Synthesis and Post-Processing of Chemically Homogeneous Nanothreads from 2,5-Furandicarboxylic Acid

Solid-state synthesis represents an alternative to solution-phase chemistry that can provide routes to materials typically unobtainable by conventional methods. However, multiple competing reaction pathways under high-pressure conditions makes the targeted synthesis of chemically homogeneous systems a challenge. Nanothreads, one-dimensional diamondoid polymers formed through the compression of aromatic hydrocarbons present a unique opportunity to carry out high pressure reactions in a controlled and predictable manner. We hypothesize that through careful consideration of molecular stacking and intermolecular forces (e.g., H-bonding), it is possible to form chemically homogeneous nanothreads that retain precisely located chemical functionality. Herein, we report the scalable solid-state polymerization of 2,5-furandicarboxylic acid through sequential [4 + 2] Diels Alder cycloaddition reactions. The resulting nanothread product is decorated with a high density of pendant carboxylate groups, presenting new opportunities for post-synthetic processing and functional applications. Transition metal coordination is demonstrated for the functionalized threads, representing proof-of-concept for the utilization of nanothreads as independent synthons and the possibility for novel, extended multidimensional networks.