Synthesis and Characterization of Two Isomers of 14π-Electron Germaaromatics:  Kinetically Stabilized 9-Germaanthracene and 9-Germaphenanthrene

The first stable 9-germaanthracene and 9-germaphenanthrene were successfully synthesized by taking advantage of kinetic stabilization utilizing effective steric protection groups, Tbt and Bbt groups (Tbt = 2,4,6-tris[bis(trimeth-ylsilyl)methyl]phenyl, Bbt = 2,6-bis[bis(trimethylsilyl)methyl]-4-[tris(trimethylsilyl)methyl]phenyl). The similarities and differences of the structures and properties between the two isomers of germaaromatics are discussed.