The bimolecular gas phase reactions of ground state silicon (Si(³P)) with the C₄H₆ isomers 1,3-butadiene, 1,2-butadiene, and 1-butyne were investigated under single collision conditions in a crossed molecular beams machine at collision energies of about 15 kJ mol⁻¹. Our data suggest each reaction proceeds indirectly via SiC₄H₆ intermediates that decompose by elimination of molecular hydrogen through tight exit transition states. In the Si(³P) plus 1,3-butadiene system, multiple product channels are open as evidenced by the observation of molecular hydrogen, hydrogen deuteride, and molecular deuterium losses in experiments utilizing isotopologues of 1,3-butadiene. Non-adiabatic reaction dynamics likely dominate the reaction mechanism in each Si(³P)-hydrocarbon system via intersystem crossing from the triplet to the singlet manifold. These systems are unique in that the reactions proceed at relatively low collision energies and yield products in overall exoergic reactions, unlike the reactions of Si(³P) with the C1-C3 hydrocarbon which have highly endoergic product channels.

在交叉分子束中单碰撞条件下研究了基态硅（Si（³ P））与C ₄ H ₆异构体1,3-丁二烯，1,2-丁二烯和1-丁炔的双分子气相反应机器在约15 kJ mol ^-1的碰撞能量下。我们的数据表明，每个反应都是通过SiC ₄ H ₆中间体间接进行的，该中间体通过紧密的出口过渡态消除分子氢而分解。在Si（³P）加1,3-丁二烯系统，通过使用1,3-丁二烯的同位素异构体进行的实验中观察到的分子氢，氘化氢和分子氘损失，证明了多种产品通道是开放的。通过从三重态到单重态歧管的系统间交叉，非绝热反应动力学很可能在每个Si（³ P）-烃系统中占主导地位的反应机理。这些系统的独特之处在于，反应在相对较低的碰撞能量下进行，并在总体放热反应中产生产物，这与Si（³ P）与具有高度内吸产物通道的C1-C3烃的反应不同。