A reversible pressure-induced bond rearrangement of flexible lanthanide 2,5-bis(allyloxy)terephthalate coordination polymer networks

Flexible coordination polymer networks reveal a plethora of structural transformations when exposed to high pressure as an external stimulus. Transformations are driven through organic linkers in a variety of ways, such as bond rotations, rearrangements and conformational shifts. We have successfully synthesised two sets of isostructural lanthanide coordination polymer networks that differ as a consequence of the lanthanide contraction. We have demonstrated that a pressure-induced reversible phase transition is possible between the two structurally distinct sets of networks. The system demonstrates a bond rearrangement due to an alteration of carboxylic acid binding modes from the 2,5-bis(allyloxy)terephthalate linker in addition to bond rotations within the flexible carbon backbone of the linker between 30-35 kbar.