Accordion and layer-sliding motion to produce anomalous thermal expansion behaviour in 2D-coordination polymers.

Solvent-free (1) and solvated (2) 2D-coordination polymers have been synthesised by varying the amount of solvent during crystallisation. 1 undergoes a unique accordion motion of 2D zig-zag interwoven layers whereas 2 experiences layer-sliding within 2D layers to produce anomalous thermal expansion behaviour.