Molecular Topologies and Architectures with Mechanical Bonds

Classically, the structure of a chemical compound can be described by three C's, its constitution, its configuration, and its conformation. This chapter refers to a catenane's topology and a rotaxane's architecture, and talks about the nature of the mechanical bond. It describes the prime links and composite links that contain only two-order vertices in their molecular graphs. The chapter focuses on topologies in which mechanical entanglements extend infinitely in at least one dimension and organic and metallo-organic chemistry. It describes polycatenanes as one-, two-, or three-dimensional when the mechanical bonds of their networks extended infinitely in one, two, or three dimesions, respectively. The chapter then focuses on rotaxanes, as opposed to pseudorotaxanes, acknowledging that a grey area lies in between these molecules and complexes, respectively. It considers oligo- and polyrotaxane architectures in which multiple bis-macrocyclic component parts thread a pair of dumbbells, forming a mechanically bonded bridge between them.