Achiral multi-chain benzil derivatives provide a missing link between mirror symmetry breaking phenomena in fluid systems of polycatenar and bent-core liquid crystals.

Mirror symmetry breaking in systems composed of achiral molecules is of importance for the design of functional materials for technological applications as well as for the understanding of the mechanisms of spontaneous emergence of chirality. Herein, we report the design and molecular selfassembly of two series of rod-like achiral polycatenar molecules derived from a π-conjugated 5,5'-diphenyl-2,2'bithiophene core with a fork-like triple alkoxylated end and a variable single alkylthio chain at the other end. In both series of liquid crystalline materials, differing in the chain length at the trialkoxylated end, helical self-assembly of the π-con-* ] ). Further chain elongation results in removing the I23 phase and the re-appearance of the Ia � 3d phase with different pitch lengths. In the second series an additional tetragonal phase separates the two cubic phase types.

Though the transition from metastable to stable crystal (from form II to form I) of isotactic poly­(butene-1) (iPB-1) after melt crystallization looks to be unavoidable, form I direct formation in bulk iPB-1 via a bypass of form II is still a charming approach to the crystalline structure control in iPB-1. However, the physics behind this transition still remains elusive and there are many arguments. In this work, DSC and WAXS were used to investigate the crystallization behaviors of iPB-1 in detail and direct formation of form I in bulk iPB-1 was found able to occur within a temperature range from the glass transition temperature T g to a critical temperature T cr = 35 °C, far below the crystallization temperature T c of form II. The temperature-dependent 3/1 helix conformation formation within this temperature range was proposed to interpret the further direct formation of form I. Formation of iPB-1 polymorphic structures seem to be controlled by temperature-dependent helix conformation formation. The results may trigger further discussions or shed light on the understanding of the physics behind polymer crystallization and polymorph selection processes as well as the development of crystal structure controlling techniques and applications of iPB-1.

First examples of multichain (polycatenar) compounds, based on the π‐conjugated [1]benzothieno[3,2‐b]benzothiophene unit are designed, synthesized, and their soft self‐assembly and charge carrier mobility are investigated. These compounds, terminated by the new fan‐shaped 2‐brominated 3,4,5‐trialkoxybenzoate moiety, form bicontinuous cubic liquid crystalline (LC) phases with helical network structure over extremely wide temperature ranges (>200 K), including ambient temperature. Compounds with short chains show an achiral cubic phase with the double network, which upon increasing the chain length, is at first replaced by a tetragonal 3D phase and then by a mirror symmetry is broken triple network cubic phase. In the networks, the capability of bypassing defects provides enhanced charge carrier mobility compared to imperfectly aligned columnar phases, and the charge transportation is non‐dispersive, as only rarely observed for LC materials. At the transition to a semicrystalline helical network phase, the conductivity is further enhanced by almost one order of magnitude. In addition, a mirror symmetry broken isotropic liquid phase is formed beside the 3D phases, which upon chain elongation is removed and replaced by a hexagonal columnar LC phase.

A novel phase sequence for the transition from the double diamond to the double gyroid cubic phases via two noncubic intermediate phases, an orthorhombic Fmmm (O 69 ) phase and a hexagonal P6 3 /m (H 176 ) phase, is reported for specifically designed bolapolyphiles composed of a linear rod-like bistolane core with sticky glycerol ends and two branched central and two linear peripheral side chains. These liquid crystalline (LC) phases represent members of a new class of unicontinuous network phases, formed by longitudinal rod bundles with polar spheres acting as junctions and the alkyl chains forming the continuum around them. In contrast to previously known bicontinuous cubic networks, they combine different junctions with different angles in a common structure, and one of them even represents a triple network instead of the usually found double networks. This provides new perspectives for the design of soft network phases with enhanced structural complexity, inspiring the search for new supramolecular networks, nano-particle arrays, and photonic band-gap materials.