[dancool]

Recently done a lab experiment forming tetraphenyltin by grignard reaction of sncl4 using bromobenzene and magnesium. tetraphenyltin was then reacted with solid iodine in chloroform to form triphenyltiniodide + phenyl iodide. triphenyltin iodide was reacted with KOH and then HCl to form solid tri phenyl tin chloride.

Was just interested in a possible reaction mechanism for:

   Ph₄Sn + I₂ --> Ph₃SnI + PhI

I thought

1. electrophilic addition of I onto phenyl ring. and then subsequent nuclophilic attack at Sn centre with I^-

but i believe electrophilic addition of I onto phenyl ring is not possible without use of an additional reagent

2. attack of I₂ at Sn centre using a lone pair. subsequent loss of Ph^- which picks up terminal I from I₂ and electron pair returned to previously two co-ordinate I to restore charge.

thanks for any contribution