Manipulating metal–ligand binding in allosteric coordination complexes through ring strain†

Abstract

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.