End-Capped Silole Dendrimers on a Carbosilane Periphery:  Potential Electroluminescent Materials

• Published in: Organometallics 2006-01, Vol.25 (3), p.766-774
• Main Authors: Son, Ho-Jin, Han, Won-Sik, Kim, Hyojeong, Kim, Chungkyun, Ko, Jaejung, Lee, Chongmok, Kang, Sang Ook
• Format: Article
• Language: English
• ISSN: 0276-7333; 1520-6041
• DOI: 10.1021/om050991v

The divergent synthesis of end-capped silole dendrimers G n -2 n+ 1 Silole (n = 1−4) using 2,4,6,8-tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane [Me(CH2CH)SiO]4 as a core molecule and allyl alcohol/dichloromethylsilane as a building block is described in this paper. The reaction of the dichloride functionalities of the carbosiloxane dendrimers G n- 2 n+ 2 Cl (n = 1−4) with the 1,4-diphenylbutadiene-1,4-dianions (1) provided an effective route for the attachment of silole functionalities to a dendritic periphery. In addition, dendritic siloles GB n -2 n Silole (n = 1−3) based on phenylethynylmethylsilane (PhC⋮C)2Me2Si as cores were synthesized. The building blocks of the dendrimers consisted of double bonds (−PhCCHMeSi−) in the inner shell and silole groups on the outermost periphery. The generational limit of the dendrimer for the two-branching type core molecule was found to have eight silole groups for the third generation. All of the dendrimers were characterized by 1H and 13C{1H} NMR, UV spectroscopy, cyclic votammetry (CV), and size exclusion chromatography (SEC). Using this methodology, a series of silole-containing dendrimer systems showing green to greenish-blue fluorescence were synthesized.