The single gyroid phase as well as the alternating double network gyroid, composed of two alternating single gyroid networks,hold asignificant place in ordered nanoscale morphologies for their potential applications as photonic crystals,m etamaterials and templates for porous ceramics and metals.Here,wereport the first alternating network cubic liquid crystals.T hey form through self-assembly of X-shaped polyphiles,w here glycerol-capped terphenyl rods lie on the gyroid surface while semiperfluorinated and aliphatic sidechains fill their respective separate channel networks.This new self-assembly mode can be considered as at wo-color symmetry-broken double gyroid morphology,p roviding at ailored way to fabricate novel chiral structures with sub-10 nm periodicities using achiral compounds.New routes to chirality from initially achiral systems are of particular contemporary interest for obtaining chiral templates in asymmetric synthesis and catalysis. [1] This is important for the use in different fields of material-and nanoscience [2] as well as for the understanding of fundamental principles of the emergence of biological homochirality. [3] Creating chirality in liquids and liquid crystals (LCs), having no fixed positions of individual molecules,i se specially challenging. [4,5] Nevertheless,i tw as recently achieved by mirror symmetry breaking through synchronization and locking-in of transient chiral conformations and configuration. [6] Here we report anew approach to spontaneous generation of chirality based on nano-phase segregation. In the reported case,b reaking the inherent mirror symmetry of the double gyroid cubic phase (Ia " 3d,Q230), known from lyotropic [7] and thermotropic liquid crystals (LCs) [8] (Figure 1a), is achieved by self-assembly of X-shaped polyphilic molecules with two different chains at opposite sides of ar od-like molecular core. [8b] Thecores organize along the gyroid minimal surface, forming aw all that separates the two enantiomeric infinite networks involving these chains.N ano-phase separation of the two poorly compatible semiperfluorinated and aliphatic side-chains,i nto their own networks (blue and red in Figure 1b), gives rise to agyroid cubic phase with two chemically non-equal networks (the "single gyroid" I4 1 32, Q214). This structure has broken mirror symmetry and represents the first alternating network gyroid cubic LC,a nd the first LC with chirality solely based on phase separation. Previous attempts to produce asingle gyroid structure were based on replication from butterflyw ings, [9] lithography [10] and templating. [11] The alternatingd ouble network gyroid wasf ound in narrow compositionr anges of multiblock copolymer blends, [11, 12] leading to structures in the > 100 nm range in allc ases.T he new concept reportedh erein providesat ailoredw ay to fabricate chiral structures withm uch smaller sub-10 nm periodicities, which are of great potential in nano-templating and as enantiospecific membranes for use in enantiomer separation.Supportinginformation and the O...

Columnar liquid crystals confined in cylindrical pores are known to orient perpendicular to the pore axis, although for potential nanoelectronic applications they would need to be aligned axially. The X-ray diffraction study reveals that while in all three compounds examined, the columns arrange in concentric circles in circular pores, axial alignment is indeed achieved for the hexagonal phase of a discotic hexa-peri-hexabenzocoronene in "triangular pores," and for the square phase of a T-shaped amphiphile in "square pores." For the third compound, a carbazole dendron with very soft hexagonal columns, a new three-circle configuration is observed by atomic force microscopy (AFM) in triangular pores. The complex structure of domain walls in columnar liquid crystals is thus seen for the first time on the level of individual columns. A simple estimation of free energies confirms that it is the distortion of polygonal columnar lattice that prevents axial orientation in circular pores. The model also explains the appearance of the three-circle arrangement of soft columns.

The single gyroid phase as well as the alternating double network gyroid, composed of two alternating single gyroid networks, hold a significant place in ordered nanoscale morphologies for their potential applications as photonic crystals, metamaterials and templates for porous ceramics and metals. Here, we report the first alternating network cubic liquid crystals. They form through self‐assembly of X‐shaped polyphiles, where glycerol‐capped terphenyl rods lie on the gyroid surface while semiperfluorinated and aliphatic side‐chains fill their respective separate channel networks. This new self‐assembly mode can be considered as a two‐color symmetry‐broken double gyroid morphology, providing a tailored way to fabricate novel chiral structures with sub‐10 nm periodicities using achiral compounds.