He Chao, Nikolayev Anatoliy A, Zhao Long, Thomas Aaron M, Doddipatla Srinivas, Galimova Galiya R, Azyazov Valeriy N, Mebel Alexander M, Kaiser Ralf I
Department of Chemistry, University of Hawai'i at Manoa, Honolulu, Hawaii 96822, United States.
Samara National Research University, Samara 443086, Russian Federation.
J Phys Chem A. 2021 Jan 14;125(1):126-138. doi: 10.1021/acs.jpca.0c08731. Epub 2021 Jan 4.
The bimolecular gas-phase reaction of the methylidyne radical (CH; XΠ) with 1,2-butadiene (CHCCHCH; XA') was investigated at a collision energy of 20.6 kJ mol under single collision conditions. Combining our laboratory data with high-level electronic structure calculations, we reveal that this bimolecular reaction proceeds through the barrierless addition of the methylidyne radical to the carbon-carbon double bonds of 1,2-butadiene leading to doublet CH intermediates. These collision adducts undergo a nonstatistical unimolecular decomposition through atomic hydrogen elimination to at least the cyclic 1-vinyl-cyclopropene (/), 1-methyl-3-methylenecyclopropene (), and 1,2-bis(methylene)cyclopropane () in overall exoergic reactions. The barrierless nature of this bimolecular reaction suggests that these cyclic CH isomers might be viable targets to be searched for in cold molecular clouds like TMC-1.
在单次碰撞条件下，研究了亚甲基自由基（CH；XΠ）与1,2-丁二烯（CHCCHCH；XA'）的双分子气相反应，碰撞能量为20.6 kJ/mol。将我们的实验室数据与高水平电子结构计算相结合，我们发现该双分子反应通过亚甲基自由基无势垒加成到1,2-丁二烯的碳-碳双键上进行，生成双重态CH中间体。这些碰撞加合物通过消除原子氢进行非统计单分子分解，在总体放能反应中至少生成环状1-乙烯基环丙烯（/）、1-甲基-3-亚甲基环丙烯（）和1,2-双（亚甲基）环丙烷（）。该双分子反应的无势垒性质表明，这些环状CH异构体可能是在诸如TMC-1等冷分子云中寻找的可行目标。
