1
|
Mucha K, Pagacz-Kostrzewa M, Krupa J, Wierzejewska M. Structure and IR spectroscopic properties of complexes of 1,2,4-triazole and 3-amino-1,2,4-triazole with dinitrogen isolated in solid argon. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2023; 285:121901. [PMID: 36182831 DOI: 10.1016/j.saa.2022.121901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 09/07/2022] [Accepted: 09/14/2022] [Indexed: 06/16/2023]
Abstract
Complexes of 1,2,4-triazole (TR) and 3-amino-1,2,4-triazole (AT) with N2 were studied computationally employing MP2 and B3LYPD3 methods and experimentally by FTIR matrix isolation technique. The results show that both triazoles interact specifically with dinitrogen in several different ways. For the 1:1 complexes of 1,2,4-triazole five stable minima were located on the potential energy surface. The most stable of them comprises a weak hydrogen bond formed between the NH group of the ring and the lone pair of the nitrogen molecule. The second most stable structure is bound by the N⋯π bond formed between one of the N atoms of the N2 molecule and the triazole ring. Three other complexes are stabilized by the C-H⋯N and N⋯N van der Waals interactions. In the case of 3-amino-1,2,4-triazole, the two most stable dinitrogen complexes are analogous to those found for the 1,2,4-triazole and involve N-H⋯N and N⋯π bonds. In other structures amino or CH groups act as proton donors to the N2 molecule. The N⋯N van der Waals interactions are also present. The analysis of the infrared spectra of low temperature matrices containing TR or AT and dinitrogen indicates that in both systems mostly 1:1 hydrogen-bonded complexes with the NH group interacting with N2 are present in solid argon.
Collapse
Affiliation(s)
- K Mucha
- Faculty of Chemistry, University of Wrocław, F. Joliot-Curie 14, 50-383 Wrocław, Poland
| | - M Pagacz-Kostrzewa
- Faculty of Chemistry, University of Wrocław, F. Joliot-Curie 14, 50-383 Wrocław, Poland
| | - J Krupa
- Faculty of Chemistry, University of Wrocław, F. Joliot-Curie 14, 50-383 Wrocław, Poland
| | - M Wierzejewska
- Faculty of Chemistry, University of Wrocław, F. Joliot-Curie 14, 50-383 Wrocław, Poland.
| |
Collapse
|
2
|
Lopes Jesus AJ, de Lucena Júnior JR, Fausto R, Reva I. Infrared Spectra and Phototransformations of meta-Fluorophenol Isolated in Argon and Nitrogen Matrices. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27238248. [PMID: 36500356 PMCID: PMC9735537 DOI: 10.3390/molecules27238248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/22/2022] [Revised: 11/18/2022] [Accepted: 11/21/2022] [Indexed: 11/29/2022]
Abstract
Monomers of meta-fluorophenol (mFP) were trapped from the gas phase into cryogenic argon and nitrogen matrices. The estimated relative energies of the two conformers are very close, and in the gas phase they have nearly equal populations. Due to the similarity of their structures (they only differ in the orientation of the OH group), the two conformers have also similar predicted vibrational signatures, which makes the vibrational characterization of the individual rotamers challenging. In the present work, it has been established that in an argon matrix only the most stable trans conformer of mFP exists (the OH group pointing away from the fluorine atom). On the other hand, the IR spectrum of mFP in a nitrogen matrix testifies to the simultaneous presence in this matrix of both the trans conformer and of the higher-energy cis conformer (the OH group pointing toward the fluorine atom), which is stabilized by interaction with the matrix gas host. We found that the exposition of the cryogenic N2 matrix to the Globar source of the infrared spectrometer affects the conformational populations. By collecting experimental spectra, either in the full mid-infrared range or only in the range below 2200 cm-1, we were able to reliably distinguish two sets of experimental bands originating from individual conformers. A comparison of the two sets of experimental bands with computed infrared spectra of the conformers allowed, for the first time, the unequivocal vibrational identification of each of them. The joint implementation of computational vibrational spectroscopy and matrix-isolation infrared spectroscopy proved to be a very accurate method of structural analysis. Some mechanistic insights into conformational isomerism (the quantum tunneling of hydrogen atom and vibrationally-induced conformational transformations) have been addressed. Finally, we also subjected matrix-isolated mFP to irradiations with UV light, and the phototransformations observed in these experiments are also described.
Collapse
Affiliation(s)
- A. J. Lopes Jesus
- CQC-IMS, Faculty of Pharmacy, University of Coimbra, 3004-295 Coimbra, Portugal
- Correspondence: (A.J.L.J.); (I.R.)
| | | | - Rui Fausto
- CQC-IMS, Department of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal
| | - Igor Reva
- CQC-IMS, Department of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal
- CIEPQPF, Department of Chemical Engineering, University of Coimbra, 3030-790 Coimbra, Portugal
- Correspondence: (A.J.L.J.); (I.R.)
| |
Collapse
|
3
|
Roque JPL, Nunes CM, Fausto R. Matrix Isolation in Heterocyclic Chemistry. HETEROCYCLES 2022. [DOI: 10.1002/9783527832002.ch12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
4
|
Crișan G, Macea AM, Andrieș G, Chiș V. Experimental and computational Raman spectroscopies applied to 2-methoxy-2-methylpropylisonitrile (MIBI) ligand of the 99mTc-sestamibi radiopharmaceutical. J Mol Struct 2021. [DOI: 10.1016/j.molstruc.2021.131159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
5
|
Experimental and Computational Studies on N-alkylation Reaction of N-Benzoyl 5-(Aminomethyl)Tetrazole. CHEMISTRY 2021. [DOI: 10.3390/chemistry3030049] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The N-alkylation reaction of N-benzoyl 5-(aminomethyl)tetrazole (5-AMT) with benzyl bromide was carried out in the presence of K2CO3 as a base. Two separable regioisomers were obtained, thus their purification led to determine the proportion of each of them, and their structures were attributed essentially based on 1H and 13C NMR spectroscopy in addition to the elemental analysis and MS data. In order to confirm the results obtained at the synthesis level, a computational study was carried out by application of density functional theory (DFT) using the Becke three-parameter hybrid exchange functional and the Lee-Yang-Parr correlation functional (B3LYP).
Collapse
|
6
|
Pagacz-Kostrzewa M, Kochman M, Gul W, Wierzejewska M. Phototransformations of 2-aminonicotinic acid resolved with matrix isolation infrared spectroscopy and ab initio calculations. J Photochem Photobiol A Chem 2021. [DOI: 10.1016/j.jphotochem.2021.113187] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
7
|
Roque JPL, Sharma A, Rosado MTS, Fausto R, Reva I. Vibrationally Induced Conformational Isomerization and Tunneling in Pyrrole-2-Carboxylic Acid. J Phys Chem A 2020; 124:10277-10287. [PMID: 33245233 DOI: 10.1021/acs.jpca.0c09141] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The conformational behavior of carboxylic acids has attracted considerable attention, as it can be used as a gateway for the study of more complex phenomena. Here, we present an experimental and computational study of pyrrole-2-carboxylic acid (PCA) conformational space and the vibrational characterization of the compound by infrared spectroscopy. The possibility of promoting conformational transformations using selective vibrational excitation of the 2ν(OH) and 2ν(NH) stretching overtones is explored. Two conformers, exhibiting the cis configuration of the COOH group (O═C-O-H dihedral angle near 0°) and differing by the orientation of the carboxylic group with respect to the pyrrole ring (i.e., showing either a cis or a trans NCC═O arrangement), were found to coexist initially for the compound isolated in a cryogenic nitrogen matrix, in an 86:14 ratio, and were characterized by infrared spectroscopy. A third conformer, with the COOH group in the trans configuration, was produced, in situ, by narrowband near-infrared (NIR) excitation of the most stable PCA form (with a cis NCC═O moiety). The photogenerated PCA conformer was found to decay back to the most stable PCA form, by H-atom quantum mechanical tunneling, with a characteristic half-life time of ∼10 min in the nitrogen matrix at 10 K. Tunneling rates were theoretically estimated and compared for the observed isomerization of pyrrole-2-carboxylic acid and for the structurally similar furan-2-carboxylic acid. This comparison showcases the effect of small modifications in the potential energy surface and the implications of quantum tunneling for the stability of short-living species.
Collapse
Affiliation(s)
- José P L Roque
- CQC, Department of Chemistry, University of Coimbra, Coimbra 3004-535, Portugal
| | - Archna Sharma
- CQC, Department of Chemistry, University of Coimbra, Coimbra 3004-535, Portugal.,Department of Physics, University of Jammu, Jammu 180001, India
| | - Mário T S Rosado
- CQC, Department of Chemistry, University of Coimbra, Coimbra 3004-535, Portugal
| | - Rui Fausto
- CQC, Department of Chemistry, University of Coimbra, Coimbra 3004-535, Portugal
| | - Igor Reva
- CQC, Department of Chemistry, University of Coimbra, Coimbra 3004-535, Portugal
| |
Collapse
|
8
|
Lopes Jesus A, Reva I, Nunes CM, Roque JP, Pinto SM, Fausto R. Kinetically unstable 2–isocyanophenol isolated in cryogenic matrices: Vibrational excitation, conformational changes and spontaneous tunneling. Chem Phys Lett 2020. [DOI: 10.1016/j.cplett.2019.137069] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
|
9
|
Complexes of Glycolic Acid with Nitrogen Isolated in Argon Matrices. II. Vibrational Overtone Excitations. Molecules 2019; 24:molecules24183245. [PMID: 31489896 PMCID: PMC6766840 DOI: 10.3390/molecules24183245] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Revised: 08/28/2019] [Accepted: 09/05/2019] [Indexed: 11/17/2022] Open
Abstract
Structural changes of glycolic acid (GA) complex with nitrogen induced by selective overtone excitation of the νOH mode were followed in argon matrices using FTIR spectroscopy. For the most stable SSC1 complex present in different trapping sites directly upon deposition site, selective changes in the νOH region were achieved upon near-infrared irradiation. Simultaneously, new conformers of the GA…N2 complex were formed, giving rise to several sets of bands in the νOH and νC=O regions of the spectra. Both position and intensity of new absorptions appeared to be highly sensitive on the wavelength of radiation used, as well as on the annealing of the matrix. Based on theoretical calculations at different levels of theory, an assignment of the observed bands is proposed and discussed.
Collapse
|
10
|
Abstract
Hydrogen bonds play a critical role in nucleobase studies as they encode genes, map protein structures, provide stability to the base pairs, and are involved in spontaneous and induced mutations. Proton transfer mechanism is a critical phenomenon that is related to the acid-base characteristics of the nucleobases in Watson-Crick base pairs. The energetic and dynamical behavior of the proton can be depicted from these characteristics and their adjustment to the water molecules or the surrounding ions. Further, new pathways open up in which protonated nucleobases are generated by proton transfer from the ionized water molecules and elimination of a hydroxyl radical in this review, the analysis will be focused on understanding the mechanism of untargeted mutations in canonical, wobble, Hoogsteen pairs, and mutagenic tautomers through the non-covalent interactions. Further, rare tautomer formation through the single proton transfer (SPT) and the double proton transfer (DPT), quantum tunneling in nucleobases, radiation-induced bystander effects, role of water in proton transfer (PT) reactions, PT in anticancer drugs-DNA interaction, displacement and oriental polarization, possible models for mutations in DNA, genome instability, and role of proton transfer using kinetic parameters for RNA will be discussed.
Collapse
|
11
|
Popova EA, Trifonov RE, Ostrovskii VA. Tetrazoles for biomedicine. RUSSIAN CHEMICAL REVIEWS 2019. [DOI: 10.1070/rcr4864] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
12
|
Pagacz-Kostrzewa M, Sałdyka M, Gul W, Wierzejewska M, Khomenko DM, Doroschuk RO. Infrared spectra and photochemistry of 2-(tetrazol-5-yl)benzoic acid isolated in nitrogen matrices. J Photochem Photobiol A Chem 2019. [DOI: 10.1016/j.jphotochem.2018.11.031] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|
13
|
Góbi S, Reva I, Csonka IP, M. Nunes C, Tarczay G, Fausto R. Selective conformational control by excitation of NH imino vibrational antennas. Phys Chem Chem Phys 2019; 21:24935-24949. [DOI: 10.1039/c9cp05370k] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We provide experimental evidence for the occurrence of selective and reversible conformational control over the SH group by vibrational excitation of remote NH groups. Using an imino group that acts as a molecular antenna has no precedents.
Collapse
Affiliation(s)
- Sándor Góbi
- CQC
- Department of Chemistry
- University of Coimbra
- Coimbra
- Portugal
| | - Igor Reva
- CQC
- Department of Chemistry
- University of Coimbra
- Coimbra
- Portugal
| | - István Pál Csonka
- MTA-ELTE Lendület Laboratory Astrochemistry Research Group
- Institute of Chemistry
- ELTE Eötvös Loránd University
- H–1518 Budapest
- Hungary
| | | | - György Tarczay
- MTA-ELTE Lendület Laboratory Astrochemistry Research Group
- Institute of Chemistry
- ELTE Eötvös Loránd University
- H–1518 Budapest
- Hungary
| | - Rui Fausto
- CQC
- Department of Chemistry
- University of Coimbra
- Coimbra
- Portugal
| |
Collapse
|
14
|
Lopes Jesus AJ, M. Nunes C, Fausto R, Reva I. Conformational control over an aldehyde fragment by selective vibrational excitation of interchangeable remote antennas. Chem Commun (Camb) 2018; 54:4778-4781. [DOI: 10.1039/c8cc01052h] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We apply vibrational antennas (OH or NH2 group) to achieve unprecedented conformational control over the heavy aldehyde fragment in 2-formyl-2H-azirine, using selective vibrational excitations of the OH or NH2 stretching overtones and combination modes.
Collapse
Affiliation(s)
| | | | - Rui Fausto
- CQC
- Department of Chemistry
- University of Coimbra
- Coimbra
- Portugal
| | - Igor Reva
- CQC
- Department of Chemistry
- University of Coimbra
- Coimbra
- Portugal
| |
Collapse
|
15
|
Lopes Jesus AJ, Fausto R, Reva I. Conformational Changes in 5-Methoxyindole: Effects of Thermal, Vibrational, and Electronic Excitations. J Phys Chem A 2017; 121:3372-3382. [DOI: 10.1021/acs.jpca.7b01713] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- A. J. Lopes Jesus
- CQC,
Department of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal
- CQC,
Faculty of Pharmacy, University of Coimbra, 3004-295 Coimbra, Portugal
| | - R. Fausto
- CQC,
Department of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal
| | - I. Reva
- CQC,
Department of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal
| |
Collapse
|
16
|
Halasa A, Reva I, Lapinski L, Nowak MJ, Fausto R. Conformational Changes in Thiazole-2-carboxylic Acid Selectively Induced by Excitation with Narrowband Near-IR and UV Light. J Phys Chem A 2016; 120:2078-88. [DOI: 10.1021/acs.jpca.5b11615] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Anna Halasa
- Institute
of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw, Poland
| | - Igor Reva
- CQC,
Department of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal
| | - Leszek Lapinski
- Institute
of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw, Poland
| | - Maciej J. Nowak
- Institute
of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw, Poland
| | - Rui Fausto
- CQC,
Department of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal
| |
Collapse
|
17
|
Meisner J, Kästner J. Atom Tunneling in Chemistry. Angew Chem Int Ed Engl 2016; 55:5400-13. [DOI: 10.1002/anie.201511028] [Citation(s) in RCA: 140] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Revised: 01/08/2016] [Indexed: 01/01/2023]
Affiliation(s)
- Jan Meisner
- Institut für Theoretische Chemie Universität Stuttgart Pfaffenwaldring 55 70569 Stuttgart Germany
| | - Johannes Kästner
- Institut für Theoretische Chemie Universität Stuttgart Pfaffenwaldring 55 70569 Stuttgart Germany
| |
Collapse
|
18
|
Affiliation(s)
- Jan Meisner
- Institut für Theoretische Chemie Universität Stuttgart Pfaffenwaldring 55 70569 Stuttgart Deutschland
| | - Johannes Kästner
- Institut für Theoretische Chemie Universität Stuttgart Pfaffenwaldring 55 70569 Stuttgart Deutschland
| |
Collapse
|
19
|
Popova EA, Trifonov RE. Synthesis and biological properties of amino acids and peptides containing a tetrazolyl moiety. RUSSIAN CHEMICAL REVIEWS 2015. [DOI: 10.1070/rcr4527] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
20
|
Lopes Jesus AJ, Reva I, Araujo-Andrade C, Fausto R. Conformational Switching by Vibrational Excitation of a Remote NH Bond. J Am Chem Soc 2015; 137:14240-3. [DOI: 10.1021/jacs.5b08588] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- António Jorge Lopes Jesus
- CQC,
Department of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal
- CQC,
Faculty of Pharmacy, University of Coimbra, 3004-295 Coimbra, Portugal
| | - Igor Reva
- CQC,
Department of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal
| | - Cuauhtémoc Araujo-Andrade
- CQC,
Department of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal
- Unidad Académica de Física de la Universidad Autónoma de Zacatecas, 98068 Zacatecas, Mexico
| | - Rui Fausto
- CQC,
Department of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal
| |
Collapse
|
21
|
Saeed A, Qasim M, Hussain M, Flörke U, Erben MF. A combined experimental and theoretical study of the tautomeric and conformational properties of (5-phenyl-tetrazol-2-yl)-acetic acid methyl ester. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2015; 150:1-8. [PMID: 26005846 DOI: 10.1016/j.saa.2015.05.046] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Revised: 05/13/2015] [Accepted: 05/15/2015] [Indexed: 06/04/2023]
Abstract
The tautomeric and conformational properties of a new tetrazole derivative are studied in a combined approach that includes the analysis of the experimental vibrational data together with theoretical calculation methods, especially in terms of natural bond orbital (NBO) population analysis. Moreover, the molecular and crystal structure was determined by single crystal X-ray diffraction. The compound crystallized as the 2-tautomeric form, monoclinic space group P21/c with Z=4, a=10.0630(14), b=8.2879(11), c=12.8375(18) Å, β=105.546(3)°, V=1031.5(2) Å(3). The tetrazole and phenyl rings are coplanar with the acetate group oriented perpendicular to the plane. The NBO analysis showed that delocalizing interactions of the lpp(N2) lone pair orbital contributes to a strong resonance interactions with both adjacent π(∗)(N3N4) and π(∗)(N1C5) antibonding orbitals of the tetrazole group.
Collapse
Affiliation(s)
- Aamer Saeed
- Department of Chemistry, Quaid-I-Azam University, Islamabad 45320, Pakistan.
| | - Muhammad Qasim
- Department of Chemistry, Quaid-I-Azam University, Islamabad 45320, Pakistan
| | - Majid Hussain
- Department of Chemistry, Quaid-I-Azam University, Islamabad 45320, Pakistan
| | - Ulrich Flörke
- Department Chemie, Fakultät fur Naturwissenschaften, Universitat Paderborn, Warburgerstrasse 100, D-33098 Paderborn, Germany
| | - Mauricio F Erben
- CEQUINOR (UNLP, CONICET-CCT La Plata), Departamento de Química, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, C.C. 962, 1900 La Plata, Argentina.
| |
Collapse
|
22
|
Lopes Jesus AJ, Jarmelo S, Fausto R, Reva I. Conformational preferences of 3,4-dihydroxyphenylacetic acid (DOPAC). SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2015; 140:54-64. [PMID: 25589387 DOI: 10.1016/j.saa.2014.12.078] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Revised: 11/22/2014] [Accepted: 12/17/2014] [Indexed: 06/04/2023]
Abstract
The conformational space of 3,4-dihydroxyphenylacetic acid (DOPAC), an important dopamine metabolite, has been investigated by quantum chemical methods (B3LYP and MP2, with the 6-311++G(d,p) basis set) and matrix-isolation infrared spectroscopy. Detailed analysis of the calculated potential energy surfaces of the molecule led to identification of thirteen unique conformers, all of them showing the acetic acid side chain out of the aromatic ring plane by 60-95°. According to the calculated Gibbs energies, the five lowest energy conformers make up 99.7% of the conformational mixture at 298.15K, exhibiting individual populations falling between 16% and 24%. The main conformational trends of this molecule were interpreted on the grounds of a thorough analysis of the structural parameters and by the application of the Natural Bond Orbital theory. The role of the intramolecular interactions on the relative stability and structure of the conformers was also investigated. The infrared spectrum of DOPAC was registered after isolation of its monomers in argon and xenon matrices. Only one of DOPAC forms populated in the gas phase could be trapped in both matrix gases. This result is in agreement with the predicted low energy barriers for conformational isomerization and is also supported by annealing experiments. The spectra of matrix-isolated model compounds, phenylacetic acid and catechol, were studied under the same experimental conditions. These data were used as references and assisted in the interpretation of the results obtained for DOPAC.
Collapse
Affiliation(s)
- A J Lopes Jesus
- Centre of Chemistry - Coimbra, Faculty of Pharmacy, University of Coimbra, 3000-548 Coimbra, Portugal.
| | - S Jarmelo
- Centre of Chemistry - Coimbra, Department of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal
| | - R Fausto
- Centre of Chemistry - Coimbra, Department of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal
| | - I Reva
- Centre of Chemistry - Coimbra, Department of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal
| |
Collapse
|
23
|
Vinţeler E, Stan NF, Luchian R, Căinap C, Ramalho JPP, Chiş V. Conformational landscape and low lying excited states of imatinib. J Mol Model 2015; 21:84. [DOI: 10.1007/s00894-015-2639-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Accepted: 02/22/2015] [Indexed: 11/28/2022]
|
24
|
Reva I, M Nunes C, Biczysko M, Fausto R. Conformational switching in pyruvic acid isolated in Ar and N₂ matrixes: spectroscopic analysis, anharmonic simulation, and tunneling. J Phys Chem A 2014; 119:2614-27. [PMID: 25332047 DOI: 10.1021/jp509578c] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Monomers of pyruvic acid (PA) isolated in cryogenic argon and nitrogen matrixes were characterized by mid- and near-infrared spectroscopy. Interpretation of the experiments was aided by fully anharmonic calculations of the fundamental modes, overtones, and combinations up to two quanta, including their infrared intensities. The initially dominating PA conformer (Tc) has a cis CCOH arrangement and is stabilized by a strong intramolecular H-bond. Selective near-infrared excitation of Tc at the first OH overtone (6630 cm(-1) in Ar, 6643 cm(-1) in N2) induced a large scale conformational conversion to the higher-energy conformer (Tt) with trans CCOH arrangement. Tt was then converted back to Tc by selective NIR irradiation at the first Tt OH overtone (6940 cm(-1) in Ar, 6894 cm(-1) in N2). In N2 matrix, the Tt form was stabilized due to interaction between the OH group and the matrix molecules. This stabilization manifested itself in the absence of Tt → Tc relaxation and in a considerable change of the vibrational Tt signature upon going from argon to nitrogen matrix. In argon, the Tt form spontaneously decayed back to Tc in the dark (characteristic lifetime +16 h). In the presence of broad-band near-infrared light, the Tt → Tc relaxation speed considerably increased. The decay mechanisms are discussed.
Collapse
Affiliation(s)
- Igor Reva
- †CQC, Department of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal
| | - Cláudio M Nunes
- †CQC, Department of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal
| | - Malgorzata Biczysko
- ‡Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126 Pisa, Italy.,§Consiglio Nazionale delle Ricerche, Istituto di Chimica dei Composti OrganoMetallici (ICCOM-CNR), UOS di Pisa, Area della Ricerca CNR, Via G. Moruzzi 1, I-56124 Pisa, Italy
| | - Rui Fausto
- †CQC, Department of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal
| |
Collapse
|
25
|
Halasa A, Lapinski L, Rostkowska H, Reva I, Nowak MJ. Tunable Diode Lasers as a Tool for Conformational Control: The Case of Matrix-Isolated Oxamic Acid. J Phys Chem A 2014; 119:2203-10. [DOI: 10.1021/jp501448m] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Anna Halasa
- Institute
of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw, Poland
| | - Leszek Lapinski
- Institute
of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw, Poland
| | - Hanna Rostkowska
- Institute
of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw, Poland
| | - Igor Reva
- Department
of Chemistry, University of Coimbra, 3004−535 Coimbra, Portugal
| | - Maciej J. Nowak
- Institute
of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw, Poland
| |
Collapse
|