Discovery of an Interlocked and Interwoven Molecular Topology in Nanocarbons via Dynamic C–C Bond Formation

Topologically complex carbon nanostructures are an exciting but largely unexplored class of materials due to their challenging synthesis. Previous methods are low yielding because they rely on irreversible C_sp²−C_sp² bond formation, which necessitates complex templating strategies to enforce entanglement. Here, reversible zirconocene coupling of alkynes is developed as a new method to access complex molecular topologies, where dynamic C−C bond formation facilitates entanglement under thermodynamic control, allowing the use of simple precursors without the need for preassembly. This strategy enables the scalable, high-yield synthesis of three topologically distinct nanocarbons, including the serendipitous discovery of a structure containing a new topological motif that was not previously identified or realized synthetically. This motif, consisting of an unusual combination of interlocking and interweaving, was recognized to be generalizable to a new topological class of molecules, introduced here as perplexanes.. Authors: Bergman, Harrison M. [Univ. of California, Berkeley, CA (United States)] (ORCID:0000000164822837); Fan, Angela T. [Univ. of California, Berkeley, CA (United States)]; Jones, Christopher G. [Univ. of California, Los Angeles, CA (United States); California Institute of Technology (CalTech), Pasadena, CA (United States)]; Rothenberger, August J. [Univ. of California, Berkeley, CA (United States)]; Jha, Kunal K. [California Institute of Technology (CalTech), Pasadena, CA (United States)]. DOE Contract: AC02-05CH11231; AC02-06CH11357. Subjects: 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; chemical structure; crystal structure; hydrocarbons; mathematical methods; monomers