Yang Tao, Thomas Aaron M, Dangi Beni B, Kaiser Ralf I, Mebel Alexander M, Millar Tom J
Department of Chemistry, University of Hawai'i at Mānoa, Honolulu, HI, 96822, USA.
State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, 200062, China.
Nat Commun. 2018 Feb 22;9(1):774. doi: 10.1038/s41467-018-03172-5.
Interstellar silicates play a key role in star formation and in the origin of solar systems, but their synthetic routes have remained largely elusive so far. Here we demonstrate in a combined crossed molecular beam and computational study that silicon dioxide (SiO) along with silicon monoxide (SiO) can be synthesized via the reaction of the silylidyne radical (SiH) with molecular oxygen (O) under single collision conditions. This mechanism may provide a low-temperature path-in addition to high-temperature routes to silicon oxides in circumstellar envelopes-possibly enabling the formation and growth of silicates in the interstellar medium necessary to offset the fast silicate destruction.
星际硅酸盐在恒星形成和太阳系起源中起着关键作用，但迄今为止，它们的合成途径在很大程度上仍不为人所知。在这里，我们通过交叉分子束和计算相结合的研究表明，在单次碰撞条件下，甲硅烷基自由基（SiH）与分子氧（O）反应可合成二氧化硅（SiO）和一氧化硅（SiO）。除了在星际包层中通过高温途径形成硅氧化物外，这种机制可能提供一条低温途径，这可能使星际介质中硅酸盐的形成和生长成为可能，从而抵消硅酸盐的快速破坏。
