1
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Toomey R, Powell J, Cheever J, Harper JK. Distinguishing between COOH, COO - , and hydrogen disordered COOH sites in solids with 13 C chemical shift anisotropy and T 1 measurements. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2024; 62:190-197. [PMID: 38237932 DOI: 10.1002/mrc.5425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 11/24/2023] [Accepted: 12/21/2023] [Indexed: 02/13/2024]
Abstract
Since 1993, it has been known that 13 C chemical shift tensor (i.e., δ11 , δ22 , and δ33 ) provides information sufficient to distinguish between COOH and COO- sites. Herein, four previously unreported metrics are proposed for differentiating COOH/COO- moieties. A new relationship is also introduced that correlates the asymmetry (i.e., δ11 -δ22 ) of COOH sites to the proximity of hydrogen bond donating partners within 2.6 Å with high accuracy (±0.05 Å). Conversely, a limitation to all proposed metrics is that they fail to distinguish between COO- and hydrogen disordered COOH sites. To reconcile this omission, a new approach is proposed based on T1 measurements of both 1 H and 13 C. The 13 C T1 values are particularly sensitive with the T1 for hydrogen disordered COOH moieties found to be nearly six times smaller than T1 's from COO- sites.
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Affiliation(s)
- Ryan Toomey
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah, USA
| | - Jacob Powell
- Department of Chemistry, Drexel University, Philadelphia, Pennsylvania, USA
| | - Jacob Cheever
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah, USA
| | - James K Harper
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah, USA
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2
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Li J, Chen J, Wang Y, Yao L. Detecting the Hydrogen Bond Cooperativity in a Protein β-Sheet by H/D Exchange. Int J Mol Sci 2022; 23:ijms232314821. [PMID: 36499147 PMCID: PMC9740688 DOI: 10.3390/ijms232314821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 11/22/2022] [Accepted: 11/24/2022] [Indexed: 12/05/2022] Open
Abstract
The hydrogen bond (H-bond) cooperativity in the β-sheet of GB3 is investigated by a NMR hydrogen/deuterium (H/D) exchange method. It is shown that the weakening of one backbone N-H…O=C H-bond between two β-strands, β1 and β2, due to the exchange of NH to ND of the H-bond donor in β1, perturbs the chemical shift of 13Cα, 13Cβ, 1Hα, 1HN, and 15N of the H-bond acceptor and its following residue in β2. Quantum mechanical calculations suggest that the -H-bond chemical shift isotope effect is caused by the structural reorganization in response to the H-bond weakening. This structural reorganization perturbs four neighboring H-bonds, with three being weaker and one being stronger, indicating that three H-bonds are cooperative and one is anticooperative with the perturbed H-bond. The sign of the cooperativity depends on the relative position of the H-bonds. This H-bond cooperativity, which contributes to β-sheet stability overall, can be important for conformational coupling across the β-sheet.
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Affiliation(s)
- Jingwen Li
- College of Chemistry and Chemical Engineering, China University of Petroleum (East China), Qingdao 266580, China
| | - Jingfei Chen
- Qingdao New Energy Shandong Laboratory, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China
- Shandong Energy Institute, Qingdao 266101, China
| | - Yefei Wang
- Qingdao New Energy Shandong Laboratory, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China
- Shandong Energy Institute, Qingdao 266101, China
- Correspondence: (Y.W.); (L.Y.)
| | - Lishan Yao
- Qingdao New Energy Shandong Laboratory, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China
- Shandong Energy Institute, Qingdao 266101, China
- Correspondence: (Y.W.); (L.Y.)
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3
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Drago VN, Dajnowicz S, Parks JM, Blakeley MP, Keen DA, Coquelle N, Weiss KL, Gerlits O, Kovalevsky A, Mueser TC. An N⋯H⋯N low-barrier hydrogen bond preorganizes the catalytic site of aspartate aminotransferase to facilitate the second half-reaction. Chem Sci 2022; 13:10057-10065. [PMID: 36128223 PMCID: PMC9430417 DOI: 10.1039/d2sc02285k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 07/20/2022] [Indexed: 11/21/2022] Open
Abstract
Pyridoxal 5'-phosphate (PLP)-dependent enzymes have been extensively studied for their ability to fine-tune PLP cofactor electronics to promote a wide array of chemistries. Neutron crystallography offers a straightforward approach to studying the electronic states of PLP and the electrostatics of enzyme active sites, responsible for the reaction specificities, by enabling direct visualization of hydrogen atom positions. Here we report a room-temperature joint X-ray/neutron structure of aspartate aminotransferase (AAT) with pyridoxamine 5'-phosphate (PMP), the cofactor product of the first half reaction catalyzed by the enzyme. Between PMP NSB and catalytic Lys258 Nζ amino groups an equally shared deuterium is observed in an apparent low-barrier hydrogen bond (LBHB). Density functional theory calculations were performed to provide further evidence of this LBHB interaction. The structural arrangement and the juxtaposition of PMP and Lys258, facilitated by the LBHB, suggests active site preorganization for the incoming ketoacid substrate that initiates the second half-reaction.
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Affiliation(s)
- Victoria N Drago
- Department of Chemistry and Biochemistry, University of Toledo Toledo OH 43606 USA
- Neutron Scattering Division, Oak Ridge National Laboratory Oak Ridge TN 37831 USA
| | - Steven Dajnowicz
- Department of Chemistry and Biochemistry, University of Toledo Toledo OH 43606 USA
- Neutron Scattering Division, Oak Ridge National Laboratory Oak Ridge TN 37831 USA
| | - Jerry M Parks
- Biosciences Division, Oak Ridge National Laboratory Oak Ridge TN 37831 USA
| | - Matthew P Blakeley
- Large Scale Structures Group, Institut Laue-Langevin 71 Avenue des Martyrs 38000 Grenoble France
| | - David A Keen
- ISIS Facility, Rutherford Appleton Laboratory, Harwell Campus Didcot OX11 0QX UK
| | - Nicolas Coquelle
- Large Scale Structures Group, Institut Laue-Langevin 71 Avenue des Martyrs 38000 Grenoble France
| | - Kevin L Weiss
- Neutron Scattering Division, Oak Ridge National Laboratory Oak Ridge TN 37831 USA
| | - Oksana Gerlits
- Department of Natural Sciences, Tennessee Wesleyan University Athens TN 37303 USA
| | - Andrey Kovalevsky
- Neutron Scattering Division, Oak Ridge National Laboratory Oak Ridge TN 37831 USA
| | - Timothy C Mueser
- Department of Chemistry and Biochemistry, University of Toledo Toledo OH 43606 USA
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4
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Liang BD, Jin T, Miao LP, Chai CY, Fan CC, Han XB, Zhang W. Deuteration triggered downward shift of dielectric phase transition temperature in a hydrogen-bonded molecular crystal. CHINESE CHEM LETT 2022. [DOI: 10.1016/j.cclet.2021.08.032] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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5
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Nikitenko SI, Chave T, Virot M, Pflieger R. Simultaneous H/D and 13C/ 12C Anomalous Kinetic Isotope Effects during the Sonolysis of Water in the Presence of Carbon Monoxide. J Phys Chem Lett 2022; 13:42-48. [PMID: 34958222 DOI: 10.1021/acs.jpclett.1c03744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Splitting of water molecules driven by ultrasound plays a central role in sonochemistry. While studies of sonoluminescence revealed the formation of a plasma inside the cavitation bubble, much less is known about the contribution of plasma chemical processes to the sonochemical mechanisms. Herein, we report for the first time sonochemical processes in water saturated with pure CO. The presence of CO causes a large increase in the H/D kinetic isotope effect (KIE) to αH = 14.6 ± 1.8 in a 10% H2O/D2O mixture under 20 kHz ultrasound. The anomalous H/D KIE is attributed to electron quantum tunneling in the plasma produced by cavitation. In addition, CO2 formed simultaneously with hydrogen during the sonochemical process is enriched with the 13C isotope, which indicates a V-V pumping mechanism typical for non-equilibrium plasma. Both observed KIEs unambiguously point to the contribution of quantum effects in sonochemical mechanisms.
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Affiliation(s)
- Sergey I Nikitenko
- ICSM, Univ Montpellier, UMR 5257, CEA, CNRS, ENSCM, Marcoule, F-30207 Bagnols sur Cèze Cedex, France
| | - Tony Chave
- ICSM, Univ Montpellier, UMR 5257, CEA, CNRS, ENSCM, Marcoule, F-30207 Bagnols sur Cèze Cedex, France
| | - Matthieu Virot
- ICSM, Univ Montpellier, UMR 5257, CEA, CNRS, ENSCM, Marcoule, F-30207 Bagnols sur Cèze Cedex, France
| | - Rachel Pflieger
- ICSM, Univ Montpellier, UMR 5257, CEA, CNRS, ENSCM, Marcoule, F-30207 Bagnols sur Cèze Cedex, France
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6
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Alkorta I, Legon A. Reduced nucleophilicity: an intrinsic property of the Lewis base atom interacting with H in hydrogen-bonds with Lewis acids HX (X = F, Cl, Br, I, CN, CCH, CP). Phys Chem Chem Phys 2022; 24:25822-25833. [DOI: 10.1039/d2cp03999k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Equilibrium hydrogen-bond dissociation energies De for the process B⋯HX = B + HX are calculated at the CCSD(T)(F12c)/cc-pVDZ-F12 level for ∼190 complexes B⋯HX. Reduced nucleophilicities of Lewis bases B are determined.
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Affiliation(s)
- Ibon Alkorta
- Instituto de Química Médica (IQM-CSIC), Juan de la Cierva, 3, E-28006 Madrid, Spain
| | - Anthony Legon
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK
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7
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Liu Y, Ho LTA, Huang GZ, Chen YC, Ungur L, Liu JL, Tong ML. Magnetization Dynamics on Isotope-Isomorphic Holmium Single-Molecule Magnets. Angew Chem Int Ed Engl 2021; 60:27282-27287. [PMID: 34668633 DOI: 10.1002/anie.202112764] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2021] [Revised: 10/16/2021] [Indexed: 11/08/2022]
Abstract
Here we reported the deuteration of the metal-binding equatorial water molecules in a reported HoIII single-molecule magnet (SMM) with pentagonal-bipyramidal geometry, from [Ho(CyPh2 PO)2 (H2 O)5 ]3+ to [Ho(CyPh2 PO)2 (D2 O)5 ]3+ . The hyperfine structures originating from the nuclear spin of 165 HoIII can be clearly observed. Moreover, the resulting magnetization dynamics revealed the switch of the relative relaxation rates for the two isotope-isomorphic complexes-respectively faster/slower at low/high temperature. The noticeable isotope effect arises from not only the paramagnetic metal center but also the diamagnetic ligands, which can be explained by the ab initio calculated tunnel splitting and the involvement of the super-hyperfine interaction related to the difference in the nuclear spin number of protium (1 H, I=1 /2 ) and deuterium (2 H, I=1).
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Affiliation(s)
- Yang Liu
- Key Lab of Bioinorganic and Synthetic Chemistry of Ministry of Education, School of Chemistry, Sun Yat-Sen University, Guangzhou, 510006, P. R. China
| | - Le Tuan Anh Ho
- Department of Chemistry, National University of Singapore, Singapore, 117543, Singapore
| | - Guo-Zhang Huang
- Key Lab of Bioinorganic and Synthetic Chemistry of Ministry of Education, School of Chemistry, Sun Yat-Sen University, Guangzhou, 510006, P. R. China
| | - Yan-Cong Chen
- Key Lab of Bioinorganic and Synthetic Chemistry of Ministry of Education, School of Chemistry, Sun Yat-Sen University, Guangzhou, 510006, P. R. China
| | - Liviu Ungur
- Department of Chemistry, National University of Singapore, Singapore, 117543, Singapore
| | - Jun-Liang Liu
- Key Lab of Bioinorganic and Synthetic Chemistry of Ministry of Education, School of Chemistry, Sun Yat-Sen University, Guangzhou, 510006, P. R. China
| | - Ming-Liang Tong
- Key Lab of Bioinorganic and Synthetic Chemistry of Ministry of Education, School of Chemistry, Sun Yat-Sen University, Guangzhou, 510006, P. R. China
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8
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Liu Y, Ho LTA, Huang G, Chen Y, Ungur L, Liu J, Tong M. Magnetization Dynamics on Isotope‐Isomorphic Holmium Single‐Molecule Magnets. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202112764] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Yang Liu
- Key Lab of Bioinorganic and Synthetic Chemistry of Ministry of Education School of Chemistry Sun Yat-Sen University Guangzhou 510006 P. R. China
| | - Le Tuan Anh Ho
- Department of Chemistry National University of Singapore Singapore 117543 Singapore
| | - Guo‐Zhang Huang
- Key Lab of Bioinorganic and Synthetic Chemistry of Ministry of Education School of Chemistry Sun Yat-Sen University Guangzhou 510006 P. R. China
| | - Yan‐Cong Chen
- Key Lab of Bioinorganic and Synthetic Chemistry of Ministry of Education School of Chemistry Sun Yat-Sen University Guangzhou 510006 P. R. China
| | - Liviu Ungur
- Department of Chemistry National University of Singapore Singapore 117543 Singapore
| | - Jun‐Liang Liu
- Key Lab of Bioinorganic and Synthetic Chemistry of Ministry of Education School of Chemistry Sun Yat-Sen University Guangzhou 510006 P. R. China
| | - Ming‐Liang Tong
- Key Lab of Bioinorganic and Synthetic Chemistry of Ministry of Education School of Chemistry Sun Yat-Sen University Guangzhou 510006 P. R. China
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9
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NMR Properties of the Cyanide Anion, a Quasisymmetric Two-Faced Hydrogen Bonding Acceptor. Symmetry (Basel) 2021. [DOI: 10.3390/sym13071298] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The isotopically enriched cyanide anion, (13C≡15N)−, has a great potential as the NMR probe of non-covalent interactions. However, hydrogen cyanide is highly toxic and can decompose explosively. It is therefore desirable to be able to theoretically estimate any valuable results of certain experiments in advance in order to carry out experimental studies only for the most suitable molecular systems. We report the effect of hydrogen bonding on NMR properties of 15N≡13CH···X and 13C≡15NH···X hydrogen bonding complexes in solution, where X = 19F, 15N, and O=31P, calculated at the ωB97XD/def2tzvp and the polarizable continuum model (PCM) approximations. In many cases, the isotropic 13C and 15N chemical shieldings of the cyanide anion are not the most informative NMR properties of such complexes. Instead, the anisotropy of these chemical shieldings and the values of scalar coupling constants, including those across hydrogen bonds, can be used to characterize the geometry of such complexes in solids and solutions. 1J(15N13C) strongly correlates with the length of the N≡C bond.
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10
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Fei S, Hsu WL, Delaunay JJ, Daiguji H. Molecular dynamics study of water confined in MIL-101 metal-organic frameworks. J Chem Phys 2021; 154:144503. [PMID: 33858173 DOI: 10.1063/5.0040909] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Molecular dynamics simulations of water adsorbed in Material Institute Lavoisier MIL-101(Cr) metal-organic frameworks are performed to analyze the kinetic properties of water molecules confined in the framework at 298.15 K and under different vapor pressures and clarify the water adsorption mechanism in MIL-101(Cr). The terahertz frequency-domain spectra (THz-FDS) of water are calculated by applying fast Fourier transform to the configurational data of water molecules. According to the characteristic frequencies in the THz-FDS, the dominant motions of water molecules in MIL-101(Cr) can be categorized into three types: (1) low-frequency translational motion (0-0.5 THz), (2) medium-frequency vibrational motion (2-2.5 THz), and (3) high-frequency vibrational motion (>6 THz). Each type of water motion is confirmed by visualizing the water configuration in MIL-101(Cr). The ratio of the number of water molecules with low-frequency translational motion to the total number of water molecules increases with the increase in vapor pressure. In contrast, that with medium-frequency vibrational motion is found to decrease with vapor pressure, exhibiting a pronounced decrease after water condensation has started in the cavities. That with the high-frequency vibrational motion is almost independent of the vapor pressure. The interactions between different types of water molecules affect the THz-FDS. Furthermore, the self-diffusion coefficient and the velocity auto-correlation function are calculated to clarify the adsorption state of the water confined in MIL-101(Cr). To confirm that the general trend of the THz-FDS does not depend on the water model, the simulations are performed using three water models, namely, rigid SPC/E, flexible SPC/E, and rigid TIP5PEw.
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Affiliation(s)
- Shubo Fei
- Department of Mechanical Engineering, The University of Tokyo, Tokyo 113-8656, Japan
| | - Wei-Lun Hsu
- Department of Mechanical Engineering, The University of Tokyo, Tokyo 113-8656, Japan
| | - Jean-Jacques Delaunay
- Department of Mechanical Engineering, The University of Tokyo, Tokyo 113-8656, Japan
| | - Hirofumi Daiguji
- Department of Mechanical Engineering, The University of Tokyo, Tokyo 113-8656, Japan
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11
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Grabowski SJ. Hydrogen Bond and Other Lewis Acid-Lewis Base Interactions as Preliminary Stages of Chemical Reactions. Molecules 2020; 25:E4668. [PMID: 33066201 PMCID: PMC7587390 DOI: 10.3390/molecules25204668] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 10/09/2020] [Accepted: 10/10/2020] [Indexed: 01/21/2023] Open
Abstract
Various Lewis acid-Lewis base interactions are discussed as initiating chemical reactions and processes. For example, the hydrogen bond is often a preliminary stage of the proton transfer process or the tetrel and pnicogen bonds lead sometimes to the SN2 reactions. There are numerous characteristics of interactions being first stages of reactions; one can observe a meaningful electron charge transfer from the Lewis base unit to the Lewis acid; such interactions possess at least partly covalent character, one can mention other features. The results of different methods and approaches that are applied in numerous studies to describe the character of interactions are presented here. These are, for example, the results of the Quantum Theory of Atoms in Molecules, of the decomposition of the energy of interaction or of the structure-correlation method.
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Affiliation(s)
- Sławomir J. Grabowski
- Polimero eta Material Aurreratuak: Fisika, Kimika eta Teknologia, Kimika Fakultatea, Euskal Herriko Unibertsitatea UPV/EHU & Donostia International Physics Center (DIPC) PK 1072, 20080 Donostia, Euskadi, Spain; ; Tel.: +34-943-018-187
- IKERBASQUE, Basque Foundation for Science, 48011 Bilbao, Spain
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12
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Grabowski SJ. Triel bond and coordination of triel centres – Comparison with hydrogen bond interaction. Coord Chem Rev 2020. [DOI: 10.1016/j.ccr.2019.213171] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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13
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Litman Y, Behler J, Rossi M. Temperature dependence of the vibrational spectrum of porphycene: a qualitative failure of classical-nuclei molecular dynamics. Faraday Discuss 2020; 221:526-546. [DOI: 10.1039/c9fd00056a] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Approximate quantum dynamics succeed in predicting a temperature-dependent blue-shift of the high-frequency stretch bands that arise from vibrational coupling between low-frequency thermally activated modes and high-frequency quantized ones. Classical nuclei molecular dynamics fail and instead predict a red-shift.
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Affiliation(s)
- Yair Litman
- Fritz Haber Institute of the Max Planck Society
- 14195 Berlin
- Germany
| | - Jörg Behler
- Universität Göttingen
- Institut für Physikalische Chemie, Theoretische Chemie
- 37077 Göttingen
- Germany
| | - Mariana Rossi
- Fritz Haber Institute of the Max Planck Society
- 14195 Berlin
- Germany
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14
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Montero MDA, Martínez FA, Aucar GA. Magnetic descriptors of hydrogen bonds in malonaldehyde and its derivatives. Phys Chem Chem Phys 2019; 21:19742-19754. [PMID: 31378797 DOI: 10.1039/c9cp02995h] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The nature of the hydrogen bond, HB, as such is still unknown, though a few of its most fundamental features has been uncovered during the last few decades. At the moment, it is possible to obtain reliable results for only a few of its broadest properties, like magnetic properties. They could give new insights into the physics underlying the strength and features of HBs. In this article we analyze the electronic origin of the NMR spectroscopic parameters of malonaldehyde, MA, and some substituted MAs. These substituted MAs are such that the H-bonds are assisted by one of two phenomena: resonance, RAHB, or charge, CAHB. We have studied the dependences of these parameters on two of the main factors which contribute the most to both phenomena, the geometrical and electronic factors, and found out how they can be used to characterize RAHB or CAHB by means of reliable theoretical calculations. We show that in the set of compounds analyzed here (i) the shielding of the proton of the H-bond can be used as a measure of the strength of the HB and (ii) the relation between the contact and non-contact mechanisms of J-couplings between donor and acceptor atoms is a reliable descriptor of whether the H-bond is resonance assisted or charge assisted.
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Affiliation(s)
- Marcos D A Montero
- Institute of Modelling and Innovation on Technology, IMIT CONICET-UNNE, Corrientes, Argentina.
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15
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Giba IS, Mulloyarova VV, Denisov GS, Tolstoy PM. Influence of Hydrogen Bonds in 1:1 Complexes of Phosphinic Acids with Substituted Pyridines on 1H and 31P NMR Chemical Shifts. J Phys Chem A 2019; 123:2252-2260. [PMID: 30807160 DOI: 10.1021/acs.jpca.9b00625] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Two series of 1:1 complexes with strong OHN hydrogen bonds formed by dimethylphosphinic and phenylphosphinic acids with 10 substituted pyridines were studied experimentally by liquid state NMR spectroscopy at 100 K in solution in a low-freezing polar aprotic solvent mixture CDF3/CDClF2. The hydrogen bond geometries were estimated using previously established correlations linking 1H NMR chemical shifts of bridging protons with the O···H and H···N interatomic distances. A new correlation is proposed allowing one to estimate the interatomic distance within the OHN bridge from the displacement of 31P NMR signal upon complexation. We show that the values of 31P NMR chemical shifts are affected by an additional CH···O hydrogen bond formed between the P═O group of the acid and ortho-CH proton of the substituted pyridines. Breaking of this bond in the case of 2,6-disubstituted bases shifts the 31P NMR signal by ca. 1.5 ppm to the high field.
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Affiliation(s)
- Ivan S Giba
- Institute of Chemistry , St. Petersburg State University , Universitetskij pr. 26 , 198504 St. Petersburg , Russia.,Department of Physics , St. Petersburg State University , Ulyanovskaya 1 , 198504 St. Petersburg , Russia
| | - Valeria V Mulloyarova
- Institute of Chemistry , St. Petersburg State University , Universitetskij pr. 26 , 198504 St. Petersburg , Russia
| | - Gleb S Denisov
- Department of Physics , St. Petersburg State University , Ulyanovskaya 1 , 198504 St. Petersburg , Russia
| | - Peter M Tolstoy
- Institute of Chemistry , St. Petersburg State University , Universitetskij pr. 26 , 198504 St. Petersburg , Russia
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16
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Jin T, Zhang W. Geometric H/D isotope effect in a series of organic salts involving short O–H⋯O hydrogen bonds between carboxyl and carboxylate groups. CrystEngComm 2019. [DOI: 10.1039/c9ce00734b] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Noticeable elongations of donor–acceptor distances upon deuteration are confirmed in short O–H⋯O hydrogen bonds between carboxyl and carboxylate groups.
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Affiliation(s)
- Tong Jin
- Ordered Matter Science Research Center and Jiangsu Key Laboratory for Science and Applications of Molecular Ferroelectrics
- Southeast University
- Nanjing 211189
- China
| | - Wen Zhang
- Ordered Matter Science Research Center and Jiangsu Key Laboratory for Science and Applications of Molecular Ferroelectrics
- Southeast University
- Nanjing 211189
- China
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17
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Gregorovič A, Apih T, Žagar V, Seliger J. 14N NQR spectroscopy reveals the proton position in N–H⋯N bonds: a case study with proton sponges. Phys Chem Chem Phys 2019; 21:306-313. [DOI: 10.1039/c8cp05183f] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The position of the proton in intramolecular N–H⋯N hydrogen bonds has been determined to a high accuracy with 14N Nuclear Quadrupole Resonance (NQR) spectroscopy.
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Affiliation(s)
| | - Tomaž Apih
- Institute “Jožef Stefan”
- 1000 Ljubljana
- Slovenia
| | | | - Janez Seliger
- Institute “Jožef Stefan”
- 1000 Ljubljana
- Slovenia
- Faculty of Mathematics and Physics
- University of Ljubljana
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18
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Tupikina E, Denisov G, Melikova S, Kucherov S, Tolstoy P. New look at the Badger-Bauer rule: Correlations of spectroscopic IR and NMR parameters with hydrogen bond energy and geometry. FHF complexes. J Mol Struct 2018. [DOI: 10.1016/j.molstruc.2018.03.018] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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19
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Wang L, Uribe-Romo FJ, Mueller LJ, Harper JK. Predicting anisotropic thermal displacements for hydrogens from solid-state NMR: a study on hydrogen bonding in polymorphs of palmitic acid. Phys Chem Chem Phys 2018; 20:8475-8487. [PMID: 29431770 PMCID: PMC5878182 DOI: 10.1039/c7cp06724k] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The hydrogen-bonding environments at the COOH moiety in eight polycrystalline polymorphs of palmitic acid are explored using solid-state NMR. Although most phases have no previously reported crystal structure, measured 13C chemical shift tensors for COOH moieties, combined with DFT modeling establish that all phases crystallize with a cyclic dimer (R22(8)) hydrogen bonding arrangement. Phases A2, Bm and Em have localized OH hydrogens while phase C has a dynamically disordered OH hydrogen. The phase designated As is a mix of five forms, including 27.4% of Bm and four novel phases not fully characterized here due to insufficient sample mass. For phases A2, Bm, Em, and C the anisotropic uncertainties in the COOH hydrogen atom positions are established using a Monte Carlo sampling scheme. Sampled points are retained or rejected at the ±1σ level based upon agreement of DFT computed 13COOH tensors with experimental values. The collection of retained hydrogen positions bear a remarkable resemblance to the anisotropic displacement parameters (i.e. thermal ellipsoids) from diffraction studies. We posit that this similarity is no mere coincidence and that the two are fundamentally related. The volumes of NMR-derived anisotropic displacement ellipsoids for phases with localized OH hydrogens are 4.1 times smaller than those derived from single crystal X-ray diffraction and 1.8 times smaller than the volume of benchmark single crystal neutron diffraction values.
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Affiliation(s)
- Luther Wang
- Department of Chemistry, University of Central Florida, 4111 Libra Drive, Orlando, FL 32816, USA.
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20
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Mulloyarova VV, Giba IS, Kostin MA, Denisov GS, Shenderovich IG, Tolstoy PM. Cyclic trimers of phosphinic acids in polar aprotic solvent: symmetry, chirality and H/D isotope effects on NMR chemical shifts. Phys Chem Chem Phys 2018; 20:4901-4910. [PMID: 29384171 DOI: 10.1039/c7cp08130h] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The hydrogen-bonded self-associates of dimethylphosphinic (1), diphenylphosphoric (2), phenylphosphinic (3), and bis(2,4,4-trimethylpentyl)phosphinic (4) acids have been studied by using liquid-state NMR down to 100 K in a low-freezing polar solvent, CDF3/CDClF2. The H/D isotope effects on 1H NMR chemical shifts caused by partial deuteration of hydroxyl groups unambiguously reveal the stoichiometry of the self-associates and the cooperativity of their hydrogen bonds. In all cases, cyclic trimers are the dominant form, while cyclic dimers are present as a minor form for 1 and 2. Due to the asymmetry of substituents, cyclic trimers of 3 exist in two isomeric forms, depending on the orientation of the phenyl groups with respect to the plane of the hydrogen bonds. The racemic mixture of 4 leads to the coexistence of up to 64 isomers of cyclic trimers, many of which are chemically equivalent or effectively isochronous. The mole fractions of such isomers deviate from the statistically expected values. This feature could provide information about the relative stabilization energies of hydrogen-bonded chiral self-associates. The complexation of 4 with SbCl5 (complex 5) suppresses the self-association and 5 exists exclusively in the monomeric form with chemically non-equivalent 31P nuclei in RS, SR and RR/SS forms.
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Affiliation(s)
- V V Mulloyarova
- Institute of Chemistry, St. Petersburg State University, Russia.
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21
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Shi C, Zhang X, Yu CH, Yao YF, Zhang W. Geometric isotope effect of deuteration in a hydrogen-bonded host-guest crystal. Nat Commun 2018; 9:481. [PMID: 29396512 PMCID: PMC5797174 DOI: 10.1038/s41467-018-02931-8] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Accepted: 01/09/2018] [Indexed: 11/11/2022] Open
Abstract
Deuteration of a hydrogen bond by replacing protium (H) with deuterium (D) can cause geometric changes in the hydrogen bond, known as the geometric H/D isotope effect (GIE). Understanding the GIEs on global structures and bulk properties is of great importance to study structure–property relationships of hydrogen-bonded systems. Here, we report a hydrogen-bonded host–guest crystal, imidazolium hydrogen terephthalate, that exemplifies striking GIEs on its hydrogen bonds, phases, and bulk dielectric transition property. Upon deuteration, the donor–acceptor distance in the O–H···O hydrogen bonds in the host structure is found to increase, which results in a change in the global hydrogen-bonded supramolecular structure and the emergence of a new phase (i.e., isotopic polymorphism). Consequently, the dynamics of the confined guest, which depend on the internal pressure exerted by the host framework, are substantially altered, showing a downward shift of the dielectric switching temperature. Deuterating a hydrogen bond can change the bond’s geometry, a phenomenon known as the geometric isotope effect (GIE). Here, the authors find that a hydrogen-bonded host–guest crystal, imidazolium hydrogen terephthalate, exhibits significant GIE on its hydrogen bonds, changing its crystal phases and bulk dielectric properties.
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Affiliation(s)
- Chao Shi
- Ordered Matter Science Research Center and Jiangsu Key Laboratory for Science and Applications of Molecular Ferroelectrics, Southeast University, 211189, Nanjing, China
| | - Xi Zhang
- Department of Physics & Shanghai Key Laboratory of Magnetic Resonance, School of Physics and Materials Science, East China Normal University, North Zhongshan Road 3663, 200062, Shanghai, China
| | - Chun-Hua Yu
- Ordered Matter Science Research Center and Jiangsu Key Laboratory for Science and Applications of Molecular Ferroelectrics, Southeast University, 211189, Nanjing, China
| | - Ye-Feng Yao
- Department of Physics & Shanghai Key Laboratory of Magnetic Resonance, School of Physics and Materials Science, East China Normal University, North Zhongshan Road 3663, 200062, Shanghai, China. .,NYU-ECNU Institute of Physics at NYU Shanghai, 3663 Zhongshan Road North, 200062, Shanghai, China.
| | - Wen Zhang
- Ordered Matter Science Research Center and Jiangsu Key Laboratory for Science and Applications of Molecular Ferroelectrics, Southeast University, 211189, Nanjing, China.
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22
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Saegusa Y, Ishizuka T, Shiota Y, Yoshizawa K, Kojima T. NH Tautomerism of a Quadruply Fused Porphyrin: Rigid Fused Structure Delays the Proton Transfer. J Phys Chem B 2018; 122:316-327. [PMID: 29224345 DOI: 10.1021/acs.jpcb.7b10945] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We report herein NH tautomerism of a freebase derivative of a quadruply fused porphyrin (H2QFP-Mes, 3), which has one mesityl group at one of the β-positions of the nonfused pyrroles to lower the structural symmetry, allowing us to observe the NH tautomerism with 1H NMR spectroscopy. Compound 3 was revealed to have the two inner NH protons on the two nonfused pyrroles, and the NH tautomerism of 3 was evidenced by variable-temperature (VT) 1H NMR experiments in various deuterated solvents. The VT-NMR studies revealed that the activation barrier for the NH tautomerism of 3 was larger than that of tetraphenylporphyrin. The positive activation entropy (ΔS‡ = 89 J mol-1 K-1), determined for the NH tautomerism, can be explained by dissociation of the π-π stacked dimer structure of 3 in the ground state, as evidenced by the crystal structure and NMR measurements. On the basis of the kinetic studies and density functional theory calculations, the stability of intermediates in the NH tautomerism of 3 and the transition states have been discussed in detail.
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Affiliation(s)
- Yuta Saegusa
- Department of Chemistry, Graduate School of Pure and Applied Sciences, University of Tsukuba , 1-1-1 Tennoudai, Tsukuba, Ibaraki 305-8571, Japan
| | - Tomoya Ishizuka
- Department of Chemistry, Graduate School of Pure and Applied Sciences, University of Tsukuba , 1-1-1 Tennoudai, Tsukuba, Ibaraki 305-8571, Japan
| | - Yoshihito Shiota
- Institute for Materials Chemistry and Engineering and IRCCS, Kyushu University , Motooka, Nishi-Ku, Fukuoka 819-0395, Japan
| | - Kazunari Yoshizawa
- Institute for Materials Chemistry and Engineering and IRCCS, Kyushu University , Motooka, Nishi-Ku, Fukuoka 819-0395, Japan
| | - Takahiko Kojima
- Department of Chemistry, Graduate School of Pure and Applied Sciences, University of Tsukuba , 1-1-1 Tennoudai, Tsukuba, Ibaraki 305-8571, Japan
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23
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Grabowski SJ. Hydrogen bonds, and σ-hole and π-hole bonds – mechanisms protecting doublet and octet electron structures. Phys Chem Chem Phys 2017; 19:29742-29759. [DOI: 10.1039/c7cp06393h] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
For various interactions electron charge shifts try to protect the former doublet or octet electronic structure of the Lewis acid centre.
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Affiliation(s)
- Sławomir J. Grabowski
- Faculty of Chemistry
- University of the Basque Country and Donostia International Physics Center (DIPC)
- P.K. 1072 20080 Donostia
- Spain
- IKERBASQUE
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24
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Fang W, Chen J, Rossi M, Feng Y, Li XZ, Michaelides A. Inverse Temperature Dependence of Nuclear Quantum Effects in DNA Base Pairs. J Phys Chem Lett 2016; 7:2125-31. [PMID: 27195654 PMCID: PMC4933496 DOI: 10.1021/acs.jpclett.6b00777] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Despite the inherently quantum mechanical nature of hydrogen bonding, it is unclear how nuclear quantum effects (NQEs) alter the strengths of hydrogen bonds. With this in mind, we use ab initio path integral molecular dynamics to determine the absolute contribution of NQEs to the binding in DNA base pair complexes, arguably the most important hydrogen-bonded systems of all. We find that depending on the temperature, NQEs can either strengthen or weaken the binding within the hydrogen-bonded complexes. As a somewhat counterintuitive consequence, NQEs can have a smaller impact on hydrogen bond strengths at cryogenic temperatures than at room temperature. We rationalize this in terms of a competition of NQEs between low-frequency and high-frequency vibrational modes. Extending this idea, we also propose a simple model to predict the temperature dependence of NQEs on hydrogen bond strengths in general.
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Affiliation(s)
- Wei Fang
- Thomas Young Centre, London Centre for Nanotechnology, Department of Chemistry, and Department of
Physics and Astronomy, University College
London, London WC1E 6BT, United Kingdom
| | - Ji Chen
- Thomas Young Centre, London Centre for Nanotechnology, Department of Chemistry, and Department of
Physics and Astronomy, University College
London, London WC1E 6BT, United Kingdom
| | - Mariana Rossi
- Physical
and Theoretical Chemistry Lab, University
of Oxford, South Parks
Road, OX1 3QZ Oxford, United Kingdom
| | - Yexin Feng
- School
of Physics and Electronics, Hunan University, Changsha 410082, People’s Republic of China
| | - Xin-Zheng Li
- International
Center for Quantum Materials, School of Physics and Collaborative
Innovation Center of Quantum Matter, Peking
University, Beijing 100871, People’s Republic of China
- E-mail: (X.-Z.L.)
| | - Angelos Michaelides
- Thomas Young Centre, London Centre for Nanotechnology, Department of Chemistry, and Department of
Physics and Astronomy, University College
London, London WC1E 6BT, United Kingdom
- E-mail: (A.M.)
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25
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[FHF]−—The Strongest Hydrogen Bond under the Influence of External Interactions. CRYSTALS 2015. [DOI: 10.3390/cryst6010003] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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26
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Kanematsu Y, Tachikawa M. Theoretical analysis of geometry and NMR isotope shift in hydrogen-bonding center of photoactive yellow protein by combination of multicomponent quantum mechanics and ONIOM scheme. J Chem Phys 2015; 141:185101. [PMID: 25399161 DOI: 10.1063/1.4900987] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Multicomponent quantum mechanical (MC_QM) calculation has been extended with ONIOM (our own N-layered integrated molecular orbital + molecular mechanics) scheme [ONIOM(MC_QM:MM)] to take account of both the nuclear quantum effect and the surrounding environment effect. The authors have demonstrated the first implementation and application of ONIOM(MC_QM:MM) method for the analysis of the geometry and the isotope shift in hydrogen-bonding center of photoactive yellow protein. ONIOM(MC_QM:MM) calculation for a model with deprotonated Arg52 reproduced the elongation of O-H bond of Glu46 observed by neutron diffraction crystallography. Among the unique isotope shifts in different conditions, the model with protonated Arg52 with solvent effect reasonably provided the best agreement with the corresponding experimental values from liquid NMR measurement. Our results implied the availability of ONIOM(MC_QM:MM) to distinguish the local environment around hydrogen bonds in a biomolecule.
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Affiliation(s)
- Yusuke Kanematsu
- Quantum Chemistry Division, Yokohama City University, Seto 22-2, Kanazawa-ku, Yokohama 236-0027, Japan
| | - Masanori Tachikawa
- Quantum Chemistry Division, Yokohama City University, Seto 22-2, Kanazawa-ku, Yokohama 236-0027, Japan
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27
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Sutter K, Aucar GA, Autschbach J. Analysis of Proton NMR in Hydrogen Bonds in Terms of Lone-Pair and Bond Orbital Contributions. Chemistry 2015; 21:18138-55. [DOI: 10.1002/chem.201502346] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Indexed: 11/10/2022]
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28
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Shenderovich IG, Lesnichin SB, Tu C, Silverman DN, Tolstoy PM, Denisov GS, Limbach HH. NMR studies of active-site properties of human carbonic anhydrase II by using (15) N-labeled 4-methylimidazole as a local probe and histidine hydrogen-bond correlations. Chemistry 2014; 21:2915-29. [PMID: 25521423 DOI: 10.1002/chem.201404083] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Revised: 11/12/2014] [Indexed: 12/24/2022]
Abstract
By using a combination of liquid and solid-state NMR spectroscopy, (15) N-labeled 4-methylimidazole (4-MI) as a local probe of the environment has been studied: 1) in the polar, wet Freon CDF3 /CDF2 Cl down to 130 K, 2) in water at pH 12, and 3) in solid samples of the mutant H64A of human carbonic anhydrase II (HCA II). In the latter, the active-site His64 residue is replaced by alanine; the catalytic activity is, however, rescued by the presence of 4-MI. For the Freon solution, it is demonstrated that addition of water molecules not only catalyzes proton tautomerism but also lifts its quasidegeneracy. The possible hydrogen-bond clusters formed and the mechanism of the tautomerism are discussed. Information about the imidazole hydrogen-bond geometries is obtained by establishing a correlation between published (1) H and (15) N chemical shifts of the imidazole rings of histidines in proteins. This correlation is useful to distinguish histidines embedded in the interior of proteins and those at the surface, embedded in water. Moreover, evidence is obtained that the hydrogen-bond geometries of His64 in the active site of HCA II and of 4-MI in H64A HCA II are similar. Finally, the degeneracy of the rapid tautomerism of the neutral imidazole ring His64 reported by Shimahara et al. (J. Biol. Chem.- 2007, 282, 9646) can be explained with a wet, polar, nonaqueous active-site conformation in the inward conformation, similar to the properties of 4-MI in the Freon solution. The biological implications for the enzyme mechanism are discussed.
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Affiliation(s)
- Ilya G Shenderovich
- University of Regensburg, Universitätsstrasse 31, 93053 Regensburg (Germany).
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29
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Kaledhonkar S, Hara M, Stalcup TP, Xie A, Hoff WD. Strong ionic hydrogen bonding causes a spectral isotope effect in photoactive yellow protein. Biophys J 2014; 105:2577-85. [PMID: 24314088 DOI: 10.1016/j.bpj.2013.10.017] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2013] [Revised: 10/07/2013] [Accepted: 10/16/2013] [Indexed: 10/25/2022] Open
Abstract
Standard hydrogen bonds are of great importance for protein structure and function. Ionic hydrogen bonds often are significantly stronger than standard hydrogen bonds and exhibit unique properties, but their role in proteins is not well understood. We report that hydrogen/deuterium exchange causes a redshift in the visible absorbance spectrum of photoactive yellow protein (PYP). We expand the range of interpretable isotope effects by assigning this spectral isotope effect (SIE) to a functionally important hydrogen bond at the active site of PYP. The inverted sign and extent of this SIE is explained by the ionic nature and strength of this hydrogen bond. These results show the relevance of ionic hydrogen bonding for protein active sites, and reveal that the inverted SIE is a novel, to our knowledge, tool to probe ionic hydrogen bonds. Our results support a classification of hydrogen bonds that distinguishes the properties of ionic hydrogen bonds from those of both standard and low barrier hydrogen bonds, and show how this classification helps resolve a recent debate regarding active site hydrogen bonding in PYP.
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30
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Klein O, Bonvehi MM, Aguilar-Parrilla F, Jagerovic N, Elguero J, Limbach HH. Hydrogen Bond Compression during Triple Proton Transfer in Crystalline Pyrazoles. A Dynamic15N NMR Study. Isr J Chem 2013. [DOI: 10.1002/ijch.199900036] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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31
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Pietrzak M, Grech E, Nowicka-Scheibe J, Hansen PE. Deuterium isotope effects on 13C chemical shifts of negatively charged NH…N systems. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2013; 51:683-688. [PMID: 24038402 DOI: 10.1002/mrc.4000] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2013] [Revised: 06/21/2013] [Accepted: 07/22/2013] [Indexed: 06/02/2023]
Abstract
Deuterium isotope effects on (13)C chemical shifts are investigated in anions of 1,8-bis(4-toluenesulphonamido)naphthalenes together with N,N-(naphthalene-1,8-diyl)bis(2,2,2-trifluoracetamide) all with bis(1,8-dimethylamino)napthaleneH(+) as counter ion. These compounds represent both "static" and equilibrium cases. NMR assignments of the former have been revised. The NH proton is deuteriated. The isotope effects on (13)C chemical shifts are rather unusual in these strongly hydrogen bonded systems between a NH and a negatively charged nitrogen atom. The formal four-bond effects are found to be negative indicating transmission via the hydrogen bond. In addition, unusual long range effects are seen. Structures, (1)H and (13)C NMR chemical shifts and changes in nuclear shieldings upon deuteriation are calculated using density functional theory methods.
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Affiliation(s)
- Mariusz Pietrzak
- Institute of Physical Chemistry, Polish Academy of Sciences, 01-224, Warsaw, Poland
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32
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Romero J, Restrepo A, Reyes A. Solvent isotope effects on the hydration of alkaline cations: H/D secondary isotope effects on electrostatic interactions. Mol Phys 2013. [DOI: 10.1080/00268976.2013.850543] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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33
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Koeppe B, Nibbering ETJ, Tolstoy PM. NMR and FT-IR Studies on the Association of Derivatives of Thymidine, Adenosine, and 6-N-Methyl-Adenosine in Aprotic Solvents. ACTA ACUST UNITED AC 2013. [DOI: 10.1524/zpch.2013.0388] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Abstract
Associates of 3',5'-O-TBDMS protected derivatives of the 2'-deoxy forms of the nucleosides adenosine, 6-N-methyl-adenosine and thymidine (henceforward simply addressed by their parents' names) and further model systems in dichloromethane and Freon (CDClF2/CDF3) solutions are studied at low temperatures by 1H NMR and FT-IR spectroscopy. N⋯N distances in hydrogen bonds are estimated from chemical shifts of protons in hydrogen bonds employing geometric and spectroscopic hydrogen bond correlations. These distances are in turn employed to derive N–H stretching frequencies from IR spectroscopic hydrogen bond correlations which may be compared to corresponding experimental results. Three isomeric hydrogen bonded dimers of thymidine are characterized in Freon solution at 120 K. Binary associates of thymidine and a series of pyridines are studied; estimated N⋯N distances in the range of 3.08 to 2.85 Å are qualitatively correlated to shifts of N–H stretching bands where in all cases considerable contributions are found in the spectral region below 3000 cm-1. For adenosine, three isomeric binary associates with 4-nitrophenol are found allowing for an assessment of site-specific acceptor capabilities. In associates of thymidine and adenosine, Watson-Crick and Hoogsteen type 1:1 associates (estimated N⋯N distances of 2.85 and 2.90 Å) as well as 2:1 associates bearing only marginally longer H-bonds could be characterized. Two 1:1 associates between thymidine and 6-N-methyl-adenosine are described that are exclusively bonded via N–H⋯N bridges of about 2.97 and 3.08 Å for Watson-Crick and Hoogsteen sites, respectively, which leads to the conclusion that cooperative effects among coupled N–H⋯O and N–H⋯N hydrogen bonds in A-T base pairs are significant as formation of the N–H⋯O bond induces a contraction of around 0.15 Å in the neighboring N–H⋯N bond.
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Affiliation(s)
| | - Erik T. J. Nibbering
- Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, Berlin, Deutschland
| | - Peter M. Tolstoy
- St. Petersburg State University, V. A. Fock Institute of Physics, St. Petersburg, Russische Föderation
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34
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Koeppe B, Guo J, Tolstoy PM, Denisov GS, Limbach HH. Solvent and H/D isotope effects on the proton transfer pathways in heteroconjugated hydrogen-bonded phenol-carboxylic acid anions observed by combined UV-vis and NMR spectroscopy. J Am Chem Soc 2013; 135:7553-66. [PMID: 23607931 DOI: 10.1021/ja400611x] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Heteroconjugated hydrogen-bonded anions A···H···X(-) of phenols (AH) and carboxylic/inorganic acids (HX) dissolved in CD2Cl2 and CDF3/CDF2Cl have been studied by combined low-temperature UV-vis and (1)H/(13)C NMR spectroscopy (UVNMR). The systems constitute small molecular models of hydrogen-bonded cofactors in proteins such as the photoactive yellow protein (PYP). Thus, the phenols studied include the PYP cofactor 4-hydroxycinnamic acid methyl thioester, and the more acidic 4-nitrophenol and 2-chloro-4-nitrophenol which mimic electronically excited cofactor states. It is shown that the (13)C chemical shifts of the phenolic residues of A···H···X(-), referenced to the corresponding values of A···H···A(-), constitute excellent probes for the average proton positions. These shifts correlate with those of the H-bonded protons, as well as with the H/D isotope effects on the (13)C chemical shifts. A combined analysis of UV-vis and NMR data was employed to elucidate the proton transfer pathways in a qualitative way. Dual absorption bands of the phenolic moiety indicate a double-well situation for the shortest OHO hydrogen bonds studied. Surprisingly, when the solvent polarity is low the carboxylates are protonated whereas the proton shifts toward the phenolic oxygens when the polarity is increased. This finding indicates that because of stronger ion-dipole interactions small anions are stabilized at high solvent polarity and large anions exhibiting delocalized charges at low solvent polarities. It also explains the large acidity difference of phenols and carboxylic acids in water, and the observation that this difference is strongly reduced in the interior of proteins when both partners form mutual hydrogen bonds.
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Affiliation(s)
- Benjamin Koeppe
- Institut für Chemie und Biochemie, Freie Universität Berlin, Takustrasse 3, D-14195 Berlin, Germany
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35
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Ueda K, Oguni M. Quantum Tunneling in the Quadruple Proton Rearrangement on a Hydroxyl Hydrogen Bond Ring in Calix[4]arene. J Phys Chem B 2012; 116:14470-6. [DOI: 10.1021/jp304689z] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Kouhei Ueda
- Department of Chemistry, Graduate School of Science
and Engineering, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro-ku, Tokyo 152-8551, Japan
| | - Masaharu Oguni
- Department of Chemistry, Graduate School of Science
and Engineering, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro-ku, Tokyo 152-8551, Japan
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36
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Ip BCK, Shenderovich IG, Tolstoy PM, Frydel J, Denisov GS, Buntkowsky G, Limbach HH. NMR Studies of Solid Pentachlorophenol-4-Methylpyridine Complexes Exhibiting Strong OHN Hydrogen Bonds: Geometric H/D Isotope Effects and Hydrogen Bond Coupling Cause Isotopic Polymorphism. J Phys Chem A 2012; 116:11370-87. [DOI: 10.1021/jp305863n] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Brenda C. K. Ip
- Institut für Chemie und
Biochemie, Freie Universität Berlin, Takustrasse 3, D-14195 Berlin,
Germany
| | - Ilya G. Shenderovich
- Institut für Chemie und
Biochemie, Freie Universität Berlin, Takustrasse 3, D-14195 Berlin,
Germany
- St. Petersburg State University, 198504 St. Petersburg, Russian Federation
| | - Peter M. Tolstoy
- Institut für Chemie und
Biochemie, Freie Universität Berlin, Takustrasse 3, D-14195 Berlin,
Germany
- St. Petersburg State University, 198504 St. Petersburg, Russian Federation
| | - Jaroslaw Frydel
- Institut für Chemie und
Biochemie, Freie Universität Berlin, Takustrasse 3, D-14195 Berlin,
Germany
| | - Gleb S. Denisov
- St. Petersburg State University, 198504 St. Petersburg, Russian Federation
| | - Gerd Buntkowsky
- Eduard-Zintl-Institut für
Anorganische und Physikalische Chemie, Technische Universität Darmstadt, Petersenstr. 20, D-64287 Darmstadt, Germany
| | - Hans-Heinrich Limbach
- Institut für Chemie und
Biochemie, Freie Universität Berlin, Takustrasse 3, D-14195 Berlin,
Germany
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37
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Heterogeneous Coordination Environments in Lithium-Neutralized Ionomers Identified Using 1H and 7Li MAS NMR. MATERIALS 2012. [PMCID: PMC5448934 DOI: 10.3390/ma5081508] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
The carboxylic acid proton and the lithium coordination environments for precise and random Li-neutralized polyethylene acrylic acid P(E-AA) ionomers were explored using high speed solid-state 1H and 7Li MAS NMR. While the 7Li NMR revealed only a single Li coordination environment, the chemical shift temperature variation was dependent on the precise or random nature of the P(E-AA) ionomer. The 1H MAS NMR revealed two different carboxylic acid proton environments in these materials. By utilizing 1H-7Li rotational echo double resonance (REDOR) MAS NMR experiments, it was demonstrated that the proton environments correspond to different average 1H-7Li distances, with the majority of the protonated carboxylic acids having a close through space contact with the Li. Molecular dynamics simulations suggest that the shortest 1H-7Li distance corresponds to un-neutralized carboxylic acids directly involved in the coordination environment of Li clusters. These solid-state NMR results show that heterogeneous structural motifs need to be included when developing descriptions of these ionomer materials.
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Carlsson ACC, Gräfenstein J, Budnjo A, Laurila JL, Bergquist J, Karim A, Kleinmaier R, Brath U, Erdélyi M. Symmetric Halogen Bonding Is Preferred in Solution. J Am Chem Soc 2012; 134:5706-15. [DOI: 10.1021/ja301341h] [Citation(s) in RCA: 135] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Anna-Carin C. Carlsson
- Department
of Chemistry and
Molecular Biology, University of Gothenburg, SE-412 96 Gothenburg, Sweden
| | - Jürgen Gräfenstein
- Department
of Chemistry and
Molecular Biology, University of Gothenburg, SE-412 96 Gothenburg, Sweden
| | - Adnan Budnjo
- Department
of Chemistry and
Molecular Biology, University of Gothenburg, SE-412 96 Gothenburg, Sweden
| | - Jesse L. Laurila
- Department
of Chemistry and
Molecular Biology, University of Gothenburg, SE-412 96 Gothenburg, Sweden
| | - Jonas Bergquist
- Analytical Chemistry, Department
of Chemistry - Biomedical Center, Uppsala University, SE-751 24, Uppsala, Sweden
| | - Alavi Karim
- Department
of Chemistry and
Molecular Biology, University of Gothenburg, SE-412 96 Gothenburg, Sweden
| | - Roland Kleinmaier
- Department
of Chemistry and
Molecular Biology, University of Gothenburg, SE-412 96 Gothenburg, Sweden
| | - Ulrika Brath
- Department
of Chemistry and
Molecular Biology, University of Gothenburg, SE-412 96 Gothenburg, Sweden
| | - Máté Erdélyi
- Department
of Chemistry and
Molecular Biology, University of Gothenburg, SE-412 96 Gothenburg, Sweden
- The Swedish NMR Centre, Medicinaregatan
5c, SE-413 90 Gothenburg, Sweden
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Koeppe B, Tolstoy PM, Limbach HH. Reaction pathways of proton transfer in hydrogen-bonded phenol-carboxylate complexes explored by combined UV-vis and NMR spectroscopy. J Am Chem Soc 2011; 133:7897-908. [PMID: 21534587 DOI: 10.1021/ja201113a] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Combined low-temperature NMR/UV-vis spectroscopy (UVNMR), where optical and NMR spectra are measured in the NMR spectrometer under the same conditions, has been set up and applied to the study of H-bonded anions A··H··X(-) (AH = 1-(13)C-2-chloro-4-nitrophenol, X(-) = 15 carboxylic acid anions, 5 phenolates, Cl(-), Br(-), I(-), and BF(4)(-)). In this series, H is shifted from A to X, modeling the proton-transfer pathway. The (1)H and (13)C chemical shifts and the H/D isotope effects on the latter provide information about averaged H-bond geometries. At the same time, red shifts of the π-π* UV-vis absorption bands are observed which correlate with the averaged H-bond geometries. However, on the UV-vis time scale, different tautomeric states and solvent configurations are in slow exchange. The combined data sets indicate that the proton transfer starts with a H-bond compression and a displacement of the proton toward the H-bond center, involving single-well configurations A-H···X(-). In the strong H-bond regime, coexisting tautomers A··H···X(-) and A(-)···H··X are observed by UV. Their geometries and statistical weights change continuously when the basicity of X(-) is increased. Finally, again a series of single-well structures of the type A(-)···H-X is observed. Interestingly, the UV-vis absorption bands are broadened inhomogeneously because of a distribution of H-bond geometries arising from different solvent configurations.
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Affiliation(s)
- Benjamin Koeppe
- Institut für Chemie und Biochemie, Freie Universität Berlin, Takustrasse 3, D-14195 Berlin, Germany
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40
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Ullah S, Ishimoto T, Williamson MP, Hansen PE. Ab initio calculations of deuterium isotope effects on chemical shifts of salt-bridged lysines. J Phys Chem B 2011; 115:3208-15. [PMID: 21388110 DOI: 10.1021/jp1111789] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Deuterium isotope effects measure the change in chemical shift on substitution of a proton by deuterium. They have been calculated by direct treatment of the H/D nuclear quantum effect using a multicomponent ab initio molecular orbital method based on a non-Born-Oppenheimer approximation. This method enables the determination of both the electronic and the protonic (deuteronic) wave functions simultaneously and can directly calculate the geometrical difference induced by H/D isotope effects. The calculations show that the one-bond deuterium isotope effects on (15)N nuclear shielding, (1)Δ(15)N(D), in ammonium and amines decrease as a counterion or water molecule moves closer to the nitrogen. (1)Δ(15)N(D) and (2)Δ(1)H(D) of the NH(3)(+) groups of lysine residues in the B1 domain of protein G have been calculated using truncated side chains and also determined experimentally by NMR. Comparisons show that the structures in solution are different from those in the crystal and that solvation plays an important role in weakening the hydrogen bonds.
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Affiliation(s)
- Saif Ullah
- Department of Science, Systems and Models, Roskilde University, Roskilde, Denmark.
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Affiliation(s)
- Sławomir Janusz Grabowski
- Kimika Fakultatea, Euskal Herriko Unibertsitatea and Donostia International Physics Center (DIPC) P.K. 1072, 20080 Donostia, Euskadi, Spain
- IKERBASQUE, Basque Foundation for Science, 48011, Bilbao, Spain
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Moreno DV, González SA, Reyes A. Turning symmetric an asymmetric hydrogen bond with the inclusion of nuclear quantum effects: The case of the [CN···H···NC]−complex. J Chem Phys 2011; 134:024115. [DOI: 10.1063/1.3521272] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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43
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Beran GJO, Chronister EL, Daemen LL, Moehlig AR, Mueller LJ, Oomens J, Rice A, Santiago-Dieppa DR, Tham FS, Theel K, Yaghmaei S, Morton TH. Vibrations of a chelated proton in a protonated tertiary diamine. Phys Chem Chem Phys 2011; 13:20380-92. [DOI: 10.1039/c1cp22065a] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Keen DA, Dove MT, Evans JSO, Goodwin AL, Peters L, Tucker MG. The hydrogen-bonding transition and isotope-dependent negative thermal expansion in H3Co(CN)6. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2010; 22:404202. [PMID: 21386563 DOI: 10.1088/0953-8984/22/40/404202] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We investigate the structures of H(3)Co(CN)(6) and D(3)Co(CN)(6) and their temperature dependence using a combination of advanced neutron and x-ray diffraction techniques. Lattice parameter refinements show marked temperature- and isotope-dependent effects in the thermal expansion behaviour. Reverse Monte Carlo modelling of neutron total scattering data characterizes the distribution of D atom positions in the deuterated compound; analysis of these distributions reveals that the two N-H/D bonds become increasingly different with increasing temperature, suggesting a mechanism for the observed thermal expansion anomalies. We discuss these results in the context of the previous crystallographic, spectroscopic and theoretical results for H(3)Co(CN)(6) and 'super-short' N···H···N systems in general.
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Affiliation(s)
- David A Keen
- ISIS Facility, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0QX, UK.
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45
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Tolstoy PM, Guo J, Koeppe B, Golubev NS, Denisov GS, Smirnov SN, Limbach HH. Geometries and Tautomerism of OHN Hydrogen Bonds in Aprotic Solution Probed by H/D Isotope Effects on 13C NMR Chemical Shifts. J Phys Chem A 2010; 114:10775-82. [DOI: 10.1021/jp1027146] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Peter M. Tolstoy
- Institute of Chemistry and Biochemistry, Free University of Berlin, Germany, and V. A. Fock Institute of Physics, St. Petersburg State University, Russia
| | - Jing Guo
- Institute of Chemistry and Biochemistry, Free University of Berlin, Germany, and V. A. Fock Institute of Physics, St. Petersburg State University, Russia
| | - Benjamin Koeppe
- Institute of Chemistry and Biochemistry, Free University of Berlin, Germany, and V. A. Fock Institute of Physics, St. Petersburg State University, Russia
| | - Nikolai S. Golubev
- Institute of Chemistry and Biochemistry, Free University of Berlin, Germany, and V. A. Fock Institute of Physics, St. Petersburg State University, Russia
| | - Gleb S. Denisov
- Institute of Chemistry and Biochemistry, Free University of Berlin, Germany, and V. A. Fock Institute of Physics, St. Petersburg State University, Russia
| | - Sergei N. Smirnov
- Institute of Chemistry and Biochemistry, Free University of Berlin, Germany, and V. A. Fock Institute of Physics, St. Petersburg State University, Russia
| | - Hans-Heinrich Limbach
- Institute of Chemistry and Biochemistry, Free University of Berlin, Germany, and V. A. Fock Institute of Physics, St. Petersburg State University, Russia
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46
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Coles MP, Aragón-Sáez PJ, Oakley SH, Hitchcock PB, Davidson MG, Maksić ZB, Vianello R, Leito I, Kaljurand I, Apperley DC. Superbasicity of a bis-guanidino compound with a flexible linker: a theoretical and experimental study. J Am Chem Soc 2010; 131:16858-68. [PMID: 19874017 DOI: 10.1021/ja906618g] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The bis-guanidino compound H(2)C{hpp}(2) (I; hppH = 1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine) has been converted to the monocation [I-H](+) and isolated as the chloride and tetraphenylborate salts. Solution-state spectroscopic data do not differentiate the protonated guanidinium from the neutral guanidino group but suggest intramolecular "-N-H...N=" hydrogen bonding to form an eight-membered C(3)N(4)H heterocycle. Solid-state CPMAS (15)N NMR spectroscopy confirms protonation at one of the imine nitrogens, although line broadening is consistent with solid-state proton transfer between guanidine functionalities. X-ray diffraction data have been recorded over the temperature range 50-273 K. Examination of the carbon-nitrogen bond lengths suggests a degree of "partial protonation" of the neutral guanidino group at higher temperatures, with greater localization of the proton at one nitrogen position as the temperature is lowered. Difference electron density maps generated from high-resolution X-ray diffraction studies at 110 K give the first direct experimental evidence for proton transfer in a poly(guanidino) system. Computational analysis of I and its conjugate acid [I-H](+) indicate strong cationic resonance stabilization of the guanidinium group, with the nonprotonated group also stabilized, albeit to a lesser extent. The maximum barrier to proton transfer calculated using the Boese-Martin for kinetics method was 2.8 kcal mol(-1), with hydrogen-bond compression evident in the transition state; addition of zero-point vibrational energy values leads to the conclusion that the proton transfer is barrierless, implying that the proton shuttles freely between the two nitrogen atoms. Calculations determining the gas-phase proton affinity and the pK(a) in acetonitrile both indicate that compound I should behave as a superbase. This has been confirmed by spectrophotometric titrations in MeCN using polyphosphazene references, which give an average pK(a) of 28.98 +/- 0.05. Triadic analysis indicates that the dominant term causing the high basicity is the relaxation energy.
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Affiliation(s)
- Martyn P Coles
- Department of Chemistry, University of Sussex, Falmer, Brighton BN1 9QJ, UK.
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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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48
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Kwiatkowska E, Majerz I. Analysis of potential energy curve for proton motion in intermolecular hydrogen bond. Chem Phys Lett 2010. [DOI: 10.1016/j.cplett.2009.11.018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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49
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Toledo EJ, Custodio R, Ramalho TC, Porto MEG, Magriotis ZM. Electrical field effects on dipole moment, structure and energetic of (H2O)n (2⩽n⩽15) cluster. ACTA ACUST UNITED AC 2009. [DOI: 10.1016/j.theochem.2009.08.035] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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50
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Limbach HH, Tolstoy PM, Pérez-Hernández N, Guo J, Shenderovich IG, Denisov GS. OHO Hydrogen Bond Geometries and NMR Chemical Shifts: From Equilibrium Structures to Geometric H/D Isotope Effects, with Applications for Water, Protonated Water, and Compressed Ice. Isr J Chem 2009. [DOI: 10.1560/ijc.49.2.199] [Citation(s) in RCA: 129] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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