Intramolecular Metal⋅⋅⋅π-Arene Interactions in Neutral and Cationic Main Group Compounds.

The role of intramolecular metal⋅⋅⋅π-arene interactions has been investigated in the solid-state structures of a series of main group compounds supported by the bulky amide ligands, [N(tBu Ar≠ )(SiR3 )]- (tBu Ar≠ =2,6-(CHPh2 )2 -4-tBuC6 H2 , R=Me, Ph). The lithium and potassium amide salts showed different patterns of solvation and demonstrated that the SiPh3 substituent is able to be involved in stabilizing the electrophilic metal. These group 1 metal compounds served as ligand transfer reagents to access a series of bismuth(III) halides. Chloride extraction from Bi(N{tBu Ar≠ }{SiPh3 })Cl2 using AlCl3 afforded the 1:1 salt [Bi(N{tBu Ar≠ }{SiPh3 })Cl][AlCl4 ]. This was accompanied by a significant rearrangement of the stabilizing π-arene contacts in the solid-state. Attempted preparation of the corresponding tetraphenylborate salt resulted in phenyl-transfer and generation of the neutral Bi(N{tBu Ar≠ }{SiPh3 })(Ph)Cl.