Straightforward Access to Stable One-Dimensional Coordination Polymers of Iridium(III) with Bridging Triiodide Anions

Here, we present a new reaction of common octahedral iridium(III) complexes, [Ir(C^N)₂(acac)] (C^N is the cyclometalated ligand, acac is acetylacetonate) with iodine, resulting in the high-yield preparation of unique crystalline polymers, [Ir(C^N)₂I₃]_<i>n</i>, in which the Ir(C^N)₂⁺ fragments are linked by triiodide bridges. The solid polymers show good photo- and thermal stability up to 200 °C in air and narrow optical bandgaps, while their synthesis proves to be robust, reproducible, scalable, and also suitable for similar rhodium(III) complexes. Overall, this study establishes a simple approach for uncovering a previously inaccessible class of coordination polymers and exploring their potential properties and functions.