Synthesis and Reactivity of Intramolecularly NHC-Stabilized Germylenes and Stannylenes

The HOMO–LUMO energy gap of germylenes bearing CNHC∧Namido chelate ligands has been calculated in order to find suitable candidates for the activation of small molecules. Identified as promising structures, intramolecularly NHC-stabilized three-coordinate germylenes and stannylenes of type [E­(CNHC∧Namido)­Cl] (E = Ge and Sn) were synthesized and characterized by NMR spectroscopy and X-ray crystallography. Chlorido substitution at the EII center for tert-butoxido or hexamethyl disilazide ligands was also performed. Chlorido abstraction with NaBArF gave rise to cationic two-coordinate germylenes and stannylenes.