Anomalous compressibility of ferroelastic and post-ferroelastic copper-containing framework materials

The large and diverse family of framework materials are attractive when seeking to design materials with specific properties. By judicious choice of metal and molecular linker we can in principle – on the atomic scale – construct materials with specific topologies, functionalities or porosity. We seek to make materials with extreme and unusual properties, such as negative thermal expansion (expansion on cooling) and negative linear compressibility (expansion in one direction upon compression). Here we seek to understand if mechanisms of NLC known in conventional materials can be found in framework materials, and if this response is larger than in previously explored systems. We propose measuring two copper-containing frameworks at high pressure to reveal their high pressure responses and mechanisms.