Liquid organic frameworks : a liquid crystalline 8-connected network with body-centered cubic symmetry

Abstract

Liquid state self-assembly is important for the understanding of the complex structures developed in abiogenesis and biogenesis as well as for numerous potential technological applications. Herein we report the first body-centered cubic liquid crystalline phase with 8-connected network topology and open octahedral network structure. It is formed by dynamic soft self-assembly of X-shaped polyphiles with oligo(para-phenylene-ethynylene) cores. The π-conjugated rods with perfluorinated inner benzene rings form networks conjoined by eight-way junctions, which are formed by nano-segregated spheres involving hydrogen-bonded polar end groups, while the branched aliphatic chains at opposite sides of the cores fill the continuum. This novel cubic phase is based on the I-WP minimal surface separating the frameworks of polyaromatic cores from the most disordered chain segments. It can also be considered as a dense sphere packing. Such liquid organic frameworks, representing hybrids of sphere packings and networks could be of interest for organic photonics and other technologies.