Novel Siloles, Hydrogenated Siloles And Their Derivatives:Synthesis, Characterization Properties And Applications

Development of new silacycles such as siloles (silacyclopentadienes),3-silolenes (silacyclopent-3-enes), disilacyclohexadienes and silirenes, is a hot current research topic owing to their unique photophysical and electronic properties and potential applications in material science and organic syntheses.The main results of the thesis are outlined as follows:In the first chapter, we present the synthesis and characterization of a series of novel siloles (silacyclopentadienes) and3-silolenes (silacyclopent-3-enes), The mechanism for the formation of siloles and3-silolenes is studied. Calculated molecular orbital amplitude plots and energy levels of siloles and3-silolenes are compared. The HOMO and LOMO levels of3-silolenes are higher than those of siloles.In the second chapter, we present the synthesis and characterization of a doublecycle-silolene from3-silolene. The mechanism of the ring-forming is investigated. Calculated molecular orbital amplitude plots and energy levels of doublecycle-silolene show that its HOMO and LOMO levels of are higher than those of siloles, but lower that those of3-silolene parent. The doublecycle-silolenes and3-silolenes show strong circular dichroism (CD) signals in the solid state.In the third chapter, we present the synthesis and characterization of functional hyperbranched polymers based on alkyne hydrosilylation of TDMSHS with diethynylsilole in the presence of Karstedt’s catalyst Pt(CH2=CHSiMe2OSiMe2CH=CH2)3. The polymer is stereoregular and possesses a high molecular weight (Mw=146000) with a narrow distribution (polydispersity index=1.5). The polymer shows good thermal and optical properties and its nanoaggregagtes in the aqueous media can detect explosive such as picric acid efficiently with large quenching constant up to414400M-’.