Manipulating metal-ligand binding in allosteric coordination complexes through ring strain

The weak-link approach (WLA) to organometallic complexes offers a powerful method to create allosteric shape-shifting coordination complexes. However, chemically tuning the metal-ligand interactions entails challenging syntheses. This study explores the influence of ring strain on the lability of the platinum-sulfur interaction within WLA complexes, providing a simpler alternative to chemical modifications. We study the relationship of ring size, and subsequent reactivity within 4- to 8-membered WLA cyclic Pt coordination complexes through solution and solid-state studies. These results show that strain can direct the energetic preference for the desired allosteric states and therefore, the choice of small molecule effectors required to facilitate such interconversions.