Double-Decker Silsesquioxanes Self-Assembled in One-Dimensional Coordination Polymeric Nanofibers with Emission Properties

ACS Appl Mater Interfaces. 2021 May 19;13(19):22806-22818. doi: 10.1021/acsami.1c02510. Epub 2021 May 7.

Abstract

The urgent needs for photoactive materials in industry drive fast evolution of synthetic procedures in many branches of chemistry, including the chemistry of silsesquioxanes. Here, we disclose an effective protocol for the synthesis of novel double-decker silsesquioxanes decorated with two (styrylethynylphenyl)terpyridine moieties (DDSQ_Ta-b). The synthesis strategy involves a series of silylative and Sonogashira coupling reactions and is reported for the first time. DDSQ_Ta-b were employed as nanocage ligands to promote self-assembly in the presence of transition metals (TM), i.e., Zn2+, Fe2+, and Eu3+ ions, to form one-dimensional (1D) coordination polymeric nanofibers. Additionally, ultraviolet-promoted and reversible E-Z isomerization of the C═C bond within the ligand structures may be exploited to tune their emission properties. These findings render such complexes promising candidates for applications in materials chemistry. This is the first example of 1D coordination polymers bearing DDSQ-based nodes with TM ions.

Keywords: E−Z isomerization; double-decker silsesquioxanes; hybrid materials; light emitting materials; nanofibers; silylative coupling reaction; sonogashira reaction.