He Chao, Yang Zhenghai, Doddipatla Srinivas, Zhao Long, Goettl Shane, Kaiser Ralf I, Silva Mateus Xavier, Galvão Breno R L
Department of Chemistry, University of Hawai'i at Manoa, Honolulu, Hawaii 96822, United States.
Centro Federal de Educação Tecnológica de Minas Gerais, CEFET-MG, Av. Amazonas 5253, 30421-169 Belo Horizonte, Minas Gerais, Brazil.
J Phys Chem Lett. 2021 Mar 18;12(10):2489-2495. doi: 10.1021/acs.jpclett.1c00085. Epub 2021 Mar 5.
The phosphinidenesilylene (HPSi; XA') molecule was prepared via a directed gas-phase synthesis in the bimolecular reaction of ground-state atomic silicon (Si; P) with phosphine (PH; XA) under single-collision conditions. The chemical dynamics are initiated on the triplet surface via addition of a silicon atom to the non-bonding electron pair of phosphine, followed by non-adiabatic dynamics and surface hopping to the singlet manifold, accompanied by isomerization via atomic hydrogen shift and decomposition to phosphinidenesilylene (HPSi, XA') along with molecular hydrogen. Statistical calculations predict that silylidynephosphine (HSiP, XΣ) is also formed, albeit with lower yields. The barrier-less route to phosphinidenesilylene opens up a multipurpose mechanism to access the hitherto obscure class of phosphasilenylidenes through silicon-phosphorus coupling via reactions of atomic silicon with alkylphosphines under single-collision conditions in the absence of successive reactions of the reaction products, which are not feasible to prepare by traditional synthetic routes.
膦亚甲基硅烯（HPSi；XA'）分子是通过基态原子硅（Si；P）与膦（PH；XA）在单碰撞条件下的双分子反应，经定向气相合成制备的。化学动力学在三重态表面通过硅原子加到膦的非键电子对开始，随后是非绝热动力学以及向单重态流形的表面跳跃，伴随着通过原子氢转移的异构化以及分解为膦亚甲基硅烯（HPSi，XA'）和分子氢。统计计算预测甲硅烷基膦（HSiP，XΣ）也会形成，尽管产率较低。通往膦亚甲基硅烯的无势垒途径开辟了一种多功能机制，可通过在单碰撞条件下原子硅与烷基膦的反应，经由硅 - 磷偶联来获得迄今仍不清楚的膦硅烯基类化合物，而无需反应产物的连续反应，这是传统合成路线无法制备的。
