Tris (pyridylmethyl-amino)cyclotriguaiacylene cavitands: An investigation of the solution and solid-state behaviour of metallo-supramolecular cages and cavitand-based corodination polymers.

Abstract

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 [Ag2{tris(3-pyridylmethylamino)cyclotriguaiacylene}2]2+ dimeric capsule motif and the [Ag4{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 4.82 coordination network in the solid state. In the absence of templating acetonitrile guests in the [Ag2(3)2]2+ capsule system, formation of a cage-based one-dimensional coordination polymer is observed.