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Vishnevskiy YV, Mitzel NW. Reply to a Comment on “The Nature of Chalcogen‐Bonding‐Type Tellurium–Nitrogen Interactions”. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202104899] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Yury V. Vishnevskiy
- Universität Bielefeld Fakultät für Chemie Lehrstuhl für Anorganische Chemie und Strukturchemie Universitätsstraße 25 33615 Bielefeld Germany
| | - Norbert W. Mitzel
- Universität Bielefeld Fakultät für Chemie Lehrstuhl für Anorganische Chemie und Strukturchemie Universitätsstraße 25 33615 Bielefeld Germany
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Vishnevskiy YV, Mitzel NW. Reply to a Comment on "The Nature of Chalcogen-Bonding-Type Tellurium-Nitrogen Interactions". Angew Chem Int Ed Engl 2021; 60:13150-13157. [PMID: 33960601 PMCID: PMC8251573 DOI: 10.1002/anie.202104899] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Indexed: 12/03/2022]
Abstract
We reply to the comment by J.‐M. Mewes, A. Hansen and S. Grimme (MHG), who challenged the accuracy of our re value for the N⋅⋅⋅Te distance in (C6F5)Te(CH2)3NMe2 determined by gas electron diffraction (GED). We conclusively demonstrate that MHG′s quoted reference calculations are less accurate than they claim for solid state and gas phase. We show by higher level calculations, that we did not miss substantial contributions from open‐chain conformers. Refinements on simulated scattering data show that such contributions would have had only an almost negligible effect on re(N⋅⋅⋅Te). MHG suggested the use of a H0‐tuned GFN method for calculating vibrational corrections ra−re, but this did not change these values substantially. Alternative amplitude calculations using higher level analytic harmonic and numeric cubic force fields (PBE0‐D3BJ/def2‐TZVP) yield a GED value for re(N⋅⋅⋅Te)=2.852(25) Å that is well within the experimental error of our original value 2.918(31) Å but far from the 2.67(8) Å predicted by MHG. A now improved error estimation accounts for inaccuracies in the calculated auxiliary values. The gas/solid difference of the weak N⋅⋅⋅Te interaction is in a realistic range compared to other systems involving weak chemical interactions. We reply to the comment which challenged the accuracy of our re value for the N⋅⋅⋅Te distance in (C6F5)Te(CH2)3NMe2 determined by gas electron diffraction. We show by higher level calculations, that we did not miss substantial contributions from open‐chain conformers.
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Affiliation(s)
- Yury V Vishnevskiy
- Universität Bielefeld, Fakultät für Chemie, Lehrstuhl für Anorganische Chemie und Strukturchemie, Universitätsstraße 25, 33615, Bielefeld, Germany
| | - Norbert W Mitzel
- Universität Bielefeld, Fakultät für Chemie, Lehrstuhl für Anorganische Chemie und Strukturchemie, Universitätsstraße 25, 33615, Bielefeld, Germany
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Morgan WJ, Matthews DA, Ringholm M, Agarwal J, Gong JZ, Ruud K, Allen WD, Stanton JF, Schaefer HF. Geometric Energy Derivatives at the Complete Basis Set Limit: Application to the Equilibrium Structure and Molecular Force Field of Formaldehyde. J Chem Theory Comput 2018; 14:1333-1350. [DOI: 10.1021/acs.jctc.7b01138] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- W. James Morgan
- Center for Computational Quantum Chemistry (CCQC), University of Georgia, Athens, Georgia 30602, United States
| | - Devin A. Matthews
- Institute for Computational Engineering and Sciences (ICES), University of Texas at Austin, Austin, Texas 78712, United States
| | - Magnus Ringholm
- Hylleraas Centre for Quantum Molecular Science, Department of Chemistry, University of Tromsø − The Arctic University of Norway, N-9037 Tromsø, Norway
| | - Jay Agarwal
- Center for Computational Quantum Chemistry (CCQC), University of Georgia, Athens, Georgia 30602, United States
| | - Justin Z. Gong
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
| | - Kenneth Ruud
- Hylleraas Centre for Quantum Molecular Science, Department of Chemistry, University of Tromsø − The Arctic University of Norway, N-9037 Tromsø, Norway
| | - Wesley D. Allen
- Center for Computational Quantum Chemistry (CCQC), University of Georgia, Athens, Georgia 30602, United States
| | - John F. Stanton
- Quantum Theory Project, University of Florida, Gainesville, Florida 32611, United States
| | - Henry F. Schaefer
- Center for Computational Quantum Chemistry (CCQC), University of Georgia, Athens, Georgia 30602, United States
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Tarasov YI, Kochikov IV, Kovtun DM, Polenov EA, Ivanov AA. Internal rotation and equilibrium structure of the 2-methyl-2-nitropropane molecule from joint processing of gas phase electron diffraction data, vibrational and microwave spectroscopy data, and quantum chemical calculation results. J STRUCT CHEM+ 2017. [DOI: 10.1134/s0022476617030106] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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5
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Kochikov IV, Kovtun DM, Tarasov YI. Electron diffraction analysis for the molecules with degenerate large amplitude motions: Intramolecular dynamics in arsenic pentafluoride. J Mol Struct 2017. [DOI: 10.1016/j.molstruc.2016.09.064] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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6
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Murphy KV, Morgan WJ, Sun Z, Schaefer HF, Agarwal J. Thioformaldehyde S-Sulfide, Sulfur Analogue of the Criegee Intermediate: Structures, Energetics, and Rovibrational Analysis. J Phys Chem A 2017; 121:998-1006. [DOI: 10.1021/acs.jpca.6b12473] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Kevin V. Murphy
- Center for Computational
Quantum Chemistry, University of Georgia, Athens, Georgia 30602, United States
| | - Whitney J. Morgan
- Center for Computational
Quantum Chemistry, University of Georgia, Athens, Georgia 30602, United States
| | - Zhi Sun
- Center for Computational
Quantum Chemistry, University of Georgia, Athens, Georgia 30602, United States
| | - Henry F. Schaefer
- Center for Computational
Quantum Chemistry, University of Georgia, Athens, Georgia 30602, United States
| | - Jay Agarwal
- Center for Computational
Quantum Chemistry, University of Georgia, Athens, Georgia 30602, United States
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7
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Claudino D, Gargano R, Carvalho-Silva VH, E Silva GM, da Cunha WF. Investigation of the Abstraction and Dissociation Mechanism in the Nitrogen Trifluoride Channels: Combined Post-Hartree-Fock and Transition State Theory Approaches. J Phys Chem A 2016; 120:5464-73. [PMID: 27355487 DOI: 10.1021/acs.jpca.6b04947] [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 present paper concludes our series of kinetics studies on the reactions involved in the complex mechanism of nitrogen trifluoride decomposition. Two other related reactions that, along with this mechanism, take part in an efficient boron nitride growth process are also investigated. We report results concerning two abstraction reactions, namely NF2 + N ⇄ 2NF and NF3 + NF ⇄ 2NF2, and two dissociations, N2F4 ⇄ 2NF2 and N2F3 ⇄ NF2 + NF. State-of-the-art electronic structure calculations at the CCSD(T)/cc-pVTZ level of theory were considered to determine geometries and frequencies of reactants, products, and transition states. Extrapolation of the energies to the complete basis set limit was used to obtain energies of all the species. We applied transition state theory to compute thermal rate constants including Wigner, Eckart, Bell, and deformed theory corrections in order to take tunneling effects into account. The obtained results are in good agreement with the experimental data available in the literature and are expected to provide a better phenomenological understanding of the NF3 decomposition role in the boron nitride growth for a wide range of temperature values.
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Affiliation(s)
- D Claudino
- Quantum Theory Project, Gainesville, Florida 32611-2085, United States
| | - R Gargano
- Institute of Physics, University of Brasilia , Brasilia, 70.919-970, Brazil
| | - Valter H Carvalho-Silva
- Grupo de Química Teórica e Estrutural de Anápolis, Ciências Exatas e Tecnológicas, Universidade Estadual de Goiás , CP 459, Anápolis, 75001-970, Brazil
| | - Geraldo M E Silva
- Institute of Physics, University of Brasilia , Brasilia, 70.919-970, Brazil
| | - W F da Cunha
- Quantum Theory Project, Gainesville, Florida 32611-2085, United States.,Institute of Physics, University of Brasilia , Brasilia, 70.919-970, Brazil
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8
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Internal rotation and equilibrium structure of 2-chloro-3-nitrothiophene from gas electron diffraction and quantum chemistry. J Mol Struct 2015. [DOI: 10.1016/j.molstruc.2015.07.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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9
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Kovtun DM, Kochikov IV, Tarasov YI. Electron Diffraction Analysis for the Molecules with Multiple Large-Amplitude Motions. 3-Nitrostyrene—A Molecule with Two Internal Rotors. J Phys Chem A 2015; 119:1657-65. [DOI: 10.1021/jp5082774] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Dmitry M. Kovtun
- Lomonosov Moscow State University, Leninskie Gory, 119991 Moscow, Russia
| | - Igor V. Kochikov
- Lomonosov Moscow State University, Leninskie Gory, 119991 Moscow, Russia
| | - Yury I. Tarasov
- Lomonosov Moscow State University of Fine Chemical Technologies, Vernadskogo Prospect 86, 119571 Moscow, Russia
- Joint Institute for High Temperatures of the Russian Academy of Sciences, Izhorskaya Street 13, Building 2, 125412 Moscow, Russia
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11
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Kalescky R, Kraka E, Cremer D. Accurate determination of the binding energy of the formic acid dimer: The importance of geometry relaxation. J Chem Phys 2014; 140:084315. [DOI: 10.1063/1.4866696] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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12
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Kalescky R, Zou W, Kraka E, Cremer D. Vibrational Properties of the Isotopomers of the Water Dimer Derived from Experiment and Computations. Aust J Chem 2014. [DOI: 10.1071/ch13479] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The water dimer and its 11 deuterated isotopomers are investigated utilizing coupled cluster theory and experimental data as input for a perturbational determination of the isotopomer frequencies. Deuterium substitution reduces the H-bond stretching frequency by maximally 12 cm–1 from 143 to 131 cm–1, which makes a spectroscopic differentiation of H- and D-bonds difficult. However, utilizing the 132 frequencies obtained in this work, the identification of all isotopomers is straightforward. The CCSD(T)/CBS value of the binding energy De is 5.00 kcal mol–1. The binding energy D0 of the water dimer increases upon deuterium substitution from 3.28 to maximally 3.71 kcal mol–1 reflecting a decrease in the zero point energy contribution. The entropy values of the D-isotopomers increase from 73 to 77 entropy units in line with the general observation that a mass increase leads to larger entropies. All 12 isotopomers possess positive free binding energies at 80 K and a reduced pressure of 110 Pa, which means that they can be spectroscopically observed under these conditions.
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Abate BA, Peralta JE. The performance of density functional approximations for the structures and relative energies of minimum energy crossing points. Chem Phys Lett 2013. [DOI: 10.1016/j.cplett.2013.10.065] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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14
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Kalescky R, Kraka E, Cremer D. Identification of the strongest bonds in chemistry. J Phys Chem A 2013; 117:8981-95. [PMID: 23927609 DOI: 10.1021/jp406200w] [Citation(s) in RCA: 110] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Increasing the effective electronegativity of two atoms forming a triple bond can increase the strength of the latter. The strongest bonds found in chemistry involve protonated species of hydrogen cyanide, carbon monoxide, and dinitrogen. CCSD(T)/CBS (complete basis set) and G4 calculations reveal that bond dissociation energies are misleading strength descriptors. The strength of the bond is assessed via the local stretching force constants, which suggest relative bond strength orders (RBSO) between 2.9 and 3.4 for heavy atom bonding (relative to the CO bond strength in methanol (RBSO = 1) and formaldehyde (RBSO = 2)) in [HCNH](+)((1)Σ(+)), [HCO](+)((1)Σ(+)), [HNN](+)((1)Σ(+)), and [HNNH](2+)((1)Σg(+)). The increase in strength is caused by protonation, which increases the electronegativity of the heavy atom and thereby decreases the energy of the bonding AB orbitals (A, B: C, N, O). A similar effect can be achieved by ionization of a nonbonding or antibonding electron in CO or NO. The strongest bond with a RBSO value of 3.38 is found for [HNNH](2+) using scaled CCSD(T)/CBS frequencies determined for CCSD(T)/CBS geometries. Less strong is the NN bond in [FNNH](2+) and [FNNF](2+).
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Affiliation(s)
- Robert Kalescky
- Department of Chemistry, Southern Methodist University , 3215 Daniel Avenue, Dallas, Texas 75275-0314, United States
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15
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Goodson DZ. Resummation methods. WILEY INTERDISCIPLINARY REVIEWS-COMPUTATIONAL MOLECULAR SCIENCE 2011. [DOI: 10.1002/wcms.92] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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16
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Lejardi A, Meaurio E, Fernández J, Sarasua JR. Miscibility of Poly(vinyl alcohol)-graft-Hydroxy Ester/Poly(vinylpyrrolidone) Blends. Macromolecules 2011. [DOI: 10.1021/ma2012305] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Ainhoa Lejardi
- School of Engineering, University of the Basque Country (EHU-UPV), Alameda de Urquijo s/n, 48013 Bilbao, Spain
| | - Emilio Meaurio
- School of Engineering, University of the Basque Country (EHU-UPV), Alameda de Urquijo s/n, 48013 Bilbao, Spain
| | - Jorge Fernández
- School of Engineering, University of the Basque Country (EHU-UPV), Alameda de Urquijo s/n, 48013 Bilbao, Spain
| | - Jose-Ramon Sarasua
- School of Engineering, University of the Basque Country (EHU-UPV), Alameda de Urquijo s/n, 48013 Bilbao, Spain
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Shepard R, Kedziora GS, Lischka H, Shavitt I, Müller T, Szalay PG, Kállay M, Seth M. The accuracy of molecular bond lengths computed by multireference electronic structure methods. Chem Phys 2008. [DOI: 10.1016/j.chemphys.2008.03.009] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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18
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Bartmess JE, Hinde RJ. The gas-phase acidities of the elemental hydrides are functions of electronegativity and bond length. CAN J CHEM 2005. [DOI: 10.1139/v05-218] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The gas-phase Brønsted acidities of the group 1, group 2, and main group elemental hydrides (XHn) are shown to be a combined function of the bond length, electronegativity, and position in the periodic table, via a separation of the acidity into coulombic and electronic reorganization enthalpy parts. The Coulombic acidity is defined as the enthalpy to separate unit positive and negative charges from the neutral acid's XH bond length to infinity; the reorganization enthalpy is the difference between that and the measured acidity, and represents the enthalpy required to reorganize the electrons of the neutral acid, creating an ion pair at the original bond distance. Predictions are made for the gas-phase Brønsted acidities of several elemental hydrides for which this quantity is not known.Key words: acidity, gas phase, coulomb, elements, hydride.
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Carlson KL, Lowe SL, Hoffmann MR, Thomasson KA. Theoretical UV Circular Dichroism of Aliphatic Cyclic Dipeptides. J Phys Chem A 2005; 109:5463-70. [PMID: 16839074 DOI: 10.1021/jp046580u] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Four cyclic dipeptides (piperazine-2,5-diones), cyclo(L-Pro-Gly), cyclo(L-Pro-L-Leu), cyclo(L-Ala-L-Ala), and cyclo(L-Pro-L-Ala), were modeled from crystal structure data. Conformations resulting from energy minimization using molecular mechanics were compared with traditional ab initio and density functional theory geometric optimizations for each dipeptide. In all computational cases, the gas phase was assumed. The pi-pi transition feature of the UV circular dichroic (CD) spectra was predicted for each peptide structure via the classical dipole interaction model. The dipole interaction model predicted CD spectra that qualitatively agreed with experiment when MP2 or DFT geometries were used. By coupling MP2 or DFT geometric optimizations with the classical physics method of the dipole interaction model, significantly better CD spectra were calculated than those using geometries obtained by molecular mechanics. Thus, one can couple quantum mechanical geometries with a classical physics model for calculation of circular dichroism.
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Affiliation(s)
- Kristine L Carlson
- Department of Chemistry, University of North Dakota, Grand Forks, North Dakota 58202-9024, USA
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Havasi B, Pasinszki T, Westwood NPC. Gas-Phase Infrared and ab Initio Study of the Unstable CF3CNO Molecule and Its Stable Furoxan Ring Dimer. J Phys Chem A 2005; 109:3864-74. [PMID: 16833703 DOI: 10.1021/jp040725f] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The unstable trifluoroacetonitrile N-oxide molecule, CF3CNO, has been generated in high yield in the gas phase from CF3BrC=NOH and studied for the first time by gas-phase mid-infrared spectroscopy. Cold trapping of this molecule followed by slow warming forms the stable ring dimer, bis(trifluoromethyl)furoxan, also investigated by gas-phase infrared spectroscopy. The spectroscopy provides an investigation into the vibrational character of the two molecules, the assignments supported by calculations of the harmonic vibrational frequencies using in the case of CF3CNO both ab initio (CCSD(T)) and density functional theory (B3LYP) and B3LYP for the ring dimer. The ground-state structures of both molecules were investigated at the B3LYP level of theory, with CF3CNO further investigated using coupled-cluster. The CCSD(T) method suggests a slightly bent (C(s)) structure for CF3CNO, while the B3LYP method (with basis sets ranging from 6-311G(d) to cc-pVTZ) suggests a close-to-linear or linear CCNO chain. The CCN bending potential in CF3CNO was explored at the CCSD(T)(fc)/cc-pVTZ level, with the results suggesting that CF3CNO exhibits strong quasi-symmetric top behavior with a barrier to linearity of 174 cm(-1). Since both isomerization and dimerization are feasible loss processes for this unstable molecule, the relative stability of CF3CNO with respect to the known cyanate (CF3OCN), isocyanate (CF3NCO), and fulminate (CF3ONC) isomers and the mechanism of the dimerization process to the ring furoxan and other isomers were studied with density functional theory.
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Affiliation(s)
- Balázs Havasi
- Department of Inorganic Chemistry, Budapest University of Technology and Economics, H-1521 Budapest, Gellért tér 4, Hungary
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Kahn K, Bruice TC. Focal-Point Conformational Analysis of Ethanol, Propanol, and Isopropanol. Chemphyschem 2005; 6:487-95. [PMID: 15799474 DOI: 10.1002/cphc.200400412] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Conformational analysis of three small alcohols--ethanol, propanol, and isopropanol--was carried out by systematically improving the basis set and the level of electron correlation. Correlation energy contributions to conformational energies are strongly basis-set-dependent but accurate energy contributions can be obtained by extrapolation to the basis-set limit. At the basis-set limit, second- and third-order electron correlation effects play a significant role for rotations around the CC-OH, HC-CO, and CC-CO bonds. Specifically, second- and third-order correlation effects strongly stabilize structures in which the hydroxylic hydrogen eclipses with the adjacent carbon; a lesser stabilization is present in structures where the CC-OH moiety is in the gauche form. Fourth-order correlation effects to the CC-OH rotation are small due to a partial cancellation of the singles, doubles, and quadruples contribution by the triples contribution. Electron correlation significantly lowers barriers for methyl-group rotations in ethanol and isopropanol, and in these cases the fourth-order correlation effects are noticeable. The relatively large overall importance of third-order correlation energy contributions raises a concern that the inability to accurately estimate this slowly converging contribution may become a limiting factor when highly accurate conformational energies in larger molecules are sought.
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Affiliation(s)
- Kalju Kahn
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA 93106, USA.
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22
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Lu SI. The accuracy of diffusion quantum Monte Carlo simulations in the determination of molecular equilibrium structures. J Chem Phys 2004; 121:10365-9. [PMID: 15549914 DOI: 10.1063/1.1809599] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
For a test set of 17 first-row small molecules, the equilibrium structures are calculated with Ornstein-Uhlenbeck diffusion quantum Monte Carlo simulations guiding by trial wave functions constructed from floating spherical Gaussian orbitals and spherical Gaussian geminals. To measure performance of the Monte Carlo calculations, the mean deviation, the mean absolute deviation, the maximum absolute deviation, and the standard deviation of Monte Carlo calculated equilibrium structures with respect to empirical equilibrium structures are given. This approach is found to yield results having a uniformly high quality, being consistent with empirical equilibrium structures and surpassing calculated values from the coupled cluster model with single, double, and noniterative triple excitations [CCSD(T)] with the basis sets of cc-pCVQZ and cc-pVQZ. The nonrelativistic equilibrium atomization energies are also presented to assess performance of the calculated methods. The mean absolute deviations regarding experimental atomization energy are 0.16 and 0.21 kcal/mol for the Monte Carlo and CCSD(T)/cc-pCV(56)Z calculations, respectively.
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Affiliation(s)
- Shih-I Lu
- Department of Applied Chemistry, Fooyin University, 151 Chinhsueh Road, Ta-Liao Hsiang, Kaohsiung Hsien 831, Taiwan.
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Giese TJ, York DM. Complete basis set extrapolated potential energy, dipole, and polarizability surfaces of alkali halide ion-neutral weakly avoided crossings with and without applied electric fields. J Chem Phys 2004; 120:7939-48. [PMID: 15267709 DOI: 10.1063/1.1690232] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Complete basis set extrapolations of alkali halide (LiF, LiCl, NaF, NaCl) energy, dipole, and polarizability surfaces are performed with and without applied fields along the internuclear axis using state-averaged multireference configuration interaction. Comparison between properties (equilibrium separation, dissociation energy, crossing distance, diabatic coupling constant, dipole, and polarizability) derived from the extrapolated potential energy (or dipole) surfaces are made with those obtained from direct extrapolation from the basis set trends. The two extrapolation procedures are generally found to agree well for these systems. Crossing distances from this work are compared to those of previous work and values obtained from the Rittner potential. Complete basis set extrapolated crossing distances agree well with those derived from the Rittner potential for LiF, but were significantly larger for LiCl, NaF, and NaCl. The results presented here serve as an important set of benchmark data for the development of new-generation many-body force fields that are able to model charge transfer.
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Affiliation(s)
- Timothy J Giese
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55415, USA
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24
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Wu A, Cremer D, Gauss J. 17O NMR Chemical Shifts of Polyoxides in Gas Phase and in Solution. J Phys Chem A 2003. [DOI: 10.1021/jp030697l] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Anan Wu
- Department of Theoretical Chemistry, Göteborg University, Reutersgatan 2, S-41320 Göteborg, Sweden, and Institut für Physikalische Chemie, Universität Mainz, D-55099 Mainz, Germany
| | - Dieter Cremer
- Department of Theoretical Chemistry, Göteborg University, Reutersgatan 2, S-41320 Göteborg, Sweden, and Institut für Physikalische Chemie, Universität Mainz, D-55099 Mainz, Germany
| | - Jürgen Gauss
- Department of Theoretical Chemistry, Göteborg University, Reutersgatan 2, S-41320 Göteborg, Sweden, and Institut für Physikalische Chemie, Universität Mainz, D-55099 Mainz, Germany
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