Role of the Silver Salt in the Stereoselective Ligand Exchange Reaction of the Diiodoiridium(III)Complex Bearing the Cp'-P Ligand with Triphenylphosphine in the Presence of AgOTf

摘要

Reaction of {eta~5:eta~1-(Ind-P)_(n=2)}IrI_2(1)with an excess amount of AgOTf in the presence of PPh_3 afforded the cationic complex,[{eta~5:eta~1-(Ind-P)_(n=2)}Ir(I)(PPh_3)][OTf](2)as a single isomer.This Stereoselective ligand exchange reaction proceeds via a lid-on-off mechanism involving the following 4 steps;i)dissociation of diphenylphosphino group in 1 and coordination of PPh_3,ii)generation of the unsaturated complex [{eta~5-(Ind-P)_(n=2)}Ir(PPh_3)(I)][OTf](5),iii)generation of the Ir-Ag_2 cluster 6,and iv)recoordination of the diphenylphosphino group.