Experimental and Theoretical Study of the OH-Initiated Degradation of Piperazine under Simulated Atmospheric Conditions

Wen Tan; Liang Zhu; Tomas Mikoviny; Claus J Nielsen; Armin Wisthaler; Barbara D'Anna; Simen Antonsen; Yngve Stenstrøm; Naomi J Farren; Jacqueline F Hamilton; Graham A Boustead; Alexander D Brennan; Trevor Ingham; Dwayne E Heard

doi:10.1021/acs.jpca.0c10223

Experimental and Theoretical Study of the OH-Initiated Degradation of Piperazine under Simulated Atmospheric Conditions

Wen Tan, Liang Zhu, Tomas Mikoviny, Claus J Nielsen, Armin Wisthaler, Barbara D'Anna, Simen Antonsen, Yngve Stenstrøm, Naomi J Farren, Jacqueline F Hamilton, Graham A Boustead, Alexander D Brennan, Trevor Ingham, Dwayne E Heard

Chemistry

Research output: Contribution to journal › Article › peer-review

Abstract

The OH-initiated photo-oxidation of piperazine and 1-nitropiperazine as well as the photolysis of 1-nitrosopiperazine were investigated in a large atmospheric simulation chamber. The rate coefficient for the reaction of piperazine with OH radicals was determined by the relative rate method to be kOH-piperazine = (2.8 ± 0.6) × 10-10 cm3 molecule-1 s-1 at 307 ± 2 K and 1014 ± 2 hPa. Product studies showed the piperazine + OH reaction to proceed both via C-H and N-H abstraction, resulting in the formation of 1,2,3,6-tetrahydropyrazine as the major product and in 1-nitropiperazine and 1-nitrosopiperazine as minor products. The branching in the piperazinyl radical reactions with NO, NO2, and O2 was obtained from 1-nitrosopiperazine photolysis experiments and employed analyses of the 1-nitropiperazine and 1-nitrosopiperazine temporal profiles observed during piperazine photo-oxidation. The derived initial branching between N-H and C-H abstraction by OH radicals, kN-H/(kN-H + kC-H), was 0.18 ± 0.04. All experiments were accompanied by substantial aerosol formation that was initiated by the reaction of piperazine with nitric acid. Both primary and secondary photo-oxidation products including 1-nitropiperazine and 1,4-dinitropiperazine were detected in the aerosol particles formed. Corroborating atmospheric photo-oxidation schemes for piperazine and 1-nitropiperazine were derived from M06-2X/aug-cc-pVTZ quantum chemistry calculations and master equation modeling of the pivotal reaction steps. The atmospheric chemistry of piperazine is evaluated, and a validated chemical mechanism for implementation in dispersion models is presented.

Original language	English
Journal	Journal of Physical Chemistry A
DOIs	https://doi.org/10.1021/acs.jpca.0c10223
Publication status	E-pub ahead of print - 30 Dec 2020

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10.1021/acs.jpca.0c10223

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Tan, W., Zhu, L., Mikoviny, T., Nielsen, C. J., Wisthaler, A., D'Anna, B., Antonsen, S., Stenstrøm, Y., Farren, N. J., Hamilton, J. F., Boustead, G. A., Brennan, A. D., Ingham, T., & Heard, D. E. (2020). Experimental and Theoretical Study of the OH-Initiated Degradation of Piperazine under Simulated Atmospheric Conditions. Journal of Physical Chemistry A. https://doi.org/10.1021/acs.jpca.0c10223

@article{3395b9ca52e741b3a7f65840db0e8c1c,

title = "Experimental and Theoretical Study of the OH-Initiated Degradation of Piperazine under Simulated Atmospheric Conditions",

abstract = "The OH-initiated photo-oxidation of piperazine and 1-nitropiperazine as well as the photolysis of 1-nitrosopiperazine were investigated in a large atmospheric simulation chamber. The rate coefficient for the reaction of piperazine with OH radicals was determined by the relative rate method to be kOH-piperazine = (2.8 ± 0.6) × 10-10 cm3 molecule-1 s-1 at 307 ± 2 K and 1014 ± 2 hPa. Product studies showed the piperazine + OH reaction to proceed both via C-H and N-H abstraction, resulting in the formation of 1,2,3,6-tetrahydropyrazine as the major product and in 1-nitropiperazine and 1-nitrosopiperazine as minor products. The branching in the piperazinyl radical reactions with NO, NO2, and O2 was obtained from 1-nitrosopiperazine photolysis experiments and employed analyses of the 1-nitropiperazine and 1-nitrosopiperazine temporal profiles observed during piperazine photo-oxidation. The derived initial branching between N-H and C-H abstraction by OH radicals, kN-H/(kN-H + kC-H), was 0.18 ± 0.04. All experiments were accompanied by substantial aerosol formation that was initiated by the reaction of piperazine with nitric acid. Both primary and secondary photo-oxidation products including 1-nitropiperazine and 1,4-dinitropiperazine were detected in the aerosol particles formed. Corroborating atmospheric photo-oxidation schemes for piperazine and 1-nitropiperazine were derived from M06-2X/aug-cc-pVTZ quantum chemistry calculations and master equation modeling of the pivotal reaction steps. The atmospheric chemistry of piperazine is evaluated, and a validated chemical mechanism for implementation in dispersion models is presented.",

author = "Wen Tan and Liang Zhu and Tomas Mikoviny and Nielsen, {Claus J} and Armin Wisthaler and Barbara D'Anna and Simen Antonsen and Yngve Stenstr{\o}m and Farren, {Naomi J} and Hamilton, {Jacqueline F} and Boustead, {Graham A} and Brennan, {Alexander D} and Trevor Ingham and Heard, {Dwayne E}",

year = "2020",

month = dec,

day = "30",

doi = "10.1021/acs.jpca.0c10223",

language = "English",

journal = "Journal of Physical Chemistry A",

issn = "1089-5639",

publisher = "American Chemical Society",

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Tan, W, Zhu, L, Mikoviny, T, Nielsen, CJ, Wisthaler, A, D'Anna, B, Antonsen, S, Stenstrøm, Y, Farren, NJ , Hamilton, JF, Boustead, GA, Brennan, AD, Ingham, T & Heard, DE 2020, 'Experimental and Theoretical Study of the OH-Initiated Degradation of Piperazine under Simulated Atmospheric Conditions', Journal of Physical Chemistry A. https://doi.org/10.1021/acs.jpca.0c10223

TY - JOUR

T1 - Experimental and Theoretical Study of the OH-Initiated Degradation of Piperazine under Simulated Atmospheric Conditions

AU - Tan, Wen

AU - Zhu, Liang

AU - Mikoviny, Tomas

AU - Nielsen, Claus J

AU - Wisthaler, Armin

AU - D'Anna, Barbara

AU - Antonsen, Simen

AU - Stenstrøm, Yngve

AU - Farren, Naomi J

AU - Hamilton, Jacqueline F

AU - Boustead, Graham A

AU - Brennan, Alexander D

AU - Ingham, Trevor

AU - Heard, Dwayne E

PY - 2020/12/30

Y1 - 2020/12/30

N2 - The OH-initiated photo-oxidation of piperazine and 1-nitropiperazine as well as the photolysis of 1-nitrosopiperazine were investigated in a large atmospheric simulation chamber. The rate coefficient for the reaction of piperazine with OH radicals was determined by the relative rate method to be kOH-piperazine = (2.8 ± 0.6) × 10-10 cm3 molecule-1 s-1 at 307 ± 2 K and 1014 ± 2 hPa. Product studies showed the piperazine + OH reaction to proceed both via C-H and N-H abstraction, resulting in the formation of 1,2,3,6-tetrahydropyrazine as the major product and in 1-nitropiperazine and 1-nitrosopiperazine as minor products. The branching in the piperazinyl radical reactions with NO, NO2, and O2 was obtained from 1-nitrosopiperazine photolysis experiments and employed analyses of the 1-nitropiperazine and 1-nitrosopiperazine temporal profiles observed during piperazine photo-oxidation. The derived initial branching between N-H and C-H abstraction by OH radicals, kN-H/(kN-H + kC-H), was 0.18 ± 0.04. All experiments were accompanied by substantial aerosol formation that was initiated by the reaction of piperazine with nitric acid. Both primary and secondary photo-oxidation products including 1-nitropiperazine and 1,4-dinitropiperazine were detected in the aerosol particles formed. Corroborating atmospheric photo-oxidation schemes for piperazine and 1-nitropiperazine were derived from M06-2X/aug-cc-pVTZ quantum chemistry calculations and master equation modeling of the pivotal reaction steps. The atmospheric chemistry of piperazine is evaluated, and a validated chemical mechanism for implementation in dispersion models is presented.

AB - The OH-initiated photo-oxidation of piperazine and 1-nitropiperazine as well as the photolysis of 1-nitrosopiperazine were investigated in a large atmospheric simulation chamber. The rate coefficient for the reaction of piperazine with OH radicals was determined by the relative rate method to be kOH-piperazine = (2.8 ± 0.6) × 10-10 cm3 molecule-1 s-1 at 307 ± 2 K and 1014 ± 2 hPa. Product studies showed the piperazine + OH reaction to proceed both via C-H and N-H abstraction, resulting in the formation of 1,2,3,6-tetrahydropyrazine as the major product and in 1-nitropiperazine and 1-nitrosopiperazine as minor products. The branching in the piperazinyl radical reactions with NO, NO2, and O2 was obtained from 1-nitrosopiperazine photolysis experiments and employed analyses of the 1-nitropiperazine and 1-nitrosopiperazine temporal profiles observed during piperazine photo-oxidation. The derived initial branching between N-H and C-H abstraction by OH radicals, kN-H/(kN-H + kC-H), was 0.18 ± 0.04. All experiments were accompanied by substantial aerosol formation that was initiated by the reaction of piperazine with nitric acid. Both primary and secondary photo-oxidation products including 1-nitropiperazine and 1,4-dinitropiperazine were detected in the aerosol particles formed. Corroborating atmospheric photo-oxidation schemes for piperazine and 1-nitropiperazine were derived from M06-2X/aug-cc-pVTZ quantum chemistry calculations and master equation modeling of the pivotal reaction steps. The atmospheric chemistry of piperazine is evaluated, and a validated chemical mechanism for implementation in dispersion models is presented.

U2 - 10.1021/acs.jpca.0c10223

DO - 10.1021/acs.jpca.0c10223

M3 - Article

C2 - 33378187

SN - 1089-5639

JO - Journal of Physical Chemistry A

JF - Journal of Physical Chemistry A

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