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A series of tour asymmetrically awl-substituted 9,9'-spiro-9-silabifluorene (SSF) derivatives, 2,2'- di-tert-butyl-7,7'-diphenyl-9,9'-spiro-9-silabifluorene (PhSSF), 2,2'-di-tert-butyl-7,7'-dipyridin-2-yl-9,9'-spiro- 9-silabifluorene (PySSF), 2,2'-di-tert-butyl-7,7'-dibiphenyl-4-yl-9,9'-spiro-9-silabitluorene (BPhSSF), and 2,2'- di-tert-butyl-7,7'-bis(2',2"-bipyridin-6-yl)-9,9'-spiro-9-silabitluorene (BPySSF) are prepared through the cyclization of the corresponding 2,2'-dilithiobiphenyls with silicon tetrachloride. These novel spiro-linked silacyclopentadienes (siloles) form transparent and stable amorphous films with relatively high glass transition temperatures (Tg = 203-228 °C). The absorbance spectrum of each compound shows a significant bathochromic shift relative to that of the corresponding carbon analogue as a result of the effective α* - π* conjugation between the α* orbital of the exocyclic Si-C bond and the π* orbital of the oligoarylene fragment. Solid-state films exhibit intense violet-blue emission (λPL = 398-415 nm) with high absolute photoluminescence quantum yields (ΦPL = 30-55%). [ABSTRACT FROM AUTHOR]