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Czekner J, Wang LS. Observation of π-Backbonding in a Boronyl-Coordinated Transition Metal Complex TaBO –. J Phys Chem A 2020; 124:10001-10007. [DOI: 10.1021/acs.jpca.0c09196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Joseph Czekner
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, United States
| | - Lai-Sheng Wang
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, United States
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2
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Li H, Suits AG. Universal crossed beam imaging studies of polyatomic reaction dynamics. Phys Chem Chem Phys 2020; 22:11126-11138. [DOI: 10.1039/d0cp00522c] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Crossed-beam imaging studies of polyatomic reactions show surprising dynamics not anticipated by extrapolation from smaller model systems.
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Affiliation(s)
- Hongwei Li
- Department of Chemistry
- University of Missouri
- Columbia
- USA
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3
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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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4
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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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5
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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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6
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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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7
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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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8
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Yang T, Parker DSN, Dangi BB, Kaiser RI, Stranges D, Su YH, Chen SY, Chang AHH, Mebel AM. Directed Gas-Phase Formation of the Ethynylsulfidoboron Molecule. J Am Chem Soc 2014; 136:8387-92. [DOI: 10.1021/ja502636u] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Tao Yang
- Department
of Chemistry, University of Hawaii at Manoa, Honolulu, Hawaii 96822, United States
| | - Dorian S. N. Parker
- Department
of Chemistry, University of Hawaii at Manoa, Honolulu, Hawaii 96822, United States
| | - Beni B. Dangi
- Department
of Chemistry, University of Hawaii at Manoa, Honolulu, Hawaii 96822, United States
| | - Ralf I. Kaiser
- Department
of Chemistry, University of Hawaii at Manoa, Honolulu, Hawaii 96822, United States
| | - Domenico Stranges
- Department
of Chemistry, Sapienza University of Rome, Rome 00185, Italy
| | - Yuan-Hsiang Su
- Department
of Chemistry, National Dong Hwa University, Shoufeng, Hualien 974, Taiwan
| | - Si-Ying Chen
- 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
| | - Alexander M. Mebel
- Department
of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199, United States
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9
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Maity S, Parker DSN, Kaiser RI, Ganoe B, Fau S, Perera A, Bartlett RJ. Gas-Phase Synthesis of Boronylallene (H 2CCCH(BO)) under Single Collision Conditions: A Crossed Molecular Beams and Computational Study. J Phys Chem A 2014; 118:3810-3819. [PMID: 24806514 DOI: 10.1021/jp501595n] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The gas phase reaction between the boron monoxide radical (11BO; X2Σ+) and allene (H2CCCH2; X1A1) was investigated experimentally under single collision conditions using the crossed molecular beam technique and theoretically exploiting ab initio electronic structure and statistical (RRKM) calculations. The reaction was found to follow indirect (complex forming) scattering dynamics and proceeded via the formation of a van der Waals complex (11BOC3H4). This complex isomerized via addition of the boron monoxide radical (11BO; X2Σ+) with the radical center located at the boron atom to the terminal carbon atom of the allene molecule forming a H2CCCH211BO intermediate on the doublet surface. The chemically activated H2CCCH211BO intermediate underwent unimolecular decomposition via atomic hydrogen elimination from the terminal carbon atom holding the boronyl group through a tight exit transition state to synthesize the boronylallene product (H2CCCH11BO) in a slightly exoergic reaction (55 ± 11 kJ mol-1). Statistical (RRKM) calculations suggest that minor reaction channels lead to the products 3-propynyloxoborane (CH2(11BO)CCH) and 1-propynyloxoborane (CH3CC11BO) with fractions of 1.5% and 0.2%, respectively. The title reaction was also compared with the cyano (CN; X2Σ+)-allene and boronyl-methylacetylene reactions to probe similarities, but also differences of these isoelectronic systems. Our investigation presents a novel gas phase synthesis and characterization of a hitherto elusive organyloxoborane (RBO) monomer-boronylallene-which is inherently tricky to isolate in the condensed phase except in matrix studies; our work further demonstrates that the crossed molecular beams approach presents a useful tool in investigating the chemistry and synthesis of highly reactive organyloxoboranes.
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Affiliation(s)
- Surajit Maity
- Department of Chemistry, University of Hawaii at Manoa , Honolulu, Hawaii 96822, United States
| | - Dorian S N Parker
- Department of Chemistry, University of Hawaii at Manoa , Honolulu, Hawaii 96822, United States
| | - Ralf I Kaiser
- Department of Chemistry, University of Hawaii at Manoa , Honolulu, Hawaii 96822, United States
| | - Brad Ganoe
- Quantum Theory Project, University of Florida , Gainesville, Florida 32611, United States
| | - Stefan Fau
- Quantum Theory Project, University of Florida , Gainesville, Florida 32611, United States
| | - Ajith Perera
- Quantum Theory Project, University of Florida , Gainesville, Florida 32611, United States
| | - Rodney J Bartlett
- Quantum Theory Project, University of Florida , Gainesville, Florida 32611, United States
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10
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Parker DSN, Mebel AM, Kaiser RI. The role of isovalency in the reactions of the cyano (CN), boron monoxide (BO), silicon nitride (SiN), and ethynyl (C2H) radicals with unsaturated hydrocarbons acetylene (C2H2) and ethylene (C2H4). Chem Soc Rev 2014; 43:2701-13. [DOI: 10.1039/c3cs60328h] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The classification of chemical reactions based on shared characteristics is at the heart of the chemical sciences, and is well exemplified by Langmuir's concept of isovalency, in which ‘two molecular entities with the same number of valence electrons have similar chemistries’.
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Affiliation(s)
- D. S. N. Parker
- Department of Chemistry
- University of Hawai'i at Manoa
- Honolulu, USA
| | - A. M. Mebel
- Department of Chemistry and Biochemistry
- Florida International University
- Miami, USA
| | - R. I. Kaiser
- Department of Chemistry
- University of Hawai'i at Manoa
- Honolulu, USA
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11
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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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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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14
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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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Parker DSN, Zhang F, Maksyutenko P, Kaiser RI, Chen SH, Chang AHH. A crossed beam and ab initio investigation on the formation of vinyl boron monoxide (C2H3BO; X1A') via reaction of boron monoxide (11BO; X2Σ+) with ethylene (C2H4; X1A(g)). Phys Chem Chem Phys 2012; 14:11099-106. [PMID: 22766689 DOI: 10.1039/c2cp40781g] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The reaction dynamics of the boron monoxide radical ((11)BO; X(2)Σ(+)) with ethylene (C(2)H(4); X(1)A(g)) were investigated at a nominal collision energy of 12.2 kJ mol(-1) employing the crossed molecular beam technique and supported by ab initio and statistical (RRKM) calculations. The reaction is governed by indirect scattering dynamics with the boron monoxide radical attacking the carbon-carbon double bond of the ethylene molecule without entrance barrier with the boron atom. This addition leads to a doublet radical intermediate (O(11)BH(2)CCH(2)), which either undergoes unimolecular decomposition through hydrogen atom emission from the C1 atom via a tight transition state located about 13 kJ mol(-1) above the separated products or isomerizes via a hydrogen shift to the O(11)BHCCH(3) radical, which also can lose a hydrogen atom from the C1 atom. Both processes lead eventually to the formation of the vinyl boron monoxide molecule (C(2)H(3)BO; X(1)A'). The overall reaction was determined to be exoergic by about 40 kJ mol(-1). The reaction dynamics are also compared to the isoelectronic ethylene (C(2)H(4); X(1)A(g)) - cyano radical (CN; X(2)Σ(+)) system studied earlier.
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Affiliation(s)
- Dorian S N Parker
- Department of Chemistry, University of Hawaii at Manoa, Honolulu, HI, USA
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16
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Guo C, Cui ZH, Ding YH. Computational identification of a global carbon–sulfur triply bonded isomer SCBO. Struct Chem 2012. [DOI: 10.1007/s11224-012-0077-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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