Photochemistry of ethyltrimethylstannane and n-propyltrimethylstannane at 185 nm

Abstract

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.