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Lichtenberg C. Aminotroponiminates: Alkali Metal Compounds Reveal Unprecedented Coordination Modes. Organometallics 2016. [DOI: 10.1021/acs.organomet.6b00042] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Crispin Lichtenberg
- Institut für Anorganische
Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
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2
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Bouchoux G. Gas-phase basicities of polyfunctional molecules. Part 4: Carbonyl groups as basic sites. MASS SPECTROMETRY REVIEWS 2015; 34:493-534. [PMID: 24399766 DOI: 10.1002/mas.21416] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Revised: 09/30/2013] [Accepted: 09/30/2013] [Indexed: 06/03/2023]
Abstract
This article constitutes the fourth part of a general review of the gas-phase protonation thermochemistry of polyfunctional molecules (Part 1: Theory and methods, Mass Spectrom Rev 2007, 26:775-835, Part 2: Saturated basic sites, Mass Spectrom Rev 2012, 31:353-390, Part 3: Amino acids, Mass Spectrom Rev 2012, 31:391-435). This fourth part is devoted to carbonyl containing polyfunctional molecules. After a short reminder of the methods of determination of gas-phase basicity and the underlying physicochemical concepts, specific examples are examined under two major chapters. In the first one, aliphatic and unsaturated (conjugated and cyclic) ketones, diketones, ketoalcohols, and ketoethers are considered. A second chapter describes the protonation energetic of gaseous acids and derivatives including diacids, diesters, diamides, anhydrides, imides, ureas, carbamates, amino acid derivatives, and peptides. Experimental data were re-evaluated according to the presently adopted basicity scale. Structural and energetic information given by G3 and G4 quantum chemistry computations on typical systems are presented.
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Affiliation(s)
- Guy Bouchoux
- Département de Chimie, Laboratoire des Mécanismes Réactionnels, Ecole Polytechnique, 91120, Palaiseau, France
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3
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Meck C, D'Erasmo MP, Hirsch DR, Murelli RP. The biology and synthesis of α-hydroxytropolones. MEDCHEMCOMM 2014; 5:842-852. [PMID: 25089179 PMCID: PMC4114738 DOI: 10.1039/c4md00055b] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
α-Hydroxytropolones are a subclass of the troponoid family of natural products that are of high interest due to their broad biological activity and potential as treatment options for several diseases. Despite this promise, there have been scarce synthetic chemistry-driven optimization studies on the molecules. The following review highlights key developments in the biological studies conducted on α-hydroxytropolones to date, including the few synthetic chemistry-driven optimization studies. In addition, we provide an overview of the methods currently available to access these molecules. This review is intended to serve as a resource for those interested in biological activity of α-hydroxytropolones, and inspire the development of new synthetic methods and strategies that could aid in this pursuit.
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Affiliation(s)
- Christine Meck
- Brooklyn College, City University of New York, Department of Chemistry, 2900 Bedford 4 Avenue, Brooklyn, New York, USA
| | - Michael P D'Erasmo
- Brooklyn College, City University of New York, Department of Chemistry, 2900 Bedford 4 Avenue, Brooklyn, New York, USA
| | - Danielle R Hirsch
- Brooklyn College, City University of New York, Department of Chemistry, 2900 Bedford 4 Avenue, Brooklyn, New York, USA
| | - Ryan P Murelli
- Brooklyn College, City University of New York, Department of Chemistry, 2900 Bedford 4 Avenue, Brooklyn, New York, USA
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LIMA NATHÁLIABD, BELARMINO MÁRCIAKDL. A STUDY OF THE STRUCTURES AND VIBRATIONAL SPECTRA OF THE N2O⋯(HX)2 AND ON2⋯(HX)2 WITH X = F, Cl, Br AND CN. JOURNAL OF THEORETICAL & COMPUTATIONAL CHEMISTRY 2013. [DOI: 10.1142/s0219633613500442] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Theoretical calculations 6-311++G(d,p) have been performed in order to obtain binding energies and molecular properties of complexes involving nitrous oxide ( N2O ) and two HX (X = F, Cl, Br and CN ) molecules. Our calculations have revealed the existence of eleven stable structures. The vibrational changes which take place in the HX acid after complexation follow the usual behavior: the HX stretching frequency is shifted downward whereas its IR intensity is much enhanced. The new vibrational modes arising upon H-bond formation, were verified, especially, those associated with the out-of-plane and in-plane HX bending modes, which are pure rotations in the HX isolated molecule.
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Affiliation(s)
- NATHÁLIA B. D. LIMA
- Departamento de Química Fundamental, Universidade Federal de Pernambuco (UFPE), 50740-540, Recife (PE), Brasil
| | - MÁRCIA K. D. L. BELARMINO
- Departamento de Química Fundamental, Universidade Federal de Pernambuco (UFPE), 50740-540, Recife (PE), Brasil
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5
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Zborowski KK, Jezierski G, Kim Y, Proniewicz LM. Tautomerism of Neutral α-Tropolone and its Protonated and Deprotonated Forms. Z PHYS CHEM 2013. [DOI: 10.1524/zpch.2013.0351] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Abstract
Possible structures of α-tropolone (2-hydroxy-2,4,6-cycloheptatrien-1-one) tautomers: four neutral, thirteen protonated, and four deprotonated, are studied at the B3LYP/6-311++G∗∗ computational level. The energies and the free energies calculated for the studied tautomers show that for each of the three forms, among all the possible tautomers in the tautomeric mixture, only one structure is expected: a keto-enol structure with an intramolecular hydrogen bond (neutral α-tropolone molecule), the structure with two deprotonated exocyclic oxygen atoms (tropolonate, deprotonated tropolone), and the structure with two hydroxyl group forming an intramolecular hydrogen bond (protonated tropolone). The relative energies of the studied tautomers are rationalized based on the results from the atomic energy integration performed within the frame of the Quantum Theory of Atoms in Molecules.
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Affiliation(s)
| | | | - Younkoyoo Kim
- Hankuk University of Foreign Studies, Department of Chemistry, Republik Korea
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6
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Radić N, Maksić ZB. Basicity of neutral organic superbases with vinamidine structure in gas phase and acetonitrile: a density functional theory study. J PHYS ORG CHEM 2013. [DOI: 10.1002/poc.2980] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Nena Radić
- Quantum Organic Chemistry Group, Division of Organic Chemistry and Biochemistry; Ruđer Bošković Institute; Zagreb; Croatia
| | - Zvonimir B. Maksić
- Quantum Organic Chemistry Group, Division of Organic Chemistry and Biochemistry; Ruđer Bošković Institute; Zagreb; Croatia
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7
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Wheeler SE. Homodesmotic reactions for thermochemistry. WILEY INTERDISCIPLINARY REVIEWS-COMPUTATIONAL MOLECULAR SCIENCE 2011. [DOI: 10.1002/wcms.72] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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8
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Computational study of the intramolecular proton transfer reactions of 3-hydroxytropolone (2,7-dihydroxycyclohepta-2,4,6-trien-1-one) and its dimers. J Mol Model 2010; 16:1877-82. [PMID: 20232098 DOI: 10.1007/s00894-010-0674-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2009] [Accepted: 02/02/2010] [Indexed: 10/19/2022]
Abstract
The proton transfer reaction and dimerization processes of 3-hydroxytropolone (3-OHTRN) have been investigated using density functional theory (DFT) at the B3LYP/6-31+G** level. The influence of the solvent on the proton transfer reaction of 3-OHTRN was examined using the self-consistent isodensity polarized continuum model (SCI-PCM) with different dielectric constants (ε = 4.9, CHCI₃; ε = 32.63, CH₃OH; ε = 78.39, H₂O). The intramolecular proton transfer reaction occurs more readily in the gas phase than in solution. Results also show that the stability of 3-OHTRN dimers in the gas phase is directly affected by the hydrogen bond length in the dimer structure.
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Wheeler SE, Houk KN, Schleyer PVR, Allen WD. A hierarchy of homodesmotic reactions for thermochemistry. J Am Chem Soc 2009; 131:2547-60. [PMID: 19182999 PMCID: PMC2711007 DOI: 10.1021/ja805843n] [Citation(s) in RCA: 394] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Chemical equations that balance bond types and atom hybridization to different degrees are often used in computational thermochemistry, for example, to increase accuracy when lower levels of theory are employed. We expose the widespread confusion over such classes of equations and demonstrate that the two most widely used definitions of "homodesmotic" reactions are not equivalent. New definitions are introduced, and a consistent hierarchy of reaction classes (RC1-RC5) for hydrocarbons is constructed: isogyric (RC1) superset of isodesmic (RC2) superset of hypohomodesmotic (RC3) superset of homodesmotic (RC4) superset of hyperhomodesmotic (RC5). Each of these successively conserves larger molecular fragments. The concept of isodesmic bond separation reactions is generalized to all classes in this hierarchy, providing a unique sectioning of a given molecule for each reaction type. Several ab initio and density functional methods are applied to the bond separation reactions of 38 hydrocarbons containing five or six carbon atoms. RC4 and RC5 reactions provide bond separation enthalpies with errors consistently less than 0.4 kcal mol(-1) across a wide range of theoretical levels, performing significantly better than the other reaction types and far superior to atomization routes. Our recommended bond separation reactions are demonstrated by determining the enthalpies of formation (at 298 K) of 1,3,5-hexatriyne (163.7 +/- 0.4 kcal mol(-1)), 1,3,5,7-octatetrayne (217.5 +/- 0.6 kcal mol(-1)), the larger polyynes C(10)H(2) through C(26)H(2), and an infinite acetylenic carbon chain.
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Affiliation(s)
- Steven E Wheeler
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, USA.
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Sanz P, Mó O, Yáñez M, Elguero J. The effects of C by N replacement on the hydrogen bonding of malonaldehyde: N-formylformimidic acid, N-(hydroxymethyl)formamide and related compounds. Phys Chem Chem Phys 2009; 11:762-9. [DOI: 10.1039/b815827d] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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11
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Sanz P, Mó O, Yáñez M, Elguero J. Bonding in tropolone, 2-aminotropone, and aminotroponimine: no evidence of resonance-assisted hydrogen-bond effects. Chemistry 2008; 14:4225-32. [PMID: 18381721 DOI: 10.1002/chem.200701827] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The properties of the intramolecular hydrogen bond (IMHB) in tropolone, aminotropone, and aminotroponimine have been compared with those in the corresponding saturated analogues at the B3LYP/6-311+G(3df,2p)//B3LYP/6-311+G(d,p) level of theory. In general, all those compounds in which the seven-membered ring is unsaturated exhibit a stronger IMHB than their saturated counterparts. Nevertheless, this enhanced strength is not primarily due to resonance-assisted hydrogen-bond effects, but to the much higher intrinsic basicity and acidity of the hydrogen-bond acceptor and donor groups, respectively, in the unsaturated compounds. These acidity and basicity enhancements have a double origin: 1) the unsaturated nature of the moiety to which the hydrogen-bond donor and acceptor are attached and 2) the cyclic nature of the compounds under scrutiny. As has been found for hydroxymethylene and aminomethylene cyclobutanones, and cyclobutenones and their nitrogen-containing analogues, the IMHB strength follows the [donor, acceptor] trend: [OH, C=NH]>[OH, C=O]>[NH(2), C=NH]>[NH(2), C=O] and fulfills a Steiner-Limbach correlation similar to that followed by intermolecular hydrogen bonds.
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Affiliation(s)
- Pablo Sanz
- Departamento de Química, C-9, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain
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12
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Sanz P, Mó O, Yáñez M, Elguero J. Non-resonance-assisted hydrogen bonding in hydroxymethylene and aminomethylene cyclobutanones and cyclobutenones and their nitrogen counterparts. Chemphyschem 2007; 8:1950-8. [PMID: 17676647 DOI: 10.1002/cphc.200700266] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The characteristics of intramolecular hydrogen bonds (IMHB) have been systematically analyzed for a series of 32 different enols of derivatives of cyclobutane, cyclobutene, and cyclobutadiene bearing oxygen and nitrogen functionalities, at the B3LYP/6-311+G(3df,2p)//B3LYP/6-311+G(d,p) level of theory. In those cases where two tautomers (interconnected by a hydrogen shift through the IMHB) exist, tautomer a, in which the HB-donor group (YH) is attached to the four-membered ring, is less stable than tautomer b, in which is the HB-acceptor (X) is the one attached to the four-membered ring. As expected the OH group behaves as a better HB-donor than the NH(2) group and the C==NH group as a better HB-acceptor than the C==O group, although the first effect clearly dominates. Accordingly, the expected IMHB strength follows the [donor, acceptor] trend: [OH,C==NH]>[OH,C==O]>[NH(2),C==NH]>[NH(2),C==O]. Quite unexpectedly, in all those compounds in which the functionality exhibiting the IMHB is unsaturated, the IMHB is weaker than in their saturated counterparts, verifying that the primary effect on the strength of the IMHB is the structure of the sigma-skeleton of the system. In the conjugated systems investigated here, the severe constraints imposed by the four-membered ring force the HB donor and acceptor to be far apart and the IMHB is rather weak. These geometrical constraints are less severe for the saturated analogues and the IMHB becomes stronger, confirming that the characteristics of the sigma-skeleton, and not the resonance-assisted hydrogen bond (RAHB) phenomenon, are the primary contributors to the strength of the IMHB in conjugated compounds.
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Affiliation(s)
- Pablo Sanz
- Departamento de Química, C-9, Universidad Autónoma de Madrid, Cantoblanco, 28049, Madrid, Spain
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Hojo M, Ueda T, Inoue T, Ike M, Kobayashi M, Nakai H. UV−Visible and 1H or 13C NMR Spectroscopic Studies on the Specific Interaction between Lithium Ions and the Anion from Tropolone or 4-Isopropyltropolone (Hinokitiol) and on the Formation of Protonated Tropolones in Acetonitrile or Other Solvents. J Phys Chem B 2007; 111:1759-68. [PMID: 17256982 DOI: 10.1021/jp066756n] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The specific interaction between lithium ions and the tropolonate ion (C(7)H(5)O(2)-: L-) was examined by means of UV-visible and 1H or 13C NMR spectroscopy in acetonitrile and other solvents. On the basis of the electronic spectra, we can propose the formation of not only coordination-type species (Li+(L-)2) and the ion pair (Li+L-) but also a "triple cation" ((Li+)2L-) in acetonitrile and acetone; however, no "triple cation" was found in N,N-dimethylformamide (DMF) and in dimethylsulfoxide (DMSO), solvents of higher donicities and only ion pair formation between Li+ and L- in methanol of much higher donicity and acceptivity. The 1H NMR chemical shifts of the tropolonate ion with increasing Li+ concentration verified the formation of (Li+)2L- species in CD3CN and acetone-d6, but not in DMF-d6 or CD(3)OD. With increasing concentration of LiClO(4) in CD(3)CN, the 1H NMR signals of 4-isopropyltropolone (HL') in coexistence with an equivalent amount of Et(3)N shifted first toward higher and then toward lower magnetic-fields, which were explained by the formation of (Li+)(Et(3)NH+)L'- and by successive replacement of Et(3)NH+ with a second Li+ to give (Li+)2L'-. In CD(3)CN, the 1,2-C signal in the 13C NMR spectrum of tetrabutylammnium tropolonate (n-Bu(4)NC(7)H(5)O) appeared at an unexpectedly lower magnetic-field (184.4 ppm vs TMS) than that of tropolone (172.7 ppm), while other signals of the tropolonate showed normal shifts toward higher magnetic-fields upon deprotonation from tropolone. Nevertheless, with addition of LiClO(4) at higher concentrations, the higher and lower shifts of magnetic-fields for 1,2-C and other signals, respectively, supported the formation of the (Li+)2L- species, which can cause redissolution of LiL precipitates. All of the data with UV-visible and 1H and 13C NMR spectroscopy demonstrated that the protonated tropolone (or the dihydroxytropylium ion), H(2)L+, was produced by addition of trifluoromethanesulfonic or methanesulfonic acid to tropolone in acetonitrile. The order of the 5-C and 3,7-C signals in 13C NMR spectra of the tropolonate ions was altered by addition of less than an equivalent amount of H+ to the tropolonate ion in CD(3)CN. Theoretical calculations satisfied the experimental 13C NMR chemical shift values of L-, HL, and H(2)L+ in acetonitrile and were in accordance with the proposed reaction schemes.
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Affiliation(s)
- Masashi Hojo
- Department of Chemistry, Faculty of Science, Kochi University, Kochi 780-8520, Japan.
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Burns LA, Murdock D, Vaccaro PH. An exploration of electronic structure and nuclear dynamics in tropolone. I. The X̃A11 ground state. J Chem Phys 2006; 124:204307. [PMID: 16774332 DOI: 10.1063/1.2200343] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The ground electronic state (X 1A1) of tropolone has been examined theoretically by exploiting extensive sets of basis functions [e.g., 6-311++G(d,p) and aug-cc-pVDZ] in conjunction with the high levels of electron correlation made possible by density functional (DFT/B3LYP), Moller-Plesset perturbation (MP2), and coupled-cluster [CCSD and CCSD(T)] methods. Unconstrained MP2 and CCSD optimization procedures performed with the reference 6-311++G(d,p) basis predict a slightly nonplanar equilibrium structure characterized by a small barrier to skeletal inversion (< or =10 cm(-1) magnitude). Complementary harmonic frequency analyses have shown this nonplanarity to be a computational artifact arising from adversely tuned carbon d-orbital exponents embodied in the standard definitions of several Pople-type basis sets. Correlation-consistent bases such as Dunning's aug-cc-pVDZ are less susceptible to these effects and were employed to confirm that the X 1A1 hypersurface supports a rigorously planar global minimum. The fully optimized geometries and vibrational force fields obtained by applying potent coupled-cluster schemes to the relaxed-equilibrium (Cs) and transition-state (C2v) conformers of tropolone afford a trenchant glimpse of the key features that mediate intramolecular hydron exchange in this model system. By incorporating perturbative triples corrections at the substantial CCSD(T) level of theory, an interoxygen distance of r(O...O)=2.528 A was determined for the minimum-energy configuration, with the accompanying proton-transfer reaction being hindered by a barrier of 2557.0 cm(-1) height. The potential energy landscape in tropolone, as well as the nature of the attendant hydron migration process, is discussed within the framework of the encompassing G4 molecular symmetry group.
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Affiliation(s)
- Lori A Burns
- Department of Chemistry, Yale University, New Haven, Connecticut 06520-8107, USA
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Redington RL. Isoelectronic Homologues and Isomers: Tropolone, 5-Azatropolone, 1-H-Azepine-4,5-dione, Saddle Points, and Ions. J Phys Chem A 2005; 110:1600-7. [PMID: 16435822 DOI: 10.1021/jp053928s] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Computational studies of 12 64-electron homologues and isomers of tropolone in the S(0) electronic ground state are reported. Three minimum-energy structures, tropolone (Tp), 5-azatropolone (5Azt), and 5-H-5-azatropolonium (5AztH(+)), have an internal H-bond and planar C(s)) geometry, and three, tropolonate (TpO(-)), 5-azatropolonate (5AzO(-)), and 1-H-azepine-4,5-dione (45Di), lack the H-bond and have twisted C(2) geometry. All 6 substances have an equal double-minimum potential energy surface and a saddle point with planar C(2)(v) geometry. The energy for the gas-phase isomerization reaction 45Di --> 5Azt is near +4 kJ mol(-1) at the MP4(SDQ)/6-311++G(df,pd)//MP2/6-311++G(df,pd) (energy//geometry) theoretical level and around -20 kJ mol(-1) at lower theoretical levels. The dipole moments computed for 45Di and 5Azt are 9.6 and 2.1 D, respectively, and this large difference contributes to MO-computed free energies of solvation that strongly favor--as experimentally observed--45Di over 5Azt in chloroform solvent. The MO-computed energy for the gas-phase protonation reaction 45Di + H(+) --> 5AztH(+) is -956.4 kJ mol(-1), leading to 926.8 kJ mol(-1) as the estimated proton affinity for 45Di at 298 K and 1 atm. The intramolecular dynamical properties predicted for 5Azt and 5AztH(+) parallel those observed for tropolone. They are therefore expected to exhibit spectral tunneling doublets. Once they are synthesized, they should contribute importantly to the understanding of multidimensional intramolecular H transfer and dynamical coupling processes.
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Affiliation(s)
- Richard L Redington
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409, USA
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Merino G, Vela A, Heine T. Description of Electron Delocalization via the Analysis of Molecular Fields. Chem Rev 2005; 105:3812-41. [PMID: 16218568 DOI: 10.1021/cr030086p] [Citation(s) in RCA: 146] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Gabriel Merino
- Institut für Physikalische Chemie und Elektrochemie, TU Dresden, D-01062 Dresden, Germany.
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The Role of Intramolecular Hydrogen Bonds vs. Other Weak Interactions on the Conformation of Hyponitrous Acid and Its Mono- and Dithio-Derivatives. Struct Chem 2005. [DOI: 10.1007/s11224-005-4461-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Claramunt R, Sanz D, Pérez-Torralba M, Pinilla E, Torres M, Elguero J. Solid-State Structure and Tautomerism of 2-Aminotroponimines Studied by X-ray Crystallography and Multinuclear NMR Spectroscopy. European J Org Chem 2004. [DOI: 10.1002/ejoc.200400389] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Affiliation(s)
- Charles E. Miller
- Department of Chemistry, Haverford College, Haverford, Pennsylvania 19041-1392
| | - Joseph S. Francisco
- Department of Chemistry and Department of Earth and Atmospheric Science, Purdue University, West Lafayette, Indiana 47907-1393
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Sanz P, Yáñez M, Mó O. Competition between X···H···Y Intramolecular Hydrogen Bonds and X····Y (X = O, S, and Y = Se, Te) Chalcogen−Chalcogen Interactions. J Phys Chem A 2002. [DOI: 10.1021/jp0143645] [Citation(s) in RCA: 119] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Kova?evi? B, Glasovac Z, Maksi? ZB. The intramolecular hydrogen bond and intrinsic proton affinity of neutral organic molecules:N,N ?,N ?-tris (3-aminopropyl)guanidine and some related systems. J PHYS ORG CHEM 2002. [DOI: 10.1002/poc.552] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Affiliation(s)
- T M Krygowski
- Department of Chemistry, University of Warsaw, Pasteura 1, 02 093 Warsaw, Poland
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Wójcik MJ, Nakamura H, Iwata S, Tatara W. Theoretical study of multidimensional proton tunneling in the excited state of tropolone. J Chem Phys 2000. [DOI: 10.1063/1.481193] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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González AI, Mó O, Yáñez M. A Gas-Phase Basicity Scale for Selenocarbonyl Compounds Based on High-Level ab Initio and Density Functional Theory Calculations. J Phys Chem A 1999. [DOI: 10.1021/jp984734y] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ana I. González
- Departamento de Quimica, C-9, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain
| | - Otilia Mó
- Departamento de Quimica, C-9, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain
| | - Manuel Yáñez
- Departamento de Quimica, C-9, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain
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Minabe M, Nozawa T, Kurose T, Kimura T, Tsubota M. Synthesis and Properties of 9-(Tropylidenehydrazono)fluorene and Related Compounds. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 1998. [DOI: 10.1246/bcsj.71.693] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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