Facile access to a Ge() dication stabilized by isocyanides

Herein, we introduce isocyanide as a ligand in main group chemistry and describe the facile isolation of a Ge( ii ) dication. The reaction of 2,6-dimethylphenylisocyanide with GeCl 2 leads to the formation of a Ge( ii ) dication with two [GeCl 3 ] − molecules as counter anions. The dicationic Ge( ii ) center is bound to four isocyanide ligands and also holds a lone pair of electrons. DFT calculations reveal that the dication is stabilized only by σ-donation from the four isocyanide ligands. Natural population analysis gives a charge of +0.74 on the Ge( ii ) center, indicating that the positive charge is shared by the isocyanide substituents. The reaction of 2,6-dimethylphenylisocyanide with GeCl 2 afforded a Ge( ii ) dication, which is stabilized by four isonitrile ligands through σ-donation.