On the Formation of Intermetalloid Clusters: Titanocene(III) diammin as a Versatile Reactant Toward Nonastannide Zintl Clusters

摘要

The reactivity of TiCp2Cl2 (d(0)) towards Zintl clusters was studied in liquid ammonia (Cp=cyclopentadienyl). Reduction of (TiCp2Cl2)-Cp-IV and ligand exchange led to the formation of [(TiCp2)-Cp-III(NH3)(2)](+), also obtainable by recrystallization of [(CpTiCl)-Cl-III](2). Upon reaction with [K4Sn9], ligand exchange leads to [TiCp2((1)-Sn-9)(NH3)](3-). A small variation of the stoichiometry led to the formation of [Ti((4)-Sn-8)Cp](3-), which cocrystallizes with [TiCp2(NH3)(2)](+) and [TiCp2((1)-Sn-9)(NH3)](3-). Finally, the large intermetalloid cluster anion [Ti4Sn15Cp5](n-) (n=4 or 5) was obtained from the reaction of K12Sn17 and TiCp2Cl2 in liquid ammonia. The isolation of three side products, [K([18]crown-6)]Cp, [K([18]crown-6)]Cp(NH3), and [K([2.2]crypt)]Cp, suggests a stepwise elimination of the Cl- and Cp- ligands from TiCp2Cl2 and thus gives a hint to the mechanism of the product formation in which [Ti((4+2)-Sn-8)Cp](3-) has a key role.