Stabilization of Triaryltin(IV) Cations Containing an O,C,O-Coordinating Pincer-Type Ligand. Isolation of a New [Ag(1-CB₁₁H₁₂)₃]^2- Anion

Reported is the stabilization of pincer-type triaryltin(IV) [Ar1SnPh2]+ and [Ar2SnPh2]+ cations (where Ar1 = 1-{2,6-(MeO)2C6H3} and Ar2 = 1-{2,6-(t-BuO)2C6H3}) with weakly coordinating carborane anions [1-CB11H12]- and [3-Co−(1,2-C2B9H11)2]-. Treatment of Ar1SnPh2Cl with Ag+[1-CB11H12]-, depending on the molar ratio, reaction time, and solvent used (CH2Cl2 or THF), resulted in the isolation of the ion-pairs [Ar1SnPh2]+[1-CB11H12]- (1) (yield 86%) and [Ar1SnPh2]+2[Ag(1-CB11H12)3]2- (2) (yield 94%). Compound 2 contains a new [Ag(1-CB11H12)3]2- anion in which the Ag+ ion is bound to the carborane cages via six hydrogen bridges. Compounds [Ar1SnPh2]+[3-Co-(1,2-C2B9H11)2]- (3) and [Ar2SnPh2]+[1-Co-(2,3-C2B9H11)2]- (4) were prepared in yields of 97 and 95%, respectively, via metathesis of the [Ar1SnPh2]+OTf- and [Ar2SnPh2]+OTf- triflates with Cs+[1-Co-(2,3-C2B9H11)2]- in CH2Cl2. The products were characterized by multinuclear (1H, 11B, and 119Sn) NMR and IR spectroscopy, ESI/MS, and elemental analyses, and the structures of compounds 2, 3, and 4 were determined by X-ray diffraction studies.