Facile construction of giant polymeric chains through strain-promoted azide-alkyne cycloaddition

Rational design of “giant” building blocks promotes the modular construction of polymeric counterparts at a large length scale. In this study, a series of biscylooctyne- and bisazide-functionalized polyhedral oligomeric silsesquioxane (POSS) monomers with different regio-configurations were synthesized. Homo and alternating giant polymeric chains were then efficiently prepared by strain-promoted azide-alkyne cycloaddition (SPAAC) polymerization. The obtained monomers and polymers were characterized by proton nuclear magnetic resonance ( 1 H NMR), size exclusion chromatography (SEC), and matrix-assisted laser desorption ionization time-of-flight (MALDI-ToF) mass spectrometry. The influence of the feeding ratio, monomer concentration, and regio-configuration on the step-growth polymerization was investigated. Due to the large monomer size, the giant chains can be purified and fractionated by preparative SEC. This work provides a facile and efficient approach for the modular construction of main-chain polymers with nanosized building blocks.