Shao Guang, Orita Akihiro, Nishijima Koji, Ishimaru Kanako, Takezaki Makoto, Wakamatsu Kan, Gleiter Rolf, Otera Junzo
Department of Applied Chemistry, Okayama University of Science, Ridai-cho, Okayama 700-0005, Japan.
Chem Asian J. 2007 Apr 2;2(4):489-98. doi: 10.1002/asia.200700007.
A variety of arylethynylsilanes (Ar-C[triple bond]C-C6H4-C[triple bond]C)(n)SiMe(4-n) were prepared successfully by reaction of the corresponding chlorosilanes Me(4-n)SiCl(n) with Ar-C[triple bond]C-C6H4-C[triple bond]CM (M = Li, MgBr), which was prepared by treatment of ethynyl(diarylethyne)s Ar-C[triple bond]C-C6H4-C[triple bond]CH with BuLi or MeMgBr. The ethynyl(diarylethyne)s were readily prepared in good yields by the double-elimination method: addition of lithium hexamethyldisilazide to a mixture of ArCH2SO2Ph, TMS-C[triple bond]C-C6H4-CHO, and ClP(O)(OEt)2, followed by desilylation. In the tetrakis(arylethynyl)silanes (Ar-C[triple bond]C-C6H4-C[triple bond]C)4Si thus prepared, through-space conjugation of four triple bonds on the silicon atom emerges as a result of participation of the silicon orbitals in the acetylenic pi orbitals. This participation enhances the emissive quantum yields of arylethynylsilanes with an increase in the number of arylethynyl moieties on silicon: quantum yields of emission (phiF) of 0.72 for (MeOC6H4-C[triple bond]C-C6H4-C[triple bond]C)4Si, 0.53 for (MeOC6H4-C[triple bond]C-C6H4-C[triple bond]C)2SiMe2, and 0.47 for MeO-C6H4-C[triple bond]C-C6H4-C[triple bond]CSiMe3 were obtained. Although this enhancement effect was also observed in the phenylethynylarylsilane (MeOC6H4-C[triple bond]C-C6H4)2SiMe2, the bis(arylethynyl)disilane (MeOC6H4-C[triple bond]C-C6H4-C[triple bond]C-SiMe2)2 exhibited non-enhanced emission.
通过相应的氯硅烷Me(4-n)SiCl(n)与Ar-C≡C-C6H4-C≡CM（M = Li，MgBr）反应，成功制备了多种芳基乙炔基硅烷(Ar-C≡C-C6H4-C≡C)(n)SiMe(4-n)，其中Ar-C≡C-C6H4-C≡CM是通过用丁基锂或甲基溴化镁处理乙炔基（二芳基乙炔）Ar-C≡C-C6H4-C≡CH制备的。乙炔基（二芳基乙炔）通过双消除法很容易以高产率制备：将六甲基二硅氮基锂加入到ArCH2SO2Ph、TMS-C≡C-C6H4-CHO和ClP(O)(OEt)2的混合物中，然后进行脱硅反应。在如此制备的四（芳基乙炔基）硅烷(Ar-C≡C-C6H4-C≡C)4Si中，由于硅轨道参与炔烃π轨道，硅原子上四个三键的空间共轭出现。这种参与随着硅上芳基乙炔基部分数量的增加提高了芳基乙炔基硅烷的发射量子产率：(MeOC6H4-C≡C-C6H4-C≡C)4Si的发射量子产率（φF）为0.72，(MeOC6H4-C≡C-C6H4-C≡C)2SiMe2为0.53，MeO-C6H4-C≡C-C6H4-C≡CSiMe3为0.47。尽管在苯基乙炔基芳基硅烷(MeOC6H4-C≡C-C6H4)2SiMe2中也观察到了这种增强效应，但双（芳基乙炔基）乙硅烷(MeOC6H4-C≡C-C6H4-C≡C-SiMe2)2表现出非增强发射。
