7',7',8',8'-Tetramethyl-2,2'-disilanobiphenyl

9,9,10,10-Tetramethyl-9,10-disilaphenanthrene

9,9,10,10-Tetramethyl-9,10-dihydro-9,10-disilaphenanthrene

9,10-Dihydro-9,9,10,10-tetramethyl-9,10-disilaphenanthrene