Reversible Pressure-Controlled Depolymerization of a Copper(II)-Containing Coordination Polymer

Jack K Clegg; Aidan J Brock; Katrina A Jolliffe; Leonard F Lindoy; Simon Parsons; Peter A Tasker; Fraser J White

doi:10.1002/chem.201703115

Reversible Pressure-Controlled Depolymerization of a Copper(II)-Containing Coordination Polymer

Chemistry. 2017 Sep 12;23(51):12480-12483. doi: 10.1002/chem.201703115. Epub 2017 Aug 16.

Authors

Jack K Clegg^{1

2}, Aidan J Brock², Katrina A Jolliffe¹, Leonard F Lindoy¹, Simon Parsons³, Peter A Tasker³, Fraser J White³

Affiliations

¹ School of Chemistry, The University of Sydney, NSW, 2006, Australia.
² School of Chemistry and Molecular Biosciences, University of Queensland, St Lucia, QLD, 4072, Australia.
³ Centre for Science at Extreme Conditions, School of Chemistry, University of Edinburgh, Edinburgh, EH9 3FJ, UK.

PMID: 28731587
DOI: 10.1002/chem.201703115

Abstract

A unique pressure-induced Cu-N bond breaking/bond forming reaction is reported. The variation of pressure on a single crystal of a one-dimensional copper- (II)-containing coordination polymer (Cu₂ L₂ (1-methylpiperazine)₂ ]_n , where H₂ L is 1,1'-(1,3-phenylene)-bis(4,4-dimethylpentane-1,3-dione)), was monitored using single crystal X-ray diffraction with the aid of a diamond anvil cell. At a very low elevated pressure (≈0.05 GPa) a remarkable reversible phase change was observed. The phase change results in the depolymerization of the material through the cleavage and formation of axial Cu-N bonds as well as "ring flips" of individual axially coordinated 1-methylpiperazine ligands. Overall, the pressure-induced phase change is associated with a surprising (and non-intuitive) shift in structure-from a 1-dimensional coordination polymer to a discrete dinuclear complex.

Keywords: X-ray structure; coordination polymer; copper; high-pressure chemistry; stimuli responsive.