A Tetragonal 2D Array of Single-Molecule Magnets with Modulated Collective Behavior.

The counterion makes a difference: A square 2D array of cobalt citrate cubanes linked by bridging six-coordinate cobalt atoms (see graphic) displays collective magnetic behavior, which changes with subtle differences in the crystalline surroundings. The magnetic properties of two solid modifications, both synthesized by using wet chemistry techniques, reveal two different relaxation processes in each system at low temperatures, each with its own timescale.