Shining a Light on the Photochemistry of Tetraaryl[3]cumulene-Based Metal-Organic Frameworks

Achieving bright and long-lived emission with π-conjugated organic chromophores in the solid state presents a significant challenge but also an opportunity for applications ranging from nanoscale electronics to heterogeneous photocatalysis. Tetraryl[n]cumulenes, organic molecules consisting of three or more cumulative double bonds, are highly modular systems with tunable redox and optoelectronic properties, yet their utility remains limited due to rapid quenching from aryl group planarization or excimer formation. Herein, we demonstrate that the incorporation of a tetraryl[3]cumulene-based organic linker within the metal-organic framework (MOF) CORN-MOF-9 (CORN = Cornell University) suppresses these quenching pathways, allowing for bright and long-lived emission. Extensive transient absorption (TA) and photoluminescence (PL) spectroscopic studies support the unique properties of the MOF and also confirm it exhibits spectral diffusion, leading to red-shifted steady-state emission compared to molecular analogs in solution. Overall, our findings represent a new avenue to unlock the promising photochemical properties of cumulenes within materials platforms, paving the way for their use in various applications. Introduction.