Effect of metallosupramolecular polymer concentration on the synthesis of poly[]catenanes

• Published in: Chemical science (Cambridge) Vol. 12; no. 25; pp. 8722 - 873
• Main Authors: Tranquilli, Marissa M, Wu, Qiong, Rowan, Stuart J
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 26.05.2021; The Royal Society of Chemistry
• Subjects: Chemical synthesis; Chemistry; INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; Low concentrations; Mathematical analysis; NMR; Nuclear magnetic resonance; Polymers
• ISSN: 2041-6520; 2041-6539
• DOI: 10.1039/d1sc02450g

Poly[ n ]catenanes are a class of polymers that are composed entirely of interlocked rings. One synthetic route to these polymers involves the formation of a metallosupramolecular polymer (MSP) that consists of alternating units of macrocyclic and linear thread components. Ring closure of the thread components has been shown to yield a mixture of cyclic, linear, and branched poly[ n ]catenanes. Reported herein are investigations into this synthetic methodology, with a focus on a more detailed understanding of the crude product distribution and how the concentration of the MSP during the ring closing reaction impacts the resulting poly[ n ]catenanes. In addition to a better understanding of the molecular products obtained in these reactions, the results show that the concentration of the reaction can be used to tune the size and type of poly[ n ]catenanes accessed. At low concentrations the interlocked product distribution is limited to primarily oligomeric and small cyclic catenanes . However, the same reaction at increased concentration can yield branched poly[ n ]catenanes with an ca. 21 kg mol −1 , with evidence of structures containing as many as 640 interlocked rings (1000 kg mol −1 ). Concentration of the metallosupramolecular polymer precursors have a significant effect on the architecture and size of the resulting poly[ n ]catenanes formed via a ring closing metathesis step.