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Kanayama K, Nakamura H, Maruta K, Bodi A, Hemberger P. The Unimolecular Decomposition Mechanism of Trimethyl Phosphate. Chemistry 2024; 30:e202401750. [PMID: 38877823 DOI: 10.1002/chem.202401750] [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: 05/03/2024] [Revised: 06/05/2024] [Accepted: 06/14/2024] [Indexed: 06/16/2024]
Abstract
Trimethyl phosphate (TMP), an organophosphorus compound (OPC), is a promising fire-retardant candidate for lithium-ion battery (LIB) electrolytes to mitigate fire spread. This study aims to understand the mechanism of TMP unimolecular thermal decomposition to support the integration of a TMP chemical kinetic model into a LIB electrolyte surrogate model. Reactive intermediates and products of TMP thermal decomposition were experimentally detected using vacuum ultraviolet (VUV) synchrotron radiation and double imaging photoelectron photoion coincidence (i2PEPICO) spectroscopy. Phosphorus-containing intermediates such as PO, HPO and HPO2 were identified. Sampling effects could successfully be obviated thanks to photoion imaging, which also showed evidence for isomerization reactions upon wall collisions in the ionization chamber. Quantum chemical calculations performed for the unimolecular decomposition of TMP revealed for the first time that isomerization channels via hydrogen and methyl transfer (barrier heights of 65.9 and 72.6 kcal/mol, respectively) are the lowest-energy primary steps of TMP decomposition followed by CH3OH/CH3/CH2O or dimethyl ether (DME) production, respectively. We found an analogous DME production channel in the unimolecular decomposition of dimethyl methylphosphonate (DMMP), another important OPC fire-retardant additive with a similar molecular structure to TMP, which are not included in currently available chemical kinetic models.
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Affiliation(s)
- Keisuke Kanayama
- Laboratory for Synchrotron Radiation and Femtochemistry, Paul Scherrer Institute, CH 5232, Villigen PSI, Switzerland
- Institute of Fluid Science, Tohoku University, 2-1-1 Katahira, Aoba, 980-8577, Sendai, Miyagi, Japan
- Graduate School of Engineering, Tohoku University, 6-6 Aramaki Aza Aoba, Aoba, 980-8579, Sendai, Miyagi, Japan
| | - Hisashi Nakamura
- Institute of Fluid Science, Tohoku University, 2-1-1 Katahira, Aoba, 980-8577, Sendai, Miyagi, Japan
| | - Kaoru Maruta
- Institute of Fluid Science, Tohoku University, 2-1-1 Katahira, Aoba, 980-8577, Sendai, Miyagi, Japan
| | - Andras Bodi
- Laboratory for Synchrotron Radiation and Femtochemistry, Paul Scherrer Institute, CH 5232, Villigen PSI, Switzerland
| | - Patrick Hemberger
- Laboratory for Synchrotron Radiation and Femtochemistry, Paul Scherrer Institute, CH 5232, Villigen PSI, Switzerland
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2
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Hu C, Rees NH, Pink M, Goicoechea JM. Isolation and characterization of a two-coordinate phosphinidene oxide. Nat Chem 2024:10.1038/s41557-024-01586-x. [PMID: 39009793 DOI: 10.1038/s41557-024-01586-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Accepted: 06/21/2024] [Indexed: 07/17/2024]
Abstract
Nitroso compounds, R-N=O, are common intermediates in organic synthesis, and are typically amenable to storage and manipulation at ambient temperature under aerobic conditions. By contrast, phosphorus-containing analogues, such as R-P=O (R = OH, CH3, OCH3, Ph), are extremely reactive and need to be studied in inert gas matrices at ultralow temperatures (3-15 K). These species are believed to be key intermediates in the degradation/combustion of organic phosphorus compounds, a class of chemicals that includes chemical warfare agents and flame retardants. Here we describe the isolation of a two-coordinate phosphorus(III) oxide under ambient conditions, enabled by the use of an extremely bulky amine ligand. Reactivity studies reveal that the phosphorus centre can be readily oxidized, and that in doing so, the P-O bond remains intact, an observation that is of interest to the proposed reactivity of transient phosphorus(III) oxides.
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Affiliation(s)
- Chenyang Hu
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Oxford, UK
- Department of Chemistry, Indiana University, Bloomington, IN, USA
| | - Nicolas H Rees
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Oxford, UK
| | - Maren Pink
- Department of Chemistry, Indiana University, Bloomington, IN, USA
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3
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Leung G, McKinney MA, Yaylayan V, Bayen S. Abiotic degradations of legacy and novel flame retardants in environmental and food matrices - a review. Food Addit Contam Part A Chem Anal Control Expo Risk Assess 2024; 41:811-832. [PMID: 38805263 DOI: 10.1080/19440049.2024.2354496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Accepted: 05/08/2024] [Indexed: 05/29/2024]
Abstract
Flame retardants (FRs) are commonly added to commercial products to achieve flammability resistance. Since most of them are not chemically bonded to the materials, they could be leached to the environment during the production and disposal cycle. These FRs were categorised based on their chemical nature, including brominated, organophosphorus-, mineral- and nitrogen-based. This review summarised the abiotic degradation reactions of these four classes of FRs, with a focus on thermal and photodegradation reactions in environmental and food matrices. Only 24 papers have reported related information on abiotic degradation reactions that could be useful for predicting possible degradation pathways, and most focused on brominated FRs. Most studies also investigated the thermal degradation of FRs under high temperatures (>400 °C), which exceeds the normal cooking temperature at 100-300 °C. For photodegradation, studies have used up to five times the energy typically used in UV radiation during food processing. It is recommended that future studies investigate the fate of these FRs in foods under more realistic processing conditions, to provide a more comprehensive picture of the estimated consumption of FRs and their degradation products from foods, and facilitate a better risk assessment of the use of these novel FRs.
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Affiliation(s)
- Gabriel Leung
- Department of Food Science and Agricultural Chemistry, McGill University, Ste-Anne-de-Bellevue, Canada
| | - Melissa A McKinney
- Department of Natural Resource Sciences, McGill University, Ste-Anne-de-Bellevue, Canada
| | - Varoujan Yaylayan
- Department of Food Science and Agricultural Chemistry, McGill University, Ste-Anne-de-Bellevue, Canada
| | - Stéphane Bayen
- Department of Food Science and Agricultural Chemistry, McGill University, Ste-Anne-de-Bellevue, Canada
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4
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Howell BA. Thermal Degradation of Organophosphorus Flame Retardants. Polymers (Basel) 2022; 14:polym14224929. [PMID: 36433056 PMCID: PMC9695522 DOI: 10.3390/polym14224929] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 11/03/2022] [Accepted: 11/11/2022] [Indexed: 11/18/2022] Open
Abstract
The development of new organophosphorus flame retardants for polymeric materials is spurred by relatively low toxicity, effectiveness, and demand for replacement of more traditional materials. To function, these compounds must decompose in a degrading polymer matrix to form species which promote modification of the solid phase or generate active radical moieties that escape to the gas phase and interrupt combustion propagating reactions. An understanding of the decomposition process for these compounds may provide insight into the nature of flame retardant action which they may offer and suggest parameters for the synthesis of effective new organophosphorus flame retardants. The thermal degradation of a series of organophosphorus esters varying in the level of oxygenation at phosphorus-alkyl phosphate, aryl phosphate, phosphonate, phosphinate-has been examined. Initial degradation in all cases corresponds to elimination of a phosphorus acid. However, the facility with which this occurs is strongly dependent on the level of oxygenation at phosphorus. For alkyl phosphates elimination occurs rapidly at relatively low temperature. The same process occurs at somewhat higher temperature for aryl phosphates. Elimination of a phosphorus acid from phosphonate or phosphinate occurs more slowly and at much higher temperature. Further, the acids formed from elimination rapidly degrade further to evolve volatile species.
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Affiliation(s)
- Bob A Howell
- Science of Advanced Materials, Center for Applications in Polymer Science, Department of Chemistry and Biochemistry, Central Michigan University, Mt. Pleasant, MI 48859-0001, USA
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5
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Chen B, Luo W, Lv J, Lin S, Zheng B, Zhang H, Chen M. A universal strategy toward flame retardant epoxy resin with ultra-tough and transparent properties. Polym Degrad Stab 2022. [DOI: 10.1016/j.polymdegradstab.2022.110132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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6
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Jiang J, Zhu B, Jiang X, Lu B, Zeng X. Photochemistry of phosphenic chloride (ClPO 2): isomerization with chlorine metaphosphite (ClOPO) and reduction by carbon monoxide. Phys Chem Chem Phys 2022; 24:20828-20836. [PMID: 36040114 DOI: 10.1039/d2cp02986c] [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
Phosphenic chloride (ClPO2) is an elusive congener of nitryl chloride (ClNO2). By high-vacuum flash pyrolysis of 2-chloro-1,3,2-dioxaphospholane in the gas phase, ClPO2 has been efficiently generated and subsequently isolated in cryogenic N2, Ar, and CO matrices (10 K) for a first time study on its photochemistry. Upon 193 nm laser irradiation, ClPO2 isomerizes to the novel chlorine metaphosphite (ClOPO) by initial cleavage of the Cl-P bond (→ ˙Cl + ˙PO2) with subsequent Cl-O bond formation inside the N2 and Ar matrix cages. The reverse transformation becomes feasible under further irradiation at 266 nm. This photochemistry is consistent with the observed absorptions of ClPO2 and ClOPO at 207 and 250 nm, respectively. When the photolysis was performed in solid CO ice, no isomerization occurs due to CO-trapping of the initially generated ˙Cl atoms by forming caged radical pair ClCO˙⋯˙PO2. Concomitantly, photolytic reduction of ClPO2 to ClPO by CO has been observed, yielding a weakly bonded molecular complex consisting of ClPO and CO2 bonded through short intermolecular C⋯O contact (2.910 Å). The characterization of ClPO, ClPO2, ClOPO, and the molecular complexes of ClPO2-CO and ClPO-CO2 using matrix-isolation IR and UV-vis spectroscopy is supported by the theoretical calculations at the B3LYP/6-311 + G(3df) level, and the photochemistry of ClPO2 is also compared with the revisited photochemistry of ClNO2 in the N2-matrix.
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Affiliation(s)
- Junjie Jiang
- Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysts and Innovative Materials, Fudan University, Shanghai, 200433, China.
| | - Bifeng Zhu
- 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.
| | - Bo Lu
- 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.
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7
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He LX, Liu XD, Zheng XT, Dong YQ, Bai WB, Lin YC, Jian RK. A versatile phosphorothioate bearing benzimidazole for the preparation of flame retardant, mechanically strong and high transparency epoxy resins. Polym Degrad Stab 2022. [DOI: 10.1016/j.polymdegradstab.2022.110056] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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8
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Mukhopadhyay DP, Gerlach M, Hartweg S, Fischer I, Loison JC. Photoelectron spectroscopy of low valent organophosphorus compounds, P-CH 3, H-PCH 2 and PCH 2. Phys Chem Chem Phys 2022; 24:10993-10999. [PMID: 35467677 DOI: 10.1039/d2cp01082h] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report the mass-selected slow photoelectron spectra of three reactive organophosphorus species, PCH2, and the two isomers, methylenephosphine or phosphaethylene, HPCH2 and methylphosphinidine, P-CH3. All spectra were recorded by double imaging photoelectron-photoion coincidence spectroscopy (i2PEPICO) using synchrotron radiation and all species were generated in a flow reactor by the reaction of trimethyl phosphine with fluorine atoms. Adiabatic ionisation energies of 8.80 ± 0.02 eV (PCH2), 10.07 ± 0.03 eV (H-PCH2) and 8.91 ± 0.04 eV (P-CH3) were determined and the vibronic structure was simulated by calculating Franck-Condon factors from optimised structures based on quantum chemical methods. Observation of biradicalic P-CH3 isomer with its triplet ground state is surprising because it is less stable than H-PCH2.
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Affiliation(s)
- Deb Pratim Mukhopadhyay
- Institute of Physical and Theoretical Chemistry, University of Würzburg, Am Hubland, D-97074 Würzburg, Germany.
| | - Marius Gerlach
- Institute of Physical and Theoretical Chemistry, University of Würzburg, Am Hubland, D-97074 Würzburg, Germany.
| | - Sebastian Hartweg
- Synchrotron SOLEIL, L'Orme des Merisiers, St Aubin, B. P. 48, F-91192 Gif sur Yvette, France
| | - Ingo Fischer
- Institute of Physical and Theoretical Chemistry, University of Würzburg, Am Hubland, D-97074 Würzburg, Germany.
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9
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Han LX, Zhao ZY, Deng C, Wang YZ. Piperazine/Alkene-Containing Phosphoramide Oligomer for the Intumescent Flame Retardation of EPDM Rubber. Polym Degrad Stab 2022. [DOI: 10.1016/j.polymdegradstab.2022.109990] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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10
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Hemberger P, Wu X, Pan Z, Bodi A. Continuous Pyrolysis Microreactors: Hot Sources with Little Cooling? New Insights Utilizing Cation Velocity Map Imaging and Threshold Photoelectron Spectroscopy. J Phys Chem A 2022; 126:2196-2210. [PMID: 35316066 DOI: 10.1021/acs.jpca.2c00766] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Resistively heated silicon carbide microreactors are widely applied as continuous sources to selectively prepare elusive and reactive intermediates with astrochemical, catalytic, or combustion relevance to measure their photoelectron spectrum. These reactors also provide deep mechanistic insights into uni- and bimolecular chemistry. However, the sampling conditions and effects have not been fully characterized. We use cation velocity map imaging to measure the velocity distribution of the molecular beam signal and to quantify the scattered, rethermalized background sample. Although translational cooling is efficient in the adiabatic expansion from the reactor, the breakdown diagrams of methane and chlorobenzene confirm that the molecular beam component exhibits a rovibrational temperature comparable with that of the reactor. Thus, rovibrational cooling is practically absent in the expansion from the microreactor. The high rovibrational temperature also affects the threshold photoelectron spectrum of both benzene and the allyl radical in the molecular beam, but to different degrees. While the extreme broadening of the benzene TPES suggests a complex ionization mechanism, the allyl TPES is in fact consistent with an internal temperature close to that of the reactor. The background, room-temperature spectra of both are superbly reproduced by Franck-Condon simulations at 300 K. On the one hand, this leads us to suggest that room-temperature reference spectra should be used in species identification. On the other hand, analysis of the allyl iodide pyrolysis data shows that iodine atoms often recombine to form molecular iodine on the chamber surfaces. Such sampling effects may distort the chemical composition of the scattered background with respect to the molecular beam signal emanating directly from the reactor. This must be considered in quantitative analyses and kinetic modeling.
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Affiliation(s)
- Patrick Hemberger
- Paul Scherrer Insitute, Forschungsstrasse 111, CH-5232 Villigen PSI, Switzerland
| | - Xiangkun Wu
- Paul Scherrer Insitute, Forschungsstrasse 111, CH-5232 Villigen PSI, Switzerland
| | - Zeyou Pan
- Paul Scherrer Insitute, Forschungsstrasse 111, CH-5232 Villigen PSI, Switzerland
| | - Andras Bodi
- Paul Scherrer Insitute, Forschungsstrasse 111, CH-5232 Villigen PSI, Switzerland
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11
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Zhu B, Jiang J, Lu B, Li X, Jiang X, Rauhut G, Zeng X. Phosphenic isocyanate (O2PNCO): Gas-phase generation, characterization, and photodecomposition reactions. Chem Commun (Camb) 2022; 58:10703-10706. [DOI: 10.1039/d2cc03178g] [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
Phosphenic isocyanate (O2PNCO), a novel phosphorus-containing small molecule has been generated by thermolysis of a dioxaphospholane-based precursor. The characterization of O2PNCO with IR and UV-vis spectroscopy in solid N2 and...
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12
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Ash T, Debnath T, Banerjee S, Ghosh A, Das AK. Theoretical study of gas-phase detoxication of DMMP and DMPT using ammonia-borane and its analogous compound. J Mol Graph Model 2021; 109:108037. [PMID: 34597884 DOI: 10.1016/j.jmgm.2021.108037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 09/03/2021] [Accepted: 09/22/2021] [Indexed: 11/28/2022]
Abstract
The detoxication of DMMP (Dimethyl methylphosphonate) and DMPT (O, S-dimethyl methylphosphonothiolate) via hydrogenation have been investigated computationally employing density functional theory (DFT). In this present study, we aim to explore the direct molecular H2 assisted as well as ammonia-borane (NH3BH3) and 3-methyl-1,2-BN-cyclopentane (denoted as cy-AB) assisted hydrogenation pathways of DMMP and DMPT in order to detoxify them. The detoxication of DMMP has been carried out by successive elimination of two -OMe groups. However, in the case of DMPT, two possibilities have been identified because of two different substituents, -OMe and -SMe. In possibility-I, the elimination of the -OMe group occurs at the beginning, followed by the -SMe group, whereas in possibility-II, the reverse order of elimination occurs for -OMe and -SMe groups. During the detoxication of DMMP using both NH3BH3 and cy-AB as the assisting reagents, the first step has been identified as the rate-determining step (RDS) in which the hydrogens attached to the N- and B-centers of NH3BH3 are transferred to the O-center of PO and P-center, respectively. In harmony with DMMP detoxication, for DMPT also, analyzing the activation barriers, it can be articulated that for both NH3BH3 and cy-AB assisted pathways, both the possibilities are equally feasible as in both the possibilities the common first step is the RDS. Therefore, our computational study is designed to explore the assisting efficiency of NH3BH3 and its cyclic analogue for detoxifying the OPCs.
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Affiliation(s)
- Tamalika Ash
- School of Mathematical and Computational Sciences, Indian Association for the Cultivation of Science, Jadavpur, Kolkata, 700032, India.
| | - Tanay Debnath
- School of Mathematical and Computational Sciences, Indian Association for the Cultivation of Science, Jadavpur, Kolkata, 700032, India
| | - Soumadip Banerjee
- School of Mathematical and Computational Sciences, Indian Association for the Cultivation of Science, Jadavpur, Kolkata, 700032, India
| | - Avik Ghosh
- School of Mathematical and Computational Sciences, Indian Association for the Cultivation of Science, Jadavpur, Kolkata, 700032, India
| | - Abhijit K Das
- School of Mathematical and Computational Sciences, Indian Association for the Cultivation of Science, Jadavpur, Kolkata, 700032, India.
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13
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Jing X, Zeng Y, Zhang X, Meng L, Li X. Competition and conversion between pnicogen bonds and hydrogen bonds involving prototype organophosphorus compounds. Phys Chem Chem Phys 2021; 23:18794-18805. [PMID: 34612418 DOI: 10.1039/d1cp00474c] [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
Ab initio calculations have been performed to investigate the competition and conversion between the pnicogen bonds and hydrogen bonds in complexes containing prototype organophosphorus compounds RPO2 (R = CH3 and CH3O). The competition between the pnicogen bonds and hydrogen bonds is controlled by the magnitude of Vs,min and Vs,max in the prototype organophosphorus compounds. Monomeric methyl metaphosphate (CH3OPO2), with more positive π-holes, is more likely to form pnicogen bonds with different electron donors, such as NH3, H2O, HNC and HCCH. Methoxyphosphinidene oxide (trans- and cis-CH3OPO) is inclined to form hydrogen bonds with H2O, HNC and HCCH. Most of the pnicogen bonds have covalent or partially covalent character, while most of the hydrogen bonds exhibit the noncovalent characteristics of weak interactions. The mechanisms of three typical conversions between the pnicogen bond and the hydrogen bond have been investigated and the breakage and formation of the bonds along the reaction pathways have been analyzed using topological analysis of electron density. For the three studied conversion processes, the transformation between the hydrogen-bonded complex and pnicogen-bonded complex is achieved readily through several T-shape structure transition states.
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Affiliation(s)
- Xinyue Jing
- College of Chemistry and Materials Science, Hebei Normal University, Shijiazhuang, 050024, P. R. China.
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14
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Steglich M, Wu X, Bodi A, Hemberger P. Double-Imaging Photoelectron Photoion Coincidence Spectroscopy Reveals the Unimolecular Thermal Decomposition Mechanism of Dimethyl Carbonate. J Phys Chem A 2021; 125:2895-2904. [PMID: 33797917 DOI: 10.1021/acs.jpca.1c00724] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We studied the thermal decomposition of dimethyl carbonate (DMC, C3H6O3) in a flash vacuum pyrolysis reactor in the 1100-1700 K range. The reaction products and intermediates were probed by vacuum ultraviolet synchrotron radiation in a photoelectron photoion coincidence (PEPICO) spectrometer to record isomer-specific photoion mass-selected threshold photoelectron (ms-TPE) spectra. Reaction pathways were explored using quantum chemical calculations, which confirmed the experimental observation that the intramolecular migration of a methyl group, yielding dimethyl ether (DME, C2H6O) and carbon dioxide, dominates the initial unimolecular decomposition chemistry. The role of a second potentially important channel, namely, C-O bond fission to yield methyl radicals, could not be determined experimentally due to the short lifetime of the ·C2H3O3 radical and overlapping sequential decomposition products. However, potential energy surface and microcanonical rate constant calculations predict 2 to 3 orders of magnitude lower rates for this channel than for decarboxylation to yield DME. Consequently, DMC pyrolysis shows bewilderingly similar products and product abundances as DME pyrolysis. This coincides with DMC combustion modeling studies, which found that DME is a key intermediate in the mechanism. Furthermore, we have detected traces of methyl formate and formaldehyde, produced after the hydrogen shift to the central carbon atom in DMC. Ethylene and acetylene could be established as bimolecular reaction products because their abundance depended strongly on the DMC concentration. It is intriguing to compare the decomposition of DMC with that of the structurally similar methylal (dimethoxymethane, DMM). While methanol and formaldehyde are produced in similar quantities in DMM, thanks to low-energy hydrogen-transfer reactions, the methanol channel is almost fully suppressed in DMC due to the absence of hydrogens at the central carbon atom and the thermodynamically favored decarboxylation. These new mechanistic insights may help the development of predictive combustion models for fuel additives and biofuels.
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Affiliation(s)
| | - Xiangkun Wu
- Paul Scherrer Institute, Villigen 5232, Switzerland
| | - Andras Bodi
- Paul Scherrer Institute, Villigen 5232, Switzerland
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15
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Grimm S, Baik SJ, Hemberger P, Bodi A, Kempf AM, Kasper T, Atakan B. Gas-phase aluminium acetylacetonate decomposition: revision of the current mechanism by VUV synchrotron radiation. Phys Chem Chem Phys 2021; 23:15059-15075. [PMID: 34231583 DOI: 10.1039/d1cp00720c] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Although aluminium acetylacetonate, Al(C5H7O2)3, is a common precursor for chemical vapor deposition (CVD) of aluminium oxide, its gas-phase decomposition is not well-known. Here, we studied its thermal decomposition in a microreactor by double imaging photoelectron photoion coincidence spectroscopy (i2PEPICO) between 325 and 1273 K. The reactor flow field was characterized by CFD. Quantum chemical calculations were used for the assignment of certain species. The dissociative ionization of the room temperature precursor molecule starts at a photon energy of 8.5 eV by the rupture of the bond to an acetylacetonate ligand leading to the formation of the Al(C5H7O2)2+ ion. In pyrolysis experiments, up to 49 species were detected and identified in the gas-phase, including reactive intermediates and isomeric/isobaric hydrocarbons, oxygenated species as well as aluminium containing molecules. We detected aluminium bis(diketo)acetylacetonate-H, Al(C5H7O2)C5H6O2, at m/z 224 together with acetylacetone (C5H8O2) as the major initial products formed at temperatures above 600 K. A second decomposition channel affords Al(OH)2(C5H7O2) along with the formation of a substituted pentalene ring species (C10H12O2) as assigned by Franck-Condon simulations and quantum chemical calculations. Acetylallene (C5H6O), acetone (C3H6O) and ketene (C2H2O) were major secondary decomposition products, formed upon decomposition of the primary products. Three gas-phase aromatic hydrocarbons were also detected and partially assigned for the first time: m/z 210, m/z 186 (C14H18 or C12H10O2) and m/z 146 (C11H14 or C9H6O2) and their formation mechanism is discussed. Finally, Arrhenius parameters are presented on the gas-phase decomposition kinetics of Al(C5H7O2)3, aided by numerical simulation of the flow field.
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Affiliation(s)
- Sebastian Grimm
- University of Duisburg-Essen, Institute of Combustion and Gas Dynamics, Chair of Thermodynamics, Duisburg 47057, Germany. and Center for NanoIntegration Duisburg-Essen (CENIDE), Duisburg 47057, Germany
| | - Seung-Jin Baik
- Center for NanoIntegration Duisburg-Essen (CENIDE), Duisburg 47057, Germany and University of Duisburg-Essen, Institute of Combustion and Gas Dynamics, Chair of Fluid Dynamics, Duisburg 47057, Germany
| | - Patrick Hemberger
- Laboratory for Synchrotron Radiation and Femtochemistry, Paul Scherrer Institute, CH-5232 Villigen-PSI, Switzerland
| | - Andras Bodi
- Laboratory for Synchrotron Radiation and Femtochemistry, Paul Scherrer Institute, CH-5232 Villigen-PSI, Switzerland
| | - Andreas M Kempf
- Center for NanoIntegration Duisburg-Essen (CENIDE), Duisburg 47057, Germany and University of Duisburg-Essen, Institute of Combustion and Gas Dynamics, Chair of Fluid Dynamics, Duisburg 47057, Germany
| | - Tina Kasper
- Center for NanoIntegration Duisburg-Essen (CENIDE), Duisburg 47057, Germany and University of Duisburg-Essen, Institute of Combustion and Gas Dynamics, Chair of Mass Spectrometry of Reactive Fluids, Duisburg 47057, Germany
| | - Burak Atakan
- University of Duisburg-Essen, Institute of Combustion and Gas Dynamics, Chair of Thermodynamics, Duisburg 47057, Germany. and Center for NanoIntegration Duisburg-Essen (CENIDE), Duisburg 47057, Germany
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16
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Chu X, Qian W, Lu B, Wang L, Qin J, Li J, Rauhut G, Trabelsi T, Francisco JS, Zeng X. The Triplet Hydroxyl Radical Complex of Phosphorus Monoxide. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202011512] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Xianxu Chu
- College of Chemistry Chemical Engineering and Materials Science Soochow University Suzhou 215123 China
| | - Weiyu Qian
- College of Chemistry Chemical Engineering and Materials Science Soochow University Suzhou 215123 China
| | - Bo Lu
- College of Chemistry Chemical Engineering and Materials Science Soochow University Suzhou 215123 China
| | - Lina Wang
- Department of Chemistry Fudan University Shanghai 200433 China
| | - Jie Qin
- School of Chemistry and Chemical Engineering and Chongqing Key Laboratory of Theoretical and Computational Chemistry Chongqing University Chongqing 401331 China
| | - Jun Li
- School of Chemistry and Chemical Engineering and Chongqing Key Laboratory of Theoretical and Computational Chemistry Chongqing University Chongqing 401331 China
| | - Guntram Rauhut
- Institute for Theoretical Chemistry University of Stuttgart Pfaffenwaldring 55 70569 Stuttgart Germany
| | - Tarek Trabelsi
- Department of Earth and Environment Science and Department of Chemistry University of Pennsylvania Philadelphia Pennsylvania 19104-6243 USA
| | - Joseph S. Francisco
- Department of Earth and Environment Science and Department of Chemistry University of Pennsylvania Philadelphia Pennsylvania 19104-6243 USA
| | - Xiaoqing Zeng
- College of Chemistry Chemical Engineering and Materials Science Soochow University Suzhou 215123 China
- Department of Chemistry Fudan University Shanghai 200433 China
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17
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Chu X, Qian W, Lu B, Wang L, Qin J, Li J, Rauhut G, Trabelsi T, Francisco JS, Zeng X. The Triplet Hydroxyl Radical Complex of Phosphorus Monoxide. Angew Chem Int Ed Engl 2020; 59:21949-21953. [PMID: 33073924 DOI: 10.1002/anie.202011512] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2020] [Indexed: 01/07/2023]
Abstract
Phosphorus monoxide (. PO) is a key intermediate in phosphorus chemistry, and its association with the hydroxyl radical (. OH) to yield metaphosphorous acid (cis-HOPO) contributes to the chemiluminescence in the combustion of phosphines. When photolyzing cis-HOPO in an Ar-matrix at 2.8 K, the simplest dioxophosphorane HPO2 and an elusive hydroxyl radical complex (HRC) of . PO form. This prototypical radical-radical complex reforms into cis-HOPO at above 12.0 K by overcoming a barrier of 0.28±0.02 kcal mol-1 . The vibrational spectra of this HRC and its D- and 18 O-isotopologues suggest a structure of . OH⋅⋅⋅OP. , for which a triplet spin multiplicity with a binding energy of -3.20 kcal mol-1 has been computed at the UCCSD(T)-F12a/aug-cc-pVTZ level.
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Affiliation(s)
- Xianxu Chu
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, 215123, China
| | - Weiyu Qian
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, 215123, China
| | - Bo Lu
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, 215123, China
| | - Lina Wang
- Department of Chemistry, Fudan University, Shanghai, 200433, China
| | - Jie Qin
- School of Chemistry and Chemical Engineering and Chongqing Key Laboratory of Theoretical and Computational Chemistry, Chongqing University, Chongqing, 401331, China
| | - Jun Li
- School of Chemistry and Chemical Engineering and Chongqing Key Laboratory of Theoretical and Computational Chemistry, Chongqing University, Chongqing, 401331, China
| | - Guntram Rauhut
- Institute for Theoretical Chemistry, University of Stuttgart, Pfaffenwaldring 55, 70569, Stuttgart, Germany
| | - Tarek Trabelsi
- Department of Earth and Environment Science and Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania, 19104-6243, USA
| | - Joseph S Francisco
- Department of Earth and Environment Science and Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania, 19104-6243, USA
| | - Xiaoqing Zeng
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, 215123, China
- Department of Chemistry, Fudan University, Shanghai, 200433, China
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18
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Weidner P, Voronova K, Bodi A, Sztáray B. Dissociative photoionization of 1,3-dioxolane: We need six channels to fit the elephant. JOURNAL OF MASS SPECTROMETRY : JMS 2020; 55:e4522. [PMID: 32510769 DOI: 10.1002/jms.4522] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Revised: 03/29/2020] [Accepted: 04/01/2020] [Indexed: 06/11/2023]
Abstract
The dissociative photoionization of 1,3-dioxolane was studied by photoelectron photoion coincidence (PEPICO) spectroscopy in the photon energy range of 9.5-13.5 eV. Our statistical thermodynamics model shows that a total of six dissociation channels are involved in the formation of three fragment ions, namely, C3 H5 O2 + (m/z 73), C2 H5 O+ (m/z 45), and C2 H4 O+ (m/z 44), with two channels contributing to the formation of each. By comparing the results of ab initio quantum chemical calculations to the experimentally derived appearance energies of the fragment ions, the most likely mechanisms for these unimolecular dissociation reactions are proposed, including a description of the relevant parts of the potential energy surface.
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Affiliation(s)
- Peter Weidner
- Department of Chemistry, University of the Pacific, Stockton, California, 95211, USA
| | - Krisztina Voronova
- Department of Chemistry, University of Nevada, Reno, Reno, Nevada, 89557, USA
| | - Andras Bodi
- Laboratory for Synchrotron Radiation and Femtochemistry, Paul Scherrer Institute, 5232, Villigen, Switzerland
| | - Bálint Sztáray
- Department of Chemistry, University of the Pacific, Stockton, California, 95211, USA
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19
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Liang S, Hemberger P, Steglich M, Simonetti P, Levalois-Grützmacher J, Grützmacher H, Gaan S. The Underlying Chemistry to the Formation of PO 2 Radicals from Organophosphorus Compounds: A Missing Puzzle Piece in Flame Chemistry. Chemistry 2020; 26:10795-10800. [PMID: 32428377 DOI: 10.1002/chem.202001388] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 05/15/2020] [Indexed: 11/08/2022]
Abstract
Reactive species, such as . PO2 and HOPO, are considered of upmost importance in flame inhibition and catalytic combustion processes of fuels. However, the underlying chemistry of their formation remains speculative due to the unavailability of suitable analytical techniques that can be used to identify the transient species which lead to their formation. This study elucidates the reaction mechanisms of the formation of phosphoryl species from dimethyl methyl phosphonate (DMMP) and dimethyl methyl phosphoramidate (DMPR) under well-defined oxidative conditions. Photoelectron photoion coincidence techniques that utilized vacuum ultraviolet synchrotron radiation were applied to isomer-selectively detect the elusive key intermediates and stable products. With the help of in situ recorded spectral fingerprints, different transient species, such as PO2 and triplet O radicals, have been exclusively identified from their isomeric components, which has helped to piece together the formation mechanisms of phosphoryl species under various conditions. It was found that . PO2 formation required oxidative conditions above 1070 K. The combined presence of O2 and H2 led to significant changes in the decomposition chemistry of both model phosphorus compounds, leading to the formation of . PO2 . The reaction . PO+O2 →. PO2 +O: was identified as the key step in the formation of . PO2 . Interestingly, the presence of O2 in DMPR thermolysis suppresses the formation of PN-containing species. In a previous study, PN species were identified as the major species formed during the pyrolysis of DMPR. Thus, the findings of this study has shed light onto the decomposition pathways of organophosphorus compounds, which are beneficial for their fuel additive and fire suppressant applications.
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Affiliation(s)
- Shuyu Liang
- Laboratory of Inorganic Chemistry, ETH Zürich, Swiss Federal Institute of Technology, Vladimir-Prelog-Weg 1-5/10, Zürich, Switzerland.,Additives and Chemistry, Advanced Fibers, Empa, Swiss Federal Laboratories for Materials Science, Lerchenfeldstrasse 5, Switzerland
| | - Patrick Hemberger
- Laboratory for Synchrotron Radiation and Femtochemistry, Paul Scherrer Institute, WSLA/115, Villigen-PSI, Switzerland
| | - Mathias Steglich
- Laboratory for Synchrotron Radiation and Femtochemistry, Paul Scherrer Institute, WSLA/115, Villigen-PSI, Switzerland
| | - Pietro Simonetti
- Additives and Chemistry, Advanced Fibers, Empa, Swiss Federal Laboratories for Materials Science, Lerchenfeldstrasse 5, Switzerland
| | - Joëlle Levalois-Grützmacher
- Laboratory of Inorganic Chemistry, ETH Zürich, Swiss Federal Institute of Technology, Vladimir-Prelog-Weg 1-5/10, Zürich, Switzerland
| | - Hansjörg Grützmacher
- Laboratory of Inorganic Chemistry, ETH Zürich, Swiss Federal Institute of Technology, Vladimir-Prelog-Weg 1-5/10, Zürich, Switzerland
| | - Sabyasachi Gaan
- Additives and Chemistry, Advanced Fibers, Empa, Swiss Federal Laboratories for Materials Science, Lerchenfeldstrasse 5, Switzerland
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20
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Mukhopadhyay DP, Schleier D, Wirsing S, Ramler J, Kaiser D, Reusch E, Hemberger P, Preitschopf T, Krummenacher I, Engels B, Fischer I, Lichtenberg C. Methylbismuth: an organometallic bismuthinidene biradical. Chem Sci 2020; 11:7562-7568. [PMID: 32874526 PMCID: PMC7450715 DOI: 10.1039/d0sc02410d] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 06/02/2020] [Indexed: 12/04/2022] Open
Abstract
We report the generation, spectroscopic characterization, and computational analysis of the first free (non-stabilized) organometallic bismuthinidene, BiMe. The title compound was generated in situ from BiMe3 by controlled homolytic Bi-C bond cleavage in the gas phase. Its electronic structure was characterized by a combination of photoion mass-selected threshold photoelectron spectroscopy and DFT as well as multi-reference computations. A triplet ground state was identified and an ionization energy (IE) of 7.88 eV was experimentally determined. Methyl abstraction from BiMe3 to give [BiMe2]• is a key step in the generation of BiMe. We reaveal a bond dissociation energy of 210 ± 7 kJ mol-1, which is substantially higher than the previously accepted value. Nevertheless, the homolytic cleavage of Me-BiMe2 bonds could be achieved at moderate temperatures (60-120 °C) in the condensed phase, suggesting that [BiMe2]• and BiMe are accessible as reactive intermediates under these conditions.
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Affiliation(s)
- Deb Pratim Mukhopadhyay
- Institute of Physical and Theoretical Chemistry , University of Würzburg , Am Hubland , D-97074 Würzburg , Germany . ;
| | - Domenik Schleier
- Institute of Physical and Theoretical Chemistry , University of Würzburg , Am Hubland , D-97074 Würzburg , Germany . ;
| | - Sara Wirsing
- Institute of Physical and Theoretical Chemistry , University of Würzburg , Am Hubland , D-97074 Würzburg , Germany . ;
| | - Jacqueline Ramler
- Institute of Inorganic Chemistry , University of Würzburg , Am Hubland , D-97074 Würzburg , Germany .
| | - Dustin Kaiser
- Institute of Physical and Theoretical Chemistry , University of Würzburg , Am Hubland , D-97074 Würzburg , Germany . ;
| | - Engelbert Reusch
- Institute of Physical and Theoretical Chemistry , University of Würzburg , Am Hubland , D-97074 Würzburg , Germany . ;
| | - Patrick Hemberger
- Laboratory for Femtochemistry and Synchrotron Radiation , Paul Scherrer Institut (PSI) , CH-5232 Villigen , Switzerland .
| | - Tobias Preitschopf
- Institute of Physical and Theoretical Chemistry , University of Würzburg , Am Hubland , D-97074 Würzburg , Germany . ;
| | - Ivo Krummenacher
- Institute of Inorganic Chemistry , University of Würzburg , Am Hubland , D-97074 Würzburg , Germany .
| | - Bernd Engels
- Institute of Physical and Theoretical Chemistry , University of Würzburg , Am Hubland , D-97074 Würzburg , Germany . ;
| | - Ingo Fischer
- Institute of Physical and Theoretical Chemistry , University of Würzburg , Am Hubland , D-97074 Würzburg , Germany . ;
| | - Crispin Lichtenberg
- Institute of Inorganic Chemistry , University of Würzburg , Am Hubland , D-97074 Würzburg , Germany .
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21
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Eco-friendly flame retardant poly(lactic acid) composites based on banana peel powders and phytic acid: flame retardancy and thermal property. JOURNAL OF POLYMER RESEARCH 2020. [DOI: 10.1007/s10965-020-02176-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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22
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Qian W, Chu X, Song C, Wu Z, Jiao M, Liu H, Zou B, Rauhut G, Tew DP, Wang L, Zeng X. Hydrogen-Atom Tunneling in Metaphosphorous Acid. Chemistry 2020; 26:8205-8209. [PMID: 32302021 DOI: 10.1002/chem.202000844] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Indexed: 11/08/2022]
Abstract
Metaphosphorous acid (HOPO), a key intermediate in phosphorus chemistry, has been generated in syn- and anti-conformations in the gas phase by high-vacuum flash pyrolysis (HVFP) of a molecular precursor ethoxyphosphinidene oxide (EtOPO→C2 H4 +HOPO) at ca. 1000 K and subsequently trapped in an N2 -matrix at 2.8 K. Unlike the two conformers of the nitrogen analogue HONO, the anti-conformer of HOPO undergoes spontaneous rotamerization at 2.8 K via hydrogen-atom tunneling (HAT) with noticeable kinetic isotope effects for H/D (>104 for DOPO) and 16 O/18 O (1.19 for H18 OPO and 1.06 for HOP18 O) in N2 -matrices.
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Affiliation(s)
- Weiyu Qian
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University, 215123, Suzhou, China
| | - Xianxu Chu
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University, 215123, Suzhou, China
| | - Chao Song
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University, 215123, Suzhou, China
| | - Zhuang Wu
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University, 215123, Suzhou, China
| | - Mengqi Jiao
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University, 215123, Suzhou, China
| | - Hanwen Liu
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University, 215123, Suzhou, China
| | - Bin Zou
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University, 215123, Suzhou, China
| | - Guntram Rauhut
- Institute for Theoretical Chemistry, University of Stuttgart, Pfaffenwaldring 55, Stuttgart, 70569, Germany
| | - David P Tew
- Max-Planck Institute for Solid State Research, Heisenbergstraße 1, Stuttgart, 70569, Germany
| | - Lina Wang
- Department of Chemistry, Fudan University, Shanghai, 200433, China
| | - Xiaoqing Zeng
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University, 215123, Suzhou, China.,Department of Chemistry, Fudan University, Shanghai, 200433, China
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23
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24
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Howell BA, Han X. Effective Biobased Phosphorus Flame Retardants from Starch-Derived bis-2,5-(Hydroxymethyl)Furan. Molecules 2020; 25:molecules25030592. [PMID: 32013211 PMCID: PMC7037623 DOI: 10.3390/molecules25030592] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 01/22/2020] [Accepted: 01/24/2020] [Indexed: 12/11/2022] Open
Abstract
A series of biobased phosphorus flame retardants has been prepared by converting starch-derived bis-2,5-(hydroxymethyl)furan to the corresponding diacrylate followed by Michael addition of phosphite to generate derivatives with phosphorus moieties attached via P–C bonds. All compounds behave as effective flame retardants in DGEBA epoxy resin. The most effective is the DOPO derivative, 2,5-di[(3-dopyl-propanoyl)methyl]furan. When incorporated into a DGEBA blend at a level to provide 2% phosphorus, a material displaying a LOI of 30, an UL 94 rating of V0 and a 40% reduction in combustion peak heat release rate compared to that for resin containing no additive is obtained. The analogous compounds generated from bisphenol A and tetrabromobisphenol A exhibit similar flame-retarding properties.
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25
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Sun Y, Wang Y, Liu L, Xiao T. The Preparation, Thermal Properties, and Fire Property of a Phosphorus-Containing Flame-Retardant Styrene Copolymer. MATERIALS (BASEL, SWITZERLAND) 2019; 13:E127. [PMID: 31892108 PMCID: PMC6981446 DOI: 10.3390/ma13010127] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 12/23/2019] [Accepted: 12/23/2019] [Indexed: 11/21/2022]
Abstract
A 9,10-dihydro-9-oxa-10-phosphaphenanthrene 10-oxide (DOPO) acrylate, (6-oxidodibenzo [c,e][1,2] oxaphosphinin-6-yl) methyl acrylate (DOPOAA), has been prepared. Copolymers of styrene (St) and DOPOAA were prepared by emulsion polymerization. The chemical structures of copolymers containing levels of DOPOAA were verified using Fourier transform infrared (FT-IR) spectroscopy and 1H nuclear magnetic resonance (1H-NMR) spectroscopy. The thermal properties and flame-retardant behaviors of DOPO-containing monomers and copolymers were observed using thermogravimetric analysis and micro calorimetry tests. From thermogravimetric analysis (TGA), it was found out that the T5% for decomposition of the copolymer was lower than that of polystyrene (PS), but the residue at 700 °C was higher than that of PS. The results from micro calorimetry (MCC) tests indicated that the rate for the heat release of the copolymer combustion was lower than that for PS. The limiting oxygen index (LOI) for combustion of the copolymer rose with increasing levels of DOPOAA. These data indicate that copolymerization of the phosphorus-containing flame-retardant monomer, DOPOAA, into a PS segment can effectively improve the thermal stability and flame retardancy of the copolymer.
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Affiliation(s)
- Yu Sun
- College of Chemistry and Chemical Engineering, Qiqihar University, Qiqihar 161006, China; (Y.S.); (L.L.)
- Heilongjiang Province Key Laboratory of Polymeric Composition Material, Qiqihar 161006, China
| | - Yazhen Wang
- Heilongjiang Province Key Laboratory of Polymeric Composition Material, Qiqihar 161006, China
- College of Materials Science and Engineering, Qiqihar University, Qiqihar 161006, China
| | - Li Liu
- College of Chemistry and Chemical Engineering, Qiqihar University, Qiqihar 161006, China; (Y.S.); (L.L.)
- Heilongjiang Province Key Laboratory of Polymeric Composition Material, Qiqihar 161006, China
| | - Tianyuan Xiao
- College of Light Industry and Textile, Qiqihar University, Qiqihar 161006, China;
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26
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Incorporation of Comonomer exo-5-(Diphenylphosphato)Isosorbide-2- endo-Acrylate to Generate Flame Retardant Poly(Styrene). Polymers (Basel) 2019; 11:polym11122038. [PMID: 31835304 PMCID: PMC6960599 DOI: 10.3390/polym11122038] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 12/02/2019] [Accepted: 12/03/2019] [Indexed: 02/06/2023] Open
Abstract
A phosphorus containing acrylate monomer has been constructed from isosorbide, a renewable biomaterial. Treatment of isosorbide with diphenylchlorophosphate generates a mixture of phosphorus esters from which exo-5-(diphenylphosphato)isosorbide-2-endo-ol may be isolated using column chromatography. Conversion of the alcohol to the corresponding acrylate by treatment with acroyl chloride provides a reactive acryloyl monomer containing a diphenylphosphato unit. Copolymerization of this monomer, at levels to provide 1% or 2% phosphorus incorporation, with styrene generates a polymer with substantially diminished flammability compared to that for styrene homopolymer.
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27
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Hu X, Yang H, Jiang Y, He H, Liu H, Huang H, Wan C. Facile synthesis of a novel transparent hyperbranched phosphorous/nitrogen-containing flame retardant and its application in reducing the fire hazard of epoxy resin. JOURNAL OF HAZARDOUS MATERIALS 2019; 379:120793. [PMID: 31252341 DOI: 10.1016/j.jhazmat.2019.120793] [Citation(s) in RCA: 67] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2019] [Revised: 06/16/2019] [Accepted: 06/17/2019] [Indexed: 05/27/2023]
Abstract
In this study, a novel hyperbranched phosphorus/nitrogen-containing flame retardant (HPNFR) was facilely synthesized via the transesterification reaction of dimethyl methylphosphonate and tris (2-hydroxyethyl) isocyanurate and characterized successfully by 1H NMR and FTIR. The sample with 4 wt% HPNFR can achieve V-0 rating in UL-94 test and possess a LOI value as high as 34.5%. Conspicuous blowing-out effect was observed during the vertical burning test. TG results indicated that the presence of HPNFR significantly improved the thermal stability of EP thermosets. From cone test, THR, p-HRR, p-SPR and TSP values of HPNFR/EP composites were decreased in comparison to those of pure EP, revealing the reduced fire hazard of EP composites with HPNFR. SEM images of EP thermoset with 4 wt% of HPNFR after cone test exhibited compact and continuous char layers, while those of pure EP are fragmentary and broken. From TG-IR test, the yield of toxic CO and other pyrolysis products was significantly reduced, indicating a decrease in toxicity. Phosphorus-containing compounds were detected in gas phase, which verified the gaseous phase flame retardant effect of HPNFR. Besides, HPNFR would not significantly damage the transparence of EP thermosets, consequently reserved it's application value in some special fields.
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Affiliation(s)
- Xin Hu
- College of Materials Science and Engineering, Chongqing University, 174 Shazhengjie, Chongqing 400044, PR China
| | - Hongyu Yang
- College of Materials Science and Engineering, Chongqing University, 174 Shazhengjie, Chongqing 400044, PR China; Chongqing Key Laboratory of New Building Materials and Engineering, Chongqing University, 174 Shazhengjie, Chongqing 400044, PR China.
| | - Yuping Jiang
- College of Materials Science and Engineering, Chongqing University, 174 Shazhengjie, Chongqing 400044, PR China
| | - Hualing He
- College of Materials Science and Engineering, Chongqing University, 174 Shazhengjie, Chongqing 400044, PR China
| | - Hongyin Liu
- College of Materials Science and Engineering, Chongqing University, 174 Shazhengjie, Chongqing 400044, PR China
| | - Hao Huang
- College of Materials Science and Engineering, Chongqing University, 174 Shazhengjie, Chongqing 400044, PR China
| | - Chaojun Wan
- College of Materials Science and Engineering, Chongqing University, 174 Shazhengjie, Chongqing 400044, PR China
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28
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Salmeia KA, Neels A, Parida D, Lehner S, Rentsch D, Gaan S. Insight into the Synthesis and Characterization of Organophosphorus-Based Bridged Triazine Compounds. Molecules 2019; 24:molecules24142672. [PMID: 31340573 PMCID: PMC6681112 DOI: 10.3390/molecules24142672] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2019] [Revised: 07/19/2019] [Accepted: 07/22/2019] [Indexed: 11/24/2022] Open
Abstract
In this article, we report the synthesis of 2,4,6-substituted s-triazine-based organophosphorus compounds via a two-step process, which enables their production in high yields, and with a high purity as solids. In the first step, a Michaelis–Arbuzov rearrangement of cyanuric chloride with triethyl phosphite afforded 2,4,6-trisdiethoxyphosphinyl-1,3,5-triazine (HEPT). Subsequently, the nucleophilic substitution reaction on the triazine carbon was achieved, owing to the electron-withdrawing ability of the phosphonate groups. This characteristic of HEPT facilitated its derivatization with bi-functional amines, producing novel P–C containing bridged triazine organophosphorus compounds. The molecular structures of all of the compounds were confirmed by NMR spectroscopy, CHN elemental analysis, and single crystal X-ray analysis. In the thermogravimetric analysis in an N2 environment, >33% char formation was observed for the bridged compounds. The chemical composition analysis of the char obtained under the oxidative thermal decomposition of the bridged compounds confirmed the presence of phosphorus- and nitrogen-enriched species, which indicate their function in the condensed phase. Comparatively, the detection of HPO and H–C≡P in the gas phase during the pyrolysis of the bridged compounds can act as a source for PO•, which is known for its gas phase flame inhibition reactions. The synergy of significant char formation and the generation of intermediates leading to PO• during pyrolysis makes these molecules promising flame-retardant additives.
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Affiliation(s)
- Khalifah A Salmeia
- Additives and Chemistry, Advanced Fibers, Empa Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland.
| | - Antonia Neels
- Center for X-ray Analytics, Swiss Federal Laboratories for Materials Science and Technology, Empa, Überlandstrasse 129, 8600 Dübendorf, Switzerland.
| | - Dambarudhar Parida
- Additives and Chemistry, Advanced Fibers, Empa Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland
| | - Sandro Lehner
- Additives and Chemistry, Advanced Fibers, Empa Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland
| | - Daniel Rentsch
- Laboratory for Functional Polymers, Empa Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, 8600 Dübendorf, Switzerland
| | - Sabyasachi Gaan
- Additives and Chemistry, Advanced Fibers, Empa Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland
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29
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Howell BA, Alrubayyi A. 2-Dopyl-1,4-di(2-dopylpropanoyl)benzene, an effective phosphorus flame retardant. Polym Degrad Stab 2019. [DOI: 10.1016/j.polymdegradstab.2018.12.017] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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30
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Wu XK, Tang XF, Zhou XG, Liu SL. Dissociation dynamics of energy-selected ions using threshold photoelectron-photoion coincidence velocity imaging. CHINESE J CHEM PHYS 2019. [DOI: 10.1063/1674-0068/cjcp1811257] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Affiliation(s)
- Xiang-kun Wu
- Hefei National Laboratory for Physical Sciences at the Microscale, iChEM (Collaborative Innovation Center of Chemistry for Energy Materials), Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, China
| | - Xiao-feng Tang
- Laboratory of Atmospheric Physico-Chemistry, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei 230031, China
| | - Xiao-guo Zhou
- Hefei National Laboratory for Physical Sciences at the Microscale, iChEM (Collaborative Innovation Center of Chemistry for Energy Materials), Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, China
| | - Shi-lin Liu
- Hefei National Laboratory for Physical Sciences at the Microscale, iChEM (Collaborative Innovation Center of Chemistry for Energy Materials), Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, China
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Ash T, Debnath T, Sarkar S, Gurey P, Das AK. Exploration of assisting behavior of molecular-MO2 (M = Ti, Zr) reagents towards the detoxication of tabun: A DFT study. Chem Phys Lett 2019. [DOI: 10.1016/j.cplett.2019.01.022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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32
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Ampadu Boateng D, Word MD, Tibbetts KM. Probing Coherent Vibrations of Organic Phosphonate Radical Cations with Femtosecond Time-Resolved Mass Spectrometry. Molecules 2019; 24:E509. [PMID: 30708973 PMCID: PMC6384684 DOI: 10.3390/molecules24030509] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 01/25/2019] [Accepted: 01/29/2019] [Indexed: 12/25/2022] Open
Abstract
Organic phosphates and phosphonates are present in a number of cellular components that can be damaged by exposure to ionizing radiation. This work reports femtosecond time-resolved mass spectrometry (FTRMS) studies of three organic phosphonate radical cations that model the DNA sugar-phosphate backbone: dimethyl methylphosphonate (DMMP), diethyl methylphosphonate (DEMP), and diisopropyl methylphosphonate (DIMP). Upon ionization, each molecular radical cation exhibits unique oscillatory dynamics in its ion yields resulting from coherent vibrational excitation. DMMP has particularly well-resolved 45 fs ( 732 ± 28 cm - 1 ) oscillations with a weak feature at 610⁻650 cm - 1 , while DIMP exhibits bimodal oscillations with a period of ∼55 fs and two frequency features at 554 ± 28 and 670⁻720 cm - 1 . In contrast, the oscillations in DEMP decay too rapidly for effective resolution. The low- and high-frequency oscillations in DMMP and DIMP are assigned to coherent excitation of the symmetric O⁻P⁻O bend and P⁻C stretch, respectively. The observation of the same ionization-induced coherently excited vibrations in related molecules suggests a possible common excitation pathway in ionized organophosphorus compounds of biological relevance, while the distinct oscillatory dynamics in each molecule points to the potential use of FTRMS to distinguish among fragment ions produced by related molecules.
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Affiliation(s)
| | - Mi'Kayla D Word
- Department of Chemistry, Virginia Commonwealth University, Richmond, VA 23284, USA.
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33
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Yu Y, Chen Z, Zhang Q, Jiang M, Zhong Z, Chen T, Jiang J. Modified montmorillonite combined with intumescent flame retardants on the flame retardancy and thermal stability properties of unsaturated polyester resins. POLYM ADVAN TECHNOL 2019. [DOI: 10.1002/pat.4533] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Yuan Yu
- College of Safety Science and Engineering; Nanjing Tech University; Nanjing 210009 China
- Jiangsu Key Laboratory of Hazardous Chemicals Safety and Control; Nanjing Tech University; Nanjing 210009 China
| | - Zhiquan Chen
- College of Safety Science and Engineering; Nanjing Tech University; Nanjing 210009 China
| | - Qingwu Zhang
- College of Safety Science and Engineering; Nanjing Tech University; Nanjing 210009 China
| | - Mengwei Jiang
- College of Safety Science and Engineering; Nanjing Tech University; Nanjing 210009 China
| | - Zhihao Zhong
- College of Chemistry and Chemical Engineering; Anhui University; Heifei 230601 China
| | - Tingting Chen
- College of Safety Science and Engineering; Nanjing Tech University; Nanjing 210009 China
| | - Juncheng Jiang
- College of Safety Science and Engineering; Nanjing Tech University; Nanjing 210009 China
- Jiangsu Key Laboratory of Hazardous Chemicals Safety and Control; Nanjing Tech University; Nanjing 210009 China
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34
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Dyke JM. Photoionization studies of reactive intermediates using synchrotron radiation. Phys Chem Chem Phys 2019; 21:9106-9136. [DOI: 10.1039/c9cp00623k] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Photoionization with synchrotron radiation enables sensitive and selective monitoring of reactive intermediates in environments such as flames and plasmas.
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35
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Phosphorus Flame Retardants for Polymeric Materials from Gallic Acid and Other Naturally Occurring Multihydroxybenzoic Acids. INT J POLYM SCI 2018. [DOI: 10.1155/2018/7237236] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The development of polymer and polymer additives from renewable biosources is becoming increasingly prominent. This reflects increasing concerns about sustainability, environmental quality, and human health. Bioproducts produced in nature are generally inexpensive and benign in the environment. Moreover, degradation of derivatives does not yield toxic products. Gallic acid (3,4,5-trihydroxybenzoic acid) is found widely in nature and has long been touted for its medicinal qualities. 3,5-Dihydroxybenzoic acid is also produced by several plants, most notably buckwheat. Both compounds, as the anilide and methyl ester, respectively, have been converted to a series of phosphorus esters, both phosphonate and phosphate. Esters have been fully characterized using spectroscopic and thermal methods. These compounds display good flame retardancy at low loadings in DGEBA epoxy resin.
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36
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Chu X, Song C, Yang Y, Zeng X. Oxidation of a phosphinidene oxide: formation of a dioxaphosphirane oxide with oxygen scrambling. Chem Commun (Camb) 2018; 55:245-248. [PMID: 30534675 DOI: 10.1039/c8cc08945k] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The oxidation of a prototypical phosphinidene oxide FP[double bond, length as m-dash]O has been studied in O2-doped Ar and N2 matrices at 10 K. Upon 266 nm laser irradiation, FP[double bond, length as m-dash]O combines with O2 and yields the cyclic peroxide, dioxaphosphirane oxide FP([double bond, length as m-dash]O)(O2). Unexpected oxygen scrambling occurs during the oxygenation as evidenced by the observation of a 1 : 2 mixture of FP([double bond, length as m-dash]16O)(18O18O) and FP([double bond, length as m-dash]18O)(16O18O) when 18O2 was used. Quantum chemical calculations suggest that the scrambling happens via the intermediacy of the low-lying triplet FPO3 by passing minimum energy crossing points (MECPs). In addition, inorganic dioxophosphorane FP([double bond, length as m-dash]O)2 has been also identified among the oxidation products of FP[double bond, length as m-dash]O.
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Affiliation(s)
- Xianxu Chu
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, 215123, China.
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37
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Bodi A, Hemberger P. Low-Energy Photoelectron Spectrum and Dissociative Photoionization of the Smallest Amides: Formamide and Acetamide. J Phys Chem A 2018; 123:272-283. [DOI: 10.1021/acs.jpca.8b10373] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Andras Bodi
- Laboratory for Synchrotron Radiation and Femtochemistry, Paul Scherrer Institute, 5232 Villigen, Switzerland
| | - Patrick Hemberger
- Laboratory for Synchrotron Radiation and Femtochemistry, Paul Scherrer Institute, 5232 Villigen, Switzerland
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38
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Hirsch F, Reusch E, Constantinidis P, Fischer I, Bakels S, Rijs AM, Hemberger P. Self-Reaction of ortho-Benzyne at High Temperatures Investigated by Infrared and Photoelectron Spectroscopy. J Phys Chem A 2018; 122:9563-9571. [PMID: 30444617 DOI: 10.1021/acs.jpca.8b09640] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
ortho-Benzyne, a Kekulé-type biradical is considered to be a key intermediate in the formation of polycyclic aromatic hydrocarbons (PAH) and soot. In the present work we study the ortho-benzyne self-reactions in a hot microreactor and identify the high-temperature products by IR/UV spectroscopy and by photoion mass-selected threshold photoelectron spectroscopy (ms-TPES) in a free jet. Ms-TPES confirms formation of ortho-benzyne as generated from benzocyclobutenedione, as well as benzene, biphenylene, diacetylene, and acetylene, originating from the reaction o-C6H4 → HCC-CCH + C2H2, and CH3. PAH molecules like naphthalene, 2-ethynylnaphthalene, fluorene, phenanthrene, and triphenylene are identified based on their IR/UV spectra. By comparison with recent computations their formation starting from o-benzyne can be readily understood and supports the importance of the biradical addition (1,4-cycloaddition followed by fragmentation) pathway to PAH molecules, recently proposed by Comandini et al.
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Affiliation(s)
- Florian Hirsch
- Institute of Physical and Theoretical Chemistry , University of Würzburg , Am Hubland, D-97074 Würzburg , Germany
| | - Engelbert Reusch
- Institute of Physical and Theoretical Chemistry , University of Würzburg , Am Hubland, D-97074 Würzburg , Germany
| | - Philipp Constantinidis
- Institute of Physical and Theoretical Chemistry , University of Würzburg , Am Hubland, D-97074 Würzburg , Germany
| | - Ingo Fischer
- Institute of Physical and Theoretical Chemistry , University of Würzburg , Am Hubland, D-97074 Würzburg , Germany
| | - Sjors Bakels
- Radboud University , Institute for Molecules and Materials, FELIX Laboratory , Toernooiveld 7c , 6525 ED Nijmegen , The Netherlands
| | - Anouk M Rijs
- Radboud University , Institute for Molecules and Materials, FELIX Laboratory , Toernooiveld 7c , 6525 ED Nijmegen , The Netherlands
| | - Patrick Hemberger
- Laboratory for Femtochemistry and Synchrotron Radiation , Paul Scherrer Institut (PSI) , CH-5232 Villigen , Switzerland
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39
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40
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Chu X, Yang Y, Lu B, Wu Z, Qian W, Song C, Xu X, Abe M, Zeng X. Methoxyphosphinidene and Isomeric Methylphosphinidene Oxide. J Am Chem Soc 2018; 140:13604-13608. [PMID: 30301345 DOI: 10.1021/jacs.8b09201] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A rare oxyphosphinidene (Me-OP) has been generated in the triplet ground state through either photolysis (266 nm) or flash-vacuum pyrolysis (FVP, 700 °C) of methoxydiazidophosphine MeOP(N3)2. Upon ArF laser irradiation (193 nm), an unprecedented isomerization from Me-OP to the long-sought methylphosphinidene oxide (Me-PO) occurs in cryogenic Ne- and N2-matrices. Alternatively, the latter can be efficiently generated through photolysis (193 nm) or FVP (ca. 700 °C) of methylphosphoryl diazide MeP(O)(N3)2, in which the elusive nitrene intermediate MeP(O)(N3)N in the triplet ground state has been also observed by IR (with 15N-labeling) and EPR (| D/ hc| = 1.545 cm-1 and | E/ hc| = 0.003 95 cm-1) spectroscopy.
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Affiliation(s)
- Xianxu Chu
- College of Chemistry, Chemical Engineering and Materials Science , Soochow University , Suzhou 215123 , China
| | - Yang Yang
- College of Chemistry, Chemical Engineering and Materials Science , Soochow University , Suzhou 215123 , China
| | - Bo Lu
- College of Chemistry, Chemical Engineering and Materials Science , Soochow University , Suzhou 215123 , China
| | - Zhuang Wu
- College of Chemistry, Chemical Engineering and Materials Science , Soochow University , Suzhou 215123 , China
| | - Weiyu Qian
- 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
| | - Xinfang Xu
- College of Chemistry, Chemical Engineering and Materials Science , Soochow University , Suzhou 215123 , China
| | - Manabu Abe
- Department of Chemistry, Graduate School of Science , Hiroshima University , 1-3-1 Kagamiyama , Higashihiroshima , Hiroshima 739-8526 , Japan
| | - Xiaoqing Zeng
- College of Chemistry, Chemical Engineering and Materials Science , Soochow University , Suzhou 215123 , China
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42
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Peng HK, Wang XX, Li TT, Huang SY, Lin Q, Shiu BC, Lou CW, Lin JH. Effects of hydrotalcite on rigid polyurethane foam composites containing a fire retarding agent: compressive stress, combustion resistance, sound absorption, and electromagnetic shielding effectiveness. RSC Adv 2018; 8:33542-33550. [PMID: 35548115 PMCID: PMC9086486 DOI: 10.1039/c8ra06361c] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2018] [Accepted: 08/29/2018] [Indexed: 11/21/2022] Open
Abstract
Polyether polyol, isocyanate, and a flame retardant (10 wt%), hydrotalcite (0, 1, 3, 5, 7, and 9 wt%) are used to form a rigid PU foam, while a nylon nonwoven fabric (400 g m−2) and a polyester aluminum foil are combined to serve as the panel. The rigid PU foam and the panel are then combined to form the rigid foam composites. The cell structure, compressive stress, combustion resistance, thermal stability, sound absorption, and electromagnetic shielding effectiveness of the rigid foam composites are evaluated, examining the effects of using hydrotalcite. When the hydrotalcite is 5 wt%, the rigid foam composites have an optimal density of 0.168 g cm−3, an average cell size of 0.2858 mm, a maximum compressive stress of 479.95 kpa, an optimal LOI of 29, an optimal EMSE of 45 dB, and the maximum thermal stability and sound absorption. The synthesis of rigid polyurethane foam.![]()
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Affiliation(s)
- Hao-Kai Peng
- Innovation Platform of Intelligent and Energy-Saving Textiles, School of Textiles, Tianjin Polytechnic University Tianjin 300387 China.,Key Laboratory of Ministry of Education of Advanced Textile Composite Materials, Tianjin Polytechnic University Tianjin 300387 China
| | - Xiao Xiao Wang
- Innovation Platform of Intelligent and Energy-Saving Textiles, School of Textiles, Tianjin Polytechnic University Tianjin 300387 China.,Key Laboratory of Ministry of Education of Advanced Textile Composite Materials, Tianjin Polytechnic University Tianjin 300387 China
| | - Ting-Ting Li
- Innovation Platform of Intelligent and Energy-Saving Textiles, School of Textiles, Tianjin Polytechnic University Tianjin 300387 China.,Key Laboratory of Ministry of Education of Advanced Textile Composite Materials, Tianjin Polytechnic University Tianjin 300387 China
| | - Shih-Yu Huang
- Department of Chemical Engineering and Materials, Ocean College, Minjiang University Fuzhou 350108 China
| | - Qi Lin
- Fujian Engineering Research Center of New Chinese Lacquer Material, Minjiang University Fuzhou 350108 China
| | - Bing-Chiuan Shiu
- Laboratory of Fiber Application and Manufacturing, Department of Fiber and Composite Materials, Feng Chia University Taichung City 40724 Taiwan
| | - Ching-Wen Lou
- Innovation Platform of Intelligent and Energy-Saving Textiles, School of Textiles, Tianjin Polytechnic University Tianjin 300387 China.,Department of Chemical Engineering and Materials, Ocean College, Minjiang University Fuzhou 350108 China .,Department of Bioinformatics and Medical Engineering, Asia University Taichung 41354 Taiwan.,School of Chinese Medicine, China Medical University Taichung City 40402 Taiwan.,College of Textile and Clothing, Qingdao University Shangdong 266071 China
| | - Jia-Horng Lin
- Innovation Platform of Intelligent and Energy-Saving Textiles, School of Textiles, Tianjin Polytechnic University Tianjin 300387 China.,Department of Chemical Engineering and Materials, Ocean College, Minjiang University Fuzhou 350108 China .,School of Chinese Medicine, China Medical University Taichung City 40402 Taiwan.,College of Textile and Clothing, Qingdao University Shangdong 266071 China.,Laboratory of Fiber Application and Manufacturing, Department of Fiber and Composite Materials, Feng Chia University Taichung City 40724 Taiwan.,Department of Fashion Design, Asia University Taichung 41354 Taiwan
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43
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44
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Kaiser D, Reusch E, Hemberger P, Bodi A, Welz E, Engels B, Fischer I. The ortho-benzyne cation is not planar. Phys Chem Chem Phys 2018; 20:3988-3996. [PMID: 29350226 DOI: 10.1039/c7cp08055g] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A recent review on the photoionisation of the C6H4 isomer ortho-benzyne suggests that bands reported in earlier photoelectron spectra might be due to side products or contaminations, while computations raise doubts, whether the cation has a planar geometry. We therefore reinvestigate the photoionisation of ortho-benzyne, generated by pyrolysis from benzocyclobutenedione, by photoion mass-selected threshold photoelectron (ms-TPE) spectroscopy using synchrotron radiation. The experiments are accompanied by a theoretical study that investigates the structure of the ortho-benzyne cation systematically as a function of the computational method, up to CASPT2(11,14) ab initio computations. Our study leads to a re-evaluation of the ionisation energy of ortho-benzyne. It reveals that the ortho-benzyne cation has indeed a twisted C2 geometry rather than a C2v structure. A vertical ionisation energy IEvert of 9.77 eV and an adiabatic ionisation energy of IEad = 9.56 eV are computed for ortho-benzyne. A Franck-Condon simulation of the photoelectron spectrum based on the CASPT2 results and including three electronic states of the cation is in agreement with the experiment and yields IEad = 9.51 eV (+50 meV/-100 meV). Since this value is in contrast with previous work, the ionisation energy has to be revised based on our study. Computational methods based on density functional theory give a reasonable description of the cationic ground state, but fail for the corresponding excited electronic states that are indispensible for a proper assignment of the photoelectron spectrum.
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Affiliation(s)
- D Kaiser
- Institute of Physical and Theoretical Chemistry, University of Würzburg, Am Hubland, D-97074 Würzburg, Germany.
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45
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Tang X, Hicks Z, Wang L, Ganteför G, Bowen KH, Tsyshevsky R, Sun J, Kuklja MM. Adsorption and decomposition of dimethyl methylphosphonate on size-selected (MoO3)3 clusters. Phys Chem Chem Phys 2018; 20:4840-4850. [DOI: 10.1039/c7cp08427g] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The adsorption and decomposition of dimethyl methylphosphonate (DMMP), a chemical warfare agent (CWA) simulant, on size-selected molybdenum oxide trimer clusters, i.e. (MoO3)3, was studied both experimentally and theoretically.
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Affiliation(s)
- Xin Tang
- Department of Chemistry
- Johns Hopkins University
- Baltimore
- USA
| | - Zachary Hicks
- Department of Chemistry
- Johns Hopkins University
- Baltimore
- USA
| | - Linjie Wang
- Department of Chemistry
- Johns Hopkins University
- Baltimore
- USA
| | - Gerd Ganteför
- Department of Physics
- University of Konstanz
- 78464 Konstanz
- Germany
| | - Kit H. Bowen
- Department of Chemistry
- Johns Hopkins University
- Baltimore
- USA
| | - Roman Tsyshevsky
- Department of Materials Science
- University of Maryland
- College Park
- USA
| | - Jianwei Sun
- Department of Physics
- Tulane University
- New Orleans
- USA
| | - Maija M. Kuklja
- Department of Materials Science
- University of Maryland
- College Park
- USA
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46
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Bouwman J, Bodi A, Hemberger P. Nitrogen matters: the difference between PANH and PAH formation. Phys Chem Chem Phys 2018; 20:29910-29917. [DOI: 10.1039/c8cp05830j] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Because of the large stability of the nitrile group, the N-substituted aromatic molecule quinoline does not form in the phenyl + acrylonitrile reaction, in contrast to naphthalene formation in the isoelectronic phenyl + vinylacetylene reaction.
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Affiliation(s)
- Jordy Bouwman
- Sackler Laboratory for Astrophysics
- Leiden Observatory
- Leiden University
- NL 2300 RA Leiden
- The Netherlands
| | - Andras Bodi
- Laboratory for Synchrotron Radiation and Femtochemistry
- Paul Scherrer Institute
- 5232 Villigen
- Switzerland
| | - Patrick Hemberger
- Laboratory for Synchrotron Radiation and Femtochemistry
- Paul Scherrer Institute
- 5232 Villigen
- Switzerland
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47
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Ampadu Boateng D, Gutsev GL, Jena P, Tibbetts KM. Ultrafast coherent vibrational dynamics in dimethyl methylphosphonate radical cation. Phys Chem Chem Phys 2018; 20:4636-4640. [DOI: 10.1039/c7cp07261a] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Coherent vibrational dynamics drive dissociation of dimethyl methylphosphonate (DMMP) radical cation.
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Affiliation(s)
| | | | - Puru Jena
- Department of Physics
- Virginia Commonwealth University
- Richmond
- USA
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48
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Li L, Chen Y, Qian L, Xu B, Xi W. Addition flame-retardant effect of nonreactive phosphonate and expandable graphite in rigid polyurethane foams. J Appl Polym Sci 2017. [DOI: 10.1002/app.45960] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Linjie Li
- School of Materials Science and Mechanical Engineering; Beijing Technology and Business University; Beijing 100048 China
- Engineering Laboratory of non-halogen flame retardants for polymers; Beijing 100048 China
- Beijing Key Laboratory of Quality Evaluation Technology for Hygiene and Safety of Plastics; Beijing 100048 China
| | - Yajun Chen
- School of Materials Science and Mechanical Engineering; Beijing Technology and Business University; Beijing 100048 China
- Engineering Laboratory of non-halogen flame retardants for polymers; Beijing 100048 China
- Beijing Key Laboratory of Quality Evaluation Technology for Hygiene and Safety of Plastics; Beijing 100048 China
| | - Lijun Qian
- School of Materials Science and Mechanical Engineering; Beijing Technology and Business University; Beijing 100048 China
- Engineering Laboratory of non-halogen flame retardants for polymers; Beijing 100048 China
- Beijing Key Laboratory of Quality Evaluation Technology for Hygiene and Safety of Plastics; Beijing 100048 China
| | - Bo Xu
- School of Materials Science and Mechanical Engineering; Beijing Technology and Business University; Beijing 100048 China
- Engineering Laboratory of non-halogen flame retardants for polymers; Beijing 100048 China
- Beijing Key Laboratory of Quality Evaluation Technology for Hygiene and Safety of Plastics; Beijing 100048 China
| | - Wang Xi
- School of Materials Science and Mechanical Engineering; Beijing Technology and Business University; Beijing 100048 China
- Engineering Laboratory of non-halogen flame retardants for polymers; Beijing 100048 China
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49
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Gutsev GL, Ampadu Boateng D, Jena P, Tibbetts KM. A Theoretical and Mass Spectrometry Study of Dimethyl Methylphosphonate: New Isomers and Cation Decay Channels in an Intense Femtosecond Laser Field. J Phys Chem A 2017; 121:8414-8424. [PMID: 29035556 DOI: 10.1021/acs.jpca.7b08889] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Using both mass spectrometry with intense femtosecond laser ionization and high-level computational methods, we have explored the structure and fragmentation patterns of dimethyl methylphosphonate (DMMP) cation. Extensive search of the geometries of both neutral and positively charged DMMP yields new isomers that are appreciably lower in total energy than those commonly synthesized using the Michaelis-Arbuzov reaction. The stability of the standard isomer with CH3PO(OCH3)2 topology is found to be due to the presence of high barriers to isomer interconversion that involves several transition states. Our femtosecond laser ionization experiments show that the relative yields of the major dissociation products as a function of peak laser intensity correlate well with the theoretical estimates for the energies of the DMMP+ decay via various channels. In contrast, the peak laser intensities required for observation of minor dissociation products exhibit no correlation with the computed decay energies, which suggests that barrier heights and/or excited electronic states of DMMP+ determine its preferred fragmentation pathways in an intense femtosecond laser field.
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Affiliation(s)
- G L Gutsev
- Department of Physics, Florida A&M University , Tallahassee, Florida 32307, United States
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50
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Pastoors JIM, Bodi A, Hemberger P, Bouwman J. Dissociative Ionization and Thermal Decomposition of Cyclopentanone. Chemistry 2017; 23:13131-13140. [PMID: 28692134 PMCID: PMC5639375 DOI: 10.1002/chem.201702376] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Indexed: 11/24/2022]
Abstract
Despite the growing use of renewable and sustainable biofuels in transportation, their combustion chemistry is poorly understood, limiting our efforts to reduce harmful emissions. Here we report on the (dissociative) ionization and the thermal decomposition mechanism of cyclopentanone, studied using imaging photoelectron photoion coincidence spectroscopy. The fragmentation of the ions is dominated by loss of CO, C2H4, and C2H5, leading to daughter ions at m/z 56 and 55. Exploring the C5H8O.+ potential energy surface reveals hydrogen tunneling to play an important role in low‐energy decarbonylation and probably also in the ethene‐loss processes, yielding 1‐butene and methylketene cations, respectively. At higher energies, pathways without a reverse barrier open up to oxopropenyl and cyclopropanone cations by ethyl‐radical loss and a second ethene‐loss channel, respectively. A statistical Rice–Ramsperger–Kassel–Marcus model is employed to test the viability of this mechanism. The pyrolysis of cyclopentanone is studied at temperatures ranging from about 800 to 1100 K. Closed‐shell pyrolysis products, namely 1,3‐butadiene, ketene, propyne, allene, and ethene, are identified based on their photoion mass‐selected threshold photoelectron spectrum. Furthermore, reactive radical species such as allyl, propargyl, and methyl are found. A reaction mechanism is derived incorporating both stable and reactive species, which were not predicted in prior computational studies.
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Affiliation(s)
- Johan I M Pastoors
- Radboud University, Institute for Molecules and Materials, FELIX Laboratory, Toernooiveld 7c, 6525 ED, Nijmegen, The Netherlands
| | - Andras Bodi
- Laboratory for Synchrotron Radiation and Femtochemistry, Paul Scherrer Institute, 5232, Villigen, Switzerland
| | - Patrick Hemberger
- Laboratory for Synchrotron Radiation and Femtochemistry, Paul Scherrer Institute, 5232, Villigen, Switzerland
| | - Jordy Bouwman
- Radboud University, Institute for Molecules and Materials, FELIX Laboratory, Toernooiveld 7c, 6525 ED, Nijmegen, The Netherlands.,Present address: Sackler Laboratory for Astrophysics, Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA, Leiden, The Netherlands
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