Atom-Precise Organometallic Zinc Clusters
Résumé
The bottom-up synthesis of organometallic zinc clusters is described. The cation \[Zn10 ](Cp*)6 Me\(+) (1) is obtained by reacting [Zn2 Cp*2 ] with [FeCp2 ][BAr4 (F) ] in the presence of ZnMe2 . In the presence of suitable ligands, the high reactivity of 1 enables the controlled abstraction of single Zn units, providing access to the lower-nuclearity clusters \[Zn9 ](Cp*)6 \ (2) and \[Zn8 ](Cp*)5 ((t) BuNC)3 \(+) (3). According to DFT calculations, 1 and 2 can be described as closed-shell species that are electron-deficient in terms of the Wade-Mingos rules because the apical ZnCp* units that constitute the cluster cage do not have three, but only one, frontier orbitals available for cluster bonding. Zinc behaves flexibly in building the skeletal metal-metal bonds, sometimes providing one major frontier orbital (like Group 11 metals) and sometimes providing three frontier orbitals (like Group 13 elements)