Thomas Aaron M, Zhao Long, He Chao, Galimova Galiya R, Mebel Alexander M, Kaiser Ralf I
Department of Chemistry, University of Hawai'i at Manoa, Honolulu, HI, 96822, USA.
Department of Chemistry and Biochemistry, Florida International University, Miami, FL, 33199, USA.
Angew Chem Int Ed Engl. 2019 Oct 21;58(43):15488-15495. doi: 10.1002/anie.201908039. Epub 2019 Sep 3.
The triafulvene molecule (c-C H )-the simplest representative of the fulvene family-has been synthesized for the first time in the gas phase through the reaction of the methylidyne radical (CH) with methylacetylene (CH CCH) and allene (H CCCH ) under single-collision conditions. The experimental and computational data suggest triafulvene is formed by the barrierless cycloaddition of the methylidyne radical to the π-electron density of either C H isomer followed by unimolecular decomposition through elimination of atomic hydrogen from the CH or CH groups of the reactants. The dipole moment of triafulvene of 1.90 D suggests that this molecule could represent a critical tracer of microwave-inactive allene in cold molecular clouds, thus defining constraints on the largely elusive hydrocarbon chemistry in low-temperature interstellar environments, such as that of the Taurus Molecular Cloud 1 (TMC-1).
三环戊二烯分子（c-C₅H₄）——富烯家族最简单的代表物——首次在气相中通过亚甲基自由基（CH）与甲基乙炔（CH₃CCH）和丙二烯（H₂CCCH₂）在单碰撞条件下的反应合成。实验和计算数据表明，三环戊二烯是由亚甲基自由基与任一C₅H₄异构体的π电子密度进行无势垒环加成，然后通过从反应物的CH或CH₂基团消除原子氢进行单分子分解而形成的。三环戊二烯的偶极矩为1.90 D，这表明该分子可能是冷分子云中微波非活性丙二烯的关键示踪剂，从而对低温星际环境（如金牛座分子云1（TMC-1））中基本上难以捉摸的碳氢化合物化学形成限制。
