Linear, branched and network polysilanes with thienyl/furyl substituted sila-alkyl side chains and their applications for the synthesis of fluorescent silver nanoparticles/clusters

Abstract

The scope of Wurtz coupling and catalytic dehydrocoupling methods for the synthesis of functional polysilanes of compositions, [RR’Si]n (linear), [(PhMeSi)x-co-(RSi)1 − x]n (branched) and [RSi]n (network) [R = Et3SiCH2CH2, 2-Fu/2-ThMe2SiCH2CH2 (Fu = Furyl, Th = Thienyl), n-Hex or Ph; R’ = H or Me] is presented. By virtue of σ-delocalized silicon backbone and variable HOMO–LUMO band gap energies, these polymers are found to be promising candidates as reducing agents for Ag(I) ions in toluene/cyclo-hexane and provide a simple approach for ‘size-controlled’ synthesis of silver nanoparticles (AgNPs) as well as fluorescent polymer–silver nanocomposites. Synthetic methods for a few linear, branched and network polysilanes bearing thienyl/furyl substituted sila–alkyl side chains are described. These polymers are useful precursors for in situ reduction of Ag(I) ions and afford stable polymer–silver nanoassemblies with control over the size domains. Photoluminescence properties of these nanoassemblies are also reported.