RESUMEN
Temperature-dependent rate coefficients for the reactions of 2-methyl tetrahydrofuran (MTHF) with Cl atoms in the temperature range of 268-343 K at atmospheric pressure were measured using the relative-rate method. Ethylene and propane were used as reference compounds. Quantitative analysis of the post-photolysis reaction mixture was conducted using a gas chromatograph paired with a flame ionization detector (GC-FID). A gas chromatograph connected to a mass spectrometer (GC-MS) was employed for the purpose of qualitative analysis. In the experimental temperature range, the derived Arrhenius expression for the title reaction is represented by the equation k M T H F + C l Expt 268 - 343 K = ( 1.48 ± 0.13 ) × 10 - 12 × e x p 1474.51 ± 25.16 T cm3 molecule-1 s-1. In addition to our experimental findings, we conducted computational calculations employing the CCSD(T)//BHandHLYP/6-31 + G(d,p) level of theory to complement our study. The canonical transition state theory (CTST) was utilized to compute the rate coefficients at 250-400 K and 760 Torr. The Arrhenius expression for the theoretically calculated "k" values is found to be k M T H F + C l Theory 250 - 400 K = ( 1.51 ± 0.10 ) × 10 - 12 × e x p 1544.97 ± 22.14 T cm3 molecule-1 s-1. The local reactivity parameters, such as Fukui functions ( f r 0 ), local softness ( s r 0 ), and global softness ( S ) were also calculated theoretically to understand the site-specific reactivity trend of MTHF towards Cl atoms. The atmospheric implications, branching ratios, degradation mechanism, and feasibility of the reaction are discussed in this study.
RESUMEN
In the present work, the temperature-dependent kinetics for the reaction of tert-butyl chloride (TBC) with OH radicals and Cl atoms were determined experimentally between 268 and 363 K, and theoretically between 200 and 400 K. Pulsed laser photolysis-laser induced fluorescence (PLP-LIF) and relative rate (RR) methods were used to obtain the rate coefficients for the reaction of TBC with OH radicals and Cl atoms, respectively. The Arrhenius equations and were obtained for both reactions based on the experimentally measured rate coefficients. The theoretical rate coefficients were determined at the CCSD(T)/aug-cc-pVTZ//M06-2X/6-31+G(d,p) level for the reaction of TBC with OH radicals and at the CCSD(T)/cc-pVDZ//MP2/6-311+G(d,p) level for the reaction with Cl atoms with incorporated tunnelling corrections. The product analysis of both reactions in the presence of oxygen (O2) was carried out, and a degradation pathway for TBC was proposed. The potential implications of these reactions in the atmosphere were discussed using the obtained kinetic parameters.