Rate Coefficients and Mechanistic Analysis for Reaction of OH with Vinyl Chloride between 293 and 730 K

Abstract

The kinetics of the title reaction were investigated between 293 and 730 K at 740 ( 10 Torr in a helium bath gas. Absolute rate measurements were obtained using a laser photolysis/laser-induced fluorescence (LP/LIF) technique under slow flow conditions. Rate coefficients exhibited complex behavior with negative temperature dependence at temperatures below 560 K, a rapid drop in rate between 560 and 620 K, and a positive temperature dependence above 620 K. The simple Arrhenius equation adequately describes the data at and below 560 K and is given by (in units of cm 3 molecule -1 s -1 ) k(293-560 K) ) (2.72 ( 0.35) × 10 -12 exp(335 ( 42)/T. Error limits are 2σ values. The low-temperature values for k are within (2σ of the most recent measurements of this reaction obtained under atmospheric pressure conditions. Above 620 K, our measurement combined with the recent measurements of Liu et al. 8 to yield the following rate expression: k(620-1173 K) ) (6.3 ( 4.0) × 10 -11 exp(-2740 ( 490)/T. Error limits are 2σ values. The rate data were interpreted using variational transition state theory and QRRK theory. OH addition to the site followed by adduct stabilization describes the low-temperature measurements. Ab initio-based transition state calculations for the H abstraction channel indicated that this mechanism is consistent with the rate measurements above 620 K. H abstraction is predicted to be the dominant reaction channel above temperatures of 800 K.

Formation of benzofuran and chlorobenzofuran from 1,3-dichloropropene: A quantum chemical investigation

“…This abstraction process is exothermic (Δ G = −167.7 kJ/mol) with a trivial activation free energy Δ G ‡ = 7.3 kJ/mol (TS5). The calculated rate parameter for this process ( k [cm 3 /molecule s] = 2.80 × 10 −12 e −Δ G ‡/ RT , Δ G ‡ = 5.2 kJ/mol) is in good agreement with literature data concerning the abstraction of OH hydrogen atoms to form water …”

“…The calculated rate parameter for this process (k [cm 3 /molecule s] 5 2.80 3 10 212 e 2DG ‡/RT , DG ‡ 5 5.2 kJ/mol) is in good agreement with literature data concerning the abstraction of OH hydrogen atoms to form water. [64][65][66][67] Ring closure of 1c, in either a clockwise or anticlockwise direction, then presents a direct route to the formation of…”

The reaction of OH with acetone and acetone-d6 from 298 to 832 K: Rate coefficients and mechanism

“…Our new measurements and previous rate measurements for k H and k D are 4 Wollenhaupt et al, 5 and Vasvári et al 6 are more consistent with our measurements, all lying ϳ12%-13% higher, and that of Tranter and Walker 8 at 753 K, derived from the influence of acetone on H 2 /O 2 chemistry, is 20% higher. Gierczak et al 9 recently published kinetic measurements of OH, OD, and 18 OH with acetone and acetoned 6 . Their results also indicate 14% and 31% higher rate constants at 298 K compared to our results for acetone and acetone-d 6 , respectively.…”

The reaction of OH with acetaldehyde and deuterated acetaldehyde: Further insight into the reaction mechanism at both low and elevated temperatures

“…The apparatus and experimental procedures are well established [16][17][18]. In brief, OH was generated in the presence of a large excess of CH 3 CHO by excimer laser photolysis of a precursor, and monitored by off-resonance laser-induced fluorescence excited at 282 nm.…”