N-N distances in the models, and demonstrate that there is no discrepancy between computed values of (2h)J(N-N) at the short N-N distances found in these systems and experimental data for proton sponges.
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Affiliation(s)
- Janet E Del Bene
- Department of Chemistry, Youngstown State University, Youngstown, Ohio 44555, USA.
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20
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Pietrzak M, Try AC, Andrioletti B, Sessler JL, Anzenbacher P, Limbach HH. The largest 15N-15N coupling constant across an NHN hydrogen bond. Angew Chem Int Ed Engl 2008; 47:1123-6. [PMID: 18161718 DOI: 10.1002/anie.200704411] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Mariusz Pietrzak
- Institut für Chemie und Biochemie, Freie Universität Berlin, Takustr. 3, 14195 Berlin, Germany
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21
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Pietrzak M, Try A, Andrioletti B, Sessler J, Anzenbacher P, Limbach HH. The Largest15N–15N Coupling Constant Across an NHN Hydrogen Bond. Angew Chem Int Ed Engl 2008. [DOI: 10.1002/ange.200704411] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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22
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Pietrzak M, Benedict C, Gehring H, Daltrozzo E, Limbach HH. NMR studies and DFT calculations of the symmetric intramolecular NHN-hydrogen bond of bis-(2-pyridyl)-acetonitrile: Isotope labeling strategy for the indirect 13C-detection of 15N15N couplings. J Mol Struct 2007. [DOI: 10.1016/j.molstruc.2007.04.023] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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23
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Jansma A, Zhang Q, Li B, Ding Q, Uno T, Bursulaya B, Liu Y, Furet P, Gray NS, Geierstanger BH. Verification of a Designed Intramolecular Hydrogen Bond in a Drug Scaffold by Nuclear Magnetic Resonance Spectroscopy. J Med Chem 2007; 50:5875-7. [DOI: 10.1021/jm700983a] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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24
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Synthesis of aluminum alkoxide and bis-alkoxide compounds containing bidentate pyrrolyl ligands. J Organomet Chem 2007. [DOI: 10.1016/j.jorganchem.2007.05.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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25
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Lloyd-Jones GC, Muñoz MP. Isotopic labelling in the study of organic and organometallic mechanism and structure: an account. J Labelled Comp Radiopharm 2007. [DOI: 10.1002/jlcr.1382] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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26
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Farrer NJ, McDonald R, McIndoe JS. Proton sponge phosphines: electrospray-active ligands. Dalton Trans 2006:4570-9. [PMID: 17016568 DOI: 10.1039/b609561e] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Attachment of a proton sponge to a phosphine ligand renders neutral complexes of the ligand highly amenable to analysis by electrospray ionisation mass spectrometry (ESI-MS). The ligand 1,8-bis(dimethylamino)naphthyldiphenylphosphine (3) is extremely efficient and highly selective in forming exclusively [M + H]+ ions, which may be detected at very low concentration. Ionisation efficiency of 3 in the presence of H+ approached 100%. The bis-substituted ligand bis{1,8-bis(dimethylamino)naphthyl}phenylphosphine (4) was also prepared and characterised, as were Fe(CO)4- (5c), Mn(eta5-C5H4Me)(CO)2- (6) and W(CO)5- (7) complexes of 3. Compounds 3, 3.HBr.EtOH, 4 and 5c were all structurally characterised.
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Affiliation(s)
- Nicola J Farrer
- Department of Chemistry, The University of Cambridge, Lensfield Road, Cambridge, UKCB2 1EW
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27
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28
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Alkorta I, Elguero J, Mó O, Yáñez * M, Del Bene JE. Do coupling constants and chemical shifts provide evidence for the existence of resonance-assisted hydrogen bonds? Mol Phys 2004. [DOI: 10.1080/00268970412331292885] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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29
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Bernatowicz P, Kowalewski J, Sandström D. NMR Relaxation Study of the Protonated Form of 1,8-Bis(dimethylamino)naphthalene in Isotropic Solution: Anisotropic Motion outside of Extreme Narrowing and Ultrafast Proton Transfer. J Phys Chem A 2004; 109:57-63. [PMID: 16839089 DOI: 10.1021/jp045454n] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The protonated form of 1,8-bis(dimethylamino)naphthalene (DMANH(+)) consists of a rigid, aromatic framework, substituted by two amino groups that are connected by a strong, symmetric (on the NMR time-scale) hydrogen bond bridge. The reorientational motion of the molecule in dimethylformamide-d7 solution was characterized by T(1) and NOE measurements for aromatic (13)C nuclei. Treating the reorientation of DMANH(+) as anisotropic rotational diffusion of a rigid body, the diffusion tensor was determined with good accuracy. Measurements and interpretation of (15)N T(1) and NOE indicate that the proton transfer between potential minima in the hydrogen bond bridge is faster than the molecular reorientation.
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Affiliation(s)
- Piotr Bernatowicz
- Physical Chemistry, Arrhenius Laboratory, Stockholm University, S-106 91 Stockholm, Sweden
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Vishweshwar P, Jagadeesh Babu N, Nangia A, Mason SA, Puschmann H, Mondal R, Howard JAK. Variable Temperature Neutron Diffraction Analysis of a Very Short O−H···O Hydrogen Bond in 2,3,5,6-Pyrazinetetracarboxylic Acid Dihydrate: Synthon-Assisted Short Oacid−H···Owater Hydrogen Bonds in a Multicenter Array. J Phys Chem A 2004. [DOI: 10.1021/jp0476848] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Peddy Vishweshwar
- School of Chemistry, University of Hyderabad, Hyderabad 500 046, India, Institut Laue-Langevin (6 rue Jules Horowitz) BP 156, 38042 Grenoble Cedex 9, France, and Department of Chemistry, University of Durham, Durham DH1 3LE, U.K
| | - N. Jagadeesh Babu
- School of Chemistry, University of Hyderabad, Hyderabad 500 046, India, Institut Laue-Langevin (6 rue Jules Horowitz) BP 156, 38042 Grenoble Cedex 9, France, and Department of Chemistry, University of Durham, Durham DH1 3LE, U.K
| | - Ashwini Nangia
- School of Chemistry, University of Hyderabad, Hyderabad 500 046, India, Institut Laue-Langevin (6 rue Jules Horowitz) BP 156, 38042 Grenoble Cedex 9, France, and Department of Chemistry, University of Durham, Durham DH1 3LE, U.K
| | - Sax A. Mason
- School of Chemistry, University of Hyderabad, Hyderabad 500 046, India, Institut Laue-Langevin (6 rue Jules Horowitz) BP 156, 38042 Grenoble Cedex 9, France, and Department of Chemistry, University of Durham, Durham DH1 3LE, U.K
| | - Horst Puschmann
- School of Chemistry, University of Hyderabad, Hyderabad 500 046, India, Institut Laue-Langevin (6 rue Jules Horowitz) BP 156, 38042 Grenoble Cedex 9, France, and Department of Chemistry, University of Durham, Durham DH1 3LE, U.K
| | - Raju Mondal
- School of Chemistry, University of Hyderabad, Hyderabad 500 046, India, Institut Laue-Langevin (6 rue Jules Horowitz) BP 156, 38042 Grenoble Cedex 9, France, and Department of Chemistry, University of Durham, Durham DH1 3LE, U.K
| | - Judith A. K. Howard
- School of Chemistry, University of Hyderabad, Hyderabad 500 046, India, Institut Laue-Langevin (6 rue Jules Horowitz) BP 156, 38042 Grenoble Cedex 9, France, and Department of Chemistry, University of Durham, Durham DH1 3LE, U.K
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Mallinson PR, Smith GT, Wilson CC, Grech E, Wozniak K. From weak interactions to covalent bonds: a continuum in the complexes of 1,8-bis(dimethylamino)naphthalene. J Am Chem Soc 2003; 125:4259-70. [PMID: 12670248 DOI: 10.1021/ja029389b] [Citation(s) in RCA: 125] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Experimental charge density distributions in a series of ionic complexes of 1,8-bis(dimethylamino)naphthalene (DMAN) with four different acids: 1,2,4,5-benzenetetracarboxylic acid (pyromellitic acid), 4,5-dichlorophthalic acid, dicyanoimidazole, and o-benzoic sulfimide dihydrate (saccharin) have been analyzed. Variation of charge density properties and derived local energy densities are investigated, over all inter- and intramolecular interactions present in altogether five complexes of DMAN. All the interactions studied [[O...H...O](-), C[bond]H...O, [N[bond]H...N](+), O[bond]H...O, C[bond]H...N, C pi...N pi, C pi...C pi, C[bond]H...Cl, N[bond]H(+)] follow exponential dependences of the electron density, local kinetic and potential energies at the bond critical points on the length of the interaction line. The local potential energy density at the bond critical points has a near-linear relationship to the electron density. There is also a Morse-like dependence of the laplacian of rho on the length of interaction line, which allows a differentiation of ionic and covalent bond characters. The strength of the interactions studied varies systematically with the relative penetration of the critical points into the van der Waals spheres of the donor and acceptor atoms, as well as on the interpenetration of the van der Waals spheres themselves. The strong, charge supported hydrogen bond in the DMANH(+) cation in each complex has a multicenter character involving a [[Me(2)N[bond]H....NMe(2)](+)....X(delta-)] assembly, where X is the nearest electronegative atom in the crystal lattice.
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Affiliation(s)
- Paul R Mallinson
- Chemistry Department, University of Glasgow, G12 8QQ, United Kingdom.
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Grech E, Klimkiewicz J, Nowicka-Scheibe J, Pietrzak M, Schilf W, Pozharski A, Ozeryanskii V, Bolvig S, Abildgaard J, Hansen P. Deuterium isotope effects on 15N, 13C and 1H chemical shifts of proton sponges. J Mol Struct 2002. [DOI: 10.1016/s0022-2860(02)00216-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Raab V, Kipke J, Gschwind RM, Sundermeyer J. 1,8-bis(tetramethylguanidino)naphthalene (TMGN): a new, superbasic and kinetically active "proton sponge". Chemistry 2002; 8:1682-93. [PMID: 11933096 DOI: 10.1002/1521-3765(20020402)8:7<1682::aid-chem1682>3.0.co;2-r] [Citation(s) in RCA: 157] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
1,8-Bis(tetramethylguanidino)naphthalene (TMGN, 1) is a new, readily accessible, and stable "proton sponge" with an experimental pK(BH(+)) value of 25.1 in MeCN, which is nearly seven orders of magnitude higher in basicity than the classical proton sponge 1,8-bis(dimethylamino)-naphthalene (DMAN). Because of the sterically less crowded character of the proton-accepting sp(2)-nitrogen atoms, TMGN also has a higher kinetic basicity than DMAN, which is shown by time-resolved proton self-exchange reactions. TMGN is more resistant to hydrolysis and is a weaker nucleophile towards the alkylating agent EtI in comparison to the commercially available guanidine 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene (MTBD). Crystal structures of the free base, of the mono- and bisprotonated base were determined. The dynamic behavior of all three species in solution was investigated by variable-temperature (1)H NMR experiments. DeltaG (++) values obtained by spectra simulation reveal a concerted mechanism of rotation about the C-N bonds of the protonated forms of TMGN.
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Affiliation(s)
- Volker Raab
- Fachbereich Chemie, Philipps-Universität Marburg Hans-Meerwein-Strasse, 35032 Marburg, Germany
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Dash AK, Jordan RF. Vinyl C−H Activation Reactions of Vinyl Esters Mediated by B(C6F5)3. Organometallics 2002. [DOI: 10.1021/om010515e] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Aswini K. Dash
- Department of Chemistry, 5735 South Ellis Avenue, The University of Chicago, Chicago, Illinois 60637
| | - Richard F. Jordan
- Department of Chemistry, 5735 South Ellis Avenue, The University of Chicago, Chicago, Illinois 60637
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