1
|
Zhu B, Zeng X. 3-Fluoro-2 H-azirine: Generation, Characterization, and Photochemistry. J Phys Chem A 2023; 127:10591-10599. [PMID: 38063135 DOI: 10.1021/acs.jpca.3c06076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2023]
Abstract
The elusive 3-fluoro-2H-azirine, cyclic NCH2CF, has been generated through the stepwise decomposition of the acryloyl azide CH2CFC(O)N3 in an N2-matrix at 10 K. The characterization of cyclic NCH2CF with matrix-isolation IR spectroscopy is supported by 15N isotope labeling and the calculations with density functional theory (DFT) at the B3LYP/6-311++G(3df,3pd) level of theory. Upon irradiation at 193 nm, cyclic NCH2CF undergoes ring opening by forming the more stable nitrile isomer CH2FCN. In contrast to the photodecomposition reactions, the high-vacuum flash pyrolysis of CH2CFC(O)N3 in the gas phase at 500 °C yields the Curtius rearrangement product CH2CFNCO along with secondary fragmentation to the atmospherically relevant fluorocarbonyl radical (FCO) and cyanomethyl radical (CH2CN). Calculations on the potential energy profile for the decomposition reactions of CH2CFC(O)N3 demonstrate that the excessive energy, arising from the highly exothermic Curtius rearrangement of the azide, plays a key role in driving further dissociation reactions of CH2CFNCO by overcoming the formidable barriers (>50 kcal mol-1) under the pyrolysis conditions.
Collapse
Affiliation(s)
- Bifeng Zhu
- Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai 200433, China
| | - Xiaoqing Zeng
- Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai 200433, China
| |
Collapse
|
2
|
Zhu B, Jiang J, Lu B, Li X, Zeng X. Fluoromethylsulfinyl radicals: spectroscopic characterization and photoisomerization via intramolecular hydrogen shift. Phys Chem Chem Phys 2022; 24:8881-8889. [PMID: 35362501 DOI: 10.1039/d1cp05556a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Two new sulfinyl radicals, CHF2SO˙ and CH2FSO˙, have been generated in the gas phase through homolytic cleavage of the weak S-S bonds in disulfane oxides CHF2S(O)SCF3 and CH2FS(O)SCF3 by high-vacuum flash pyrolysis (HVFP) at ca. 500 °C. The IR spectroscopy characterization of the two fluoromethylsulfinyl radicals in solid N2 (10 K), Ar (10 K), and Ne (3 K) matrices reveals the presence of two conformers for CHF2SO˙ (gauche and cis) and one conformer for CH2FSO˙ (gauche). Upon 266 nm laser irradiation, these radicals undergo both isomerization and decomposition in the matrices. In addition to the dominant formation of the elusive oxathiyl radicals CHF2OS˙ (gauche and cis) and CH2FOS˙ (gauche) via 1,2-alkyl migration, two higher-energy carbon-centered radicals ˙CF2SOH and ˙CHFSOH bearing similar molecular structures to hydroperoxyalkyl radicals (˙QOOH) form via intramolecular 1,3-hydrogen shift in the two sulfinyl radicals. Additionally, the involvement of 1,3-hydrogen shift in CHF2OS˙ and CH2FOS˙ is also indicated by the observation of the fragmentation species. The identification of these radicals by matrix-isolation IR and UV-vis spectroscopy is aided by the quantum chemical calculations at the B3LYP/6-311++G(3df,3pd) level of theory. The stability of the isomers of the two sulfinyl radicals CHF2SO˙ and CH2FSO˙ has been discussed according to the experimental observations and also based on the CCSD(T)-F12a/aug-cc-pVTZ//B3LYP/6-311++G(3df,3pd) calculated energy profiles.
Collapse
Affiliation(s)
- Bifeng Zhu
- Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysts and Innovative Materials, Fudan University, Shanghai, 200433, China.
| | - Junjie Jiang
- Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysts and Innovative Materials, Fudan University, Shanghai, 200433, China.
| | - Bo Lu
- 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.
| | - Xiaoqing Zeng
- Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysts and Innovative Materials, Fudan University, Shanghai, 200433, China.
| |
Collapse
|
3
|
Baskir EG, Nefedov OM. IR spectroscopic study of the dichloromethyl peroxyl radical and its deuterated analogs in the argon matrix. Russ Chem Bull 2022. [DOI: 10.1007/s11172-021-3339-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
4
|
Zhu B, Wu Z, Wang L, Lu B, Trabelsi T, Francisco JS, Zeng X. Matrix-isolated trifluoromethylthiyl radical: sulfur atom transfer, isomerization and oxidation reactions. Chem Commun (Camb) 2021; 57:12143-12146. [PMID: 34724519 DOI: 10.1039/d1cc04654c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
By high-vacuum flash pyrolysis of bis(trifluoromethyl)disulfane oxide (CF3S(O)SCF3) at 400 °C, the elusive trifluoromethylthiyl radical (CF3S˙) has been efficiently generated in the gas phase. Subsequent isolation of CF3S˙ in cryogenic matrixes (Ne, Ar, and N2) allows a first time characterization with IR and UV-vis spectroscopy by combining with computations at the CCSD(T)/aug-cc-pV(T + d)Z level. In addition to the photo-induced sulfur atom transfer (SAT) from CF3S˙ to N2 and CO and the isomerization to ˙CF2SF, the O2-oxidation via the intermediacy of the novel thiylperoxy radical CF3SOO˙ has been observed.
Collapse
Affiliation(s)
- Bifeng Zhu
- Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysts and Innovative Materials, Fudan University, Shanghai 200433, China.
| | - Zhuang Wu
- Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysts and Innovative Materials, Fudan University, Shanghai 200433, China.
| | - Lina Wang
- Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysts and Innovative Materials, Fudan University, Shanghai 200433, China.
| | - Bo Lu
- Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysts and Innovative Materials, Fudan University, Shanghai 200433, China.
| | - Tarek Trabelsi
- Department of Earth and Environment Science and Department of Chemistry, University of Pennsylvania, Pennsylvania, 19104-6243, USA.
| | - Joseph S Francisco
- Department of Earth and Environment Science and Department of Chemistry, University of Pennsylvania, Pennsylvania, 19104-6243, USA.
| | - Xiaoqing Zeng
- Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysts and Innovative Materials, Fudan University, Shanghai 200433, China.
| |
Collapse
|
5
|
Wang Z, Tong S, Chen M, Jing B, Li W, Guo Y, Ge M, Wang S. Study on ozonolysis of asymmetric alkenes with matrix isolation and FT-IR spectroscopy. CHEMOSPHERE 2020; 252:126413. [PMID: 32197171 DOI: 10.1016/j.chemosphere.2020.126413] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 02/24/2020] [Accepted: 03/02/2020] [Indexed: 06/10/2023]
Abstract
O3 and alkenes are important reactants in the formation of SOA in the atmosphere. The intermediates and reaction mechanism of ozonation of alkene is an important topic in atmospheric chemistry. In this study, the low-temperature matrix isolation was used to capture the intermediates such as Primary ozonides (POZs), Criegee Intermediates (CIs), and Secondary ozonides (SOZs) generated from ozonation of 2-methyl-1-butene (2M1B) and 2-methyl-2-butene (2M2B). The results have been identified by the vacuum infrared spectroscopy and theoretical calculation. Our results show that during the ozonation of asymmetric alkenes, two kinds of CIs and more than two kinds of SOZs were generated due to the different decomposition modes of POZs. The infrared absorption peaks of (CH3)2COO and CH3CH2C(CH3)OO for O-O telescopic vibration was determined to be 889 cm-1 and 913 cm-1, respectively. Using the merged jet method, it was found that a large amount of HCHO was produced during the ozonation of 2M1B, and glyoxal and methylglyoxal were produced in the ozonation of 2M2B. Our findings highlight the importance of asymmetric alkene ozonolysis reactions in producing CIs, further improving the understanding of the generation of CIs from ozonation of alkenes.
Collapse
Affiliation(s)
- Zhen Wang
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, PR China; University of Chinese Academy of Sciences, Beijing, 100049, PR China
| | - Shengrui Tong
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, PR China.
| | - Meifang Chen
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, PR China; College of Chemistry and Material Science, The Key Laboratory of Functional Molecular Solids, Ministry of Education, Anhui Laboratory of Molecule-Based Materials, Anhui Normal University, Wuhu, 241000, PR China
| | - Bo Jing
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, PR China
| | - Weiran Li
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, PR China; University of Chinese Academy of Sciences, Beijing, 100049, PR China
| | - Yucong Guo
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, PR China
| | - Maofa Ge
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, PR China; University of Chinese Academy of Sciences, Beijing, 100049, PR China; Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, PR China.
| | - Sufan Wang
- College of Chemistry and Material Science, The Key Laboratory of Functional Molecular Solids, Ministry of Education, Anhui Laboratory of Molecule-Based Materials, Anhui Normal University, Wuhu, 241000, PR China
| |
Collapse
|
6
|
Lu B, Qin YY, Song C, Qian WY, Wang LN, Zeng XQ. O2-oxidation of cyanomethylene radical: Infrared identification of criegee intermediates syn- and anti-NCC(H)OO. CHINESE J CHEM PHYS 2020. [DOI: 10.1063/1674-0068/cjcp2001004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Bo Lu
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China
| | - Yuan-yuan Qin
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China
| | - Chao Song
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China
| | - Wei-yu Qian
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China
| | - Li-na Wang
- Department of Chemistry, Fudan University, Shanghai 200433, China
| | - Xiao-qing Zeng
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China
- Department of Chemistry, Fudan University, Shanghai 200433, China
| |
Collapse
|
7
|
Lu B, Song C, Liu J, Trabelsi T, Francisco JS, Wang L, Zeng X. Dihalogenated Methylperoxy Radicals: Spectroscopic Characterization and Photodecomposition by Release of HO .. Chemistry 2020; 26:2817-2820. [PMID: 31899574 DOI: 10.1002/chem.201905858] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Indexed: 11/08/2022]
Abstract
Two atmospherically relevant dihalogenated methylperoxy radicals CHX2 OO. (X=F and Cl) have been generated through O2 -oxidation of the corresponding alkyl radicals CHX2 . in the gas phase. The IR spectroscopic characterization of both radicals in cryogenic Ar- and N2 -matrices (15 K) is supported by 18 O-labeling and ab initio calculations at the UCCSD(T)/aug-cc-pVTZ level. Upon 266 nm laser irradiation, both radicals decompose mainly by releasing hydroxyl radicals (→HO. +X2 CO) via the intermediacy of intriguing α-hydroperoxyalkyl radicals (. CX2 OOH), implying that the photooxidation of dihalogenated hydrocarbons might serve as important sources of HO. radicals in the atmosphere.
Collapse
Affiliation(s)
- Bo Lu
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, 215123, P. R. China
| | - Chao Song
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, 215123, P. R. China
| | - Jie Liu
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, 215123, P. R. China
| | - Tarek Trabelsi
- Department of Earth and Environmental Science and Department of, Chemistry, University of Pennsylvania, Pennsylvania, 19104, USA
| | - Joseph S Francisco
- Department of Earth and Environmental Science and Department of, Chemistry, University of Pennsylvania, Pennsylvania, 19104, USA
| | - Lina Wang
- Department of Chemistry, Fudan University, Shanghai, 200433, P. R. China
| | - Xiaoqing Zeng
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, 215123, P. R. China.,Department of Chemistry, Fudan University, Shanghai, 200433, P. R. China
| |
Collapse
|
8
|
Liu Q, Wu Z, Xu J, Lu Y, Li H, Zeng X. Methoxysulfinyl Radical CH3OSO: Gas-Phase Generation, Photochemistry, and Oxidation. J Phys Chem A 2017; 121:3818-3825. [DOI: 10.1021/acs.jpca.7b02561] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Qifan Liu
- College
of Chemistry, Chemical Engineering and Materials Science, Soochow University, 215123 Suzhou, P. R. China
| | - Zhuang Wu
- College
of Chemistry, Chemical Engineering and Materials Science, Soochow University, 215123 Suzhou, P. R. China
| | - Jian Xu
- College
of Chemistry, Chemical Engineering and Materials Science, Soochow University, 215123 Suzhou, P. R. China
| | - Yan Lu
- College
of Chemistry, Chemical Engineering and Materials Science, Soochow University, 215123 Suzhou, P. R. China
| | - Hongmin Li
- College
of Chemistry, Chemical Engineering and Materials Science, Soochow University, 215123 Suzhou, P. R. China
| | - Xiaoqing Zeng
- College
of Chemistry, Chemical Engineering and Materials Science, Soochow University, 215123 Suzhou, P. R. China
| |
Collapse
|
9
|
Manetti MD, Burgos Paci MA, Argüello GA. Trifluoromethyl Fluoroformyl Trioxicarbonate, CF3OC(O)OOOC(O)F: The First Nonsymmetric Acyl Trioxide. J Phys Chem A 2009; 113:8523-8. [DOI: 10.1021/jp9022772] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Martín D. Manetti
- INFIQC, Departamento de Fisicoquímica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, 5000 Córdoba, Argentina
| | - Maximiliano A. Burgos Paci
- INFIQC, Departamento de Fisicoquímica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, 5000 Córdoba, Argentina
| | - Gustavo A. Argüello
- INFIQC, Departamento de Fisicoquímica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, 5000 Córdoba, Argentina
| |
Collapse
|
10
|
Zhou M, Ma R, Yuan D, Chen M. Reaction of Chloromethyl Radical with Dioxygen: Formation of the Chloromethylperoxy Radical and Its Photodissociation in Solid Argon. J Phys Chem A 2009; 113:2826-30. [DOI: 10.1021/jp809683n] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Mingfei Zhou
- Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysts and Innovative Materials, Advanced Materials Laboratory, Fudan University, Shanghai 200433, P. R. China
| | - Renhu Ma
- Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysts and Innovative Materials, Advanced Materials Laboratory, Fudan University, Shanghai 200433, P. R. China
| | - Dongmei Yuan
- Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysts and Innovative Materials, Advanced Materials Laboratory, Fudan University, Shanghai 200433, P. R. China
| | - Mohua Chen
- Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysts and Innovative Materials, Advanced Materials Laboratory, Fudan University, Shanghai 200433, P. R. China
| |
Collapse
|
11
|
von Hobe M, Stroh F, Beckers H, Benter T, Willner H. The UV/Vis absorption spectrum of matrix-isolated dichlorine peroxide, ClOOCl. Phys Chem Chem Phys 2009; 11:1571-80. [PMID: 19240934 DOI: 10.1039/b814373k] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
UV/Vis absorption spectra of ClOOCl isolated in neon matrices were measured in the wavelength range 220-400 nm. The purity of the trapped samples was checked by infrared and UV/Vis matrix spectroscopy as well as low-temperature Raman spectroscopy. At wavelengths below 290 nm, the results agree with the UV spectrum recently published by Pope et al. [J. Phys. Chem. A, 2007, 111, 4322-4332]. However, the observed absorption in the long wavelength tail of the spectrum-relevant for polar stratospheric ozone loss-is substantially higher than reported by Pope et al. Our results suggest the existence of a ClOOCl electronic state manifold leading to an absorption band similar to those of the near UV spectrum of Cl(2). The differences to previous studies can be accounted for quantitatively by contributions to the reported absorption spectra caused by impurities. The observed band in the long wavelength tail is supported by several high-level ab initio calculations. However, questions arise concerning absolute values of the ClOOCl cross sections, an issue that needs to be revisited in future studies. With calculated photolysis rates based on our spectrum scaled to previous cross sections at the peak absorption, the known polar catalytic ozone-destruction cycles to a large extent account for the observed ozone depletion in the spring polar stratosphere.
Collapse
Affiliation(s)
- Marc von Hobe
- Forschungszentrum Jülich GmbH, Institute for Chemistry and Dynamics of the Geosphere ICG-1: Stratosphere, Jülich, Germany.
| | | | | | | | | |
Collapse
|
12
|
von Ahsen S, García P, Willner H, Argüello GA. Trifluoromethoxycarbonyl Peroxynitrate, CF3OC(O)OONO2. Inorg Chem 2005; 44:5713-8. [PMID: 16060622 DOI: 10.1021/ic0504994] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The trioxide, CF(3)OC(O)OOOC(O)OCF(3), reacts with NO(2) at 0 degrees C to yield the new peroxynitrate, CF(3)OC(O)OONO(2), which is stable for hours at room temperature. It is spectroscopically characterized and some thermal properties are reported. From the vapor pressure, ln(p/p(0)) = 14.06 - 4565/T, of the liquid above the melting point of -89 degrees C, the extrapolated boiling point is 52 degrees C. CF(3)OC(O)OONO(2) dissociates at higher temperatures and low pressures into the radicals CF(3)OC(O)OO and NO(2) as demonstrated by matrix isolation experiments. The matrix-isolated peroxy radicals consist in a rotameric mixture of trans,trans,trans-CF(3)OC(O)OO and trans,trans,cis-CF(3)OC(O)OO, where trans and cis denote dihedral angles of ca. 180 degrees and 0 degree, respectively, around beta F-C-O-C, beta C-O-C-O, and beta O-C-O-O, with an equilibrium composition dependent on the thermolysis temperature. The radical trans,trans,cis-CF(3)OC(O)OO is found to be ca. 3 kJ mol(-1) higher in enthalpy than trans,trans,trans-CF(3)OC(O)OO. DFT calculations are performed to support the vibrational assignments and to provide structural information about CF(3)OC(O)OONO(2).
Collapse
Affiliation(s)
- Stefan von Ahsen
- FB C/Anorganische Chemie, Bergische Universität Wuppertal, Germany
| | | | | | | |
Collapse
|
13
|
Affiliation(s)
- Marc Kronberg
- Fachbereich C, Anorganische Chemie, Bergische Universität Wuppertal, Gaussstrasse 20, 42097 Wuppertal, Germany
| | | | | | | |
Collapse
|
14
|
|
15
|
Pernice H, Garcia P, Willner H, Francisco JS, Mills FP, Allen M, Yung YL. Laboratory evidence for a key intermediate in the Venus atmosphere: peroxychloroformyl radical. Proc Natl Acad Sci U S A 2004; 101:14007-10. [PMID: 15375212 PMCID: PMC521112 DOI: 10.1073/pnas.0405501101] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
For two decades, the peroxychloroformyl radical, ClC(O)OO, has played a central role in models of the chemical stability of the Venus atmosphere. No confirmation, however, has been possible in the absence of laboratory measurements for ClC(O)OO. We report the isolation of ClC(O)OO in a cryogenic matrix and its infrared and ultraviolet spectral signatures. These experiments show that ClC(O)OO is thermally and photolytically stable in the Venus atmosphere. These experimental discoveries validate the existence of ClC(O)OO, confirm several longstanding model assumptions, and provide a basis for the astronomical search for this important radical species.
Collapse
Affiliation(s)
- Holger Pernice
- Fachbereich C-Anorganische Chemie, Universität Wuppertal, Gauss-Strasse 20, D-42119 Wuppertal, Germany
| | | | | | | | | | | | | |
Collapse
|
16
|
von Ahsen S, Willner H, Francisco JS. Thermal decomposition of peroxy acetyl nitrate CH3C(O)OONO2. J Chem Phys 2004; 121:2048-57. [PMID: 15260758 DOI: 10.1063/1.1767813] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The thermal decomposition of peroxy acetyl nitrate (PAN) is investigated by low pressure flash thermolysis of PAN highly diluted in noble gases and subsequent isolation of the products in noble gas matrices at low temperatures and by density functional computations. The IR spectroscopically observed formation of CH3C(O)OO and H2CCO (ketene) besides NO2, CO2, and HOO implies a unimolecular decay pathway for the thermal decomposition of PAN. The major decomposition reaction of PAN is bond fission of the O-N single bond yielding the peroxy radical. The O-O bond fission pathway is a minor route. In the latter case the primary reaction products undergo secondary reactions whose products are spectroscopically identified. No evidence for rearrangement processes as the formation of methyl nitrate is observed. A detailed mapping of the reaction pathways for primary and secondary reactions using quantum chemical calculations is in good agreement with the experiment and predicts homolytic O-N and O-O bond fissions within the PAN molecule as the lowest energetic primary processes. In addition, the first IR spectroscopic characterization of two rotameric forms for the radical CH3C(O)OO is given.
Collapse
Affiliation(s)
- Stefan von Ahsen
- FB C/Anorganische Chemie, Bergische Universität Wuppertal, 42097, Germany
| | | | | |
Collapse
|
17
|
|
18
|
Trautner F, Gholivand K, García P, Willner H, Erben MF, Della Védova CO, Oberhammer H. Perfluoromethyl fluorocarbonyl peroxide, CF3OOC(O)F: structure, conformations, and vibrational spectra studied by experimental and theoretical methods. Inorg Chem 2003; 42:3079-85. [PMID: 12716204 DOI: 10.1021/ic0262583] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The conformational properties and the geometric structure of perfluoromethyl fluorocarbonyl peroxide, CF(3)OOC(O)F, have been studied by matrix IR spectroscopy, gas electron diffraction, and quantum chemical calculations (HF, B3LYP, and MP2 methods with 6-311G* basis sets). Matrix IR spectra imply a mixture of syn and anti conformers (orientation of the C=O bond relative to the O-O bond) with DeltaH degrees = H(anti) degrees - H(syn) degrees = 2.16(22) kcal/mol. At room temperature, the contribution of the anti rotamer is about 3.0%. The O-O bond (1.422(15) A) is within the experimental uncertainties equal to those in related symmetrically substituted peroxides CF(3)OOCF(3) and FC(O)OOC(O)F (1.419(20) and 1.419(9) A, respectively), and the dihedral angle delta(COOC) (111(5) degrees ) is intermediate between the values in these two compounds (123(4) degrees and 83.5(14) degrees, respectively).
Collapse
Affiliation(s)
- Frank Trautner
- Institut für Physikalische und Theoretische Chemie, Universität Tübingen, D-72076 Tübingen, Germany
| | | | | | | | | | | | | |
Collapse
|
19
|
Finze M, Bernhardt E, Terheiden A, Berkei M, Willner H, Christen D, Oberhammer H, Aubke F. Tris(trifluoromethyl)borane carbonyl, (CF3)3BCO-synthesis, physical, chemical and spectroscopic properties, gas phase, and solid state structure. J Am Chem Soc 2002; 124:15385-98. [PMID: 12487614 DOI: 10.1021/ja0209924] [Citation(s) in RCA: 139] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Tris(trifluoromethyl)borane carbonyl, (CF(3))(3)BCO, is obtained in high yield by the solvolysis of K[B(CF(3))(4)] in concentrated sulfuric acid. The in situ hydrolysis of a single bonded CF(3) group is found to be a simple, unprecedented route to a new borane carbonyl. The related, thermally unstable borane carbonyl, (C(6)F(5))(3)BCO, is synthesized for comparison purposes by the isolation of (C(6)F(5))(3)B in a matrix of solid CO at 16 K and subsequent evaporation of excess CO at 40 K. The colorless liquid and vapor of (CF(3))(3)BCO decomposes slowly at room temperature. In the gas phase t(1/2) is found to be 45 min. In the presence of a large excess of (13)CO, the carbonyl substituent at boron undergoes exchange, which follows a first-order rate law. Its temperature dependence yields an activation energy (E(A)) of 112 kJ mol(-)(1). Low-pressure flash thermolysis of (CF(3))(3)BCO with subsequent isolation of the products in low-temperature matrixes, indicates a lower thermal stability of the (CF(3))(3)B fragment, than is found for (CF(3))(3)BCO. Toward nucleophiles (CF(3))(3)BCO reacts in two different ways: Depending on the nucleophilicity of the reagent and the stability of the adducts formed, nucleophilic substitution of CO or nucleophilic addition to the C atom of the carbonyl group are observed. A number of examples for both reaction types are presented in an overview. The molecular structure of (CF(3))(3)BCO in the gas phase is obtained by a combined microwave-electron diffraction analysis and in the solid state by single-crystal X-ray diffraction. The molecule possesses C(3) symmetry, since the three CF(3) groups are rotated off the two possible positions required for C(3)(v)() symmetry. All bond parameters, determined in the gas phase or in the solid state, are within their standard deviations in fair agreement, except for internuclear distances most noticeably the B-CO bond lengths, which is 1.69(2) A in the solid state and 1.617(12) A in the gas phase. A corresponding shift of nu(CO) from 2267 cm(-)(1) in the solid state to 2251 cm(-)(1) in the gas phase is noted in the vibrational spectra. The structural and vibrational study is supported by DFT calculations, which provide, in addition to the equilibrium structure, confirmation of experimental vibrational wavenumbers, IR-band intensities, atomic charge distribution, the dipole moment, the B-CO bond energy, and energies for the elimination of CF(2) from (CF(3))(x)()BF(3)(-)(x)(), x = 1-3. In the vibrational analysis 21 of the expected 26 fundamentals are observed experimentally. The (11)B-, (13)C-, and (19)F-NMR data, as well as the structural parameters of (CF(3))(3)BCO, are compared with those of related compounds.
Collapse
Affiliation(s)
- Maik Finze
- Fakultät 4, Anorganische Chemie, Gerhard Mercator Universität Duisburg, Lotharstrasse 1, D-47048 Duisburg, Germany
| | | | | | | | | | | | | | | |
Collapse
|
20
|
Abstract
Low pressure flash thermolysis of different precursor molecules containing-ClO, -ClO3 or -OClO3 yield, when highly diluted in Ne or O2 and subsequent quenching of the products in a matrix at 5 or 15 K, ClOx (x = 1, 3, 4) radicals, respectively. If Ne or O2 gas is directed over solid ClO2 at -120 degrees C and the resulting gas mixtures are immediately deposited as a matrix, a high fraction of (OClO)2 is trapped. This enables recording of IR and UV spectra of weakly bonded (OClO)2 dimers and detailed studying of their photochemistry. For Ne or O2 matrix isolated ClO radicals the vibrational wavenumbers and electronic transitions are only slightly affected compared with the gas phase. In this study strong evidence is found for long lived ClO in the electronically excited 2 [symbol: see text] 1/2 state. A comprehensive IR study of Ne matrix isolated ClO3 (fundamentals at 1081, 905, 567, 476 cm-1) yield i) a reliable force field; ii) a OClO bond angle of alpha e = 113.8 +/- 1 degrees and iii) a ClO bond length of 148.5 +/- 2 pm in agreement with predicted data from quantum chemical calculations. The UV/Vis spectrum of ClO3 isolated in a Ne matrix (lambda max at 32,100 and 23,150 cm-1) agrees well with the photoelectron spectrum of ClO3- and theoretical predictions. The origin of the structured high energy absorption is at 22,696 cm-1 and three fundamentals (794, 498, 280 cm-1) are detected in the C2E state. By photolysis of ClO3 with visible light the complex ClO.O2 with ClO in the 2 [symbol: see text] 1/2 state is formed. In an extended spectroscopic study of the elusive ClO4 radical, isolated in a Ne or O2 matrix, three additional IR bands, a complete UV spectrum and a strong interaction with O2 are found. This leads to the conclusion that ClO4 exhibits C2v or Cs symmetry with a shallow potential minimum and forms with O2 the previously unknown peroxy radical O3ClO-O2. All these results are discussed in the context of recent developments in the chemistry and spectroscopy of the important and interesting ClOx (x = 1-4) family of radicals.
Collapse
Affiliation(s)
- Rodion Kopitzky
- Fakultät 4, Anorganische Chemie Gerhard-Mercator Universität Duisburg, Lotharstrasse 1 47048 Duisburg, Germany
| | | | | |
Collapse
|
21
|
|
22
|
Argüello GA, Willner H. IR and UV Absorption Spectrum of the Trifluoromethoxy Radical, CF3O·, Isolated in Rare Gas Matrices. J Phys Chem A 2001. [DOI: 10.1021/jp002960d] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Gustavo A. Argüello
- FB 6-Anorganische Chemie, Gerhard-Mercator-Universität Duisburg, Lotharstrasse 1, D-47048 Duisburg, Germany
| | - Helge Willner
- FB 6-Anorganische Chemie, Gerhard-Mercator-Universität Duisburg, Lotharstrasse 1, D-47048 Duisburg, Germany
| |
Collapse
|
23
|
|