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Wang J, Chen H, Liu H, Wang R, Qin Z, Zhu M. Surface modifications of short quartz fibers and their influence on the physicochemical properties and in vitro cell viability of dental composites. Dent Mater 2024; 40:e1-e10. [PMID: 38821838 DOI: 10.1016/j.dental.2024.05.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 05/20/2024] [Accepted: 05/22/2024] [Indexed: 06/02/2024]
Abstract
OBJECTIVE Although glass fibers are more common, quartz fibers (QFs) are also considered as the ideal reinforcing material in dentistry, due to their superior mechanical strength, high purity, and good photoconductive properties. However, the relatively inert surfaces limit their further applications. Therefore, the aim of this study is to modify the fiber surface properties to improve the interfacial interactions with polymeric resins. METHODS In this study, we systematically introduced four different surface modification strategies onto short quartz fibers (SQFs) for the preparation of dental composites. Particularly, the acid etching was a facile way to create mechanical interlocking structures. In addition, the silanization process, the sol-gel treatment, and the polymer grafting were further proposed to increase the surface roughness and the reactive sites. The effect of surface modifications on the fiber surface morphological changes, mechanical properties, water stability, and in vitro cell viability of dental composites were investigated. RESULTS Among all surface-modified SQFs, SQFs-POSS (SQFs modified with methacrylate-POSS) exhibited the roughest surface morphology and highest grafting rates compared with other three materials. Furthermore, all these SQFs were applied as reinforcements to make dimethacrylate-based dental resin composites. Of all fillers, SQFs-POSS demonstrated the best reinforcing effect, providing significantly higher improvements of 55.7 %, 114.3 %, and 164.7 % for flexural strength, flexural modulus, and breaking energy, respectively, over those of SQFs-filled composite. The related reinforcing mechanism was further investigated. The SQFs-POSS-filled composite also exhibited the best water stability performance and in vitro cell viability. SIGNIFICANCE This work provided valuable insights into the optimization of filler-matrix interaction through fiber surface modifications. Specifically, SQFs-POSS markedly outperformed other formulations in terms of the physicochemical performance and in vitro cytotoxicity, which offers possibilities for developing high-performance dental composites for clinical applications in restorative dentistry.
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Affiliation(s)
- Junjun Wang
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620, PR China
| | - Hongyan Chen
- Shanghai Engineering Research Center of Advanced Dental Technology and Materials, Shanghai Key Laboratory of Stomatology, Shanghai Research Institute of Stomatology, National Clinical Research Center for Oral Diseases, Shanghai Ninth People's Hospital, College of Stomatology, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, PR China
| | - Hongmei Liu
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620, PR China
| | - Ruili Wang
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620, PR China.
| | - Zongyi Qin
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620, PR China
| | - Meifang Zhu
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620, PR China.
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Hanna FE, Root AJ, Hunter CA. Polarisation effects on the H-bond acceptor properties of secondary amides. Chem Sci 2023; 14:11151-11157. [PMID: 37860643 PMCID: PMC10583693 DOI: 10.1039/d3sc03823h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Accepted: 09/24/2023] [Indexed: 10/21/2023] Open
Abstract
H-bonding interactions in networks are stabilised by cooperativity, but the relationship between the chemical structures of the interacting functional groups and the thermodynamic consequences is not well-understood. We have used compounds with an intramolecular H-bond between a pyridine H-bond acceptor and an amide NH group to quantify cooperative effects on the H-bond acceptor properties of the amide carbonyl group. 1H NMR experiments in n-octane confirm the presence of the intramolecular H-bond and show that this interaction is intact in the 1 : 1 complex formed with perfluoro-tert-butanol (PFTB). UV-vis absorption titrations were used to measure the relationship between the association constant for formation of this complex and the H-bond acceptor properties of the pyridine involved in the intramolecular H-bond. Electron-donating substituents on the pyridine increase the strength of the intermolecular H-bond between PFTB and the amide. There is a linear relationship between the H-bond acceptor parameter β measured for the amide carbonyl group and the H-bond acceptor parameter for the pyridine. The cooperativity parameter κ determined from this relationship is 0.2, i.e. β for an amide carbonyl group is increased by one fifth of the value of β of an acceptor that interacts with the NH group. This result is reproduced by DFT calculations of H-bond parameters for the individual molecules in the gas phase, which implies that the observed cooperativity can be understood as polarisation of the electron density in the amide π-system in response to formation of a H-bond. The cooperativity parameter κ measured for the secondary amide H-bond donor and H-bond acceptor is identical, which implies that polarisation of an amide mediates the interaction between an external donor or acceptor in a reciprocal manner.
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Affiliation(s)
- Fergal E Hanna
- Yusuf Hamied Department of Chemistry, University of Cambridge Lensfield Road Cambridge CB2 1EW UK
| | - Alexander J Root
- Yusuf Hamied Department of Chemistry, University of Cambridge Lensfield Road Cambridge CB2 1EW UK
| | - Christopher A Hunter
- Yusuf Hamied Department of Chemistry, University of Cambridge Lensfield Road Cambridge CB2 1EW UK
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3
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Soloviev DO, Hanna FE, Misuraca MC, Hunter CA. H-bond cooperativity: polarisation effects on secondary amides. Chem Sci 2022; 13:11863-11868. [PMID: 36320903 PMCID: PMC9580511 DOI: 10.1039/d2sc04271a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 09/19/2022] [Indexed: 11/21/2022] Open
Abstract
Formation of a H-bond with an amide carbonyl oxygen atom increases the strength of subsequent H-bonds formed by the amide NH, due to polarisation of the bond. The magnitude of this effect has been quantified by measuring association constants for the formation of 1 : 1 complexes of 2-hydroxylbenzamides with tri-n-butyl phosphine oxide. In 2-hydroxybenzamides, there is an intramolecular H-bond between the phenol OH group and the carbonyl oxygen atom. Comparison of the association constants measured for compounds with and without the 2-hydroxy group allows direct quantification of the effect of the intramolecular H-bond on the H-bond donor properties of the amide NH group. Substituents were used to modulate the strength of the intramolecular and intermolecular H-bonds. The presence of an intramolecular H-bond increases the strength of the intermolecular H-bond by more than one order of magnitude in n-octane solution. The increase in the H-bond donor parameter used to describe the amide NH group is directly proportional to the H-bond donor parameter of the phenol OH group that makes the intramolecular H-bond. These polarisation effects will lead to substantial cooperativity in complex systems that feature networks of non-covalent interactions, and the measurements described here provide a quantitative basis for understanding such phenomena. Formation of an intramolecular phenol-amide H-bond leads to a dramatic increase in the H-bond donor strength of the amide NH group. Polarisation of the amide group is directly proportional to the polarity of the phenol H-bond donor.![]()
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Affiliation(s)
- Daniil O. Soloviev
- Yusuf Hamied Department of Chemistry, University of CambridgeLensfield RoadCambridge CB2 1EWUK
| | - Fergal E. Hanna
- Yusuf Hamied Department of Chemistry, University of CambridgeLensfield RoadCambridge CB2 1EWUK
| | - Maria Cristina Misuraca
- Yusuf Hamied Department of Chemistry, University of CambridgeLensfield RoadCambridge CB2 1EWUK
| | - Christopher A. Hunter
- Yusuf Hamied Department of Chemistry, University of CambridgeLensfield RoadCambridge CB2 1EWUK
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4
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Yi J, Fang H. Effect of water on excited‐state double proton transfer in 7‐azaindole‐H
2
O complex: A theoretical study. J PHYS ORG CHEM 2020. [DOI: 10.1002/poc.4060] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Jiacheng Yi
- Department of Chemistry and Material Science, College of ScienceNanjing Forestry University Nanjing China
| | - Hua Fang
- Department of Chemistry and Material Science, College of ScienceNanjing Forestry University Nanjing China
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5
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Saha S, Sastry GN. Quantifying cooperativity in water clusters: an attempt towards obtaining a generalised equation. Mol Phys 2015. [DOI: 10.1080/00268976.2015.1072648] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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6
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Saha S, Sastry GN. Cooperative or Anticooperative: How Noncovalent Interactions Influence Each Other. J Phys Chem B 2015; 119:11121-35. [DOI: 10.1021/acs.jpcb.5b03005] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Soumen Saha
- Centre for Molecular Modeling, CSIR-Indian Institute of Chemical Technology, Tarnaka, Hyderabad 500007, Andhra Pradesh, India
| | - G. Narahari Sastry
- Centre for Molecular Modeling, CSIR-Indian Institute of Chemical Technology, Tarnaka, Hyderabad 500007, Andhra Pradesh, India
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Abstract
Positive cooperativity is found in beryllium bonded complexes similar to that described for hydrogen bonded systems.
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Affiliation(s)
- Ibon Alkorta
- Instituto de Química Médica (IQM-CSIC)
- 28006-Madrid, Spain
| | - José Elguero
- Instituto de Química Médica (IQM-CSIC)
- 28006-Madrid, Spain
| | - Manuel Yáñez
- Departamento de Química
- Módulo 13
- Universidad Autónoma de Madrid
- Campus de Excelencia UAM-CSIC
- 28049 Madrid, Spain
| | - Otilia Mó
- Departamento de Química
- Módulo 13
- Universidad Autónoma de Madrid
- Campus de Excelencia UAM-CSIC
- 28049 Madrid, Spain
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8
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Sun CL, Ding F, Ding YL, Li Y. The effect of water molecules upon the hydrogen-bonding cooperativity of three-stranded antiparallel β-sheet models. RSC Adv 2014. [DOI: 10.1039/c3ra45892j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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9
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Sakota K, Harada S, Sekiya H. Infrared spectroscopy of hydrated N-(2-phenylethyl)acetamide clusters: The electron-redistribution within the solute weakens local hydrogen bond. Chem Phys 2013. [DOI: 10.1016/j.chemphys.2013.01.020] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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10
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Albrecht L, Boyd RJ, Mó O, Yáñez M. Cooperativity between hydrogen bonds and beryllium bonds in (H2O)(n)BeX2 (n = 1-3, X = H, F) complexes. A new perspective. Phys Chem Chem Phys 2012; 14:14540-7. [PMID: 23014263 DOI: 10.1039/c2cp42534c] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The interaction of BeX(2) (X = H, F) with water molecules has been analyzed at the B3LYP/6-311+G(3df,2p)//B3LYP/6-311+G(d,p) level of theory. The formation of strong beryllium bonds between water molecules and the BeX(2) derivative triggers significant electron density redistribution within the whole system, resulting in significant changes in the proton donor and proton acceptor capacity of the water molecules involved. Hence, significant cooperative and anti-cooperative effects are present, explaining why there is no case in which the global minimum corresponds to a tetracoordinated beryllium atom. In fact, the most stable clusters can be viewed as the result of the attachment of BeX(2) to the water trimer and the water dimer, respectively, and not as the result of the solvation of the BeX(2) molecule. We have also shown that the decomposition of the interaction energy into atomic components is a reliable quantitative tool to describe all the closed-shell interactions present in the clusters investigated herein, namely hydrogen bonds, beryllium bonds and dihydrogen bonds. Indeed, we have shown that the changes in the atomic energy components are correlated with the changes in the strength of these interactions, and they provide a quantitative measure of cooperative effects directly in terms of energies.
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Affiliation(s)
- Laura Albrecht
- Department of Chemistry, Dalhousie University, Halifax, Nova Scotia, Canada
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11
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Mó O, Yáñez M, Alkorta I, Elguero J. Modulating the Strength of Hydrogen Bonds through Beryllium Bonds. J Chem Theory Comput 2012; 8:2293-300. [PMID: 26588962 DOI: 10.1021/ct300243b] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The mutual influence between beryllium bonds and inter- or intramolecular hydrogen bonds (HBs) has been investigated at the B3LYP/6-311++G(3df,2p) level of theory, using the complexes between imidazole dimer and malonaldehyde with BeH2 and BeF2 as suitable model systems. Imidazole and its dimer form very strong beryllium bonds with both BeH2 and BeF2, accompanied by a significant geometry distortion of the Lewis acid. More importantly, we have found a clear cooperativity between these two noncovalent interactions, since the intermolecular HB between the two imidazole molecules in the dimer-BeX2 complex becomes much stronger than in the isolated dimer, whereas the beryllium bond becomes also stronger in the dimer-BeX2 complex, with respect to that found in the imidazole-BeX2 complex. The effects of beryllium bonds are also dramatic on the strength of intramolecular HBs. Depending on to which center the BeX2 is attached, the intramolecular HB becomes much stronger or much weaker. The first situation is found when the beryllium derivative is attached to the HB donor, whereas the second occurs if it is attached to the HB acceptor. The first effect can be so strong as to produce a spontaneous proton transfer, as it is actually the case of the malonaldehyde-BeF2 complex.
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Affiliation(s)
- Otilia Mó
- Departamento de Química, Módulo 13, Universidad Autónoma de Madrid , Campus de Excelencia UAM-CSIC, Cantoblanco, 28049 Madrid, Spain
| | - Manuel Yáñez
- Departamento de Química, Módulo 13, Universidad Autónoma de Madrid , Campus de Excelencia UAM-CSIC, Cantoblanco, 28049 Madrid, Spain
| | - Ibon Alkorta
- Instituto de Química Médica (CSIC) , Juan de la Cierva, 3, 28006-Madrid, Spain
| | - José Elguero
- Instituto de Química Médica (CSIC) , Juan de la Cierva, 3, 28006-Madrid, Spain
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12
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Zahn S, Wendler K, Delle Site L, Kirchner B. Depolarization of water in protic ionic liquids. Phys Chem Chem Phys 2011; 13:15083-93. [DOI: 10.1039/c1cp20288j] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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13
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Abstract
First, different approaches to detect hydrogen bonds and to evaluate their energies are introduced newly or are extended. Supermolecular interaction energies of 256 dimers, each containing one single hydrogen bond, were correlated to various descriptors by a fit function depending both on the donor and acceptor atoms of the hydrogen bond. On the one hand, descriptors were orbital-based parameters as the two-center or three-center shared electron number, products of ionization potentials and shared electron numbers, and the natural bond orbital interaction energy. On the other hand, integral descriptors examined were the acceptor-proton distance, the hydrogen bond angle, and the IR frequency shift of the donor-proton stretching vibration. Whereas an interaction energy dependence on 1/r(3.8) was established, no correlation was found for the angle. Second, the fit functions are applied to hydrogen bonds in polypeptides, amino acid dimers, and water cluster, thus their reliability is demonstrated. Employing the fit functions to assign intramolecular hydrogen bond energies in polypeptides, several side chain CH...O and CH...N hydrogen bonds were detected on the fly. Also, the fit functions describe rather well intermolecular hydrogen bonds in amino acid dimers and the cooperativity of hydrogen bond energies in water clusters.
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Affiliation(s)
- Katharina Wendler
- Lehrstuhl für Theoretische Chemie, Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig, Germany
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14
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Vallejos MM, Angelina EL, Peruchena NM. Bifunctional Hydrogen Bonds in Monohydrated Cycloether Complexes. J Phys Chem A 2010; 114:2855-63. [PMID: 20136161 DOI: 10.1021/jp906372t] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Margarita M. Vallejos
- Laboratorio de Estructura Molecular y Propiedades, Área de Química Física, Departamento de Química, Facultad de Ciencias Exactas y Naturales y Agrimensura, Universidad Nacional del Nordeste, Avenida Libertad 5460, (3400) Corrientes, Argentina, and Facultad Regional Resistancia, Universidad Tecnológica Nacional, French 414, (3500) Resistancia, Chaco, Argentina
| | - Emilio L. Angelina
- Laboratorio de Estructura Molecular y Propiedades, Área de Química Física, Departamento de Química, Facultad de Ciencias Exactas y Naturales y Agrimensura, Universidad Nacional del Nordeste, Avenida Libertad 5460, (3400) Corrientes, Argentina, and Facultad Regional Resistancia, Universidad Tecnológica Nacional, French 414, (3500) Resistancia, Chaco, Argentina
| | - Nélida M. Peruchena
- Laboratorio de Estructura Molecular y Propiedades, Área de Química Física, Departamento de Química, Facultad de Ciencias Exactas y Naturales y Agrimensura, Universidad Nacional del Nordeste, Avenida Libertad 5460, (3400) Corrientes, Argentina, and Facultad Regional Resistancia, Universidad Tecnológica Nacional, French 414, (3500) Resistancia, Chaco, Argentina
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15
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Kirchner B, Spickermann C, Reckien W, Schalley CA. Uncovering Individual Hydrogen Bonds in Rotaxanes by Frequency Shifts. J Am Chem Soc 2009; 132:484-94. [DOI: 10.1021/ja902628n] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- Barbara Kirchner
- Lehrstuhl für Theoretische Chemie, Wilhelm-Ostwald Institut für Physikalische und Theoretische Chemie, Universität Leipzig, Linnéstr. 2, D-04103 Leipzig, Germany, and Organische Chemie, Institut für Chemie und Biochemie, Freie Universität Berlin, Takusstrasse 3, D-14195 Berlin, Germany
| | - Christian Spickermann
- Lehrstuhl für Theoretische Chemie, Wilhelm-Ostwald Institut für Physikalische und Theoretische Chemie, Universität Leipzig, Linnéstr. 2, D-04103 Leipzig, Germany, and Organische Chemie, Institut für Chemie und Biochemie, Freie Universität Berlin, Takusstrasse 3, D-14195 Berlin, Germany
| | - Werner Reckien
- Lehrstuhl für Theoretische Chemie, Wilhelm-Ostwald Institut für Physikalische und Theoretische Chemie, Universität Leipzig, Linnéstr. 2, D-04103 Leipzig, Germany, and Organische Chemie, Institut für Chemie und Biochemie, Freie Universität Berlin, Takusstrasse 3, D-14195 Berlin, Germany
| | - Christoph A. Schalley
- Lehrstuhl für Theoretische Chemie, Wilhelm-Ostwald Institut für Physikalische und Theoretische Chemie, Universität Leipzig, Linnéstr. 2, D-04103 Leipzig, Germany, and Organische Chemie, Institut für Chemie und Biochemie, Freie Universität Berlin, Takusstrasse 3, D-14195 Berlin, Germany
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16
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Jiang XN, Wang CS. Rapid Prediction of the Hydrogen Bond Cooperativity in N-methylacetamide Chains. Chemphyschem 2009; 10:3330-6. [DOI: 10.1002/cphc.200900591] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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17
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Kageura Y, Sakota K, Sekiya H. Charge Transfer Interaction of Intermolecular Hydrogen Bonds in 7-Azaindole(MeOH)n (n = 1, 2) with IR-Dip Spectroscopy and Natural Bond Orbital Analysis. J Phys Chem A 2009; 113:6880-5. [DOI: 10.1021/jp9019377] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Yutaka Kageura
- Department of Chemistry, Faculty of Sciences and Department of Molecular Chemistry, Graduate School of Science, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan
| | - Kenji Sakota
- Department of Chemistry, Faculty of Sciences and Department of Molecular Chemistry, Graduate School of Science, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan
| | - Hiroshi Sekiya
- Department of Chemistry, Faculty of Sciences and Department of Molecular Chemistry, Graduate School of Science, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan
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18
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Viswanathan R, Etra A, Jiang J. Effect of solvent environment on the CO band position in the infrared spectrum of trans-[FeII(CN)4(CO)2]2−. Inorganica Chim Acta 2009. [DOI: 10.1016/j.ica.2008.12.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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19
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Sakota K, Kageura Y, Sekiya H. Cooperativity of hydrogen-bonded networks in 7-azaindole(CH3OH)n (n=2,3) clusters evidenced by IR-UV ion-dip spectroscopy and natural bond orbital analysis. J Chem Phys 2008; 129:054303. [PMID: 18698896 DOI: 10.1063/1.2961031] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
IR-UV ion-dip spectra of the 7-azaindole (7AI)(CH(3)OH)(n) (n=1-3) clusters have been measured in the hydrogen-bonded NH and OH stretching regions to investigate the stable structures of 7AI(CH(3)OH)(n) (n=1-3) in the S(0) state and the cooperativity of the H-bonding interactions in the H-bonded networks. The comparison of the IR-UV ion-dip spectra with IR spectra obtained by quantum chemistry calculations shows that 7AI(CH(3)OH)(n) (n=1-3) have cyclic H-bonded structures, where the NH group and the heteroaromatic N atom of 7AI act as the proton donor and proton acceptor, respectively. The H-bonded OH stretch fundamental of 7AI(CH(3)OH)(2) is remarkably redshifted from the corresponding fundamental of (CH(3)OH)(2) by 286 cm(-1), which is an experimental manifestation of the cooperativity in H-bonding interaction. Similarly, two localized OH fundamentals of 7AI(CH(3)OH)(3) also exhibit large redshifts. The cooperativity of 7AI(CH(3)OH)(n) (n=2,3) is successfully explained by the donor-acceptor electron delocalization interactions between the lone-pair orbital in the proton acceptor and the antibonding orbital in the proton donor in natural bond orbital (NBO) analyses.
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Affiliation(s)
- Kenji Sakota
- Department of Chemistry, Faculty of Sciences, Graduate School of Science, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan
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20
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Nucci NV, Scott JN, Vanderkooi JM. Coupling of complex aromatic ring vibrations to solvent through hydrogen bonds: effect of varied on-ring and off-ring hydrogen-bonding substitutions. J Phys Chem B 2008; 112:4022-35. [PMID: 18331017 DOI: 10.1021/jp0758770] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In this study, we examine the coupling of a complex ring vibration to solvent through hydrogen-bonding interactions. We compare phenylalanine, tyrosine, l-dopa, dopamine, norepinephrine, epinephrine, and hydroxyl-dl-dopa, a group of physiologically important small molecules that vary by single differences in H-bonding substitution. By examination of the temperature dependence of infrared absorptions of these molecules, we show that complex, many-atom vibrations can be coupled to solvent through hydrogen bonds and that the extent of that coupling is dependent on the degree of both on- and off-ring H-bonding substitution. The coupling is seen as a temperature-dependent frequency shift in infrared spectra, but the determination of the physical origin of that shift is based on additional data from temperature-dependent optical experiments and ab initio calculations. The optical experiments show that these small molecules are most sensitive to their immediate H-bonding environment rather than to bulk solvent properties. Ab initio calculations demonstrate H-bond-mediated vibrational coupling for the system of interest and also show that the overall small molecule solvent dependence is determined by a complex interplay of specific interactions and bulk solvation characteristics. Our findings indicate that a full understanding of biomolecule vibrational properties must include consideration of explicit hydrogen-bonding interactions with the surrounding microenvironment.
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Affiliation(s)
- Nathaniel V Nucci
- Department of Biochemistry and Biophysics, University of Pennsylvania, 422 Curie Boulevard, Philadelphia, Pennsylvania 19104, USA.
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21
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Viswanathan R, Dannenberg JJ. A density functional theory study of vibrational coupling in the amide I band of beta-sheet models. J Phys Chem B 2008; 112:5199-208. [PMID: 18386875 DOI: 10.1021/jp8001004] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We report the first molecular orbital/density functional theory (DFT) calculations on the vibrational frequencies involved in the amide I band of completely geometrically optimized models for beta-sheet peptides based upon (up to 16) glycine residues. These calculations use the B3LYP/D95** level of DFT. The primary means of vibrational coupling occurs through H bond, rather than through space, interactions, which is consistent with a previous report on alpha-helical polyalanines and H-bonding chains of both formamides and 4-pyridones. We decoupled the C=O stretching vibrations using selected 14C substitutions to probe the coupling mechanism and to determine "natural" frequencies for individual 14C=Os. The intermolecular H-bonding interactions affect the geometries of the amide groups. Those near the center of H-bonding chains have long C=O bonds. The C=O bond lengths correlate with these "natural" frequencies, The frequencies obtained from the DFT calculations are generally more coupled, and the most intense are more red shifted than those calculated by transition dipole coupling (TDC). TDC inverts the order of the shifted frequencies compared to DFT in several cases.
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Affiliation(s)
- Raji Viswanathan
- Department of Chemistry, Yeshiva College, 500 West 185th Street, New York, New York 10033, USA
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Wieczorek R, Dannenberg JJ. Amide I Vibrational Frequencies of α-Helical Peptides Based upon ONIOM and Density Functional Theory (DFT) Studies. J Phys Chem B 2008; 112:1320-8. [DOI: 10.1021/jp077527j] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Robert Wieczorek
- Department of Chemistry, City University of New YorkHunter College and the Graduate School, 695 Park Avenue, New York, New York 10065, and Faculty of Chemistry, University of Wroclaw, F. Joliot-Curie 14, Wroclaw, Poland
| | - J. J. Dannenberg
- Department of Chemistry, City University of New YorkHunter College and the Graduate School, 695 Park Avenue, New York, New York 10065, and Faculty of Chemistry, University of Wroclaw, F. Joliot-Curie 14, Wroclaw, Poland
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