A Ball-Joint-Type Host-Guest System that Consists of Conglomerate Helical Metallacyclophanes

摘要

If suitable molecular units could be advantageously arranged, what would the resultant properties of their molecular aggregates be? This sort has inspired molecular engineers for the past decade. The assembly and the related properties of novel supramolecular aggregates are a hot topic and, not entirely coincidentally, a great challenge in the field of molecular chemistry. A full understanding of the driving forces behind those aggregations is a prerequisite for the design and construction of molecular arrays. Cyclophanes are attractive models for understanding weak transannular interactions as well as'distinct π··· systems. They can also serve as basic examples for explaining molecular recognition, chemosensing, molecular electronics, and electrical, magnetic, and capsule effects that are introduced by significant donor-acceptor and electron-transfer processes, or by through-space effects. Metallacyclophanes have been synthesized by the coordination-directed self-assembly of metals and multidentate ligands. These structures are of particular interest owing to the many and various advantages inherent to organic cyclophanes: easily accessible modularity for dimensions and topology/and straightforward incorporation of functions, such as catalytic effects, luminescence,redox-activity, electron transfer, and helicity. The elucidation of the thermodynamics and kinetics of such metallacyclophane systems would certainly provide important insights into the evolution and emergence of delicate supramolecular systems. To that end, three important synthetic approaches have been introduced: angular directional bonding, symmetry interaction, and weak interaction.