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Franke PR, Stanton JF. Rotamers of Methanediol: Composite Ab Initio Predictions of Structures, Frequencies, and Rovibrational Constants. J Phys Chem A 2023; 127:924-937. [PMID: 36657011 DOI: 10.1021/acs.jpca.2c06686] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Geminal diols are known to be important intermediates in atmospheric ozonolysis and the aerosol cycle. Recently, the simplest member of this class, methanediol, was interrogated in the gas phase with infrared spectroscopy. To aid in future spectroscopic investigations of methanediol, including in the interstellar medium, we report fundamental frequencies and rovibrational constants for the two rotamers of this molecule using ab initio composite methods along with vibrational perturbation theory. Sensitivity of the predictions to the level of theory and the treatment of anharmonic resonances are carefully assessed. The OH stretching harmonic frequencies of both rotamers are particularly sensitive to the level of theory. The CH stretches of the Cs rotamer are sensitive to the treatment of anharmonic resonances with VPT2-based effective Hamiltonian models. Equilibrium bond distances and harmonic frequencies are converged conservatively to within 0.0005 Å and 3 cm-1, respectively. The effect of tunneling on the rotational constants is investigated with a 2D variational calculation, based on a relaxed hydroxyl torsional potential energy surface. Tunneling is found to be negligible in the lower energy C2 rotamer but should modify the rotational constants of the Cs rotamer on the order of MHz, giving rise to rotational line splittings of the same order. The rovibrational constants of the Cs rotamer are dominated by hydroxyl torsional effects, and here we see evidence for the breakdown of vibrational perturbation theory.
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Affiliation(s)
- Peter R Franke
- Department of Chemistry, University of Florida, Gainesville, Florida32611, United States
| | - John F Stanton
- Department of Chemistry, University of Florida, Gainesville, Florida32611, United States
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2
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Spectroscopic, computational DFT, in vitro, and molecular docking investigations of newly isolated 2, 3, 9, and 10-tetrahydroacridin-3-one from the methanolic extract of nilavembu kudineer chooranam. RESEARCH ON CHEMICAL INTERMEDIATES 2022. [DOI: 10.1007/s11164-022-04906-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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3
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Roy T, Thimmakondu VS, Ghosal S. New Carbenes and Cyclic Allenes Energetically Comparable to Experimentally Known 1-Azulenylcarbene. ACS OMEGA 2022; 7:30149-30160. [PMID: 36061723 PMCID: PMC9435053 DOI: 10.1021/acsomega.2c03224] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 08/09/2022] [Indexed: 06/15/2023]
Abstract
1-Azulenylcarbene (18; 0 kJ mol-1) is experimentally known as the key reactive intermediate for the rearrangement reactions of aryl carbenes in the laboratory. Here, using coupled-cluster methods up to the fc-CCSD(T)/cc-pVTZ//fc-CCSD(T)/cc-pVDZ level, thirteen new carbenes and one new cyclic allene are theoretically identified within the C11H8 elemental composition that either energetically lie below or very close to 18. While the cyclic allene, bicyclo[5.4.0]undeca-2,3,5,7,9,11-hexene (1; -166 kJ mol-1), is the experimentally known lowest energy isomer, three other cyclic allenes, bicyclo[5.4.0]undeca-1,2,4,6,8,10-hexene (2; -100 kJ mol-1), bicyclo[5.4.0]undeca-1,3,4,6,8,10-hexene (3; -97 kJ mol-1), and bicyclo[6.3.0]undeca-1,2,4,6,8,10-hexene (13; -42 kJ mol-1), demand new experimental studies. In total, thirty-one isomers are studied in this work (within -166 to +15 kJ mol-1 from 18) and all are found to be polar (μ ≠ 0). Among these, 1H-benzo[7]annulen-1-ylidene (17; -4 kJ mol-1; μ = 5.24 D), bicyclo[5.4.0]undeca-2,4,6,8,11-pentaene-10-ylidene (24; 13 kJ mol-1; μ = 7.59 D), 5-methylene-naphthalen-1-ylidene (26; 15 kJ mol-1; μ = 5.32 D), 6-methylene-naphthalen-2-ylidene (27; -43 kJ mol-1; μ = 6.60 D), and 8-methylene-naphthalen-2-ylidene (28; -39 kJ mol-1; μ = 5.55 D) are competitively polar compared to 18 (μ = 5.39 D). Therefore, these carbene molecules are potential targets for rotational spectroscopists and radioastronomers. Considering the importance of naphthyl and azulenylcarbenes in reactive intermediate chemistry, mechanisms of different rearrangement reactions and plausible formation pathways of some of these new carbenes are studied in this work using density functional theory.
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Affiliation(s)
- Tarun Roy
- Department
of Chemistry, National Institute of Technology
Durgapur, M G Avenue, Durgapur 713
209, India
| | - Venkatesan S. Thimmakondu
- Department
of Chemistry and Biochemistry, San Diego
State University, San Diego, California 92182-1030, United States
| | - Subhas Ghosal
- Department
of Chemistry, National Institute of Technology
Durgapur, M G Avenue, Durgapur 713
209, India
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4
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Field-Theodore TE, Taylor PR. Conjugation trumps cumulation: the global minimum on the C3H4O surface. Mol Phys 2021. [DOI: 10.1080/00268976.2021.1979263] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Terri E. Field-Theodore
- School of Pharmaceutical Science and Technology, Tianjin University, Tianjin, People's Republic of China
| | - Peter R. Taylor
- School of Pharmaceutical Science and Technology, Tianjin University, Tianjin, People's Republic of China
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da Silva C, Nisioka K, Moura-Moreira M, Macedo R, Del Nero J. Tunneling rules for electronic transport in 1-D systems. Mol Phys 2021. [DOI: 10.1080/00268976.2021.1976427] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- C.A.B. da Silva
- Faculdade de Física, Universidade Federal do Pará, Ananindeua, Brazil
| | - K.R. Nisioka
- Faculdade de Engenharia de Materiais, Universidade Federal do Pará, Ananindeua, Brazil
| | - M. Moura-Moreira
- Programa de Pós-Graduação em Engenharia Elétrica, Universidade Federal do Pará, Belém, Brazil
| | - R.F. Macedo
- Faculdade de Geologia, Universidade Federal do Pará, Belém, Brazil
| | - J. Del Nero
- Facudade de Física, Universidade Federal do Pará, Belém, Brazil
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Tsuyuki M, Kugaya Y, Kanamori H, Yabushita S. Size-Dependent π g + π u Combination Band Intensities of Polyynes C 2nH 2 ( n = 1-9) Analyzed by the Local CCH Bending and the Linear Response Functions. J Phys Chem A 2021; 125:6404-6419. [PMID: 34275276 DOI: 10.1021/acs.jpca.1c04168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Polyynes (C2nH2) show the unusually strong πg + πu combination bands in the infrared absorption spectra. We calculated them as the first overtone of the local CCH bending; the strong intensities are interpreted as a consequence of the large-amplitude bending vibration of the acidic acetylenic hydrogen combined with the size-dependent π electron conjugation. Our theoretical calculations show that the absorption intensity increases steadily and their increase rate is gradually slowed down by increasing the number of acetylene units up to n = 9. However, the calculated vibrational wavenumber converges quickly in agreement with the experimental observation. The second-order electron density deformation caused by the local CCH bending was analyzed using the linear response functions, including the linear and nonlinear contributions, to explain the n dependence. The easily polarizable π electron density caused two kinds of deformation-dominant but dark δxx-yy type and minor but bright σ type. Both of them exhibit interesting zigzag sign alternations, consistent with the law of alternating polarity of Coulson and Longuet-Higgins. The electron density polarization in these intra- and interacetylene units induces a large axial component molecular dipole moment, contributing to the intensity that increases with n. The difference between the curvilinear and rectilinear bending coordinates is interpreted within the present theoretical scheme.
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Affiliation(s)
- Masafumi Tsuyuki
- Department of Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan
| | - Yuto Kugaya
- Department of Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan
| | - Hideto Kanamori
- Department of Physics, Tokyo Institute of Technology, Ohokayama 2-12-1, Tokyo 152-8551, Japan
| | - Satoshi Yabushita
- Department of Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan
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Job N, Karton A, Thirumoorthy K, Cooksy AL, Thimmakondu VS. Theoretical Studies of SiC 4H 2 Isomers Delineate Three Low-Lying Silylidenes Are Missing in the Laboratory. J Phys Chem A 2020; 124:987-1002. [PMID: 31904236 DOI: 10.1021/acs.jpca.9b11742] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Eleven isomers of SiC4H2 lying within 50 kcal mol-1 have been theoretically investigated using density functional theory and high-level coupled-cluster methods. Among them, four isomers, 1-ethynyl-3-silacycloprop-1(2)-en-3-ylidene (1), diethynylsilylidene (2), 1-sila-1,2,3,4-pentatetraenylidene (4), and 1,3-butadiynylsilylidene (5), have already been identified in the laboratory. The current investigation reports three low-lying (<1 eV) silylidenes [2-methylenesilabicyclo[1.1.0]but-1(3)-en-4-ylidene (3), 4-sila-2-methylenebicyclo[1.1.0]but-1(3)-en-4-ylidene (6), and 3-ethynyl-1-silapropadienylidene (7)] and three high-lying (>1 eV) silylidenes [2-sila-(didehydrovinylidene)cyclopropene (8), an isomer with a planar tetracoordinate carbon (ptC) atom (10), and 1-ethynyl-1-silapropadienylidene (11)], which remain elusive in the laboratory to date. Isomer 9 also contains a ptC atom, which turned out to be a transition state at all levels. Though all isomers are polar (μ ≠ 0), rotational spectrum is available only for 4. Using matrix isolation, three isomers (1, 2, and 5) have been trapped in the laboratory at 10 K. Considering the astrochemical relevance of silicon-carbide clusters in the interstellar medium, the current theoretical data demand new molecular spectroscopic studies on SiC4H2. Surprisingly, unlike the isovalent C5H2 isomers, where the bent carbenes are yet to be identified in the laboratory, the bent silylidenes (2 and 5) have been trapped in the case of SiC4H2. In both the cases, molecules with transannular C-C and/or Si-C bonds remain elusive, though they lie in the low-lying region. Using suitable precursors, whether these peculiar geometries (especially 3 and 6) would be identified or not in the laboratory needs to be addressed by molecular spectroscopists. The present investigation documents structural and spectroscopic information of SiC4H2 isomers, which may compliment future molecular spectroscopic observations including radioastronomical searches.
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Affiliation(s)
- Nisha Job
- Department of Chemistry, School of Advanced Sciences , Vellore Institute of Technology , Vellore 632014 , Tamil Nadu , India
| | - Amir Karton
- School of Molecular Sciences , The University of Western Australia , Perth , Western Australia 6009 , Australia
| | - Krishnan Thirumoorthy
- Department of Chemistry, School of Advanced Sciences , Vellore Institute of Technology , Vellore 632014 , Tamil Nadu , India
| | - Andrew L Cooksy
- Department of Chemistry and Biochemistry , San Diego State University , San Diego , California 92182-1030 , United States
| | - Venkatesan S Thimmakondu
- Department of Chemistry and Biochemistry , San Diego State University , San Diego , California 92182-1030 , United States
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Thirumoorthy K, Viji M, Pandey AP, Netke TG, Sekar B, Yadav G, Deshpande S, Thimmakondu VS. Many unknowns below or close to the experimentally known cumulene carbene – A case study of C9H2 isomers. Chem Phys 2019. [DOI: 10.1016/j.chemphys.2019.110496] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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9
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Abplanalp MJ, Frigge R, Kaiser RI. Low-temperature synthesis of polycyclic aromatic hydrocarbons in Titan's surface ices and on airless bodies. SCIENCE ADVANCES 2019; 5:eaaw5841. [PMID: 31663015 PMCID: PMC6795510 DOI: 10.1126/sciadv.aaw5841] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Accepted: 09/22/2019] [Indexed: 06/10/2023]
Abstract
Titan's equatorial dunes represent the most monumental surface structures in our Solar System, but the chemical composition of their dark organics remains a fundamental, unsolved enigma, with solid acetylene detected near the dunes implicated as a key feedstock. Here, we reveal in laboratory simulation experiments that aromatics such as benzene, naphthalene, and phenanthrene-prospective building blocks of the organic dune material-can be efficiently synthesized via galactic cosmic ray exposure of low-temperature acetylene ices on Titan's surface, hence challenging conventional wisdom that aromatic hydrocarbons are formed solely in Titan's atmosphere. These processes are also of critical importance in unraveling the origin and chemical composition of the dark surfaces of airless bodies in the outer Solar System, where hydrocarbon precipitation from the atmosphere cannot occur. This finding notably advances our understanding of the distribution of carbon throughout our Solar System such as on Kuiper belt objects like Makemake.
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Affiliation(s)
- Matthew J. Abplanalp
- W. M. Keck Research Laboratory in Astrochemistry, University of Hawaii at Manoa, Honolulu, HI 96822, USA
- Department of Chemistry, University of Hawaii at Manoa, Honolulu, HI 96822, USA
| | - Robert Frigge
- W. M. Keck Research Laboratory in Astrochemistry, University of Hawaii at Manoa, Honolulu, HI 96822, USA
- Department of Chemistry, University of Hawaii at Manoa, Honolulu, HI 96822, USA
| | - Ralf I. Kaiser
- W. M. Keck Research Laboratory in Astrochemistry, University of Hawaii at Manoa, Honolulu, HI 96822, USA
- Department of Chemistry, University of Hawaii at Manoa, Honolulu, HI 96822, USA
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Thimmakondu VS, Ulusoy I, Wilson AK, Karton A. Theoretical Studies of Two Key Low-Lying Carbenes of C 5H 2 Missing in the Laboratory. J Phys Chem A 2019; 123:6618-6627. [PMID: 31269401 DOI: 10.1021/acs.jpca.9b06036] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The equilibrium geometries and spectroscopic properties of two key singlet carbenes, buta-1,3-diynylcarbene (6) and 2-methylenebicyclo[1.1.0]but-1(3)-en-4-ylidene (9), which have not been experimentally observed to date, are investigated using high-level coupled-cluster (CC) methods. The current theoretical study necessitates new experimental data on C5H2 isomers considering the relevance of these molecules to interstellar chemistry. Bent-pentadiynylidene (4) has been missing in the laboratory and the prime focus of our earlier theoretical work. The present theoretical study indicates that isomers 6 and 9 are also viable experimental targets. Apart from ethynylcyclopropenylidene (2), pentatetraenylidene (3), ethynylpropadienylidene (5), and 3-(didehydrovinylidene)cyclopropene (8), which are identified by Fourier transform microwave spectroscopy, the dipole moments of elusive 4, 6, and 9 are also nonzero (μ ≠ 0). The relative energies of these isomers, calculated at the CCSDT(Q)/CBS level of theory, with respect to linear triplet pentadiynylidene (1) reveal that they all lie within 25.1 kcal mol-1. Therefore, geometric, energetic, aromatic, and spectroscopic parameters are reported here, which may assist the efforts of molecular spectroscopists in the future. Anharmonic vibrational calculations on isomers 6 and 9 indicate that the former is loosely bound and would be challenging to be detected experimentally. Among the undetected carbenes, 9 may be considered as a potential target molecule considering its higher polarity and aromatic nature.
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Affiliation(s)
- Venkatesan S Thimmakondu
- Department of Chemistry and Biochemistry , San Diego State University , San Diego , California 92182-1030 , United States
| | - Inga Ulusoy
- Theoretical Chemistry, Institute of Physical Chemistry , Heidelberg University , Im Neuenheimer Feld 229 , 69120 Heidelberg , Germany.,Department of Chemistry , Michigan State University , East Lansing , Michigan 48824-1322 , United States
| | - Angela K Wilson
- Department of Chemistry , Michigan State University , East Lansing , Michigan 48824-1322 , United States
| | - Amir Karton
- School of Molecular Sciences , The University of Western Australia , Perth , Western Australia 6009 , Australia
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Bâldea I. Alternation of Singlet and Triplet States in Carbon‐Based Chain Molecules and Its Astrochemical Implications: Results of an Extensive Theoretical Study. ADVANCED THEORY AND SIMULATIONS 2019. [DOI: 10.1002/adts.201900084] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Ioan Bâldea
- Theoretische ChemieUniversität HeidelbergINF 229 D‐69120 Heidelberg Germany
- Institute for Space SciencesNational Institute for LasersPlasmas, and Radiation PhysicsRO 077125 Bucharest‐Măgurele Romania
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12
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Pigulski B, Gulia N, Szafert S. Reactivity of Polyynes: Complex Molecules from Simple Carbon Rods. European J Org Chem 2019. [DOI: 10.1002/ejoc.201801350] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Bartłomiej Pigulski
- Faculty of Chemistry; University of Wrocław; F. Joliot-Curie 14 50-383 Wrocław Poland
| | - Nurbey Gulia
- Faculty of Chemistry; University of Wrocław; F. Joliot-Curie 14 50-383 Wrocław Poland
| | - Sławomir Szafert
- Faculty of Chemistry; University of Wrocław; F. Joliot-Curie 14 50-383 Wrocław Poland
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Ravichandran L, Banik S. Anomalous description of the anharmonicity of bending motions of carbon–carbon double bonded molecules with the MP2 method: ethylene as a case study. Phys Chem Chem Phys 2018; 20:27329-27341. [DOI: 10.1039/c8cp04682d] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In this work, we report anomalous descriptions of bending modes of the smallest carbon–carbon double bonded molecule ethylene with the MP2 method.
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Affiliation(s)
| | - Subrata Banik
- Department of Chemistry and Chemical Sciences
- Central University of Jammu
- Samba-181143
- India
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