1
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Cong F, Cheng J, Cho HG, Huang T, Wang X, Andrews L. M←NCCH 3, M-η 2-(NC)-CH 3, and CN-M-CH 3 Prepared by Reactions of Ce, Sm, Eu, and Lu Atoms with Acetonitrile: Matrix Infrared Spectra and Theoretical Calculations. Inorg Chem 2021; 60:17649-17656. [PMID: 34747602 DOI: 10.1021/acs.inorgchem.1c02232] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The reactions of laser-ablated Ce, Sm, Eu, and Lu atoms with acetonitrile were studied by matrix infrared spectra in a neon matrix, and M←NCCH3, M-η2-(NC)-CH3, and CN-M-CH3 were identified with isotopic substitution and quantum chemical calculations. The major product is the insertion complex (CN-M-CH3), while the end-on and side-on complexes (M←NCCH3 and M-η2-(NC)-CH3) are also trapped in the matrix. The CCN antisymmetric stretching mode for Ce-η2-(NC)-CH3 was observed at 1536.9 cm-1, which is much lower than the same modes observed for other lanthanides. NBO analysis reveals that Ce exhibits a remarkable 4f-orbital contribution in bonding to N and to C, reconfirming an active 4f-orbital contribution of cerium in bonding in the side-on complex, while the 4f contributions of Sm and Eu to the M-N and M-C bonds are much lower and the 4f orbital of Lu is not involved in bonding.
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Affiliation(s)
- Fei Cong
- School of Chemical Science and Engineering, Shanghai Key Lab of Chemical Assessment and Sustainability, Tongji University, Shanghai 200092, China
| | - Juanjuan Cheng
- School of Chemical Science and Engineering, Shanghai Key Lab of Chemical Assessment and Sustainability, Tongji University, Shanghai 200092, China
| | - Han-Gook Cho
- Department of Chemistry, Incheon National University, 119 Academy-ro, Yeonsu-gu, Incheon 22012 South Korea
| | - Tengfei Huang
- School of Chemical Science and Engineering, Shanghai Key Lab of Chemical Assessment and Sustainability, Tongji University, Shanghai 200092, China
| | - Xuefeng Wang
- School of Chemical Science and Engineering, Shanghai Key Lab of Chemical Assessment and Sustainability, Tongji University, Shanghai 200092, China
| | - Lester Andrews
- Department of Chemistry, University of Virginia, P.O. Box 400319, Charlottesville, Virginia 22904-4319, United States
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2
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Turner AM, Chandra S, Fortenberry RC, Kaiser RI. A Photoionization Reflectron Time-of-Flight Mass Spectrometric Study on the Detection of Ethynamine (HCCNH 2 ) and 2H-Azirine (c-H 2 CCHN). Chemphyschem 2021; 22:985-994. [PMID: 33797172 DOI: 10.1002/cphc.202100064] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 03/23/2021] [Indexed: 11/07/2022]
Abstract
Ices of acetylene (C2 H2 ) and ammonia (NH3 ) were irradiated with energetic electrons to simulate interstellar ices processed by galactic cosmic rays in order to investigate the formation of C2 H3 N isomers. Supported by quantum chemical calculations, experiments detected product molecules as they sublime from the ices using photoionization reflectron time-of-flight mass spectrometry (PI-ReTOF-MS). Isotopically-labeled ices confirmed the C2 H3 N assignments while photon energies of 8.81 eV, 9.80 eV, and 10.49 eV were utilized to discriminate isomers based on their known ionization energies. Results indicate the formation of ethynamine (HCCNH2 ) and 2H-azirine (c-H2 CCHN) in the irradiated C2 H2 :NH3 ices, and the energetics of their formation mechanisms are discussed. These findings suggest that these two isomers can form in interstellar ices and, upon sublimation during the hot core phase, could be detected using radio astronomy.
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Affiliation(s)
- Andrew M Turner
- Department of Chemistry, University of Hawaii at Manoa, 2545 McCarthy Mall, Honolulu, HI 96822, USA.,W. M. Keck Laboratory in Astrochemistry, University of Hawaii at Manoa, 2545 McCarthy Mall, Honolulu, HI 96822, USA
| | - Sankhabrata Chandra
- Department of Chemistry, University of Hawaii at Manoa, 2545 McCarthy Mall, Honolulu, HI 96822, USA.,W. M. Keck Laboratory in Astrochemistry, University of Hawaii at Manoa, 2545 McCarthy Mall, Honolulu, HI 96822, USA
| | - Ryan C Fortenberry
- Department of Chemistry & Biochemistry, University of Mississippi, Mississippi, 38677-1848, USA
| | - Ralf I Kaiser
- Department of Chemistry, University of Hawaii at Manoa, 2545 McCarthy Mall, Honolulu, HI 96822, USA.,W. M. Keck Laboratory in Astrochemistry, University of Hawaii at Manoa, 2545 McCarthy Mall, Honolulu, HI 96822, USA
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3
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Ohno K, Kishimoto N, Iwamoto T, Satoh H, Watanabe H. High performance global exploration of isomers and isomerization channels on quantum chemical potential energy surface of H 5 C 2 NO 2. J Comput Chem 2021; 42:192-204. [PMID: 33146910 DOI: 10.1002/jcc.26446] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2020] [Revised: 10/14/2020] [Accepted: 10/16/2020] [Indexed: 11/07/2022]
Abstract
High performance global exploration of isomers and isomerization channels on the quantum chemical potential energy surface (PES) is performed for H5 C2 NO2 by using the scaled hypersphere search-anharmonic downward distortion following (SHS-ADDF) method. A multi-node operation, NeoGRRM, has achieved high performance exploration calculations for the large system by submitting SHS-ADDF sub-jobs into many cores in parallel and unifying the results of sub-jobs into the total lists of the main-job. Global exploration of equilibrium (EQ) and transition-state structures at the level of B3LYP/6-31G(d) gave 3210 EQs and 23278 TSs. Nine compounds were found in the low energy regions of 0-100 kJ/mol; the lowest energy compound is N-methylcarbamic acid, the second is methyl carbamate, and the third is glycine (the most fundamental amino acid). Interconversion pathways between the conformers of each of the low energy compounds were surveyed. Isomerization channels around glycine were explored in detail. The lowest energy barriers around some of the EQs turned to be negative after zero-point energy corrections. This indicates that those structures cannot exist as independent structures because they spontaneously collapse into more stable structures. The global PES search showed various interesting dissociating channels which indicate synthon reaction pathways in the reverse directions.
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Affiliation(s)
- Koichi Ohno
- Institute for Quantum Chemical Exploration, Tokyo, Japan.,Department of Chemistry, Graduate School of Science, Tohoku University, Sendai, Japan
| | - Naoki Kishimoto
- Department of Chemistry, Graduate School of Science, Tohoku University, Sendai, Japan
| | - Takeaki Iwamoto
- Department of Chemistry, Graduate School of Science, Tohoku University, Sendai, Japan
| | - Hiroko Satoh
- Institute for Quantum Chemical Exploration, Tokyo, Japan.,Department of Chemistry, University of Zurich, Zurich, Switzerland.,Research Organization of Information and Systems (ROIS), Tokyo, Japan
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4
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Cho HG, Andrews L. Infrared Spectra of CH 3CN→M, M-η 2-(NC)-CH 3, CH 3-MNC Prepared by Reactions of Laser-Ablated Fe, Ru, and Pt Atoms with Acetonitrile in Excess Argon. Inorg Chem 2019; 58:16194-16204. [PMID: 31710217 DOI: 10.1021/acs.inorgchem.9b02716] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Reactions of laser-ablated Fe, Ru, and Pt atoms with acetonitrile have been carried out in excess argon, and the products identified in the matrix spectra. CH3CN→Fe and Fe-η2-(NC)-CH3 observed in the original deposition spectra converted to CH3-FeNC on uv irradiation. CH3CN→Ru, the only product detected in the Ru system, dissociated on uv irradiation, but was partly reproduced on subsequent visible irradiation and annealing. Similar behavior was found for CH3CN→Pt. The major products (CH3-FeNC, CH3CN→Ru, and CH3CN→Pt) are the most stable constituents in the previously proposed reaction path for Group 4, 5, 6, and 7 metal atoms and acetonitrile, parallel with the previous results. The Group 8 metal π-coordination products are weakly bound complexes due to limited back-donation to the π*-orbitals of CH3CN. Calculations show that the Fe insertion product has a much less bent structure than the Ru analogue, in line with its higher s-character from the first row transition-metal to the C-Fe bond, and the group 8 metal methylidenes are not agostically distorted. The Pt to N bond in CH3CN→Pt is the strongest of all the metals we have investigated owing in large part to its higher electron affinity, which prevents nitrogen lone pair density from entering the pi* orbitals of the C-N group.
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Affiliation(s)
- Han-Gook Cho
- Department of Chemistry , Incheon National University , 119 Academy-ro , Yeonsu-gu, Incheon , 22012 South Korea
| | - Lester Andrews
- Department of Chemistry , University of Virginia , P.O. Box 400319, Charlottesville , Virginia 22904-4319 , United States
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5
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Kodaya Y, Yamakado H, Ohno K. Limited Search Characteristics of the Scaled Hypersphere Search Method: A Systematic Case Study for Isomers of BCNOS. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2018. [DOI: 10.1246/bcsj.20180107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Yoshitomo Kodaya
- Graduate School of Systems Engineering, Wakayama University, 930 Sakaedani, Wakayama 640-8510, Japan
| | - Hideo Yamakado
- Faculty of Systems Engineering, Wakayama University, 930 Sakaedani, Wakayama 640-8510, Japan
| | - Koichi Ohno
- Graduate School of Science, Tohoku University, 6-3 Aramaki Aza-Aoba, Aoba-ku, Sendai, Miyagi 980-8579, Japan
- Institute for Quantum Chemical Exploration, LOOP-X, 3-9-15 Kaigan, Minato-ku, Tokyo 108-0022, Japan
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6
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Manna S, Ray SS, Ghosh P, Chattopadhyay S. On the conversion XCN ⟷ XNC via an efficient and economic perturbative wave function approach. Mol Phys 2018. [DOI: 10.1080/00268976.2018.1464224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Affiliation(s)
- Shovan Manna
- Department of Chemistry, Indian Institute of Engineering Science and Technology , Shibpur, India
| | - Suvonil Sinha Ray
- Department of Chemistry, Indian Institute of Engineering Science and Technology , Shibpur, India
| | - Pradipta Ghosh
- Department of Chemistry, Jhargram Raj College , Jhargram, India
| | - Sudip Chattopadhyay
- Department of Chemistry, Indian Institute of Engineering Science and Technology , Shibpur, India
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7
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Gronowski M, Eluszkiewicz P, Custer T. Structure and Spectroscopy of C2HNO Isomers. J Phys Chem A 2017; 121:3263-3273. [DOI: 10.1021/acs.jpca.6b12609] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Marcin Gronowski
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
| | - Piotr Eluszkiewicz
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
| | - Thomas Custer
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
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8
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Ohno K, Kishimoto N, Iwamoto T, Satoh H. Global exploration of isomers and isomerization channels on the quantum chemical potential energy surface of H3
CNO3. J Comput Chem 2017; 38:669-687. [DOI: 10.1002/jcc.24732] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 12/23/2016] [Accepted: 12/29/2016] [Indexed: 11/08/2022]
Affiliation(s)
- Koichi Ohno
- Institute for Quantum Chemical Exploration, Kaigan 3-9-15; Minato-ku Tokyo 108-0022 Japan
- Department of Chemistry; Graduate School of Science, Tohoku University, Aramaki Aza-Aoba 6-3, Aoba-ku; Sendai Miyagi 980-8577 Japan
| | - Naoki Kishimoto
- Department of Chemistry; Graduate School of Science, Tohoku University, Aramaki Aza-Aoba 6-3, Aoba-ku; Sendai Miyagi 980-8577 Japan
| | - Takeaki Iwamoto
- Department of Chemistry; Graduate School of Science, Tohoku University, Aramaki Aza-Aoba 6-3, Aoba-ku; Sendai Miyagi 980-8577 Japan
| | - Hiroko Satoh
- Institute for Quantum Chemical Exploration, Kaigan 3-9-15; Minato-ku Tokyo 108-0022 Japan
- Department of Chemistry; University of Zurich; Zurich 8057 Switzerland
- Research Organization of Information and Systems (ROIS); Tokyo 105-0001 Japan
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9
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Ohno K. Study of Potential Energy Surfaces towards Global Reaction Route Mapping. CHEM REC 2016; 16:2198-2218. [PMID: 27059804 DOI: 10.1002/tcr.201500284] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2015] [Indexed: 11/11/2022]
Abstract
The potential energy surface (PES) is just a theoretical construct based on the Born-Oppenheimer approximation, but it underlies various phenomena, including molecular vibrations, collisional ionizations, and chemical reactions. This account describes how a new idea for global reaction route mapping (GRRM), which had seemed to be impossible for chemical systems with more than three atoms, was born and has been developed during the course of the study of the PES. GRRM has pioneered new fields of chemistry. Furthermore, techniques for GRRM are still developing, and GRRM is further extending its application to various areas of chemistry and chemical physics.
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Affiliation(s)
- Koichi Ohno
- Institute for Quantum Chemical Exploration, Minato-ku, Tokyo, 108-0022, Japan.
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10
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Satoh H, Oda T, Nakakoji K, Uno T, Tanaka H, Iwata S, Ohno K. Potential Energy Surface-Based Automatic Deduction of Conformational Transition Networks and Its Application on Quantum Mechanical Landscapes of d-Glucose Conformers. J Chem Theory Comput 2016; 12:5293-5308. [PMID: 27673598 DOI: 10.1021/acs.jctc.6b00439] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
This paper describes our approach that is built upon the potential energy surface (PES)-based conformational analysis. This approach automatically deduces a conformational transition network, called a conformational reaction route map (r-map), by using the Scaled Hypersphere Search of the Anharmonic Downward Distortion Following method (SHS-ADDF). The PES-based conformational search has been achieved by using large ADDF, which makes it possible to trace only low transition state (TS) barriers while restraining bond lengths and structures with high free energy. It automatically performs sampling the minima and TS structures by simply taking into account the mathematical feature of PES without requiring any a priori specification of variable internal coordinates. An obtained r-map is composed of equilibrium (EQ) conformers connected by reaction routes via TS conformers, where all of the reaction routes are already confirmed during the process of the deduction using the intrinsic reaction coordinate (IRC) method. The postcalculation analysis of the deduced r-map is interactively carried out using the RMapViewer software we have developed. This paper presents computational details of the PES-based conformational analysis and its application to d-glucose. The calculations have been performed for an isolated glucose molecule in the gas phase at the RHF/6-31G level. The obtained conformational r-map for α-d-glucose is composed of 201 EQ and 435 TS conformers and that for β-d-glucose is composed of 202 EQ and 371 TS conformers. For the postcalculation analysis of the conformational r-maps by using the RMapViewer software program we have found multiple minimum energy paths (MEPs) between global minima of 1C4 and 4C1 chair conformations. The analysis using RMapViewer allows us to confirm the thermodynamic and kinetic predominance of 4C1 conformations; that is, the potential energy of the global minimum of 4C1 is lower than that of 1C4 (thermodynamic predominance) and that the highest energy of those of all the TS structures along a route from 4C1 to 1C4 is lower than that of 1C4 to 4C1 (kinetic predominance).
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Affiliation(s)
- Hiroko Satoh
- Research Organization of Information and Systems (ROIS), Tokyo 105-0001, Japan.,Department of Chemistry, University of Zurich , 8057 Zurich, Switzerland.,National Institute of Informatics (NII), Tokyo 101-8430, Japan.,Institute for Quantum Chemical Exploration (IQCE), Tokyo 108-0022, Japan
| | - Tomohiro Oda
- Software Research Associates Inc., Tokyo 171-8513, Japan
| | - Kumiyo Nakakoji
- Center for the Promotion of Interdisciplinary Education and Research, Kyoto University , Kyoto 606-8501, Japan
| | - Takeaki Uno
- National Institute of Informatics (NII), Tokyo 101-8430, Japan
| | - Hiroaki Tanaka
- Department of Mathematical Informatics, University of Tokyo , Tokyo 113-8654, Japan
| | - Satoru Iwata
- Department of Mathematical Informatics, University of Tokyo , Tokyo 113-8654, Japan
| | - Koichi Ohno
- Institute for Quantum Chemical Exploration (IQCE), Tokyo 108-0022, Japan.,Department of Chemistry, Graduate School of Science, Tohoku University , Sendai 980-8578, Japan
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11
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Cho H, Andrews L. IR Spectra and DFT Calculations of M–η
2
‐(NC)–CH
3
, CH
3
–MNC, and CH
2
=M(H)NC Prepared by Reactions of Laser‐Ablated Hf and Ti Atoms with Acetonitrile. Eur J Inorg Chem 2015. [DOI: 10.1002/ejic.201500624] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Han‐Gook Cho
- Department of Chemistry, Incheon National University, 119 Academy‐ro, Yeonsu‐gu, Incheon, 406‐772, South Korea
- Department of Chemistry, University of Virginia, P. O. Box 400319, Charlottesville, Virginia 22904‐4319, USA, http://chem.virginia.edu/faculty‐research/emeritus‐faculty/lester‐s‐andrews/
| | - Lester Andrews
- Department of Chemistry, University of Virginia, P. O. Box 400319, Charlottesville, Virginia 22904‐4319, USA, http://chem.virginia.edu/faculty‐research/emeritus‐faculty/lester‐s‐andrews/
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12
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Martínez-Núñez E. An automated transition state search using classical trajectories initialized at multiple minima. Phys Chem Chem Phys 2015; 17:14912-21. [DOI: 10.1039/c5cp02175h] [Citation(s) in RCA: 84] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
TS finding using iterative TSSCDS with trajectories initialized at different minima.
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Affiliation(s)
- Emilio Martínez-Núñez
- Departamento de Química Física and Centro Singular de Investigación en Química Biológica y Materiales Moleculares (CIQUS)
- Campus Vida
- Universidade de Santiago de Compostela
- Santiago de Compostela
- Spain
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13
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Maeda S, Taketsugu T, Morokuma K, Ohno K. Anharmonic Downward Distortion Following for Automated Exploration of Quantum Chemical Potential Energy Surfaces. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2014. [DOI: 10.1246/bcsj.20140189] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Satoshi Maeda
- Department of Chemistry, Faculty of Science, Hokkaido University
| | | | - Keiji Morokuma
- Fukui Institute for Fundamental Chemistry, Kyoto University
- Cherry L. Emerson Center for Scientific Computation and Department of Chemistry, Emory University
| | - Koichi Ohno
- Graduate School of Science, Tohoku University
- Institute for Quantum Chemical Exploration
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14
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Martínez-Núñez E. An automated method to find transition states using chemical dynamics simulations. J Comput Chem 2014; 36:222-34. [DOI: 10.1002/jcc.23790] [Citation(s) in RCA: 121] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Accepted: 11/05/2014] [Indexed: 02/01/2023]
Affiliation(s)
- Emilio Martínez-Núñez
- Departamento de Química Física and Centro Singular de Investigación en Química Biológica y Materiales Moleculares; Campus Vida, Universidade de Santiago de Compostela; 15782 Santiago de Compostela Spain
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15
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Vikas, Kaur G. Global reaction route mapping of isomerization pathways of exotic C6H molecular species. J Chem Phys 2013; 139:224311. [DOI: 10.1063/1.4840755] [Citation(s) in RCA: 18] [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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16
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Cho HG. Matrix Infrared Spectra and DFT Computations of CH2CNH and CH2NCH Produced from CH3CN by Laser-Ablation Plume Radiation. B KOREAN CHEM SOC 2013. [DOI: 10.5012/bkcs.2013.34.5.1361] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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17
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Iwai Y, Ozaki T, Takita R, Uchiyama M, Shimokawa J, Fukuyama T. Modified McFadyen–Stevens reaction for a versatile synthesis of aliphatic/aromatic aldehydes: design, optimization, and mechanistic investigations. Chem Sci 2013. [DOI: 10.1039/c2sc22045h] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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18
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Maeda S, Ohno K, Morokuma K. Systematic exploration of the mechanism of chemical reactions: the global reaction route mapping (GRRM) strategy using the ADDF and AFIR methods. Phys Chem Chem Phys 2013; 15:3683-701. [DOI: 10.1039/c3cp44063j] [Citation(s) in RCA: 358] [Impact Index Per Article: 32.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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19
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Cho HG, Andrews L. Infrared Spectra of the Complexes Os←NCCH3, Re←NCCH3, CH3–ReNC, CH2═Re(H)NC, and CH≡Re(H)2NC and their Mn Counterparts Prepared by Reactions of Laser-Ablated Os, Re, and Mn Atoms with Acetonitrile in Excess Argon. Organometallics 2012. [DOI: 10.1021/om300456k] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Han-Gook Cho
- Department
of Chemistry, University of Incheon, 119 Academy-ro, Yonsu-gu, Incheon, 406-772, South Korea
| | - Lester Andrews
- Department of Chemistry, University of Virginia, P.O. Box 400319, Charlottesville, Virginia
22904-4319, United States
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20
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Cho HG, Andrews L. Infrared spectra and density functional calculations of the M←NCCCH3, η2–M(NC)–CH3, CH3–MNC, CH2M(H)NC, and CHM(H)2NC complexes produced by reactions of Group 6 metal atoms with acetonitrile. J Organomet Chem 2012. [DOI: 10.1016/j.jorganchem.2011.12.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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21
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Liu Y, Evans AS, Toscano JP. Nanosecond time-resolved IR study of thiobenzoylnitrene. Phys Chem Chem Phys 2012; 14:10438-44. [DOI: 10.1039/c2cp40327g] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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22
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Cho HG, Andrews L. Infrared Spectra of the η2-M(NC)-CH3, CH3-MNC, and CH2═M(H)NC Complexes Prepared by Reactions of Thorium and Uranium Atoms with Acetonitrile. Organometallics 2011. [DOI: 10.1021/om200957j] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- Han-Gook Cho
- Department of Chemistry, University of Incheon, 119 Academy-ro, Yonsu-gu, Incheon, 406-772,
South Korea, and Department of Chemistry, University of Virginia, P.O. Box 400319, Charlottesville, Virginia
22904-4319, United States
| | - Lester Andrews
- Department of Chemistry, University of Incheon, 119 Academy-ro, Yonsu-gu, Incheon, 406-772,
South Korea, and Department of Chemistry, University of Virginia, P.O. Box 400319, Charlottesville, Virginia
22904-4319, United States
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23
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Cho HG, Andrews L. Matrix Infrared Spectra and Density Functional Calculations of the H2CCN and H2CNC Radicals Produced from CH3CN. J Phys Chem A 2011; 115:8638-42. [DOI: 10.1021/jp204887y] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Han-Gook Cho
- Department of Chemistry, University of Incheon, 119 Academy-ro, Songdo-dong,
Yonsu-gu, Incheon, 406-772, South Korea
| | - Lester Andrews
- Department of Chemistry, University of Virginia, P.O. Box 400319, Charlottesville,
Virginia 22904-4319, United States
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24
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Gao SM, Fu LJ, Cui ZH, Ding YH. Can isocyanogen azide exist? Mol Phys 2011. [DOI: 10.1080/00268976.2010.541888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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25
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Sada M, Komagawa S, Uchiyama M, Kobata M, Mizuno T, Utimoto K, Oshima K, Matsubara S. Reaction Pathway of Methylenation of Carbonyl Compounds with Bis(iodozincio)methane. J Am Chem Soc 2010; 132:17452-8. [DOI: 10.1021/ja104439w] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Mutsumi Sada
- Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Kyoudai-katsura, Nishikyo, Kyoto 615-8510, Japan, The Institute of Physical and Chemical Research (RIKEN), Wako, Saitama 351-0198, Japan, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan, and Department of Industrial Chemistry, Faculty of Engineering, Kyoto University, Yoshida, Sakyo, Kyoto 606-8510, Japan
| | - Shinsuke Komagawa
- Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Kyoudai-katsura, Nishikyo, Kyoto 615-8510, Japan, The Institute of Physical and Chemical Research (RIKEN), Wako, Saitama 351-0198, Japan, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan, and Department of Industrial Chemistry, Faculty of Engineering, Kyoto University, Yoshida, Sakyo, Kyoto 606-8510, Japan
| | - Masanobu Uchiyama
- Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Kyoudai-katsura, Nishikyo, Kyoto 615-8510, Japan, The Institute of Physical and Chemical Research (RIKEN), Wako, Saitama 351-0198, Japan, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan, and Department of Industrial Chemistry, Faculty of Engineering, Kyoto University, Yoshida, Sakyo, Kyoto 606-8510, Japan
| | - Masami Kobata
- Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Kyoudai-katsura, Nishikyo, Kyoto 615-8510, Japan, The Institute of Physical and Chemical Research (RIKEN), Wako, Saitama 351-0198, Japan, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan, and Department of Industrial Chemistry, Faculty of Engineering, Kyoto University, Yoshida, Sakyo, Kyoto 606-8510, Japan
| | - Tsuyoshi Mizuno
- Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Kyoudai-katsura, Nishikyo, Kyoto 615-8510, Japan, The Institute of Physical and Chemical Research (RIKEN), Wako, Saitama 351-0198, Japan, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan, and Department of Industrial Chemistry, Faculty of Engineering, Kyoto University, Yoshida, Sakyo, Kyoto 606-8510, Japan
| | - Kiitiro Utimoto
- Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Kyoudai-katsura, Nishikyo, Kyoto 615-8510, Japan, The Institute of Physical and Chemical Research (RIKEN), Wako, Saitama 351-0198, Japan, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan, and Department of Industrial Chemistry, Faculty of Engineering, Kyoto University, Yoshida, Sakyo, Kyoto 606-8510, Japan
| | - Koichiro Oshima
- Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Kyoudai-katsura, Nishikyo, Kyoto 615-8510, Japan, The Institute of Physical and Chemical Research (RIKEN), Wako, Saitama 351-0198, Japan, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan, and Department of Industrial Chemistry, Faculty of Engineering, Kyoto University, Yoshida, Sakyo, Kyoto 606-8510, Japan
| | - Seijiro Matsubara
- Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Kyoudai-katsura, Nishikyo, Kyoto 615-8510, Japan, The Institute of Physical and Chemical Research (RIKEN), Wako, Saitama 351-0198, Japan, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan, and Department of Industrial Chemistry, Faculty of Engineering, Kyoto University, Yoshida, Sakyo, Kyoto 606-8510, Japan
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Infrared spectra of CH2=M(H)NC, CH3-MNC, and eta2-M(NC)-CH3 produced by reactions of laser-ablated group 5 metal atoms with acetonitrile. J Phys Chem A 2010; 114:5997-6006. [PMID: 20426458 DOI: 10.1021/jp1012686] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Methylidene isocyanides, methyl isocyanides, and eta(2)-nitrile-pi-complexes are observed in the matrix IR spectra from reactions of Group 5 metals with acetonitrile isotopomers. The primary isocyanide products with no trace of cyanide complexes are consistent with the reaction path proposed in the analogous Zr study. The major products (CH(2)=Ta(H)NC, CH(3)-NbNC, eta(2)-Nb(NC)-CH(3), and eta(2)-V(NC)-CH(3)) after codeposition and reaction of metal with CH(3)CN clearly show the increasing preference for the higher oxidation-state complex on going down the group column, and the subsequent photochemistry provides further information for molecular rearrangements. The Group 5 metal methylidene isocyanides exhibit more agostic distortion than the Zr counterparts and are comparable to the previously studied Group 5 metal methylidene hydrides and halides. The computed structures and observed frequencies indicate that the effects of metal conjugation (C=Ta-N=C:) are minor.
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Iwamoto T, Ohnishi N, Gui Z, Ishida S, Isobe H, Maeda S, Ohno K, Kira M. Synthesis and structure of stable base-free dialkylsilanimines. NEW J CHEM 2010. [DOI: 10.1039/c0nj00121j] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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Cho HG, Andrews L. Infrared Spectra of CH2═Zr(H)NC, CH3−ZrNC, and η2-Zr(NC)-CH3 Produced by Reactions of Laser-Ablated Zr Atoms with Acetonitrile. J Phys Chem A 2009; 114:891-7. [DOI: 10.1021/jp9099368] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Han-Gook Cho
- Department of Chemistry, University of Incheon, 12-1 Songdo-dong, Yonsu-ku, Incheon, 406-840, South Korea, and Department of Chemistry, University of Virginia, P.O. Box 400319, Charlottesville, Virginia 22904-4319
| | - Lester Andrews
- Department of Chemistry, University of Incheon, 12-1 Songdo-dong, Yonsu-ku, Incheon, 406-840, South Korea, and Department of Chemistry, University of Virginia, P.O. Box 400319, Charlottesville, Virginia 22904-4319
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Maeda S, Ohno K, Morokuma K. An Automated and Systematic Transition Structure Explorer in Large Flexible Molecular Systems Based on Combined Global Reaction Route Mapping and Microiteration Methods. J Chem Theory Comput 2009; 5:2734-43. [DOI: 10.1021/ct9003383] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Satoshi Maeda
- Department of Chemistry and Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, Toyota Physical and Chemical Research Institute, Nagakute, Aichi 480-1192, Japan, and Fukui Institute for Fundamental Chemistry, Kyoto University, Kyoto 606-8103, Japan
| | - Koichi Ohno
- Department of Chemistry and Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, Toyota Physical and Chemical Research Institute, Nagakute, Aichi 480-1192, Japan, and Fukui Institute for Fundamental Chemistry, Kyoto University, Kyoto 606-8103, Japan
| | - Keiji Morokuma
- Department of Chemistry and Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, Toyota Physical and Chemical Research Institute, Nagakute, Aichi 480-1192, Japan, and Fukui Institute for Fundamental Chemistry, Kyoto University, Kyoto 606-8103, Japan
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Luo Y, Maeda S, Ohno K. Automated exploration of stable isomers of H+(H2O)n(n= 5-7) viaab initiocalculations: An application of the anharmonic downward distortion following algorithm. J Comput Chem 2009; 30:952-61. [DOI: 10.1002/jcc.21117] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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31
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Moteki M, Maeda S, Ohno K. Systematic Search for Isomerization Pathways of Hexasilabenzene for Finding Its Kinetic Stability. Organometallics 2009. [DOI: 10.1021/om800881y] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Masahiro Moteki
- Department of Chemistry, Graduate School of Science, Tohoku University, Aramaki, Aoba-ku, Sendai 980-8578, Japan
| | - Satoshi Maeda
- Department of Chemistry, Graduate School of Science, Tohoku University, Aramaki, Aoba-ku, Sendai 980-8578, Japan
| | - Koichi Ohno
- Department of Chemistry, Graduate School of Science, Tohoku University, Aramaki, Aoba-ku, Sendai 980-8578, Japan
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Maeda S, Ohno K, Morokuma K. Automated Global Mapping of Minimal Energy Points on Seams of Crossing by the Anharmonic Downward Distortion Following Method: A Case Study of H2CO. J Phys Chem A 2009; 113:1704-10. [DOI: 10.1021/jp810898u] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Satoshi Maeda
- Department of Chemistry and Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, Department of Chemistry, Tohoku University, Sendai 980-8578, Japan, and Fukui Institute for Fundamental Chemistry, Kyoto University, Kyoto 606-8103, Japan
| | - Koichi Ohno
- Department of Chemistry and Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, Department of Chemistry, Tohoku University, Sendai 980-8578, Japan, and Fukui Institute for Fundamental Chemistry, Kyoto University, Kyoto 606-8103, Japan
| | - Keiji Morokuma
- Department of Chemistry and Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, Department of Chemistry, Tohoku University, Sendai 980-8578, Japan, and Fukui Institute for Fundamental Chemistry, Kyoto University, Kyoto 606-8103, Japan
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Yamakita Y, Okazaki T, Ohno K. Conformation-Specific Raman Bands and Electronic Conjugation in Substituted Thioanisoles. J Phys Chem A 2008; 112:12220-7. [DOI: 10.1021/jp807027q] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Yoshihiro Yamakita
- Department of Chemistry, Graduate School of Science, Tohoku University, Aramaki, Aoba-ku, Sendai 980-8578, Japan
| | - Tomohiro Okazaki
- Department of Chemistry, Graduate School of Science, Tohoku University, Aramaki, Aoba-ku, Sendai 980-8578, Japan
| | - Koichi Ohno
- Department of Chemistry, Graduate School of Science, Tohoku University, Aramaki, Aoba-ku, Sendai 980-8578, Japan
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Luo Y, Maeda S, Ohno K. Decomposition of alkyl hydroperoxide by a copper(I) complex: insights from density functional theory. Tetrahedron Lett 2008. [DOI: 10.1016/j.tetlet.2008.09.065] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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A new global reaction route map on the potential energy surface of H2CO with unrestricted level. Chem Phys Lett 2008. [DOI: 10.1016/j.cplett.2008.06.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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36
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Luo Y, Maeda S, Ohno K. DFT Study on Isomerization and Decomposition of Cuprous Dialkyldithiophosphate and Its Reaction with Alkylperoxy Radical. J Phys Chem A 2008; 112:5720-6. [DOI: 10.1021/jp801571b] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Yi Luo
- Department of Chemistry, Graduate School of Science, Tohoku University, Aramaki, Aoba-ku, Sendai 980-8578, Japan
| | - Satoshi Maeda
- Department of Chemistry, Graduate School of Science, Tohoku University, Aramaki, Aoba-ku, Sendai 980-8578, Japan
| | - Koichi Ohno
- Department of Chemistry, Graduate School of Science, Tohoku University, Aramaki, Aoba-ku, Sendai 980-8578, Japan
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Maeda S, Ohno K. Microsolvation of Hydrogen Sulfide: Exploration of H2S·(H2O)n and SH-·H3O+·(H2O)n-1 (n = 5−7) Cluster Structures on Ab Initio Potential Energy Surfaces by the Scaled Hypersphere Search Method. J Phys Chem A 2008; 112:2962-8. [DOI: 10.1021/jp710494n] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Satoshi Maeda
- Department of Chemistry, Graduate School of Science, Tohoku University, Aramaki, Aoba-ku, Sendai 980-8578, Japan
| | - Koichi Ohno
- Department of Chemistry, Graduate School of Science, Tohoku University, Aramaki, Aoba-ku, Sendai 980-8578, Japan
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da Silva G, Bozzelli JW. Retro-[3 + 2]-Cycloaddition Reactions in the Decomposition of Five-Membered Nitrogen-Containing Heterocycles. J Org Chem 2008; 73:1343-53. [DOI: 10.1021/jo701914y] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Gabriel da Silva
- Department of Chemistry and Environmental Science, New Jersey Institute of Technology, Newark, New Jersey 07102, and Department of Chemical and Biomolecular Engineering, University of Melbourne, Victoria 3010, Australia
| | - Joseph W. Bozzelli
- Department of Chemistry and Environmental Science, New Jersey Institute of Technology, Newark, New Jersey 07102, and Department of Chemical and Biomolecular Engineering, University of Melbourne, Victoria 3010, Australia
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Maeda S, Ohno K. Automated Exploration of Adsorption Structures of an Organic Molecule on RuH2−BINAP by the ONIOM Method and the Scaled Hypersphere Search Method. J Phys Chem A 2007; 111:13168-71. [DOI: 10.1021/jp709874f] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Satoshi Maeda
- Department of Chemistry, Graduate School of Science, Tohoku University, Aramaki, Aoba-ku, Sendai 980-8578, Japan
| | - Koichi Ohno
- Department of Chemistry, Graduate School of Science, Tohoku University, Aramaki, Aoba-ku, Sendai 980-8578, Japan
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Watanabe Y, Maeda S, Ohno K. Global reaction route mapping on potential energy surfaces of C2H7+ and C3H9+. Chem Phys Lett 2007. [DOI: 10.1016/j.cplett.2007.09.002] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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41
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Yang X, Maeda S, Ohno K. Insight into Global Reaction Mechanism of [C2, H4, O] System from ab Initio Calculations by the Scaled Hypersphere Search Method. J Phys Chem A 2007; 111:5099-110. [PMID: 17506536 DOI: 10.1021/jp071238d] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A detailed computational study is performed on the singlet potential energy surface (PES) for possible isomerization and dissociation reactions of CH(3)CHO at the DFT (B3LYP/6-311++G(d,p)) and CCSD(T)/cc-pVTZ//B3LYP/6-311++G(d,p) levels. The pathways around the equilibrium structures can be discovered by the scaled hypersphere search (SHS) method, which enables us to make a global analysis of the PES for a given chemical composition. Fourteen isomers inclusive of 11 single-molecules and three "non-stabilized" oxygen-based ylides, 5 energetically favored complexes, and 79 interconversion transition states have been found on the singlet PES. Four lowest lying isomers with thermodynamic stability are also kinetically stable with respect to metastable intermediates. It was revealed that vinyl alcohols, which could be generated by the tautomerization of acetaldehyde, could undergo dissociation to form acetylene and water. In addition, recombination channels between some fragments, such as H(2)CO + (1)CH(2) and (1)CHOH + (1)CH(2), are energetically accessible via collision complex or oxygen-based ylides. Most of available unimolecular decompositions are found to be responsible for favorable hydrogen abstraction processes.
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Affiliation(s)
- Xia Yang
- Department of Chemistry, Graduate School of Science, Tohoku University, Aramaki, Sendai 980-8578, Japan
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Howle CR, Arrowsmith AN, Chikan V, Leone SR. State-Resolved Dynamics of the CN(B2Σ+) and CH(A2Δ) Excited Products Resulting from the VUV Photodissociation of CH3CN. J Phys Chem A 2007; 111:6637-48. [PMID: 17388380 DOI: 10.1021/jp068544w] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Fourier transform visible spectroscopy, in conjunction with VUV photons produced by a synchrotron, is employed to investigate the photodissociation of CH3CN. Emission is observed from both the CN(B2Sigma+-X2Sigma+) and CH(A2Delta-X2Pi) transitions; only the former is observed in spectra recorded at 10.2 and 11.5 eV, whereas both are detected in the 16 eV spectrum. The rotational and vibrational temperatures of both the CN(B2Sigma+) and CH(A2Delta) radical products are derived using a combination of spectral simulations and Boltzmann plots. The CN(B2Sigma+) fragment displays a bimodal rotational distribution in all cases. Trot(CN(B2Sigma+)) ranges from 375 to 600 K at lower K' and from 1840 to 7700 K at higher K' depending on the photon energy used. Surprisal analyses indicate clear bimodal rotational distributions, suggesting CN(B2Sigma+) is formed via either linear or bent transition states, respectively, depending on the extent of rotational excitation in this fragment. CH(A2Delta) has a single rotational distribution when produced at 16 eV, which results in Trot(CH(A2Delta))=4895+/-140 K in v'=0 and 2590+/-110 K in v'=1. From thermodynamic calculations, it is evident that CH(A2Delta) is produced along with CN(X2Sigma+)+H2. These products can be formed by a two step mechanism (via excited CH3* and ground state CN(X2Sigma+)) or a process similar to the "roaming" atom mechanism; the data obtained here are insufficient to definitively conclude whether either pathway occurs. A comparison of the CH(A2Delta) and CN(B2Sigma+) rotational distributions produced by 16 eV photons allows the ratio between the two excited fragments at this energy to be determined. An expression that considers the rovibrational populations of both band systems results in a CH(A2Delta):CN(B2Sigma+) ratio of (1.2+/-0.1):1 at 16 eV, thereby indicating that production of CH(A2Delta) is significant at 16 eV.
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Affiliation(s)
- Chris R Howle
- Departments of Chemistry and Physics, University of California and Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
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Maeda S, Ohno K. Conversion pathways between a fullerene and a ring among C20 clusters by a sphere contracting walk method: Remarkable difference in local potential energy landscapes around the fullerene and the ring. J Chem Phys 2006; 124:174306. [PMID: 16689570 DOI: 10.1063/1.2192784] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Conversion pathways from a fullerene to a ring and vice versa among C(20) clusters have been explored. A new technique has been developed for discovering multistep reaction pathways, which can be searched by finding constrained energy minima on spheres whose surfaces are contracting from the starting point to the terminal. Local landscapes that appeared on the pathways were found to be considerably different around the fullerene and the ring, from which one can make a new interpretation for no generation of the C(20) fullerene in laser vaporization of graphite.
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Affiliation(s)
- Satoshi Maeda
- Department of Chemistry, Graduate School of Science, Tohoku University, Aramaki, Aoba-ku, Sendai 980-8578, Japan
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Ohno K, Maeda S. D–L Conversion Pathways between Optical Isomers of Alanine: Applications of the Scaled Hypersphere Search Method to Explore Unknown Reaction Routes in a Chiral System. CHEM LETT 2006. [DOI: 10.1246/cl.2006.492] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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45
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Yang X, Maeda S, Ohno K. Global analysis of reaction pathways on the potential energy surface of cyanoacetylene by the scaled hypersphere search method. Chem Phys Lett 2006. [DOI: 10.1016/j.cplett.2005.10.132] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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46
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A scaled hypersphere interpolation technique for efficient construction of multidimensional potential energy surfaces. Chem Phys Lett 2005. [DOI: 10.1016/j.cplett.2005.08.063] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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