Plasmonic visible–near infrared photothermal activation of olefin metathesis enabling photoresponsive materials

Light-induced catalysis and thermoplasmonics are promising fields creating many opportunities for innovative research. Recent advances in light-induced olefin metathesis have led to new applications in polymer and material science, but further improvements to reaction scope and efficiency are desired. Herein, we present the activation of latent ruthenium-based olefin metathesis catalysts via the photothermal response of plasmonic gold nanobipyramids. Simple synthetic control over gold nanobipyramid size results in tunable localized surface plasmon resonance bands enabling catalyst initiation with low-energy visible and infrared light. This approach was applied to the ROMP of dicyclopentadiene, affording plasmonic polymer composites with exceptional photoresponsive and mechanical properties. Moreover, this method of catalyst activation was proven to be remarkably more efficient than activation through conventional heating in all the metathesis processes tested. This study paves the way for providing a wide range of photoinduced olefin metathesis processes in particular and photoinduced latent organic reactions in general by direct photothermal activation of thermally latent catalysts. Current strategies for photoinduced olefin metathesis lack wavelength tunability. Now, plasmonic nanoparticles have been used to activate latent ruthenium catalysts, enabling light-induced olefin metathesis in the infrared range with several advantages when compared with conventional heating. Implementing this approach in ring-opening metathesis polymerization resulted in photoresponsive polymer–nanoparticle composites with enhanced mechanical properties.