Isolation and Structure of Germylene-Germyliumylidenes Stabilized by N-Heterocyclic Imines.

The ditopic germanium complex FGe(NIPr)2 Ge[BF4 ] (3[BF4 ]; IPr=1,3-bis(2,6-diisopropylphenyl)imidazolin-2-ylidene) is prepared by the reaction of the amino(imino)germylene (Me3 Si)2 NGeNIPr (1) with BF3 ⋅OEt2 . This monocation is converted into the germylene-germyliumylidene 3[BAr(F) 4 ] [Ar(F) =3,5-(CF3 )2 -C6 H3 ] by treatment with Na[BAr(F) 4 ]. The tetrafluoroborate salt 3[BF4 ] reacts with 2 equivalents of Me3 SiOTf to give the novel complex (OTf)(GeNIPr)2 [OTf] (4[OTf]), which affords 4[BAr(F) 4 ] and 4[Al(OR(F) )4 ] [R(F) =C(CF3 )3 ] after anion exchange with Na[BAr(F) 4 ] or Ag[Al(OR(F) )4 ], respectively. The computational, as well as crystallographic study, reveals that 4(+) has significant bis(germyliumylidene) dication character.