A Self-assembled Bicontinuous Cubic Phase with Single Diamond Network.

The first single-diamond cubic phase in a liquid crystal is reported. This skeletal structure with the Fd (3) over barm space group is formed by self-assembly of bolaamphiphiles with swallow-tailed lateral chains. It consists of bundles of pi-conjugated p-terphenyl rods fused into an infinite network by hydrogen-bonded spheres at tetrahedral four-way junctions. We also present a quantitative model relating molecular architecture to the space-filling requirements of six possible bicontinuous cubic phases, that is, the single- and double-network versions of gyroid, diamond, and plumber's nightmare.