Ethyltrimethylstannane vapour (ets) yields several gaseous hydrocarbons on photolysis together with a yellow polymer which deposits on the cell window. Addition of nitrogen or argon (130 mbar) reduces the yields by 90 % but there is a residual reaction which is unaffected by pressure of inert gas. Addition of oxygen reduces some yields to zero. The major primary reactions are C2H5Sn(CH3)3+hν(λ= 185 nm)→C2H4+(CH3)3SnH, ϕ∼0.40; →C2H5+CH3+Sn(CH3)2, ϕ∼0.55. The quantum yields of formation of the radical products are increased by radical abstraction from the stannane. Similar results were found for propyltrimethylstannane (pts) but the principal free radical reaction is C3H7Sn(CH3)3+hν(λ= 185 nm)→ C3H7+ 2CH3+ Sn(CH3). The quenching effect is attributed to the deactivation of one of the two excited state precursors of the reaction.
乙基
三甲基锡烷蒸气(ets)在光解过程中生成几种气态烃以及沉积在反应室窗口上的黄色聚合物。加入氮气或
氩气(130 毫巴)可将产率降低 90%,但存在一种不受惰性气体压力影响的残余反应。加入
氧气可使某些产率降至零。主要初级反应为:
C2H5Sn(
CH3)3 + hν(λ= 185 nm) →
C2H4 + ( )3SnH,量子产率 ϕ ≈ 0.40;→
C2H5 + + Sn( )2,量子产率 ϕ ≈ 0.55。
锡烷中自由基的抽取使得自由基产物的形成量子产率增加。对于丙基
三甲基锡烷(pts)也得到了类似结果,但其主要自由基反应为 Sn( )3 + hν(λ= 185 nm) →
C3H7 + 2 + Sn( )。熄灭效应归因于反应的两个激发态前体之一的失活。