1
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Naumkin FY. Metalloid-Organic Intermolecular Complexes with Charge State-Controlled Conformations. Molecules 2024; 29:1635. [PMID: 38611914 PMCID: PMC11013210 DOI: 10.3390/molecules29071635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Revised: 03/25/2024] [Accepted: 04/02/2024] [Indexed: 04/14/2024] Open
Abstract
Shape alterations of molecular systems, induced by their (electric) charging/discharging, could facilitate useful electronic and/or mechanical functions in molecular-scale devices and machines. The present study reports structures, stabilities, charge distributions, and IR spectra for a group of complexes of a main-group metalloid (boron) atom with hydrocarbon molecules. The considered systems include the smallest species demonstrating the basic principle of operation, as well as their size-extended analogues, generalizing it to larger counterparts based on such units. The system geometries vary considerably between neutral and ionic counterparts and exhibit two-three typical conformations related to twisting by up to about 90 degrees. The predicted structures correlate with specific infrared spectra, which can enable their experimental identification and transformation tracking. The above-mentioned characteristics suggest the potential utility of such systems for intermolecular switches, with the possible spectral monitoring of their functioning.
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Affiliation(s)
- Fedor Y Naumkin
- Faculty of Science, Ontario Tech University/UOIT, Oshawa, ON L1G 0C5, Canada
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2
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Deng G, Medel R, Lu Y, Riedel S. Photoinduced Dual C-F Bond Activation of Hexafluorobenzene Mediated by Boron Atom. Chemistry 2024:e202303874. [PMID: 38193267 DOI: 10.1002/chem.202303874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 01/06/2024] [Accepted: 01/09/2024] [Indexed: 01/10/2024]
Abstract
The reaction of laser-ablated boron atoms with hexafluorobenzene (C6 F6 ) was investigated in neon and argon matrices, and the products are identified by matrix isolation infrared spectroscopy and quantum-chemical calculations. The reaction is triggered by a boron atom insertion into one C-F bond of hexafluorobenzene on annealing, forming a fluoropentafluorophenyl boryl radical (A). UV-Vis light irradiation of fluoropentafluorophenyl boryl radical causes generation of a 2-difluoroboryl-tetrafluorophenyl radical (B) via a second C-F bond activation. A perfluoroborepinyl radical (C) is also observed upon deposition and under UV-Vis light irradiation. This finding reveals the new example of a dual C-F bond activation of hexafluorobenzene mediated by a nonmetal and provides a possible route for synthesis of new perfluorinated organo-boron compounds.
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Affiliation(s)
- Guohai Deng
- Freie Universität Berlin, Institut für Chemie und Biochemie-Anorganische Chemie, Fabeckstrasse 34/36, 14195, Berlin, Germany
| | - Robert Medel
- Freie Universität Berlin, Institut für Chemie und Biochemie-Anorganische Chemie, Fabeckstrasse 34/36, 14195, Berlin, Germany
| | - Yan Lu
- Freie Universität Berlin, Institut für Chemie und Biochemie-Anorganische Chemie, Fabeckstrasse 34/36, 14195, Berlin, Germany
| | - Sebastian Riedel
- Freie Universität Berlin, Institut für Chemie und Biochemie-Anorganische Chemie, Fabeckstrasse 34/36, 14195, Berlin, Germany
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3
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Xu J, Xu X, Li D, Xie BB, Jian J. Photoinduced boron atom insertion of benzocyclobutene forming an unprecedented fused boron heterocyclic radical. Chem Commun (Camb) 2023; 59:1529-1532. [PMID: 36661048 DOI: 10.1039/d2cc06566e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Two novel boron heterocyclic radicals, an addition bicyclo[4.2.1]octa-1,3,5-trien-1-yl-borane radical (A) and an insertion 7-1H-borolo[1,2-a]borinine radical (B), were synthesized, and characterized in the reaction of atomic boron with benzocyclobutene. Species B involving a fused boron heterocyclic was spectroscopically characterized for the first time. This work is a new approach for boron-mediated molecular editing and the synthesis of fused boron heterocyclic compounds.
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Affiliation(s)
- Jiaping Xu
- Hangzhou Institute of Advanced Studies, Zhejiang Normal University, 1108 Gengwen Road, Hangzhou 311231, China.
| | - Xin Xu
- Hangzhou Institute of Advanced Studies, Zhejiang Normal University, 1108 Gengwen Road, Hangzhou 311231, China.
| | - Danyang Li
- Hangzhou Institute of Advanced Studies, Zhejiang Normal University, 1108 Gengwen Road, Hangzhou 311231, China.
| | - Bin-Bin Xie
- Hangzhou Institute of Advanced Studies, Zhejiang Normal University, 1108 Gengwen Road, Hangzhou 311231, China.
| | - Jiwen Jian
- Hangzhou Institute of Advanced Studies, Zhejiang Normal University, 1108 Gengwen Road, Hangzhou 311231, China.
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4
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Wang L, Li X, Jiang X, Zeng X, Zhou M. Spectroscopic Identification of the Heterocumulenic Isocyanatoborane Radical HBNCO. J Phys Chem Lett 2022; 13:2619-2624. [PMID: 35294206 DOI: 10.1021/acs.jpclett.2c00208] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The highly elusive isocyanatoborane radical HBNCO has been generated by the reaction of laser-ablated boron atoms with HNCO and also by the light-induced chemical transformation of the hydrogen-bonded molecule-radical complex BNH···CO in solid neon matrix. IR spectroscopic and theoretical studies indicate that the HBNCO radical possesses a quasilinear B═N═C═O heterocumulenic structure with the unpaired electron mainly located at the boron atom. This is in sharp contrast to the bonding properties of the isoelectronic analogues HCCCO and NCCO, in which the unpaired electron is located at the terminal CO moiety.
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Affiliation(s)
- Lina Wang
- Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysts and Innovative Materials, Fudan University, Shanghai 200433, China
| | - Xiaolong Li
- Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysts and Innovative Materials, Fudan University, Shanghai 200433, China
| | - Xin Jiang
- Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysts and Innovative Materials, Fudan University, Shanghai 200433, China
| | - Xiaoqing Zeng
- Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysts and Innovative Materials, Fudan University, Shanghai 200433, China
| | - Mingfei Zhou
- Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysts and Innovative Materials, Fudan University, Shanghai 200433, China
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5
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Xu J, Xu X, Li D, Jian J. Spectroscopic Characterization of Two Boron Heterocyclic Radicals in the Solid Neon Matrix. Phys Chem Chem Phys 2022; 24:7961-7968. [DOI: 10.1039/d2cp00076h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Two novel boron heterocyclic radicals, 3,4,5-trihydroborinine radical and 1-methyl-2-dihydro-1H-borole radical, were observed in the reaction of boron atom with cyclopentene. These radicals were trapped in solid neon and identified by...
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6
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He C, Fujioka K, Nikolayev AA, Zhao L, Doddipatla S, Azyazov VN, Mebel AM, Sun R, Kaiser RI. A chemical dynamics study of the reaction of the methylidyne radical (CH, X 2Π) with dimethylacetylene (CH 3CCCH 3, X 1A 1g). Phys Chem Chem Phys 2021; 24:578-593. [PMID: 34908056 DOI: 10.1039/d1cp04443e] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The gas-phase reaction of the methylidyne (CH; X2Π) radical with dimethylacetylene (CH3CCCH3; X1A1g) was studied at a collision energy of 20.6 kJ mol-1 under single collision conditions with experimental results merged with ab initio calculations of the potential energy surface (PES) and ab initio molecule dynamics (AIMD) simulations. The crossed molecular beam experiment reveals that the reaction proceeds barrierless via indirect scattering dynamics through long-lived C5H7 reaction intermediate(s) ultimately dissociating to C5H6 isomers along with atomic hydrogen with atomic hydrogen predominantly released from the methyl groups as verified by replacing the methylidyne with the D1-methylidyne reactant. AIMD simulations reveal that the reaction dynamics are statistical leading predominantly to p28 (1-methyl-3-methylenecyclopropene, 13%) and p8 (1-penten-3-yne, 81%) plus atomic hydrogen with a significant amount of available energy being channeled into the internal excitation of the polyatomic reaction products. The dynamics are controlled by addition to the carbon-carbon triple bond with the reaction intermediates eventually eliminating a hydrogen atom from the methyl groups of the dimethylacetylene reactant forming 1-methyl-3-methylenecyclopropene (p28). The dominating pathways reveal an unexpected insertion of methylidyne into one of the six carbon-hydrogen single bonds of the methyl groups of dimethylacetylene leading to the acyclic intermediate, which then decomposes to 1-penten-3-yne (p8). Therefore, the methyl groups of dimethylacetylene effectively 'screen' the carbon-carbon triple bond from being attacked by addition thus directing the dynamics to an insertion process as seen exclusively in the reaction of methylidyne with ethane (C2H6) forming propylene (CH3C2H3). Therefore, driven by the screening of the triple bond, one propynyl moiety (CH3CC) acts in four out of five trajectories as a spectator thus driving an unexpected, but dominating chemistry in analogy to the methylidyne - ethane system.
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Affiliation(s)
- Chao He
- Department of Chemistry, University of Hawai'i at Manoa, Honolulu, Hawaii 96822, USA.
| | - Kazuumi Fujioka
- Department of Chemistry, University of Hawai'i at Manoa, Honolulu, Hawaii 96822, USA.
| | - Anatoliy A Nikolayev
- Lebedev Physical Institute, Samara 443011, Russia.,Samara National Research University, Samara 443086, Russia
| | - Long Zhao
- Department of Chemistry, University of Hawai'i at Manoa, Honolulu, Hawaii 96822, USA.
| | - Srinivas Doddipatla
- Department of Chemistry, University of Hawai'i at Manoa, Honolulu, Hawaii 96822, USA.
| | - Valeriy N Azyazov
- Lebedev Physical Institute, Samara 443011, Russia.,Samara National Research University, Samara 443086, Russia
| | - Alexander M Mebel
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199, USA.
| | - Rui Sun
- Department of Chemistry, University of Hawai'i at Manoa, Honolulu, Hawaii 96822, USA.
| | - Ralf I Kaiser
- Department of Chemistry, University of Hawai'i at Manoa, Honolulu, Hawaii 96822, USA.
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7
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Goettl SJ, Yang Z, Doddipatla S, He C, Alves MO, Galvão BRL, Kaiser RI. A Crossed Molecular Beams and Computational Study of the Formation of the Astronomically Elusive Thiosilaformyl Radical (HSiS, X 2A'). J Phys Chem Lett 2021; 12:5979-5986. [PMID: 34161096 DOI: 10.1021/acs.jpclett.1c01706] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The formation pathways to silicon- and sulfur-containing molecules are crucial to the understanding of silicon-sulfur chemistry in interstellar and circumstellar environments. While multiple silicon- and sulfur-containing species have been observed in deep space, their fundamental formation mechanisms are largely unknown. The crossed molecular beams technique combined with electronic structure and Rice-Ramsperger-Kassel-Marcus (RRKM) calculations was utilized to study the bimolecular reaction of atomic silicon (Si(3Pj)) with thiomethanol (CH3SH, X1A') leading to the thiosilaformyl radical (HSiS, X2A') via an exclusive methyl radical (CH3, X2A2″) loss via indirect scattering dynamics which involves barrierless addition and hydrogen migration in an overall exoergic reaction, indicating the possibility that HSiS can form in cold molecular clouds. The astronomically elusive thiosilaformyl radical may act as a tracer of an exotic silicon-sulfur chemistry to be deciphered toward, for example, the star-forming region SgrB2, thus leading to a better understanding of the formation of silicon-sulfur bonds in deep space.
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Affiliation(s)
- Shane J Goettl
- Department of Chemistry, University of Hawai'i at Ma̅noa, Honolulu, Hawaii 96822, United States
| | - Zhenghai Yang
- Department of Chemistry, University of Hawai'i at Ma̅noa, Honolulu, Hawaii 96822, United States
| | - Srinivas Doddipatla
- Department of Chemistry, University of Hawai'i at Ma̅noa, Honolulu, Hawaii 96822, United States
| | - Chao He
- Department of Chemistry, University of Hawai'i at Ma̅noa, Honolulu, Hawaii 96822, United States
| | - Márcio O Alves
- Centro Federal de Educação Tecnológica de Minas Gerais, CEFET-MG, Av. Amazonas 5253, 30421-169 Belo Horizonte, Minas Gerais, Brazil
| | - Breno R L Galvão
- Centro Federal de Educação Tecnológica de Minas Gerais, CEFET-MG, Av. Amazonas 5253, 30421-169 Belo Horizonte, Minas Gerais, Brazil
| | - Ralf I Kaiser
- Department of Chemistry, University of Hawai'i at Ma̅noa, Honolulu, Hawaii 96822, United States
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8
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Li H, Kamasah A, Suits AG. Imaging H abstraction dynamics in crossed molecular beams: O(3P) + propanol isomers. Phys Chem Chem Phys 2019; 21:14186-14194. [DOI: 10.1039/c8cp06351f] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Direct rebound dynamics are revealed for bimolecular reaction of the ground state O(3P) atom with propanol isomers, involving the post transition state long-range dipole–dipole interaction between the dipolar OH and hydroxypropyl radicals.
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Affiliation(s)
- Hongwei Li
- Department of Chemistry
- University of Missouri Columbia
- MO 65211
- USA
| | | | - Arthur G. Suits
- Department of Chemistry
- University of Missouri Columbia
- MO 65211
- USA
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9
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Jian J, Li W, Wu X, Zhou M. Double C-H bond activation of acetylene by atomic boron in forming aromatic cyclic-HBC 2BH in solid neon. Chem Sci 2017; 8:4443-4449. [PMID: 28936331 PMCID: PMC5590098 DOI: 10.1039/c7sc01399j] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 04/12/2017] [Indexed: 01/08/2023] Open
Abstract
Boron atoms react with acetylene to form an aromatic cyclic-HBC2BH molecule via double C–H bond activation of acetylene in solid neon.
The organo-boron species formed from the reactions of boron atoms with acetylene in solid neon are investigated using matrix isolation infrared spectroscopy with isotopic substitutions as well as quantum chemical calculations. Besides the previously reported single C–H bond activation species, a cyclic-HBC2BH diboron species is formed via double C–H bond activation of acetylene. It is characterized to have a closed-shell singlet ground state with planar D2h symmetry. Bonding analysis indicates that it is a doubly aromatic species involving two delocalized σ electrons and two delocalized π electrons. This finding reveals the very first example of double C–H bond activation of acetylene in forming new organo-boron compounds.
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Affiliation(s)
- Jiwen Jian
- Department of Chemistry , Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials , Collaborative Innovation Center of Chemistry for Energy Materials , Fudan University , Shanghai 200433 , China .
| | - Wei Li
- Department of Chemistry , Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials , Collaborative Innovation Center of Chemistry for Energy Materials , Fudan University , Shanghai 200433 , China .
| | - Xuan Wu
- Department of Chemistry , Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials , Collaborative Innovation Center of Chemistry for Energy Materials , Fudan University , Shanghai 200433 , China .
| | - Mingfei Zhou
- Department of Chemistry , Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials , Collaborative Innovation Center of Chemistry for Energy Materials , Fudan University , Shanghai 200433 , China .
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10
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Kaiser RI, Balucani N. Exploring the Gas Phase Synthesis of the Elusive Class of Boronyls and the Mechanism of Boronyl Radical Reactions under Single Collision Conditions. Acc Chem Res 2017; 50:1154-1162. [PMID: 27991767 DOI: 10.1021/ar300308u] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Until recently, the chemistry of boronyl (BO), a diatomic radical isolectronic with the cyano (CN) species, has remained unknown. The boronyl group is characterized by a boron-oxygen multiple bond, and because of the inherent electron deficiency of the boron atom, boronyls (RBO) are highly reactive and typically only exist in their cyclotrimeric form (RBO)3. Due to their invaluable role as reactants, the isolation of the monomers in gas phase experiments has been extensively sought after by the organic synthesis and physical organic chemistry communities but never achieved. Besides the interests from a physical organic and synthetic point of view, boronyls also play a role as reaction intermediates in boron-assisted rocket propulsion systems. In this Account, we review recent experimental work in which gas phase organo boronyl monomers (RBO) are formed via bimolecular reactions of the boronyl radical (BO) with C2-C6 unsaturated hydrocarbons. The investigated hydrocarbons are widely exploited as fuels, and their reactions with boronyl radicals under single collision conditions lead to the formation of organo boronyls. Our studies also elucidate the mechanisms of their formation reactions thus furnishing a comprehension at the molecular level of this reaction class. The variety of the employed hydrocarbon substrates has allowed us to systematically classify the chemical behavior of the boronyl radicals. With the exception of the case of the dimethylacetylene reaction, the boron monoxide radical versus atomic hydrogen exchange mechanisms were always open leading to the formation of highly unsaturated organo boronyl monomers (RBO), which could be easily identified because they cannot trimerize under single collision conditions. Besides the hydrogen displacement pathway, methylacetylene, dimethylacetylene, and propylene, carrying one or two methyl groups, were also found to eliminate a methyl group. In all systems, the reactions were barrierless, indirect, and initiated by addition of the boron monoxide radical to the π electron density of the hydrocarbon molecule, with the radical center located at the boron atom of the BO radical, thus leading to doublet radical intermediates. These intermediates either decompose via hydrogen or methyl loss or isomerize prior to their decomposition via atomic hydrogen or migration of the BO moiety. A consistent trend suggests that all exit transition states are rather tight with those involved in the hydrogen atom loss depicting exit barriers of typically 25 to 35 kJ mol-1, whereas the methyl loss pathways are associated with tighter exit transition states located about 30-50 kJ mol-1 above the separated products. Further, the overall energetics suggest that those bimolecular reactions are exoergic by 40-90 kJ mol-1. These findings confirm that this reaction class leads to the formation of highly unsaturated organo boronyl molecules.
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Affiliation(s)
- Ralf I. Kaiser
- Department of Chemistry, University of Hawaii at Manoa, Honolulu, Hawaii 96822, United States
| | - Nadia Balucani
- Dipartimento
di Chimica, Biologia e Biotecnologie, Università di Perugia, 06123 Perugia, Italy
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11
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Parker DSN, Kaiser RI. On the formation of nitrogen-substituted polycyclic aromatic hydrocarbons (NPAHs) in circumstellar and interstellar environments. Chem Soc Rev 2017; 46:452-463. [DOI: 10.1039/c6cs00714g] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The chemical evolution of extraterrestrial environments leads to the formation of nitrogen substituted polycyclic aromatic hydrocarbons (NPAHs) via gas phase radical mediated aromatization reactions.
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Affiliation(s)
| | - Ralf I. Kaiser
- Department of Chemistry
- University of Hawai’i at Manoa
- Honolulu
- USA
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12
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Pan H, Liu K, Caracciolo A, Casavecchia P. Crossed beam polyatomic reaction dynamics: recent advances and new insights. Chem Soc Rev 2017; 46:7517-7547. [DOI: 10.1039/c7cs00601b] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This review summarizes the developments in polyatomic reaction dynamics, focusing on reactions of unsaturated hydrocarbons with O-atoms and methane with atoms/radicals.
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Affiliation(s)
- Huilin Pan
- Institute of Atomic and Molecular Sciences (IAMS)
- Academia Sinica
- Taipei
- Taiwan
| | - Kopin Liu
- Institute of Atomic and Molecular Sciences (IAMS)
- Academia Sinica
- Taipei
- Taiwan
- Department of Physics
| | - Adriana Caracciolo
- Dipartimento di Chimica
- Biologia e Biotecnologie
- Università degli Studi di Perugia
- 06123 Perugia
- Italy
| | - Piergiorgio Casavecchia
- Dipartimento di Chimica
- Biologia e Biotecnologie
- Università degli Studi di Perugia
- 06123 Perugia
- Italy
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13
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Yang T, Thomas AM, Dangi BB, Kaiser RI, Wu MH, Sun BJ, Chang AHH. Formation of the 2,3-Dimethyl-1-silacycloprop-2-enylidene Molecule via the Crossed Beam Reaction of the Silylidyne Radical (SiH; X2Π) with Dimethylacetylene (CH3CCCH3; X1A1g). J Phys Chem A 2016; 120:7262-8. [DOI: 10.1021/acs.jpca.6b06995] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Tao Yang
- Department
of Chemistry, University of Hawai’i at Manoa, Honolulu, Hawaii 96822, United States
| | - Aaron M. Thomas
- Department
of Chemistry, University of Hawai’i at Manoa, Honolulu, Hawaii 96822, United States
| | - Beni B. Dangi
- Department
of Chemistry, University of Hawai’i at Manoa, Honolulu, Hawaii 96822, United States
| | - Ralf I. Kaiser
- Department
of Chemistry, University of Hawai’i at Manoa, Honolulu, Hawaii 96822, United States
| | - Mei-Hung Wu
- Department of Chemistry, National Dong Hwa University, Shoufeng, Hualien 974, Taiwan
| | - Bing-Jian Sun
- Department of Chemistry, National Dong Hwa University, Shoufeng, Hualien 974, Taiwan
| | - Agnes H. H. Chang
- Department of Chemistry, National Dong Hwa University, Shoufeng, Hualien 974, Taiwan
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14
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Farfán-García ED, Castillo-Mendieta NT, Ciprés-Flores FJ, Padilla-Martínez II, Trujillo-Ferrara JG, Soriano-Ursúa MA. Current data regarding the structure-toxicity relationship of boron-containing compounds. Toxicol Lett 2016; 258:115-125. [PMID: 27329537 DOI: 10.1016/j.toxlet.2016.06.018] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Revised: 05/29/2016] [Accepted: 06/17/2016] [Indexed: 02/07/2023]
Abstract
Boron is ubiquitous in nature, being an essential element of diverse cells. As a result, humans have had contact with boron containing compounds (BCCs) for a long time. During the 20th century, BCCs were developed as antiseptics, antibiotics, cosmetics and insecticides. Boric acid was freely used in the nosocomial environment as an antiseptic and sedative salt, leading to the death of patients and an important discovery about its critical toxicology for humans. Since then the many toxicological studies done in relation to BCCs have helped to establish the proper limits of their use. During the last 15 years, there has been a boom of research on the design and use of new, potent and efficient boron containing drugs, finding that the addition of boron to some known drugs increases their affinity and selectivity. This mini-review summarizes two aspects of BCCs: toxicological data found with experimental models, and the scarce but increasing data about the structure-activity relationship for toxicity and therapeutic use. As is the case with boron-free compounds, the biological activity of BCCs is related to their chemical structure. We discuss the use of new technology to discover potent and efficient BCCs for medicinal therapy by avoiding toxic effects.
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Affiliation(s)
- E D Farfán-García
- Departamento de Bioquímica, Sección de Estudios de Posgrado e Investigación. Escuela Superior de Medicina, Instituto Politécnico Nacional. Plan de San Luis y Díaz Mirón, 11340, México City, México; Departamento de Fisiología, Sección de Estudios de Posgrado e Investigación. Escuela Superior de Medicina, Instituto Politécnico Nacional. Plan de San Luis y Díaz Mirón, 11340, México City, México
| | - N T Castillo-Mendieta
- Departamento de Fisiología, Sección de Estudios de Posgrado e Investigación. Escuela Superior de Medicina, Instituto Politécnico Nacional. Plan de San Luis y Díaz Mirón, 11340, México City, México
| | - F J Ciprés-Flores
- Departamento de Bioquímica, Sección de Estudios de Posgrado e Investigación. Escuela Superior de Medicina, Instituto Politécnico Nacional. Plan de San Luis y Díaz Mirón, 11340, México City, México; Departamento de Fisiología, Sección de Estudios de Posgrado e Investigación. Escuela Superior de Medicina, Instituto Politécnico Nacional. Plan de San Luis y Díaz Mirón, 11340, México City, México
| | - I I Padilla-Martínez
- Unidad Profesional Interdisciplinaria de Biotecnología, Instituto Politécnico Nacional, Avenida Acueducto s/n, Barrio La Laguna Ticomán, 07340, México
| | - J G Trujillo-Ferrara
- Departamento de Bioquímica, Sección de Estudios de Posgrado e Investigación. Escuela Superior de Medicina, Instituto Politécnico Nacional. Plan de San Luis y Díaz Mirón, 11340, México City, México
| | - M A Soriano-Ursúa
- Departamento de Fisiología, Sección de Estudios de Posgrado e Investigación. Escuela Superior de Medicina, Instituto Politécnico Nacional. Plan de San Luis y Díaz Mirón, 11340, México City, México.
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15
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Jian J, Lin H, Luo M, Chen M, Zhou M. Observation of Spontaneous C=C Bond Breaking in the Reaction between Atomic Boron and Ethylene in Solid Neon. Angew Chem Int Ed Engl 2016; 55:8371-4. [PMID: 27240114 DOI: 10.1002/anie.201603345] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Revised: 04/28/2016] [Indexed: 11/09/2022]
Abstract
A ground-state boron atom inserts into the C=C bond of ethylene to spontaneously form the allene-like compound H2 CBCH2 on annealing in solid neon. This compound can further isomerize to the propyne-like HCBCH3 isomer under UV light excitation. The observation of this unique spontaneous C=C bond insertion reaction is consistent with theoretical predictions that the reaction is thermodynamically exothermic and kinetically facile. This work demonstrates that the stronger C=C bond, rather than the less inert C-H bond, can be broken to form organoboron species from the reaction of a boron atom with ethylene even at cryogenic temperatures.
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Affiliation(s)
- Jiwen Jian
- Collaborative Innovation Center of Chemistry for Energy Materials, Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysts and Innovative Materials, Fudan University, Shanghai, 200433, China
| | - Hailu Lin
- Collaborative Innovation Center of Chemistry for Energy Materials, Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysts and Innovative Materials, Fudan University, Shanghai, 200433, China.,Department of Applied Chemistry, East China Institute of Technology, Nanchang, Jiangxi Province, 330013, China
| | - Mingbiao Luo
- Department of Applied Chemistry, East China Institute of Technology, Nanchang, Jiangxi Province, 330013, China
| | - Mohua Chen
- Collaborative Innovation Center of Chemistry for Energy Materials, Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysts and Innovative Materials, Fudan University, Shanghai, 200433, China
| | - Mingfei Zhou
- Collaborative Innovation Center of Chemistry for Energy Materials, Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysts and Innovative Materials, Fudan University, Shanghai, 200433, China.
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Jian J, Lin H, Luo M, Chen M, Zhou M. Observation of Spontaneous C=C Bond Breaking in the Reaction between Atomic Boron and Ethylene in Solid Neon. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201603345] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Jiwen Jian
- Collaborative Innovation Center of Chemistry for Energy Materials; Department of Chemistry; Shanghai Key Laboratory of Molecular Catalysts and Innovative Materials; Fudan University; Shanghai 200433 China
| | - Hailu Lin
- Collaborative Innovation Center of Chemistry for Energy Materials; Department of Chemistry; Shanghai Key Laboratory of Molecular Catalysts and Innovative Materials; Fudan University; Shanghai 200433 China
- Department of Applied Chemistry; East China Institute of Technology; Nanchang Jiangxi Province 330013 China
| | - Mingbiao Luo
- Department of Applied Chemistry; East China Institute of Technology; Nanchang Jiangxi Province 330013 China
| | - Mohua Chen
- Collaborative Innovation Center of Chemistry for Energy Materials; Department of Chemistry; Shanghai Key Laboratory of Molecular Catalysts and Innovative Materials; Fudan University; Shanghai 200433 China
| | - Mingfei Zhou
- Collaborative Innovation Center of Chemistry for Energy Materials; Department of Chemistry; Shanghai Key Laboratory of Molecular Catalysts and Innovative Materials; Fudan University; Shanghai 200433 China
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17
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Wang Y, Guo X, Tang M, Wei D. Theoretical Investigations toward the Asymmetric Insertion Reaction of Diazoester with Aldehyde Catalyzed by N-Protonated Chiral Oxazaborolidine: Mechanisms and Stereoselectivity. J Phys Chem A 2015; 119:8422-31. [DOI: 10.1021/acs.jpca.5b04793] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Yang Wang
- The College of Chemistry
and Molecular Engineering, Center of Computational Chemistry, Zhengzhou University, Zhengzhou, Henan Province 450001, P. R. China
| | - Xiaokang Guo
- The College of Chemistry
and Molecular Engineering, Center of Computational Chemistry, Zhengzhou University, Zhengzhou, Henan Province 450001, P. R. China
| | - Mingsheng Tang
- The College of Chemistry
and Molecular Engineering, Center of Computational Chemistry, Zhengzhou University, Zhengzhou, Henan Province 450001, P. R. China
| | - Donghui Wei
- The College of Chemistry
and Molecular Engineering, Center of Computational Chemistry, Zhengzhou University, Zhengzhou, Henan Province 450001, P. R. China
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18
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Kaiser RI, Parker DS, Mebel AM. Reaction Dynamics in Astrochemistry: Low-Temperature Pathways to Polycyclic Aromatic Hydrocarbons in the Interstellar Medium. Annu Rev Phys Chem 2015; 66:43-67. [DOI: 10.1146/annurev-physchem-040214-121502] [Citation(s) in RCA: 89] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Ralf I. Kaiser
- Department of Chemistry, University of Hawaii at Manoa, Honolulu, Hawaii 96822;
| | - Dorian S.N. Parker
- Department of Chemistry, University of Hawaii at Manoa, Honolulu, Hawaii 96822;
| | - Alexander M. Mebel
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199
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19
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Maity S, Dangi BB, Parker DSN, Kaiser RI, Lin HM, E HP, Sun BJ, Chang AHH. Combined crossed molecular beam and ab initio investigation of the reaction of boron monoxide (BO; X(2)Σ(+)) with 1,3-butadiene (CH2CHCHCH2; X(1)Ag) and its deuterated counterparts. J Phys Chem A 2015; 119:1094-107. [PMID: 25626151 DOI: 10.1021/jp511715e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The reactions of the boron monoxide ((11)BO; X(2)Σ(+)) radical with 1,3-butadiene (CH2CHCHCH2; X(1)Ag) and its partially deuterated counterparts, 1,3-butadiene-d2 (CH2CDCDCH2; X(1)Ag) and 1,3-butadiene-d4 (CD2CHCHCD2; X(1)Ag), were investigated under single collision conditions exploiting a crossed molecular beams machine. The experimental data were combined with the state-of-the-art ab initio electronic structure calculations and statistical RRKM calculations to investigate the underlying chemical reaction dynamics and reaction mechanisms computationally. Our investigations revealed that the reaction followed indirect scattering dynamics through the formation of (11)BOC4H6 doublet radical intermediates via the barrierless addition of the (11)BO radical to the terminal carbon atom (C1/C4) and/or the central carbon atom (C2/C3) of 1,3-butadiene. The resulting long-lived (11)BOC4H6 intermediate(s) underwent isomerization and/or unimolecular decomposition involving eventually at least two distinct atomic hydrogen loss pathways to 1,3-butadienyl-1-oxoboranes (CH2CHCHCH(11)BO) and 1,3-butadienyl-2-oxoboranes (CH2C ((11)BO)CHCH2) in overall exoergic reactions via tight exit transition states. Utilizing partially deuterated 1,3-butadiene-d2 and -d4, we revealed that the hydrogen loss from the methylene moiety (CH2) dominated with 70 ± 10% compared to an atomic hydrogen loss from the methylidyne group (CH) of only 30 ± 10%; these data agree nicely with the theoretically predicted branching ratio of 80% versus 19%.
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Affiliation(s)
- Surajit Maity
- Department of Chemistry, University of Hawai'i at Manoa , Honolulu, Hawaii 96822, United States
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20
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Abstract
Through an extensive isomeric search utilizing a “skeleton-ligand” cluster-growth strategy, the global minimum of C2B4H4 is found to adopt a ribbon-like structure (01) rather than the previously reported hypercloso structure (04).
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Affiliation(s)
- Xiao-yong Zhang
- State Key Laboratory of Theoretical and Computational Chemistry
- Institute of Theoretical Chemistry
- Jilin University
- Changchun 130023
- People's Republic of China
| | - Yi-hong Ding
- State Key Laboratory of Theoretical and Computational Chemistry
- Institute of Theoretical Chemistry
- Jilin University
- Changchun 130023
- People's Republic of China
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21
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Jing N, Zhang XY, Xu J, Ding YH. Structures and stabilities of CBHz(z≤ 8) and CxB3-xHz(x= 1, 2,z≤ 14): prediction of novel organo-boron radicals. Mol Phys 2014. [DOI: 10.1080/00268976.2014.985772] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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22
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Maity S, Dangi BB, Parker DSN, Kaiser RI, An Y, Sun BJ, Chang AHH. Combined crossed molecular beam and ab initio investigation of the multichannel reaction of boron monoxide (BO; X2Σ+) with Propylene (CH3CHCH2; X1A'): competing atomic hydrogen and methyl loss pathways. J Phys Chem A 2014; 118:9632-45. [PMID: 25238644 DOI: 10.1021/jp507001r] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The reaction dynamics of boron monoxide ((11)BO; X(2)Σ(+)) with propylene (CH(3)CHCH(2); X(1)A') were investigated under single collision conditions at a collision energy of 22.5 ± 1.3 kJ mol(-1). The crossed molecular beam investigation combined with ab initio electronic structure and statistical (RRKM) calculations reveals that the reaction follows indirect scattering dynamics and proceeds via the barrierless addition of boron monoxide radical with its radical center located at the boron atom. This addition takes place to either the terminal carbon atom (C1) and/or the central carbon atom (C2) of propylene reactant forming (11)BOC(3)H(6) intermediate(s). The long-lived (11)BOC(3)H(6) doublet intermediate(s) underwent unimolecular decomposition involving at least three competing reaction mechanisms via an atomic hydrogen loss from the vinyl group, an atomic hydrogen loss from the methyl group, and a methyl group elimination to form cis-/trans-1-propenyl-oxo-borane (CH(3)CHCH(11)BO), 3-propenyl-oxo-borane (CH(2)CHCH(2)(11)BO), and ethenyl-oxo-borane (CH(2)CH(11)BO), respectively. Utilizing partially deuterated propylene (CD(3)CHCH(2) and CH(3)CDCD(2)), we reveal that the loss of a vinyl hydrogen atom is the dominant hydrogen elimination pathway (85 ± 10%) forming cis-/trans-1-propenyl-oxo-borane, compared to the loss of a methyl hydrogen atom (15 ± 10%) leading to 3-propenyl-oxo-borane. The branching ratios for an atomic hydrogen loss from the vinyl group, an atomic hydrogen loss from the methyl group, and a methyl group loss are experimentally derived to be 26 ± 8%:5 ± 3%:69 ± 15%, respectively; these data correlate nicely with the branching ratios calculated via RRKM theory of 19%:5%:75%, respectively.
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Affiliation(s)
- Surajit Maity
- Department of Chemistry, University of Hawaii at Manoa , Honolulu, Hawaii 96822, United States
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23
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Yang T, Dangi BB, Parker DSN, Kaiser RI, An Y, Chang AHH. A combined crossed molecular beams and ab initio investigation on the formation of vinylsulfidoboron (C₂H₃¹¹B³²S). Phys Chem Chem Phys 2014; 16:17580-7. [PMID: 25026168 DOI: 10.1039/c4cp01651c] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We exploited crossed molecular beams techniques and electronic structure calculations to provide compelling evidence that the vinylsulfidoboron molecule (C2H3(11)B(32)S) - the simplest member of hitherto elusive olefinic organo-sulfidoboron molecules (RBS) - can be formed via the gas phase reaction of boron monosulfide ((11)B(32)S) with ethylene (C2H4) under single collision conditions. The reaction mechanism follows indirect scattering dynamics via a barrierless addition of the boron monosulfide radical to the carbon-carbon double bond of ethylene. The initial reaction complex can either decompose to vinylsulfidoboron (C2H3(11)B(32)S) via the emission of a hydrogen atom from the sp(3) hybridized carbon atom, or isomerize via a 1,2-hydrogen shift prior to a hydrogen loss from the terminal carbon atom to form vinylsulfidoboron. Statistical (RRKM) calculations predict branching ratios of 8% and 92% for both pathways leading to vinylsulfidoboron, respectively. A comparison between the boron monosulfide ((11)B(32)S) plus ethylene and the boron monoxide ((11)BO) plus ethylene systems indicates that both reactions follow similar reaction mechanisms involving addition - elimination and addition - hydrogen migration - elimination pathways. Our experimental findings open up a novel pathway to access the previously poorly-characterized class of organo-sulfidoboron molecules via bimolecular gas phase reactions, which are difficult to form through 'classical' organic synthesis.
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Affiliation(s)
- Tao Yang
- Department of Chemistry, University of Hawaii at Manoa, Honolulu, Hawaii 96822, USA.
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24
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Fu T, Qiao H, Peng Z, Hu G, Wu X, Gao Y, Zhao Y. Palladium-catalyzed air-based oxidative coupling of arylboronic acids with H-phosphine oxides leading to aryl phosphine oxides. Org Biomol Chem 2014; 12:2895-902. [DOI: 10.1039/c3ob42470g] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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25
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Kaiser RI, Maity S, Dangi BB, Su YS, Sun BJ, Chang AHH. A crossed molecular beam and ab initio investigation of the exclusive methyl loss pathway in the gas phase reaction of boron monoxide (BO; X2Σ+) with dimethylacetylene (CH3CCCH3; X1A1g). Phys Chem Chem Phys 2014; 16:989-97. [DOI: 10.1039/c3cp53930j] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Parker DSN, Dangi BB, Balucani N, Stranges D, Mebel AM, Kaiser RI. Gas-phase synthesis of phenyl oxoborane (C6H5BO) via the reaction of boron monoxide with benzene. J Org Chem 2013; 78:11896-900. [PMID: 24191702 DOI: 10.1021/jo401942z] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Organyl oxoboranes (RBO) are valuable reagents in organic synthesis due to their role in Suzuki coupling reactions. However, organyl oxoboranes (RBO) are only found in trimeric forms (RBO3) commonly known as boronic acids or boroxins; obtaining their monomers has proved a complex endeavor. Here, we demonstrate an oligomerization-free formation of organyl oxoborane (RBO) monomers in the gas phase by a radical substitution reaction under single-collision conditions in the gas phase. Using the cross molecular beams technique, phenyl oxoborane (C6H5BO) is formed through the reaction of boronyl radicals (BO) with benzene (C6H6). The reaction is indirect, initially forming a van der Waals complex that isomerizes below the energy of the reactants and eventually forming phenyl oxoborane by hydrogen emission in an overall exoergic radical-hydrogen atom exchange mechanism.
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Affiliation(s)
- Dorian S N Parker
- Department of Chemistry, University of Hawaii at Manoa , 2545 The Mall, Honolulu, Hawaii 96822-2275, United States
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27
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Maity S, Parker DSN, Dangi BB, Kaiser RI, Fau S, Perera A, Bartlett RJ. A crossed molecular beam and ab-initio investigation of the reaction of boron monoxide (BO; X2Σ+) with methylacetylene (CH3CCH; X1A1): competing atomic hydrogen and methyl loss pathways. J Phys Chem A 2013; 117:11794-807. [PMID: 23651442 DOI: 10.1021/jp402743y] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The gas-phase reaction of boron monoxide ((11)BO; X(2)Σ(+)) with methylacetylene (CH3CCH; X(1)A1) was investigated experimentally using crossed molecular beam technique at a collision energy of 22.7 kJ mol(-1) and theoretically using state of the art electronic structure calculation, for the first time. The scattering dynamics were found to be indirect (complex forming reaction) and the reaction proceeded through the barrier-less formation of a van-der-Waals complex ((11)BOC3H4) followed by isomerization via the addition of (11)BO(X(2)Σ(+)) to the C1 and/or C2 carbon atom of methylacetylene through submerged barriers. The resulting (11)BOC3H4 doublet radical intermediates underwent unimolecular decomposition involving three competing reaction mechanisms via two distinct atomic hydrogen losses and a methyl group elimination. Utilizing partially deuterated methylacetylene reactants (CD3CCH; CH3CCD), we revealed that the initial addition of (11)BO(X(2)Σ(+)) to the C1 carbon atom of methylacetylene was followed by hydrogen loss from the acetylenic carbon atom (C1) and from the methyl group (C3) leading to 1-propynyl boron monoxide (CH3CC(11)BO) and propadienyl boron monoxide (CH2CCH(11)BO), respectively. Addition of (11)BO(X(2)Σ(+)) to the C1 of methylacetylene followed by the migration of the boronyl group to the C2 carbon atom and/or an initial addition of (11)BO(X(2)Σ(+)) to the sterically less accessible C2 carbon atom of methylacetylene was followed by loss of a methyl group leading to the ethynyl boron monoxide product (HCC(11)BO) in an overall exoergic reaction (78 ± 23 kJ mol(-1)). The branching ratios of these channels forming CH2CCH(11)BO, CH3CC(11)BO, and HCC(11)BO were derived to be 4 ± 3%, 40 ± 5%, and 56 ± 15%, respectively; these data are in excellent agreement with the calculated branching ratios using statistical RRKM theory yielding 1%, 38%, and 61%, respectively.
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Affiliation(s)
- Surajit Maity
- Department of Chemistry, University of Hawai'i at Manoa , Honolulu, Hawaii 96822, United States
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28
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Parker DSN, Balucani N, Stranges D, Kaiser RI, Mebel A. A crossed beam and ab initio investigation on the formation of boronyldiacetylene (HCCCC11BO; X1Σ+) via the reaction of the boron monoxide radical (11BO; X2Σ+) with diacetylene (C4H2; X1Σg(+)). J Phys Chem A 2013; 117:8189-98. [PMID: 23879375 DOI: 10.1021/jp405228f] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The reaction dynamics of the boron monoxide radical ((11)BO; X(2)Σ(+)) with diacetylene (C4H2; X(1)Σg(+)) were investigated at a nominal collision energy of 17.5 kJ mol(-1) employing the crossed molecular beam technique and supported by ab initio and statistical (RRKM) calculations. The reaction is governed by indirect (complex forming) scattering dynamics with the boron monoxide radical adding with its boron atom to the carbon-carbon triple bond of the diacetylene molecule at one of the terminal carbon atoms without entrance barrier. This leads to a doublet radical intermediate (C4H2(11)BO), which undergoes unimolecular decomposition through hydrogen atom emission from the C1 carbon atom via a tight exit transition state located about 18 kJ mol(-1) above the separated products. This process forms the hitherto elusive boronyldiacetylene molecule (HCCCC(11)BO; X(1)Σ(+)) in a bimolecular gas phase reaction under single collision conditions. The overall reaction was determined to be exoergic by 62 kJ mol(-1). The reaction dynamics are compared to the isoelectronic diacetylene (C4H2; X(1)Σg(+))-cyano radical (CN; X(2)Σ(+)) system studied previously in our group. The characteristics of boronyl-diacetylene and the boronyldiacetylene molecule (HCCCC(11)BO; X(1)Σ(+)) as well as numerous intermediates are reported for the first time.
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Affiliation(s)
- Dorian S N Parker
- Department of Chemistry, University of Hawaii at Manoa, Honolulu, Hawaii 96822, United States
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KHEIRJOU SOMAYYEH, MEHRPAJOUH SIMA, FATTAHI ALIREZA. DRASTIC INFLUENCE OF BORON ATOM ON THE ACIDITY OF ALCOHOL IN BOTH GAS PHASE AND SOLUTION PHASE, A DFT STUDY. JOURNAL OF THEORETICAL & COMPUTATIONAL CHEMISTRY 2013. [DOI: 10.1142/s0219633612501039] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
In this study, the drastic influence of the boron atom on the acidity of alcohol has been considered. The calculated ΔH acid (320.9–338.1 kcal/mol) and pKa range of boron containing alcohol (-0.1–9.4) indicate that the boronation of alcohol leads to considerable enhancement of its acidity. For instance, we have obtained the ΔH acid values 338.1, 335.2 kcal/mol and the pKa values 4.12, 2.81 for BH2CH2OH , BF2CH2OH alcohols, respectively, which are much smaller than that of CH3OH (with ΔH acid = 374.9 kcal/mol and pKa = 15). The increase in the acidity of boronated alcohol can be related to the stabilization of alkoxy ion due to overlap of unoccupied orbital of boron atom with the electron pairs of negative oxygen. All gas phase computations were performed at MP2/6-311++G(d,p)//(B3LYP/6-31+G(d)) level. The primary results indicate that the presence of boron atom in an alcohol might make it as acidic as nitric acid. The geometry optimization of studied structures was performed with DFT computation and optimized structures were used to carry out natural bond orbital (NBO) analysis. NBO analysis revealed that the increase in the acidity of boron-containing alcohols is due to the charge transfer from the negative oxygen (in deprotonated structure) to the empty orbital of - BH2 and - BF2 . Quantum theory of atoms in molecules (QTAIM) was also applied to determine the nature of bonds formed in the deprotonated structure.
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Affiliation(s)
- SOMAYYEH KHEIRJOU
- Department of Chemistry, Sharif University of Technology, P.O. Box: 11365-9516, Tehran, Iran
| | - SIMA MEHRPAJOUH
- Department of Chemistry, Sharif University of Technology, P.O. Box: 11365-9516, Tehran, Iran
| | - ALIREZA FATTAHI
- Department of Chemistry, Sharif University of Technology, P.O. Box: 11365-9516, Tehran, Iran
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Kheirjou S, Abedin A, Fattahi A. Theoretical descriptors response to the calculations of the relative pKa values of some boronic acids in aqueous solution: A DFT study. COMPUT THEOR CHEM 2012. [DOI: 10.1016/j.comptc.2012.08.012] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Kaiser RI, Mebel AM. On the formation of polyacetylenes and cyanopolyacetylenes in Titan's atmosphere and their role in astrobiology. Chem Soc Rev 2012; 41:5490-501. [DOI: 10.1039/c2cs35068h] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Maksyutenko P, Parker DSN, Zhang F, Kaiser RI. An LIF characterization of supersonic BO (X2Σ+) and CN (X2Σ+) radical sources for crossed beam studies. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2011; 82:083107. [PMID: 21895233 DOI: 10.1063/1.3624695] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Various ablation sources generating supersonic boron monoxide (BO; X(2)Σ(+)) radical beams utilizing oxygen (O(2)), carbon dioxide (CO(2)), methanol (CH(3)OH), and water (H(2)O) as seeding gases were characterized in a crossed molecular beams setup by mass resolved time-of-flight spectroscopy and spectroscopically via laser induced fluorescence. Intensities of the sources as well as rovibrational energy distributions were analyzed. The molecular oxygen source was found to produce excessive amount of an unwanted BO(2) byproduct. Internal vibrational energy of boron monoxide generated in the water and methanol sources was too high to be considered for the study of dynamics of ground state radicals. The best combination of intensity, purity, and low internal energy was found in the carbon dioxide source to generate boron monoxide. We successfully tested the boron monoxide (BO; X(2)Σ(+)) radical beam source in crossed beams reactions with acetylene (C(2)H(2)) and ethylene (C(2)H(4)). The source was also compared with supersonic beams of the isoelectronic cyano (CN; X(2)Σ(+)) radical.
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Affiliation(s)
- Pavlo Maksyutenko
- Department of Chemistry, University of Hawaii at Manoa, Honolulu, Hawaii 96822, USA
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Balucani N, Casavecchia P. Crossed molecular beam studies of astronomically relevant bimolecular reactions. RENDICONTI LINCEI 2011. [DOI: 10.1007/s12210-011-0128-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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34
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Parker DSN, Zhang F, Maksyutenko P, Kaiser RI, Chang AHH. A crossed beam and ab initio investigation of the reaction of boron monoxide (11BO; X2Σ+) with acetylene (C2H2; X1Σ+g). Phys Chem Chem Phys 2011; 13:8560-70. [DOI: 10.1039/c0cp02458a] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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