New sila-alkyl substituted cyclotetrasiloxanes, [RMe2SiCH2CH2(Me)SiO]4 [R = Ph(1), 2-thienyl(2), 2-furyl(3)] have been synthesized by a hydrosilylation reaction between 2,4,6,8-tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane, (D4Vi) and dimethylphenylsilane/dimethyl-2-thienylsilane/dimethyl-2-furylsilane in the presence of Karstedt's catalyst. X-ray crystallographic studies of 1 and 2 reveal all-trans conformation of the methyl groups bonded to puckered siloxane core and formation of 3D supramolecular assemblies by virtue of intermolecular C–H⋯π interactions. These siloxanes act as potential templates for expeditious one pot synthesis of gold nanowires of varying aspect ratios which are obtained by reduction of HAuCl4·3H2O with triethylsilane (CHCl3, RT). On the other hand, the use of linear polysiloxane, [2-ThMe2SiCH2CH2(Me)SiO]n (4) in lieu of the cyclosiloxane 2 affords predominant formation of polydispersed AuNPs along with a few extended structures. These results suggest that conformational confinement of the appended groups on the cyclosiloxanes, 1–3 plays an important role to impart morphological control of the gold nanowire assemblies.
通过 2,4,6,8-四甲基-2,4,6,8-四
乙烯基环四
硅氧烷 (
D4Vi) 和二甲基苯基
硅烷/二甲基-2-
噻吩基
硅烷之间的氢
硅化反应,合成了新的
硅烷基取代环四
硅氧烷 [RMe2SiCH2CH2(Me)SiO]4 [R = Ph(1),2-
噻吩基(2),2-
呋喃基(3)]、6,8-四甲基-2,4,6,8-四
乙烯基环四
硅氧烷 (
D4Vi) 和二甲基苯基
硅烷/二甲基-2-
噻吩基
硅烷/二甲基-2-
呋喃基
硅烷在卡氏催化剂存在下发生氢化
硅烷化反应而合成的。对 1 和 2 的 X 射线晶体学研究表明,甲基全反式构象与皱褶
硅氧烷核心结合,并通过分子间 C-H⋯π 相互作用形成三维超分子组装体。这些
硅氧烷可作为潜在的模板,通过用三乙基
硅烷(
CHCl3,RT)还原 HAuCl4-3H2O 来快速合成不同长宽比的
金纳米线。另一方面,使用线性聚
硅氧烷[2-ThMe2SiCH2CH2(Me)SiO]n (4)代替环
硅氧烷 2 主要形成了多分散的 AuNPs 以及一些扩展结构。这些结果表明,环
硅氧烷 1-3 上附加基团的构象限制对
金纳米线组装的形态控制起着重要作用。