Hydrogen atom abstraction from Piperazine by hydroxyl radical: a theoretical investigation

Sarma, Plaban Jyoti; Gour, Nand Kishor; Bhattacharjee, Debojyoti; Mishra, Bhupesh Kumar; Deka, Ramesh Chandra

doi:10.1080/00268976.2017.1294714

Cited by 10 publications

(18 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The M06-2X IRC-calculations locate a prereaction adduct to N–H abstraction on a nearly flat surface in the vicinity of the saddle point SP 1 N H . Similar results have been reported for the OH reactions with methylamine and piperazine . We notice that the basis set superposition error (BSSE) in the M06-2X calculations of PRE NH , estimated by the Counterpoise method, is respectively 2.25 (aug-cc-pVDZ) and 0.75 (aug-cc-pVTZ) kJ mol –1 .…”

Section: Results and Discussionsupporting

confidence: 83%

See 1 more Smart Citation

Theoretical and Experimental Study on the Reaction of tert-Butylamine with OH Radicals in the Atmosphere

et al. 2018

View full text Add to dashboard Cite

The OH-initiated atmospheric degradation of tert-butylamine (tBA), (CH)CNH, was investigated in a detailed quantum chemistry study and in laboratory experiments at the European Photoreactor (EUPHORE) in Spain. The reaction was found to mainly proceed via hydrogen abstraction from the amino group, which in the presence of nitrogen oxides (NO ), generates tert-butylnitramine, (CH)CNHNO, and acetone as the main reaction products. Acetone is formed via the reaction of tert-butylnitrosamine, (CH)CNHNO, and/or its isomer tert-butylhydroxydiazene, (CH)CN═NOH, with OH radicals, which yield nitrous oxide (NO) and the (CH)Ċ radical. The latter is converted to acetone and formaldehyde. Minor predicted and observed reaction products include formaldehyde, 2-methylpropene, acetamide and propan-2-imine. The reaction in the EUPHORE chamber was accompanied by strong particle formation which was induced by an acid-base reaction between photochemically formed nitric acid and the reagent amine. The tert-butylaminium nitrate salt was found to be of low volatility, with a vapor pressure of 5.1 × 10 Pa at 298 K. The rate of reaction between tert-butylamine and OH radicals was measured to be 8.4 (±1.7) × 10 cm molecule s at 305 ± 2 K and 1015 ± 1 hPa.

show abstract

Section: Results and Discussionsupporting

confidence: 83%

“…The reaction enthalpies (ΔH Θ , in kJ mol −1 ) stem from G4 calculations and refer to 298 K. Stationary points on the tBA + OH potential energy surface 50 were located in M06-2X and MP2 calculations employing the aug-cc-pVTZ basis set. Improved energies were obtained in CCSD(T*)-F12a/aug-cc-pVTZ computations.…”

Section: Resultsmentioning

confidence: 99%

Theoretical and Experimental Study on the Reaction of tert-Butylamine with OH Radicals in the Atmosphere

et al. 2018

View full text Add to dashboard Cite

show abstract

“…Both compounds were observed, but not quantified, in previous PZ photo-oxidation experiments in the ∼200 m 3 European Photoreactor (EUPHORE), 8 and in the more recent experiments employing a ∼18 m 3 indoor smog chamber. 9 The open literature includes two theoretical studies on the kinetics of the hydrogen abstraction from PZ by OH radicals, in which the branching between the N−H and C−H abstraction reactions 1a and 1b were predicted to be 0.07 10 and 0.01, 11 respectively, at 298 K. The latter theoretical study also includes an investigation of the atmospheric degradation following the C−H abstraction. A theoretical report of the Clatom-initiated oxidation of PZ suggests that this reaction proceeds with 99.8% N−H abstraction at 298 K; 12 the study also includes a mapping of the potential energy surfaces for the piperazinyl radical reactions with NO and O 2 .…”

Section: Introductionmentioning

confidence: 99%

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

et al. 2020

View full text Add to dashboard Cite

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 k OH-piperazine = (2.8 ± 0.6) × 10 –10 cm 3 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, NO 2 , and O 2 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, k N–H /( k N–H + k C–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.

show abstract

“…7 These fast kinetics and the predominance of C−H abstraction have been confirmed in two subsequent theoretical papers. 21,46 However, as a cyclic amine, with two secondary amine groups (generally faster kinetics than primary amines), this may not be the best comparator for N-methyl-1,3-propanediamine. An alternative comparison would be to consider N-methyl-1,3propanediamine in a comparison with ethylamine and dimethylamine; the combination of these two rate coefficients, 2.54 × 10 −11 cm 3 molecule −1 s −1 + 6.4 × 10 −11 cm 3 molecule −1 s −1 = 8.94 × 10 −11 cm 3 molecule −1 s −1 , is in better agreement with our measured value of 7.09 × 10 −11 cm 3 molecule −1 s −1 , which we believe to be a lower limit for the true rate coefficient.…”

Section: Conclusion and Comparison With The Sarmentioning

confidence: 99%

OH Kinetics with a Range of Nitrogen-Containing Compounds: N-Methylformamide, t-Butylamine, and N-Methyl-propane Diamine

et al. 2021

View full text Add to dashboard Cite

Emissions of amines and amides to the atmosphere are significant from both anthropogenic and natural sources, and amides can be formed as secondary pollutants. Relatively little kinetic data exist on overall rate coefficients with OH, the most important tropospheric oxidant, and even less on site-specific data which control the product distribution. Structure−activity relationships (SARs) can be used to estimate both quantities. Rate coefficients for the reaction of OH with t-butylamine (k 1 ), N-methyl-1,3-propanediamine (k 2 ), and N-methylformamide (k 3 ) have been measured using laser flash photolysis coupled with laser-induced fluorescence. Proton-transferreaction mass spectrometry (PTR-MS) has been used to ensure the reliable introduction of these low-vapor pressure N-containing compounds and to give qualitative information on products. Supporting ab initio calculations are presented for the t-butylamine system. The following rate coefficients have been determined: k 1,298K = (1.66 ± 0.20) × 10 −11 cm 3 molecule −1 s −1 , k(T) 1 = 1.65 × 10 −11 (T/300) −0.69 cm 3 molecule −1 s −1 , k 2,293K = (7.09 ± 0.22) × 10 −11 cm 3 molecule −1 s −1 , and k 3,298K = (1.03 ± 0.23) × 10 −11 cm 3 molecule −1 s −1 . For OH + t-butylamine, ab initio calculations predict that the fraction of N−H abstraction is 0.87. The dominance of this channel was qualitatively confirmed using end-product analysis. The reaction of OH with N-methyl-1,3-propanediamine also had a negative temperature dependence, but the reduction in the rate coefficient was complicated by reagent loss. The measured rate coefficient for reaction 3 is in good agreement with a recent relative rate study. The results of this work and the literature data are compared with the recent SAR estimates for the reaction of OH with reduced nitrogen compounds. Although the SARs reproduce the overall rate coefficients for reactions, site-specific agreement with this work and other literature studies is less strong.

show abstract

Hydrogen atom abstraction from Piperazine by hydroxyl radical: a theoretical investigation

Cited by 10 publications

References 33 publications

Theoretical and Experimental Study on the Reaction of tert-Butylamine with OH Radicals in the Atmosphere

Theoretical and Experimental Study on the Reaction of tert-Butylamine with OH Radicals in the Atmosphere

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

OH Kinetics with a Range of Nitrogen-Containing Compounds: N-Methylformamide, t-Butylamine, and N-Methyl-propane Diamine

Contact Info

Product

Resources

About