Kumar Avinash, Gonu Srinivasulu, Vijayakumar S, Ramya C B, Rajakumar B
Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036, India.
Department of Applied Chemistry, Samrat Ashok Technological Institute, Vidisha 464001, Madhya Pradesh, India.
J Phys Chem A. 2021 Jan 21;125(2):523-535. doi: 10.1021/acs.jpca.0c08130. Epub 2021 Jan 6.
The gas-phase kinetics for the reactions of OH radicals and Cl atoms with 1,1,1,3,3,3-hexafluoro-2-methyl-2-propanol (HF2M2P) were measured at temperatures between 268 and 363 K using the relative rate experimental technique. Methane and acetonitrile were used as reference compounds to measure the rate coefficients of the title reactions. For the reactions of HF2M2P with OH radicals and Cl atoms, the rate coefficients were measured to be (7.07 ± 1.21) × 10 and (2.85 ± 0.54) × 10 cm molecule s, respectively, at 298 K. The obtained Arrhenius expressions for the reactions of HF2M2P with OH radicals and Cl atoms are = (7.84 ± 0.75) × 10 exp [-(717 ± 59)/] and = (3.21 ± 0.45) × 10 exp [-(1395 ± 83)/] cm molecule s. In addition to the experimental measurements, computational kinetic calculations were also performed for the title reactions at the M06-2X/MG3S//M06-2X/6-31 + G(d,p) level of theory using advanced methods such as the canonical variational transition-state theory coupled with small curvature tunneling corrections at temperatures between 200 and 400 K. Theoretical calculations reveal that the H-abstraction from the CH group is a more favorable reaction channel than that from the OH group. Thermochemistry, branching ratios, cumulative atmospheric lifetime, global warming potential, acidification potential, and photochemical ozone creation potential of HF2M2P were calculated in the present investigation.
采用相对速率实验技术，在268至363 K的温度范围内测量了OH自由基和Cl原子与1,1,1,3,3,3-六氟-2-甲基-2-丙醇（HF2M2P）反应的气相动力学。甲烷和乙腈用作参考化合物来测量上述反应的速率系数。对于HF2M2P与OH自由基和Cl原子的反应，在298 K时测得的速率系数分别为(7.07 ± 1.21) × 10和(2.85 ± 0.54) × 10 cm³·分子⁻¹·s⁻¹。得到的HF2M2P与OH自由基和Cl原子反应的阿伦尼乌斯表达式分别为 = (7.84 ± 0.75) × 10 exp [-(717 ± 59)/T]和 = (3.21 ± 0.45) × 10 exp [-(1395 ± 83)/T] cm³·分子⁻¹·s⁻¹。除了实验测量外，还在M06-2X/MG3S//M06-2X/6-31 + G(d,p)理论水平上，使用诸如正则变分过渡态理论结合小曲率隧道效应校正等先进方法，对200至400 K温度范围内的上述反应进行了计算动力学计算。理论计算表明，从CH基团上夺取H比从OH基团上夺取H是更有利的反应通道。本研究计算了HF2M2P的热化学、分支比、累积大气寿命、全球变暖潜势、酸化潜势和光化学臭氧生成潜势。
