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Salvitti G, Sigismondi S, Melandri S, López JC, Blanco S, Maris A. Structure and dynamics of 3'-aminoacetophenone and 4'-aminoacetophenone from rotational spectroscopy. Phys Chem Chem Phys 2024; 26:1881-1890. [PMID: 38175733 DOI: 10.1039/d3cp05608b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2024]
Abstract
The rotational spectra of 4'-aminoacetophenone, and those of two conformers (Z and E arrangement of the CO and NH2 groups) of 3'-aminoacetophenone and their 13C and 15N isotopologues were investigated both in the microwave (2-8 GHz) and millimetre (59.6-74.4 GHz) frequency regions using chirped pulse Fourier transform and free-jet absorption techniques, respectively. The spectra consist of μa and μb type lines that show a hyperfine structure due to both the nuclear quadrupole coupling of the 14N nucleus and the methyl internal rotation. Relative intensity measurements show that the Z form in 3'-aminoacetophenone is favoured with respect to E and the measured energy difference upper limit is about 5.5(1) kJ mol-1. Barriers to methyl internal rotation are V3 = 7.04(2) and 6.530(6) kJ mol-1 for 3'(Z)- and 4'-aminoacetophenone, respectively. Flexible model analyses of the amino inversion motion based on ab initio potential energy paths, suggest that the corresponding vibrational splitting increases up to 78% from aniline to 3'(E)-, 3'(Z), and 4-aminoacetophenone. However, due to supersonic expansion cooling, no splitting related to amine inversion is observed.
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Affiliation(s)
- Giovanna Salvitti
- Department of Chemistry G. Ciamician, University of Bologna, I-40126 Bologna, Italy.
| | - Silvia Sigismondi
- Department of Chemistry G. Ciamician, University of Bologna, I-40126 Bologna, Italy.
| | - Sonia Melandri
- Department of Chemistry G. Ciamician, University of Bologna, I-40126 Bologna, Italy.
| | - Juan Carlos López
- Department of Physical Chemistry and Inorganic Chemistry, IU-CINQUIMA, University of Valladolid, E-47011 Valladolid, Spain.
| | - Susana Blanco
- Department of Physical Chemistry and Inorganic Chemistry, IU-CINQUIMA, University of Valladolid, E-47011 Valladolid, Spain.
| | - Assimo Maris
- Department of Chemistry G. Ciamician, University of Bologna, I-40126 Bologna, Italy.
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2
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Salvitti G, Pizzano E, Baroncelli F, Melandri S, Evangelisti L, Negri F, Coreno M, Prince KC, Ciavardini A, Sa'adeh H, Pori M, Mazzacurati M, Maris A. Spectroscopic and quantum mechanical study of a scavenger molecule: N,N-diethylhydroxylamine. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2022; 281:121555. [PMID: 35926273 DOI: 10.1016/j.saa.2022.121555] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 06/20/2022] [Accepted: 06/22/2022] [Indexed: 06/15/2023]
Abstract
We report a combination of quantum mechanical calculations and a range of spectroscopic measurements in the gas phase of N,N-diethylhydroxylamine, an important scavenger compound. Three conformers were observed by pulsed jet Fourier transform microwave spectroscopy in the 6.5-18.5 GHz frequency range. They are characterized by the hydroxyl hydrogen atom being in trans orientation with respect to the bisector of the CNC angle while the side alkyl chains can be both trans (global minimum, Cs symmetry, A = 7608.1078(4), B = 2020.2988(2) and C = 1760.5423(2) MHz) or one trans and the other gauche (second energy minimum, A = 5302.896(1), B = 2395.9822(4) and C = 1804.8567(3) MHz) or gauche' (third energy minimum, A = 5960.8025(6), B = 2273.6627(4) and C = 1975.8074(4) MHz). For the global minimum, the 13Cα,13Cβ and 15N isotopologues were observed in natural abundance, allowing for an accurate partial structure determination. Moreover, several lines were detected by free jet absorption millimeter wave spectroscopy in the 59.6-74.4 GHz spectral range. The electron binding energies of the highest occupied molecular orbital and the next-to-highest occupied molecular orbital, determined by photoelectron spectroscopy, are 8.95 and 10.76 eV, respectively. Supporting calculations evidence that, (i) upon ionization of the HOMO, the molecular structure changes from an amine to an N-oxoammonium arrangement and (ii) the 0-0 of the HOMO-1 photoionization is 10.46 eV. The K-shell binding energies, determined by X-ray photoelectron spectroscopy, are 290.42 eV (Cβ), 291.45 eV (Cα), 405.98 eV (N) and 538.75 eV (O). The Fourier transform near infrared spectrum is reported and a tentative assignment is proposed. The equilibrium wavenumber (ω̃ = 3811 cm-1) and the anharmonicity constant (ω̃χ = -87.5 cm-1) of the hydroxyl stretching mode were estimated using a quadratic model.
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Affiliation(s)
- Giovanna Salvitti
- Department of Chemistry "G. Ciamician", University of Bologna, I-40126 Bologna, Italy
| | - Emanuele Pizzano
- Department of Chemistry "G. Ciamician", University of Bologna, I-40126 Bologna, Italy; BASF Italia S.p.A., Pontecchio Marconi, I-40037 Bologna, Italy
| | - Filippo Baroncelli
- Department of Chemistry "G. Ciamician", University of Bologna, I-40126 Bologna, Italy
| | - Sonia Melandri
- Department of Chemistry "G. Ciamician", University of Bologna, I-40126 Bologna, Italy; Interdepartmental Centre for Industrial Aerospace Research (CIRI Aerospace), University of Bologna, I-47121 Forlì, Italy; Interdepartmental Centre for Industrial Agrifood Research (CIRI Agrifood), University of Bologna, I-47521 Cesena, Italy
| | - Luca Evangelisti
- Interdepartmental Centre for Industrial Aerospace Research (CIRI Aerospace), University of Bologna, I-47121 Forlì, Italy; Interdepartmental Centre for Industrial Agrifood Research (CIRI Agrifood), University of Bologna, I-47521 Cesena, Italy; Department of Chemistry "G. Ciamician", University of Bologna I-48123 Ravenna, Italy
| | - Fabrizia Negri
- Department of Chemistry "G. Ciamician", University of Bologna, I-40126 Bologna, Italy; INSTM, UdR Bologna, I-40126 Bologna, Italy
| | - Marcello Coreno
- CNR-ISM, Trieste LD2 Unit, I-34149 Basovizza, Trieste, Italy
| | - Kevin C Prince
- Elettra-Sincrotrone Trieste, in Area Science Park, I-34149 Basovizza, Trieste, Italy; Department of Chemistry and Biotechnology, School of Science, Computing and Engineering Technology, Swinburne University of Technology, Hawthorn, Victoria, Australia
| | - Alessandra Ciavardini
- CNR-ISM, Trieste LD2 Unit, I-34149 Basovizza, Trieste, Italy; Elettra-Sincrotrone Trieste, in Area Science Park, I-34149 Basovizza, Trieste, Italy; Laboratory of Quantum Optics, University of Nova Gorica, Sl-5001 Nova Gorica, Slovenia
| | - Hanan Sa'adeh
- Elettra-Sincrotrone Trieste, in Area Science Park, I-34149 Basovizza, Trieste, Italy; Department of Physics, The University of Jordan, JO-11942 Amman, Jordan
| | - Matteo Pori
- BASF Italia S.p.A., Pontecchio Marconi, I-40037 Bologna, Italy
| | | | - Assimo Maris
- Department of Chemistry "G. Ciamician", University of Bologna, I-40126 Bologna, Italy; Interdepartmental Centre for Industrial Aerospace Research (CIRI Aerospace), University of Bologna, I-47121 Forlì, Italy.
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Vigorito A, Calabrese C, Maris A, Loru D, Peña I, Sanz ME, Melandri S. The Shapes of Sulfonamides: A Rotational Spectroscopy Study. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27092820. [PMID: 35566169 PMCID: PMC9101976 DOI: 10.3390/molecules27092820] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/10/2022] [Revised: 04/24/2022] [Accepted: 04/26/2022] [Indexed: 11/23/2022]
Abstract
Benzenesulfonamides are a class of molecules of extreme interest in the biochemical field because many of them are active against a variety of diseases. In this work, the pharmacophoric group benzensulfonamide, its derivatives para-toluensulfonamide and ortho-toluensulfonamide, and the bioactive molecule sulfanilamide, were investigated using rotational spectroscopy to determine their conformations and the influence of different substituents on their structures. For all species, the hyperfine structure due to the 14N atom was analyzed, and this provided crucial information for the unambiguous identification of the observed conformation of all molecules. In addition, for ortho-toluensulfonamide, the vibration–rotation hyperfine structure related to the methyl torsion was analyzed, and the methyl group rotation barrier was determined. For benzensulfonamide, partial rS and r0 structures were established from the experimental rotational constants of the parent and two deuterated isotopic species. In all compounds except ortho-toluensulfonamide, the amino group of the sulfonamide group lies perpendicular to the benzene plane with the aminic hydrogens eclipsing the oxygen atoms. In ortho-toluensulfonamide, where weak attractive interactions occur between the nitrogen lone pair and the methyl hydrogen atoms, the amino group lies in a gauche orientation, retaining the eclipsed configuration with respect to the SO2 frame. A comparison of the geometrical arrangements found in the PDB database allowed us to understand that the bioactive conformations are different from those found in isolated conditions. The conformations within the receptor are reached with an energy cost, which is balanced by the interactions established in the receptor.
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Affiliation(s)
- Annalisa Vigorito
- Dipartimento di Chimica “G. Ciamician” dell’Università, via Selmi 2, I-40126 Bologna, Italy; (A.V.); (C.C.); (A.M.)
| | - Camilla Calabrese
- Dipartimento di Chimica “G. Ciamician” dell’Università, via Selmi 2, I-40126 Bologna, Italy; (A.V.); (C.C.); (A.M.)
| | - Assimo Maris
- Dipartimento di Chimica “G. Ciamician” dell’Università, via Selmi 2, I-40126 Bologna, Italy; (A.V.); (C.C.); (A.M.)
| | - Donatella Loru
- Department of Chemistry, King’s College London, Britannia House, 7 Trinity Street, London SE1 1DB, UK; (D.L.); (I.P.); (M.E.S.)
| | - Isabel Peña
- Department of Chemistry, King’s College London, Britannia House, 7 Trinity Street, London SE1 1DB, UK; (D.L.); (I.P.); (M.E.S.)
| | - M. Eugenia Sanz
- Department of Chemistry, King’s College London, Britannia House, 7 Trinity Street, London SE1 1DB, UK; (D.L.); (I.P.); (M.E.S.)
| | - Sonia Melandri
- Dipartimento di Chimica “G. Ciamician” dell’Università, via Selmi 2, I-40126 Bologna, Italy; (A.V.); (C.C.); (A.M.)
- Correspondence:
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Skeletal Torsion Tunneling and Methyl Internal Rotation: The Coupled Large Amplitude Motions in Phenyl Acetate. Molecules 2022; 27:molecules27092730. [PMID: 35566082 PMCID: PMC9105391 DOI: 10.3390/molecules27092730] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Revised: 04/17/2022] [Accepted: 04/19/2022] [Indexed: 02/05/2023] Open
Abstract
The rotational spectrum of phenyl acetate, CH3COOC6H5, is measured using a free jet absorption millimeter-wave spectrometer in the range from 60 to 78 GHz and two pulsed jet Fourier transform microwave spectrometers covering a total frequency range from 2 to 26.5 GHz. The features of two large amplitude motions, the methyl group internal rotation and the skeletal torsion of the CH3COO group with respect to the phenyl ring C6H5 (tilted at about 70°), characterize the spectrum. The vibrational ground state is split into four widely spaced sublevels, labeled as A0, E0, A1, and E1, each of them with its set of rotational transitions and with additional interstate transitions. A global fit of the line frequencies of the four sublevels leads to the determination of 51 spectroscopic parameters, including the ΔEA0/A1 and ΔEE0/E1 vibrational splittings of ~36.4 and ~33.5 GHz, respectively. The V3 barrier to methyl internal rotation (~136 cm−1) and the skeletal torsion B2 barrier to the orthogonality of the two planes (~68 cm−1) are deduced.
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Kalbagh MR, Karuturi D, Kulala S, Montgomery M, Kamath P, Lal M. Synthesis of novel 2-(2,2,2-trifluoro-1-aryl-ethylidene)cyclohexane-1,3-dione: Scaffolds for reagent-based diversity-oriented synthesis. SYNTHETIC COMMUN 2020. [DOI: 10.1080/00397911.2020.1791343] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Mahesh R. Kalbagh
- Syngenta Biosciences Pvt. Ltd., Ilhas, India
- Department of Chemistry, Mangalore University, Mangaluru, India
| | - Damodar Karuturi
- Syngenta Biosciences Pvt. Ltd., Ilhas, India
- Department of Chemistry, Mangalore University, Mangaluru, India
| | | | - Mark Montgomery
- Syngenta Jealott’s Hill International Research Centre, Bracknell, UK
| | | | - Mukul Lal
- Syngenta Biosciences Pvt. Ltd., Ilhas, India
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6
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Calabrese C, Maris A, Vigorito A, Mariotti S, Fathi P, Geppert WD, Melandri S. Structure, Dynamics, and Accurate Laboratory Rotational Frequencies of the Acrylonitrile-Methanol Complex. J Phys Chem A 2020; 124:3601-3608. [PMID: 32279497 PMCID: PMC8007102 DOI: 10.1021/acs.jpca.0c01334] [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: 02/16/2020] [Revised: 04/10/2020] [Indexed: 11/28/2022]
Abstract
The hydrogen-bonded complex between acrylonitrile (CH2═CHCN) and methanol has been characterized spectroscopically in the millimeter wave range (59.6-74.4 GHz) using a free jet absorption millimeter wave spectrometer. Precise values of the rotational and centrifugal distortion constants were obtained from the measured frequencies of the complex of acrylonitrile with CH3OH and CD3OD. The analysis of the splittings of the rotational lines due to the hindered internal rotation of the methanol methyl group led to the determination of a V3 value of 221.9(7) and 218(5) cm-1 for the complexes of CH3OH and CD3OD, respectively, and these values are about 40% lower than that of free methanol. The structure of the observed conformation is in agreement with the global minimum determined at the MP2/aug-cc-pVTZ level of calculation, and the counterpoise corrected intermolecular binding energy, obtained at the same theoretical level, is De = 26.3 kJ mol-1.
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Affiliation(s)
- Camilla Calabrese
- Dipartimento
di Chimica “G. Ciamician”, Università di Bologna, via Selmi 2, I-40126 Bologna, Italy
- Departamento
Química Física, Facultad de Ciencia y Tecnología Universidad del País
Vasco (UPV/EHU), Apartado
644, E-48080 Bilbao, Spain
- Biofisika
Institute, (CSIC, UPV/EHU), University of
the Basque Country (UPV/EHU), Barrio Sarriena, S/N, 48940 Leioa, Spain
| | - Assimo Maris
- Dipartimento
di Chimica “G. Ciamician”, Università di Bologna, via Selmi 2, I-40126 Bologna, Italy
| | - Annalisa Vigorito
- Dipartimento
di Chimica “G. Ciamician”, Università di Bologna, via Selmi 2, I-40126 Bologna, Italy
| | - Sergio Mariotti
- INAF
- Osservatorio di Radioastronomia, via P. Gobetti, 101, I-40129 Bologna, Italy
| | - Pantea Fathi
- Department
of Physics, Stockholm University, Albanova University Center, SE-106 91 Stockholm, Sweden
| | - Wolf D. Geppert
- Department
of Physics, Stockholm University, Albanova University Center, SE-106 91 Stockholm, Sweden
| | - Sonia Melandri
- Dipartimento
di Chimica “G. Ciamician”, Università di Bologna, via Selmi 2, I-40126 Bologna, Italy
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8
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Calabrese C, Li W, Prampolini G, Evangelisti L, Uriarte I, Cacelli I, Melandri S, Cocinero EJ. A General Treatment to Study Molecular Complexes Stabilized by Hydrogen‐, Halogen‐, and Carbon‐Bond Networks: Experiment and Theory of (CH
2
F
2
)
n
⋅⋅⋅(H
2
O)
m. Angew Chem Int Ed Engl 2019; 58:8437-8442. [DOI: 10.1002/anie.201902753] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 04/05/2019] [Indexed: 11/08/2022]
Affiliation(s)
- Camilla Calabrese
- Departament of Physical ChemistryUniversity of the Basque Country (UPV/EHU) Barrio Sarriena, S/N 48940 Leioa Spain
- Biofisika Institute, (CSIC, UPV/EHU) 48080 Bilbao Spain
| | - Weixing Li
- Dipartimento di Chimica “Giacomo Ciamician”Università degli Studi di Bologna via Selmi 2 I-40126 Bologna Italy
| | - Giacomo Prampolini
- Istituto di Chimica dei Composti OrganoMetallici (ICCOM-CNR)Area della Ricerca via G. Moruzzi 1 I-56124 Pisa Italy
| | - Luca Evangelisti
- Dipartimento di Chimica “Giacomo Ciamician”Università degli Studi di Bologna via Selmi 2 I-40126 Bologna Italy
- Department of ChemistryUniversity of Virginia McCormick Road VA 22903 Charlottesville USA
| | - Iciar Uriarte
- Departament of Physical ChemistryUniversity of the Basque Country (UPV/EHU) Barrio Sarriena, S/N 48940 Leioa Spain
- Biofisika Institute, (CSIC, UPV/EHU) 48080 Bilbao Spain
| | - Ivo Cacelli
- Istituto di Chimica dei Composti OrganoMetallici (ICCOM-CNR)Area della Ricerca via G. Moruzzi 1 I-56124 Pisa Italy
- Dipartimento di Chimica e Chimica IndustrialeUniversità di Pisa via Risorgimento 35 I-56126 Pisa Italy
| | - Sonia Melandri
- Dipartimento di Chimica “Giacomo Ciamician”Università degli Studi di Bologna via Selmi 2 I-40126 Bologna Italy
| | - Emilio J. Cocinero
- Departament of Physical ChemistryUniversity of the Basque Country (UPV/EHU) Barrio Sarriena, S/N 48940 Leioa Spain
- Biofisika Institute, (CSIC, UPV/EHU) 48080 Bilbao Spain
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9
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Calabrese C, Li W, Prampolini G, Evangelisti L, Uriarte I, Cacelli I, Melandri S, Cocinero EJ. A General Treatment to Study Molecular Complexes Stabilized by Hydrogen‐, Halogen‐, and Carbon‐Bond Networks: Experiment and Theory of (CH
2
F
2
)
n
⋅⋅⋅(H
2
O)
m
. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201902753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Camilla Calabrese
- Departament of Physical ChemistryUniversity of the Basque Country (UPV/EHU) Barrio Sarriena, S/N 48940 Leioa Spain
- Biofisika Institute, (CSIC, UPV/EHU) 48080 Bilbao Spain
| | - Weixing Li
- Dipartimento di Chimica “Giacomo Ciamician”Università degli Studi di Bologna via Selmi 2 I-40126 Bologna Italy
| | - Giacomo Prampolini
- Istituto di Chimica dei Composti OrganoMetallici (ICCOM-CNR)Area della Ricerca via G. Moruzzi 1 I-56124 Pisa Italy
| | - Luca Evangelisti
- Dipartimento di Chimica “Giacomo Ciamician”Università degli Studi di Bologna via Selmi 2 I-40126 Bologna Italy
- Department of ChemistryUniversity of Virginia McCormick Road VA 22903 Charlottesville USA
| | - Iciar Uriarte
- Departament of Physical ChemistryUniversity of the Basque Country (UPV/EHU) Barrio Sarriena, S/N 48940 Leioa Spain
- Biofisika Institute, (CSIC, UPV/EHU) 48080 Bilbao Spain
| | - Ivo Cacelli
- Istituto di Chimica dei Composti OrganoMetallici (ICCOM-CNR)Area della Ricerca via G. Moruzzi 1 I-56124 Pisa Italy
- Dipartimento di Chimica e Chimica IndustrialeUniversità di Pisa via Risorgimento 35 I-56126 Pisa Italy
| | - Sonia Melandri
- Dipartimento di Chimica “Giacomo Ciamician”Università degli Studi di Bologna via Selmi 2 I-40126 Bologna Italy
| | - Emilio J. Cocinero
- Departament of Physical ChemistryUniversity of the Basque Country (UPV/EHU) Barrio Sarriena, S/N 48940 Leioa Spain
- Biofisika Institute, (CSIC, UPV/EHU) 48080 Bilbao Spain
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10
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Calabrese C, Maris A, Evangelisti L, Piras A, Parravicini V, Melandri S. Rotational Spectrum and Conformational Analysis of N-Methyl-2-Aminoethanol: Insights into the Shape of Adrenergic Neurotransmitters. Front Chem 2018. [PMID: 29520356 PMCID: PMC5827360 DOI: 10.3389/fchem.2018.00025] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
We describe an experimental and quantum chemical study for the accurate determination of the conformational space of small molecular systems governed by intramolecular non-covalent interactions. The model systems investigated belong to the biological relevant aminoalcohol's family, and include 2-amino-1-phenylethanol, 2-methylamino-1-phenylethanol, noradrenaline, adrenaline 2-aminoethanol, and N-methyl-2-aminoethanol. For the latter molecule, the rotational spectrum in the 6–18 and 59.6–74.4 GHz ranges was recorded in the isolated conditions of a free jet expansion. Based on the analysis of the rotational spectra, two different conformational species and 11 isotopologues were observed and their spectroscopic constants, including 14N-nuclear hyperfine coupling constants and methyl internal rotation barriers, were determined. From the experimental data a structural determination was performed, which was also used to benchmark accurate quantum chemical calculations on the whole conformational space. Atom in molecules and non-covalent interactions theories allowed the characterization of the position of the intramolecular non-covalent interactions and the energies involved, highlighting the subtle balance responsible of the stabilization of all the molecular systems.
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Affiliation(s)
- Camilla Calabrese
- Dipartimento di Chimica "G. Ciamician" dell'Università, Bologna, Italy
| | - Assimo Maris
- Dipartimento di Chimica "G. Ciamician" dell'Università, Bologna, Italy
| | - Luca Evangelisti
- Dipartimento di Chimica "G. Ciamician" dell'Università, Bologna, Italy
| | - Anna Piras
- Dipartimento di Chimica "G. Ciamician" dell'Università, Bologna, Italy
| | | | - Sonia Melandri
- Dipartimento di Chimica "G. Ciamician" dell'Università, Bologna, Italy
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11
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Abramova I, Rudshteyn B, Liebman JF, Greer A. Computed Regioselectivity and Conjectured Biological Activity of Ene Reactions of Singlet Oxygen with the Natural Product Hyperforin. Photochem Photobiol 2017; 93:626-631. [PMID: 28052331 DOI: 10.1111/php.12706] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Accepted: 11/16/2016] [Indexed: 01/12/2023]
Abstract
Hyperforin is a constituent of St. John's wort and coexists with the singlet oxygen sensitizer hypericin. Density functional theory, molecular mechanics and Connolly surface calculations show that accessibility in the singlet oxygen "ene" reaction favors the hyperforin "southwest" and "southeast" prenyl (2-methyl-2-butenyl) groups over the northern prenyl groups. While the southern part of hyperforin is initially more susceptible to oxidation, up to 4 "ene" reactions of singlet oxygen can take place. Computational results assist in predicting the fate of adjacent hydroperoxides in hyperforin, where the loss of hydrogen atoms may lead to the formation of a hydrotrioxide and a carbonyl instead of a Russell reaction.
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Affiliation(s)
- Inna Abramova
- Department of Chemistry, Graduate Center, City University of New York, Brooklyn College, Brooklyn, NY
| | - Benjamin Rudshteyn
- Department of Chemistry, Graduate Center, City University of New York, Brooklyn College, Brooklyn, NY
| | - Joel F Liebman
- Department of Chemistry and Biochemistry, University of Maryland, Baltimore County, Baltimore, MD
| | - Alexander Greer
- Department of Chemistry, Graduate Center, City University of New York, Brooklyn College, Brooklyn, NY
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12
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Vigorito A, Calabrese C, Paltanin E, Melandri S, Maris A. Regarding the torsional flexibility of the dihydrolipoic acid's pharmacophore: 1,3-propanedithiol. Phys Chem Chem Phys 2017; 19:496-502. [PMID: 27905582 DOI: 10.1039/c6cp05606g] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The great flexibility of 1,3-propanedithiol is probed using freejet absorption microwave spectroscopy and quantum chemistry calculations.
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Affiliation(s)
- Annalisa Vigorito
- Dipartimento di Chimica G. Ciamician
- Università degli Studi di Bologna
- 40126 Bologna
- Italy
| | - Camilla Calabrese
- Dipartimento di Chimica G. Ciamician
- Università degli Studi di Bologna
- 40126 Bologna
- Italy
| | - Ettore Paltanin
- Dipartimento di Chimica G. Ciamician
- Università degli Studi di Bologna
- 40126 Bologna
- Italy
| | - Sonia Melandri
- Dipartimento di Chimica G. Ciamician
- Università degli Studi di Bologna
- 40126 Bologna
- Italy
| | - Assimo Maris
- Dipartimento di Chimica G. Ciamician
- Università degli Studi di Bologna
- 40126 Bologna
- Italy
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13
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Calabrese C, Maris A, Uriarte I, Cocinero EJ, Melandri S. Effects of Chlorination on the Tautomeric Equilibrium of 2‐Hydroxypyridine: Experiment and Theory. Chemistry 2016; 23:3595-3604. [DOI: 10.1002/chem.201604891] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Indexed: 11/08/2022]
Affiliation(s)
- Camilla Calabrese
- Dipartimento di Chimica “G. Ciamician” Università degli Studi di Bologna Via Selmi 2 40126 Bologna Italy
| | - Assimo Maris
- Dipartimento di Chimica “G. Ciamician” Università degli Studi di Bologna Via Selmi 2 40126 Bologna Italy
| | - Iciar Uriarte
- Dpto. Química Física Universidad del País Vasco (UPV/EHU) Apartado 644 48080 Bilbao Spain
| | - Emilio J. Cocinero
- Dpto. Química Física Universidad del País Vasco (UPV/EHU) Apartado 644 48080 Bilbao Spain
| | - Sonia Melandri
- Dipartimento di Chimica “G. Ciamician” Università degli Studi di Bologna Via Selmi 2 40126 Bologna Italy
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Calabrese C, Gou Q, Maris A, Melandri S, Caminati W. Conformational Equilibrium and Internal Dynamics of E-Anethole: A Rotational Study. J Phys Chem B 2016; 120:6587-91. [PMID: 27341010 DOI: 10.1021/acs.jpcb.6b04883] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The rotational spectra of the two conformers of E-anethole have been investigated using the free jet broadband millimeter-wave spectroscopic technique combined with theoretical calculations. Anti and syn conformers differ for the relative orientation of the propenyl and methoxy chains, with all heavy atoms coplanar to the benzene ring. Relative intensity measurements prove that the anti form is the global minimum, about 2.0(5) kJ mol(-1) lower in energy with respect to the syn conformer, solving the contrasting results supplied by different theoretical methods. For both conformers, the barriers to internal rotation of the propenyl -CH3 group are low enough to generate fully resolved A-E splittings of the rotational transitions. The corresponding V3 barriers have been determined to be 7.080(5) and 6.978(4) kJ mol(-1), respectively.
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Affiliation(s)
- Camilla Calabrese
- Dipartimento di Chimica "G. Ciamician" dell'Università , Via Selmi 2, I-40126 Bologna, Italy
| | - Qian Gou
- Dipartimento di Chimica "G. Ciamician" dell'Università , Via Selmi 2, I-40126 Bologna, Italy
| | - Assimo Maris
- Dipartimento di Chimica "G. Ciamician" dell'Università , Via Selmi 2, I-40126 Bologna, Italy
| | - Sonia Melandri
- Dipartimento di Chimica "G. Ciamician" dell'Università , Via Selmi 2, I-40126 Bologna, Italy
| | - Walther Caminati
- Dipartimento di Chimica "G. Ciamician" dell'Università , Via Selmi 2, I-40126 Bologna, Italy
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Vigorito A, Gou Q, Calabrese C, Melandri S, Maris A, Caminati W. How CO2Interacts with Carboxylic Acids: A Rotational Study of Formic Acid-CO2. Chemphyschem 2015; 16:2961-7. [DOI: 10.1002/cphc.201500531] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Indexed: 12/24/2022]
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16
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Maris A, Calabrese C, Melandri S, Blanco S. Accurate spectroscopy of polycyclic aromatic compounds: From the rotational spectrum of fluoren-9-one in the millimeter wave region to its infrared spectrum. J Chem Phys 2015; 142:024317. [DOI: 10.1063/1.4905134] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Assimo Maris
- Dipartimento di Chimica “Giacomo Ciamician”, Università degli Studi di Bologna, via Selmi, 2, I-40126 Bologna, Italy
| | - Camilla Calabrese
- Dipartimento di Chimica “Giacomo Ciamician”, Università degli Studi di Bologna, via Selmi, 2, I-40126 Bologna, Italy
| | - Sonia Melandri
- Dipartimento di Chimica “Giacomo Ciamician”, Università degli Studi di Bologna, via Selmi, 2, I-40126 Bologna, Italy
| | - Susana Blanco
- Departamento de Química-Física y Química Inorgánica, Facultad de Ciencias, Universidad de Valladolid, Paseo Belén 7, E-47005 Valladolid, Spain
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Kumar S, Singh SK, Calabrese C, Maris A, Melandri S, Das A. Structure of saligenin: microwave, UV and IR spectroscopy studies in a supersonic jet combined with quantum chemistry calculations. Phys Chem Chem Phys 2014; 16:17163-71. [DOI: 10.1039/c4cp01693a] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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