Higher Assemblies of Coordination Cage-Catenanes Linked by Copper(II) Chloride Clusters: Networks and Transformations.

Cage-catenanes are chemical constructs where two or more cage-like molecules or assemblies are mechanically interlocked together. We report a new class of cage-catenanes where dimeric metal-organic cage-catenanes are linked into larger assemblies through additional bridging metal chloride links. These crystalline materials are obtained from the reaction of tris(nicotinoyl)cyclotriguaiacylene (L1) with Cu(II) salts, and all feature a tetramer of cages where two {Cu(L1)(X)} cages (X=anion) are mechanically interlocked, and link to each other and to another {Cu(L1)(X)} cage-catenane through a planar, linear tetranuclear {Cu(μ-Cl)Cl} cluster. The complex of discrete tetrameric {Cu(L1)(X)} assemblies (dimers of cage-catenanes) transforms through solvent-exchange processes to 1D coordination chain structures through additional {Cu(μ-Cl)} bridges between the tetrameric {Cu(L1)(X)} assemblies. Complex [Cu(L1)Cl(HO)] ⋅ (HO) ⋅ 15(DMF) C2 features a 2D coordination network of 6 topology linked through three different Cu(II) clusters, namely {Cu(μ-Cl)}, {Cu(μ-Cl)} and a rare linear {Cu(μ-Cl)} linkage. Break-down of C2 in water likely proceeds through hydrolysis of this unusual linear Cu-Cl-Cl bond.