Highly Photostable and Fluorescent Microporous Solids Prepared via Solid-State Entrapment of Boron Dipyrromethene Dyes in a Nascent Metal–Organic Framework

Abstract

We report a strategy to synthesize highly emissive, photostable, microporous materials by solid-state entrapment of boron dipyrromethene (BODIPY) fluorophores in a metal-organic framework. Solvent-free mechanochemistry or accelerated aging enabled quantitative capture and dispersal of the PM605 dye within the ZIF-8 framework starting from inexpensive, commercial materials. While the design of emissive BODIPY solids is normally challenged by quenching in a densely packed environment, herein reported PM605@ZIF-8 materials show excellent emissive properties and to the best of our knowledge an unprecedented ∼10-fold enhancement of BODIPY photostability. Time-resolved and steady-state fluorescence studies of PM605@ZIF-8 show that interchromophore interactions are minimal at low dye loadings, but at higher ones lead to through-pore energy transfer between chromophores and to aggregate species.