A Cyclic Germadicarbene (“Germylone”) from Germyliumylidene

By
employing the chelate dicarbene 1, the new chloro­germylium­ylidene
complex 2 could be synthesized and isolated in 95% yield.
Dechlorination of 2 with sodium naphthalenide furnishes
the unique cyclic germadicarbene 3 which could be isolated
in 45% yield. Compound 3 is the first isolable Ge(0)
complex with a single germanium atom stabilized by a dicarbene. Its
molecular structure is in accordance with DFT calculations which underline
the peculiar electronic structure of 3 with two lone
pairs of electrons at the Ge atom.