Tris(pyridylmethylamino)cyclotriguaiacylene cavitands: An investigation of the solution and solid-state behaviour of metallo-supramolecular cages and cavitand-based coordination polymers

The synthesis of the three isomeric tris(pyridylmethylamino)cyclotriguaiacylene cavitands is reported, along with the crystal structures of the 2- and 4-pyridyl derivatives. The generality of a previously described [Ag-2{tris(3-pyridylmethylamino)cyclotriguaiacylene}(2)](2+) dimeric capsule motif and the [Ag-4{tris(4-pyridylmethylamino)cyclotriguaiacylene}(4)](4+) tetrahedron with several silver salts was confirmed in the solid state and the corresponding solution species were investigated by NMR spectroscopy. Host-guest interactions in these systems have been probed and these interactions are demonstrated to alter and influence the self-assembly outcome of the reaction. Notably, introduction of larger glutaronitrile guest molecules to the [Ag4L4](4+) tetrahedron system prevents formation of the tetrahedral structure, resulting instead in the formation of a 4.8(2) coordination network in the solid state. In the absence of templating acetonitrile guests in the [Ag-2(3)(2)](2+) capsule system, formation of a cage-based one-dimensional coordination polymer is observed.