In the solid state, interlocking of the lateral phen ligands at the acute angle sites of the molecular [Cu2(bpa)2(phen)2(H2O)]2 rhombi via aromatic π–π stacking interactions into the cavities of the adjacent rhombi generates laminated polyrotaxanes that are further assembled into a 3D network via similar interactions between the phen ligands at the obtuse angle sites.
![Graphical abstract: Interlocking of molecular rhombi into a 2D polyrotaxane network via π–π interactions. Crystal structure of [Cu2(bpa)2(phen)2(H2O)]2·2H2O (bpa2− = biphenyl-4,4′-dicarboxylate, phen = 1,10-phenanthroline)](http://hg.y866.cn/compound/lib/scimg/usr/1/B202716J.jpg)
