Theoretical investigation of reactions between ammonia and precursors from the ozonolysis of ethene

Jørgensen, Solvejg; Gross, Allan

doi:10.1016/j.chemphys.2009.05.020

Cited by 11 publications

(11 citation statements)

References 43 publications

(45 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Furthermore, the effect of NH 3 gas on the SOA formation of α-pinene by dark ozonolysis and photoxidation was investigated using the newly-developed flow reactor [17]. The theoretical work by Jørgensen and Gross afforded an insight into the experimental work of Naa and co-workers by surveying plausible, pertinent reaction mechanisms [18]. Moreover, our previous work on ozonolysis reactions provided good initial guesses that helped us attain a complete picture about the proposed mechanisms for this study [7,[19][20][21][22][23].…”

Section: Introductionmentioning

confidence: 92%

Computational Study of the Dissociation Reactions of Secondary Ozonide

et al. 2020

View full text Add to dashboard Cite

This contribution presents a comprehensive computational study on the reactions of secondary ozonide (SOZ) with ammonia and water molecules. The mechanisms were studied in both a vacuum and the aqueous medium. All the molecular geometries were optimized using the B3LYP functional in conjunction with several basis sets. M06-2X, APFD, and ωB97XD functionals with the full basis set were also used. In addition, single-point energy calculations were performed with the G4MP2 and G3MP2 methods. Five different mechanistic pathways were studied for the reaction of SOZ with ammonia and water molecules. The most plausible mechanism for the reaction of SOZ with ammonia yields HC(O)OH, NH3, and HCHO as products, with ammonia herein acting as a mediator. This pathway is exothermic and exergonic, with an overall barrier height of only 157 kJ mol−1 using the G3MP2 method. All the reaction pathways between SOZ and water molecules are endothermic and endergonic reactions. The most likely reaction pathway for the reaction of SOZ with water involves a water dimer, in which the second water molecule acts as a mediator, with an overall barrier height of only 135 kJ mol−1 using the G3MP2 method. Solvent effects were found to incur a significant reduction in activation energies. When the second H2O molecule acts as a mediator in the reaction of SOZ with water, the barrier height of the rate-determining step state decreases significantly.

show abstract

Section: Introductionmentioning

confidence: 92%

Computational Study of the Dissociation Reactions of Secondary Ozonide

et al. 2020

View full text Add to dashboard Cite

show abstract

“…For the calculation of k tot for the multistep mechanism, the steady state approximation is applied, which is reported to produce good results for the multistep reactions. 74,75 All the partition functions used in the calculations, imaginary frequencies of the transition states (ν i ) with onedimensional Wigner tunneling correction (Γ(T )) for the rate constants of the reaction between TDMAT and NH 3 are provided in Tables S1 and S2, respectively, in the ESI. † The calculated equilibrium constant for the first step (K eq ), the stepwise rate constants (k i ), and the total rate constants (k tot ) are collected in Table 2.…”

Section: Kineticsmentioning

confidence: 99%

Towards a comprehensive understanding of the chemical vapor deposition of titanium nitride using Ti(NMe2)4: a density functional theory approach

et al. 2014

View full text Add to dashboard Cite

A gas phase mechanistic investigation of the chemical vapor deposition (CVD) of titanium nitride (TiN) from the decomposition of Ti(NMe2)4, tetrakis(dimethylamido)titanium (TDMAT) as a single source precursor as well as from the reaction of Ti(NMe2)4 with NH3, i.e., the ammonia assisted mechanism is carried out and reported herein within the framework of density functional theory. Contrary to the theoretical result reported previously for a model TDMAT, metallacycle formation and β-H elimination pathways are found to be the major decomposition pathways responsible for the decomposition of TDMAT, and this finding is in accord with the experimental observation. Interestingly, agostic interaction is found to play a key role in promoting β-H elimination in the decomposition of TDMAT. A new additional pathway of decomposition of TDMAT has been identified theoretically in this present study. Exploration of the complex gas phase mechanism and thereby a detailed identification of the reaction intermediates enable us in realizing the origin of incorporation of carbon contamination in TiN films produced from TDMAT alone and then how the contamination is removed in the presence of ammonia. The ammonia assisted mechanism is found to proceed through the formation of a pre-equilibrium complex. The computed barrier height of 7.3 kcal mol(-1) for the initial transamination process associated with the Ti(NMe2)4 + NH3 reaction is found to be in very good agreement with the experimental activation energy. The total rate constant ktot for the ammonia assisted mechanism is calculated to be 1.28 × 10(-51) cm(3) molecule(-1) s(-1) at 298.15 K.

show abstract

“…Adding NH 3 into the reactor after 3 h photo-oxidation of these complex mixtures, the particle number concentration and mass concentrations increased rapidly, but the average carbon oxidation state of SOA remained almost unchanged. In theoretical calculations, Jørgensen & Gross investigated the reactions between NH 3 with a secondary ozonide and a hydroxyl substituted ester firstly, which formed in the ozonolysis of ethene [ 22 ]. Then the reactions between NH 3 and three simplest carbonyl oxides (H 2 COO, CH 3 HCOO and (CH 3 ) 2 COO) were studied detail [ 23 ].…”

Section: Introductionmentioning

confidence: 99%

“…Thereafter several studies have been carried out to detect •CH 2 OO• and (CH 3 ) 2Ċ OO• and study the kinetics of their unimolecular reactions using synchrotron photoionization mass spectrometry and spectroscopic methods [10][11][12][13][14]. More researches have been done using theoretical methods to investigate the reaction kinetics and mechanisms of bimolecular reactions, including the reactions of CI with NH 3 , NO x , SO 2 , (H 2 O) x , HO x and others [7,[15][16][17][18][19][20][21][22][23][24][25][26].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

The influences of ammonia on aerosol formation in the ozonolysis of styrene: roles of Criegee intermediate reactions

Lin

Yang

et al. 2018

R. Soc. open sci.

View full text Add to dashboard Cite

The influences of ammonia (NH3) on secondary organic aerosol (SOA) formation from ozonolysis of styrene have been investigated using chamber experiments and quantum chemical calculations. With the value of [O3]0/[styrene]0 ratios between 2 and 4, chamber experiments were carried out without NH3 or under different [NH3]/[styrene]0 ratios. The chamber experiments reveal that the addition of NH3 led to significant decrease of SOA yield. The overall SOA yield decreased with the [NH3]0/[styrene]0 increasing. In addition, the addition of NH3 at the beginning of the reaction or several hours after the reaction occurs had obviously different influence on the yield of SOA. Gas phase reactions of Criegee intermediates (CIs) with aldehydes and NH3 were studied in detail by theoretical methods to probe into the mechanisms behind these phenomena. The calculated results showed that 3,5-diphenyl-1,2,4-trioxolane, a secondary ozonide formed through the reactions of C6H5ĊHOO· with C6H5CHO, could make important contribution to the aerosol composition. The addition of excess NH3 may compete with aldehydes, decreasing the secondary ozonide yield to some extent and thus affect the SOA formation.

show abstract

Theoretical investigation of reactions between ammonia and precursors from the ozonolysis of ethene

Cited by 11 publications

References 43 publications

Computational Study of the Dissociation Reactions of Secondary Ozonide

Computational Study of the Dissociation Reactions of Secondary Ozonide

Towards a comprehensive understanding of the chemical vapor deposition of titanium nitride using Ti(NMe2)4: a density functional theory approach

The influences of ammonia on aerosol formation in the ozonolysis of styrene: roles of Criegee intermediate reactions

Contact Info

Product

Resources

About