Presented by:Â Andrew B. Cairns & Dr. Amber L. Thompson
Research Leader:Â Dr. Andrew L. Goodwin
Published:Â Journal of the American Chemical Society (cover article)
Negative Linear Compressibility (NLC) is where a material unusually expands in one direction under increasing pressure. Potassium manganese dicyanoargentate exhibits the largest NLC over an extended range of any known material: ‑12.0(8) TPa–1. The structural features are both beautiful and unique to cause this effect. [MnN6] octahedra are connected via almost linear ‘floppy’ NC–Ag–CN units, with K+ ions positioned above and below alternating Ag3 Kagome triangles (top). The lattice framework is made up of three independent interpenetrated a-Polonium nets (bottom right), with only weak argentophilic interactions between the nets. Variable temperature SCXRD was carried out in Oxford and the variable pressure work was the first pressure experiment carried out on WISH at ISIS.
Structure of the Month – September 2011