A linear Cu(II) coordination polymer was transformed to a sheet or ladder structure by the loss of coordinated DMF when the single crystals or the ground powder, respectively, were used. Further, the sheet structure rearranged to a ladder polymer when the desolvated single crystals were ground to powder, as monitored by 1H-NMR spectroscopy.
![Graphical abstract: [2 + 2] Cycloaddition reaction as a tool to monitor the formation of thermodynamically stable ladder coordination polymers](http://hg.y866.cn/compound/lib/scimg/usr/1/C3CE41176A.jpg)
