1
|
Jóźwiak K, Jezierska A, Panek JJ, Łydżba-Kopczyńska B, Filarowski A. Renewed spectroscopic and theoretical research of hydrogen bonding in ascorbic acid. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2024; 320:124585. [PMID: 38850825 DOI: 10.1016/j.saa.2024.124585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2024] [Revised: 05/15/2024] [Accepted: 05/31/2024] [Indexed: 06/10/2024]
Abstract
The studies of two isomers of ascorbic acid and their deuteroanalogues, presented in the paper, have been accomplished by vibrational spectroscopy methods and quantum-chemical simulations. The spectroscopic research of L-ascorbic and D-isoascorbic acids have been carried out by the infrared (IR) and Raman (R) techniques. On the basis of the obtained results the spectral interpretation of the hydrogen bonded groups of ascorbic acids has been performed. Car-Parrinello Molecular Dynamics (CPMD) and Density Functional Theory (DFT) have been employed to support spectroscopic experimental findings and shed light onto the bridged proton dynamics in the L- and D- isomers of ascorbic acids. The accurate assignments of the hydrogen bond modes have been accomplished with the application of deuterosubstitution, CPMD-solid state simulations and Potential Energy Distribution (PED) analysis. The spectral and structural results have shown that dependency ν(OH) = f(γ(OH)) is the most common for the OHO hydrogen bond, whereas dependency d(OO) = f(γ(OH)) differs as for the ionic and resonance assisted hydrogen bonds.
Collapse
Affiliation(s)
- Kinga Jóźwiak
- Faculty of Chemistry, University of Wrocław, 14 F. Joliot-Curie str., 50-383, Wrocław, Poland
| | - Aneta Jezierska
- Faculty of Chemistry, University of Wrocław, 14 F. Joliot-Curie str., 50-383, Wrocław, Poland
| | - Jarosław J Panek
- Faculty of Chemistry, University of Wrocław, 14 F. Joliot-Curie str., 50-383, Wrocław, Poland
| | | | - Aleksander Filarowski
- Faculty of Chemistry, University of Wrocław, 14 F. Joliot-Curie str., 50-383, Wrocław, Poland.
| |
Collapse
|
2
|
Zhang L, Huang X, Cole T, Lu H, Hang J, Li W, Tang SY, Boyer C, Davis TP, Qiao R. 3D-printed liquid metal polymer composites as NIR-responsive 4D printing soft robot. Nat Commun 2023; 14:7815. [PMID: 38016940 PMCID: PMC10684855 DOI: 10.1038/s41467-023-43667-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Accepted: 11/16/2023] [Indexed: 11/30/2023] Open
Abstract
4D printing combines 3D printing with nanomaterials to create shape-morphing materials that exhibit stimuli-responsive functionalities. In this study, reversible addition-fragmentation chain transfer polymerization agents grafted onto liquid metal nanoparticles are successfully employed in ultraviolet light-mediated stereolithographic 3D printing and near-infrared light-responsive 4D printing. Spherical liquid metal nanoparticles are directly prepared in 3D-printed resins via a one-pot approach, providing a simple and efficient strategy for fabricating liquid metal-polymer composites. Unlike rigid nanoparticles, the soft and liquid nature of nanoparticles reduces glass transition temperature, tensile stress, and modulus of 3D-printed materials. This approach enables the photothermal-induced 4D printing of composites, as demonstrated by the programmed shape memory of 3D-printed composites rapidly recovering to their original shape in 60 s under light irradiation. This work provides a perspective on the use of liquid metal-polymer composites in 4D printing, showcasing their potential for application in the field of soft robots.
Collapse
Affiliation(s)
- Liwen Zhang
- Australian Institute of Bioengineering & Nanotechnology, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Xumin Huang
- Australian Institute of Bioengineering & Nanotechnology, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Tim Cole
- Department of Electronic, Electrical, and Systems Engineering, University of Birmingham, Birmingham, UK
| | - Hongda Lu
- Australian Institute of Bioengineering & Nanotechnology, The University of Queensland, Brisbane, QLD, 4072, Australia
- School of Mechanical, Materials, Mechatronic and Biomedical Engineering, University of Wollongong, Wollongong, NSW, 2522, Australia
| | - Jiangyu Hang
- Australian Institute of Bioengineering & Nanotechnology, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Weihua Li
- School of Mechanical, Materials, Mechatronic and Biomedical Engineering, University of Wollongong, Wollongong, NSW, 2522, Australia
| | - Shi-Yang Tang
- School of Electronics and Computer Science, University of Southampton, Southampton, SO17 1BJ, UK.
| | - Cyrille Boyer
- Cluster for Advanced Macromolecular Design, School of Chemical Engineering, The University of New South Wales, Sydney, NSW, 2052, Australia
| | - Thomas P Davis
- Australian Institute of Bioengineering & Nanotechnology, The University of Queensland, Brisbane, QLD, 4072, Australia.
| | - Ruirui Qiao
- Australian Institute of Bioengineering & Nanotechnology, The University of Queensland, Brisbane, QLD, 4072, Australia.
| |
Collapse
|
3
|
Venianakis T, Siskos MG, Papamokos G, Gerothanassis IP. Structural Studies of Monounsaturated and ω-3 Polyunsaturated Free Fatty Acids in Solution with the Combined Use οf NMR and DFT Calculations-Comparison with the Liquid State. Molecules 2023; 28:6144. [PMID: 37630396 PMCID: PMC10459368 DOI: 10.3390/molecules28166144] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2023] [Revised: 08/14/2023] [Accepted: 08/18/2023] [Indexed: 08/27/2023] Open
Abstract
Molecular structures, in chloroform and DMSO solution, of the free fatty acids (FFAs) caproleic acid, oleic acid, α-linolenic acid, eicosapentanoic acid (EPA) and docosahexaenoic acid (DHA) are reported with the combined use of NMR and DFT calculations. Variable temperature and concentration chemical shifts of the COOH protons, transient 1D NOE experiments and DFT calculations demonstrate the major contribution of low molecular weight aggregates of dimerized fatty acids through intermolecular hydrogen bond interactions of the carboxylic groups, with parallel and antiparallel interdigitated structures even at the low concentration of 20 mM in CDCl3. For the dimeric DHA, a structural model of an intermolecular hydrogen bond through carboxylic groups and an intermolecular hydrogen bond between the carboxylic group of one molecule and the ω-3 double bond of a second molecule is shown to play a role. In DMSO-d6 solution, NMR and DFT studies show that the carboxylic groups form strong intermolecular hydrogen bond interactions with a single discrete solvation molecule of DMSO. These solvation species form parallel and antiparallel interdigitated structures of low molecular weight, as in chloroform solution. This structural motif, therefore, is an intrinsic property of the FFAs, which is not strongly affected by the length and degree of unsaturation of the chain and the hydrogen bond ability of the solvent.
Collapse
Affiliation(s)
| | | | - George Papamokos
- Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, 45110 Ioannina, Greece; (T.V.); (M.G.S.)
| | - Ioannis P. Gerothanassis
- Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, 45110 Ioannina, Greece; (T.V.); (M.G.S.)
| |
Collapse
|
4
|
Jóźwiak K, Jezierska A, Panek JJ, Kochel A, Filarowski A. Inter- vs. Intra-Molecular Hydrogen Bond in Complexes of Nitrophthalic Acids with Pyridine. Int J Mol Sci 2023; 24:ijms24065248. [PMID: 36982321 PMCID: PMC10048863 DOI: 10.3390/ijms24065248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Accepted: 03/07/2023] [Indexed: 03/12/2023] Open
Abstract
This study covers the analysis of isomeric forms of nitrophthalic acids with pyridine. This work dwells on the complementary experimental (X-ray, IR and Raman) and theoretical (Car-Parrinello Molecular Dynamics (CPMD) and Density Functional Theory (DFT)) studies of the obtained complexes. The conducted studies showed that steric repulsion between the nitro group in ortho-position and the carboxyl group causes significant isomeric changes. Modeling of the nitrophthalic acid—pyridine complex yielded a short strong intramolecular hydrogen bond (SSHB). The transition energy from the isomeric form with an intermolecular hydrogen bond to the isomeric form with an intramolecular hydrogen bond was estimated.
Collapse
|
5
|
Venianakis T, Siskos M, Papamokos G, Gerothanassis IP. NMR and DFT studies of monounsaturated and ω-3 polyunsaturated free fatty acids in the liquid state reveal a novel atomistic structural model of DHA. J Mol Liq 2023. [DOI: 10.1016/j.molliq.2023.121459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
|
6
|
Tupikina EY, Titova AA, Kaplanskiy MV, Chakalov ER, Kostin MA, Tolstoy PM. Estimations of OH·N hydrogen bond length from positions and intensities of IR bands. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2022; 275:121172. [PMID: 35366525 DOI: 10.1016/j.saa.2022.121172] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 03/02/2022] [Accepted: 03/15/2022] [Indexed: 06/14/2023]
Abstract
In this computational work applicability of IR spectral parameters for evaluations of OH···N hydrogen bond length is discussed. For a set of 124 complexes with OH···N hydrogen bond formed by combinations of methanol/acetic acid and pyridine (and their fluorine substituted versions) geometries, energies and IR parameters were calculated at MP2/def2-TZVP level of theory. For a number of IR parameters (the shift of proton donor group stretching vibration Δνs, increase of its intensity I, the low-frequency hydrogen bond stretching vibration νσ, bending in-plane δ and out-of-plane γ vibrations) equations linking them with interatomic distances are proposed, the robustness and accuracy of such equations are discussed. The enthalpy of OH···N hydrogen bond formation ΔH was also linked with electron density parameters in (3; -1) critical point.
Collapse
Affiliation(s)
- E Yu Tupikina
- Institute of Chemistry, St. Petersburg State University, St. Petersburg, Russia.
| | - A A Titova
- Institute of Chemistry, St. Petersburg State University, St. Petersburg, Russia
| | - M V Kaplanskiy
- Institute of Chemistry, St. Petersburg State University, St. Petersburg, Russia
| | - E R Chakalov
- Institute of Chemistry, St. Petersburg State University, St. Petersburg, Russia
| | - M A Kostin
- Institute of Chemistry, St. Petersburg State University, St. Petersburg, Russia; Department of Physics, St. Petersburg State University, St. Petersburg, Russia
| | - P M Tolstoy
- Institute of Chemistry, St. Petersburg State University, St. Petersburg, Russia.
| |
Collapse
|
7
|
Jia X, Yuan Z, Yang Y, Huang X, Han N, Liu X, Lin X, Ma T, Xu B, Wang P, Lei H. Multi-functional self-assembly nanoparticles originating from small molecule natural product for oral insulin delivery through modulating tight junctions. J Nanobiotechnology 2022; 20:116. [PMID: 35248067 PMCID: PMC8898475 DOI: 10.1186/s12951-022-01260-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 01/12/2022] [Indexed: 12/25/2022] Open
Abstract
Background Oral administration of insulin (INS) could be absorbed into systemic circulation only if the carrier protected it from the hostile gastrointestinal conditions. However, traditional macromolecular carriers have not totally overcome challenges in addressing these biological barriers. Result In this study, inspired by small molecule natural products (SMNPs), we demonstrate the multi-functional self-assembly nanoparticles (BA-Al NPs) originating from baicalin (BA) and AlCl3 through coordination bonds and hydrogen bonds. As a novel carrier for oral insulin delivery (INS@BA-Al NPs), it displayed effective capacity in pH stimuli-responsive insulin release, intestinal mucoadhesion and transepithelial absorption enhance. Meanwhile, BA improved the paracellular permeability for insulin absorption, because of its downregulation at both mRNA and protein level on internal tight junction proteins. In vivo experiments exhibited remarkable bioavailability of INS and an ideal glucose homeostasis in the type I diabetic rat model. Conclusion This study offers a novel frontier of multi-functional carriers based on SMNPs with self-assembly character and bioactivity, which could be a promising strategy for diabetes therapy. Graphical Abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s12951-022-01260-9.
Collapse
|
8
|
Hetmańczyk Ł, Goremychkin EA, Waliszewski J, Vener MV, Lipkowski P, Tolstoy PM, Filarowski A. Spectroscopic Identification of Hydrogen Bond Vibrations and Quasi-Isostructural Polymorphism in N-Salicylideneaniline. Molecules 2021; 26:molecules26165043. [PMID: 34443632 PMCID: PMC8401763 DOI: 10.3390/molecules26165043] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Revised: 08/13/2021] [Accepted: 08/16/2021] [Indexed: 11/16/2022] Open
Abstract
The ortho-hydroxy aryl Schiff base 2-[(E)-(phenylimino)methyl]phenol and its deutero-derivative have been studied by the inelastic incoherent neutron scattering (IINS), infrared (IR) and Raman experimental methods, as well as by Density Functional Theory (DFT) and Density-Functional Perturbation Theory (DFPT) simulations. The assignments of vibrational modes within the 3500–50 cm−1 spectral region made it possible to state that the strong hydrogen bond in the studied compound can be classified as the so-called quasi-aromatic bond. The isotopic substitution supplemented by the results of DFT calculations allowed us to identify vibrational bands associated with all five major hydrogen bond vibrations. Quasi-isostructural polymorphism of 2-[(E)-(phenylimino)methyl]phenol (SA) and 2-[(E)-(phenyl-D5-imino)methyl]phenol (SA-C6D5) has been studied by powder X-ray diffraction in the 20–320 K temperature range.
Collapse
Affiliation(s)
- Łukasz Hetmańczyk
- Faculty of Chemistry, Jagiellonian University, 2 Gronostajowa Str., 30-387 Cracow, Poland;
| | - Eugene A. Goremychkin
- Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research 6 F. Joliot-Curie str., 141980 Dubna, Russia;
| | - Janusz Waliszewski
- Faculty of Physics, University of Bialystok, 1L Ciolkowskiego str., 15-245 Bialystok, Poland;
| | - Mikhail V. Vener
- Quantum Chemistry Department, Mendeleev University of Chemical Technology, Miusskaya Square 9, 125047 Moscow, Russia;
- Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences, Leninskii Prosp. 31, 119991 Moscow, Russia
| | - Paweł Lipkowski
- Department of Physical and Quantum Chemistry, Wrocław University of Science and Technology, Wybrzeże Wyspiańnskiego 27, 50-370 Wrocław, Poland;
| | - Peter M. Tolstoy
- Institute of Chemistry, St. Petersburg State University, Universitetskij pr. 26, 198504 Saint Petersburg, Russia
- Correspondence: (P.M.T.); (A.F.); Tel.: +48-71-375-7229 (A.F.)
| | - Aleksander Filarowski
- Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research 6 F. Joliot-Curie str., 141980 Dubna, Russia;
- Faculty of Chemistry, University of Wrocław 14 F. Joliot-Curie str., 50-383 Wrocław, Poland
- Correspondence: (P.M.T.); (A.F.); Tel.: +48-71-375-7229 (A.F.)
| |
Collapse
|
9
|
Raczyński K, Pihut A, Panek JJ, Jezierska A. Competition of Intra- and Intermolecular Forces in Anthraquinone and Its Selected Derivatives. Molecules 2021; 26:3448. [PMID: 34204133 PMCID: PMC8201066 DOI: 10.3390/molecules26113448] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 06/01/2021] [Accepted: 06/04/2021] [Indexed: 11/16/2022] Open
Abstract
Intra- and intermolecular forces competition was investigated in the 9,10-anthraquinone (1) and its derivatives both in vacuo and in the crystalline phase. The 1,8-dihydroxy-9,10-anthraquinone (2) and 1,8-dinitro-4,5-dihydroxy-anthraquinone (3) contain Resonance-Assisted Hydrogen Bonds (RAHBs). The intramolecular hydrogen bonds properties were studied in the electronic ground and excited states employing Møller-Plesset second-order perturbation theory (MP2), Density Functional Theory (DFT) method in its classical formulation as well as its time-dependent extension (TD-DFT). The proton potential functions were obtained via scanning the OH distance and the dihedral angle related to the OH group rotation. The topological analysis was carried out on the basis of theories of Atoms in Molecules (AIM-molecular topology, properties of critical points, AIM charges) and Electron Localization Function (ELF-2D maps showing bonding patterns, calculation of electron populations in the hydrogen bonds). The Symmetry-Adapted Perturbation Theory (SAPT) was applied for the energy decomposition in the dimers. Finally, Car-Parrinello molecular dynamics (CPMD) simulations were performed to shed light onto bridge protons dynamics upon environmental influence. The vibrational features of the OH stretching were revealed using Fourier transformation of the autocorrelation function of atomic velocity. It was found that the presence of OH and NO2 substituents influenced the geometric and electronic structure of the anthraquinone moiety. The AIM and ELF analyses showed that the quantitative differences between hydrogen bonds properties could be neglected. The bridged protons are localized on the donor side in the electronic ground state, but the Excited-State Intramolecular Proton Transfer (ESIPT) was noticed as a result of the TD-DFT calculations. The hierarchy of interactions determined by SAPT method indicated that weak hydrogen bonds play modifying role in the organization of these crystal structures, but primary ordering factor is dispersion. The CPMD crystalline phase results indicated bridged proton-sharing in the compound 2.
Collapse
Affiliation(s)
| | | | | | - Aneta Jezierska
- Faculty of Chemistry, University of Wrocław, ul. F. Joliot-Curie 14, 50-383 Wrocław, Poland; (K.R.); (A.P.); (J.J.P.)
| |
Collapse
|
10
|
Actual Symmetry of Symmetric Molecular Adducts in the Gas Phase, Solution and in the Solid State. Symmetry (Basel) 2021. [DOI: 10.3390/sym13050756] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
This review discusses molecular adducts, whose composition allows a symmetric structure. Such adducts are popular model systems, as they are useful for analyzing the effect of structure on the property selected for study since they allow one to reduce the number of parameters. The main objectives of this discussion are to evaluate the influence of the surroundings on the symmetry of these adducts, steric hindrances within the adducts, competition between different noncovalent interactions responsible for stabilizing the adducts, and experimental methods that can be used to study the symmetry at different time scales. This review considers the following central binding units: hydrogen (proton), halogen (anion), metal (cation), water (hydrogen peroxide).
Collapse
|
11
|
Two Faces of Water in the Formation and Stabilization of Multicomponent Crystals of Zwitterionic Drug-Like Compounds. Symmetry (Basel) 2021. [DOI: 10.3390/sym13030425] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Two new hydrated multicomponent crystals of zwitterionic 2-aminonicotinic acid with maleic and fumaric acids have been obtained and thoroughly characterized by a variety of experimental (X-ray analysis and terahertz Raman spectroscopy) and theoretical periodic density functional theory calculations, followed by Bader analysis of the crystalline electron density) techniques. It has been found that the Raman-active band in the region of 300 cm−1 is due to the vibrations of the intramolecular O-H...O bond in the maleate anion. The energy/enthalpy of the intermolecular hydrogen bonds was estimated by several empirical approaches. An analysis of the interaction networks reflects the structure-directing role of the water molecule in the examined multicomponent crystals. A general scheme has been proposed to explain the proton transfer between the components during the formation of multicomponent crystals in water. Water molecules were found to play the key role in this process, forming a “water wire” between the COOH group of the dicarboxylic acid and the COO– group of the zwitterion and the rendering crystal lattice of the considered multicomponent crystals.
Collapse
|
12
|
Modeling of Solute-Solvent Interactions Using an External Electric Field-From Tautomeric Equilibrium in Nonpolar Solvents to the Dissociation of Alkali Metal Halides. Molecules 2021; 26:molecules26051283. [PMID: 33652943 PMCID: PMC7956811 DOI: 10.3390/molecules26051283] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 02/07/2021] [Accepted: 02/22/2021] [Indexed: 12/18/2022] Open
Abstract
An implicit account of the solvent effect can be carried out using traditional static quantum chemistry calculations by applying an external electric field to the studied molecular system. This approach allows one to distinguish between the effects of the macroscopic reaction field of the solvent and specific solute-solvent interactions. In this study, we report on the dependence of the simulation results on the use of the polarizable continuum approximation and on the importance of the solvent effect in nonpolar solvents. The latter was demonstrated using experimental data on tautomeric equilibria between the pyridone and hydroxypyridine forms of 2,6-di-tert-butyl-4-hydroxy-pyridine in cyclohexane and chloroform.
Collapse
|
13
|
Shenderovich IG. Editorial to the Special Issue "Gulliver in the Country of Lilliput: An Interplay of Noncovalent Interactions". Molecules 2020; 26:E158. [PMID: 33396433 PMCID: PMC7794748 DOI: 10.3390/molecules26010158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 12/30/2020] [Indexed: 11/18/2022] Open
Abstract
Noncovalent interactions allow our world to exist [...].
Collapse
Affiliation(s)
- Ilya G Shenderovich
- Institute of Organic Chemistry, Faculty of Chemistry and Pharmacy, University of Regensburg, Universitaetstrasse 31, 93053 Regensburg, Germany
| |
Collapse
|
14
|
Symmetry/Asymmetry of the NHN Hydrogen Bond in Protonated 1,8-Bis(dimethylamino)naphthalene. Symmetry (Basel) 2020. [DOI: 10.3390/sym12111924] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Experimental and theoretical results are presented based on vibrational spectra and motional dynamics of 1,8-bis(dimethylamino)naphthalene (DMAN) and its protonated forms (DMANH+ and the DMANH+ HSO4− complex). The studies of these compounds have been performed in the gas phase and solid-state. Spectroscopic investigations were carried out by infrared spectroscopy (IR), Raman, and incoherent inelastic neutron scattering (IINS) experimental methods. Density functional theory (DFT) and Car–Parrinello molecular dynamics (CPMD) methods were applied to support our experimental findings. The fundamental investigations of hydrogen bridge vibrations were accomplished on the basis of isotopic substitutions (NH → ND). Special attention was paid to the bridged proton dynamics in the DMANH+ complex, which was found to be affected by interactions with the HSO4− anion.
Collapse
|