Replacing pure inorganic materials by functional organic-inorganic hybrid ones to lower production costs has become a major challenge, in particular for the optoelectronic industry. Adding nanostructuration abilities meanwhile preserving homogeneity is even more challenging for this class of new materials. Here we show that red-NIR emissive ternary molybdenum cluster salts can be assembled to liquid crystalline 15C5 crown ethers. The resulting hybrids are homogeneous and stable up to high temperature despite the weakness of the supramolecular interactions binding both components. These are illustrated by Cs MAS NMR. All hybrids show hexagonal columnar arrangements and strong red-NIR emission. Surprisingly, when chlorinated clusters are used instead of brominated ones, the mesophase stability is largely enhanced.

The Li+- and K+-complexes of new discotic mesogens, where two n-alkoxy-substituted triphenylene cores are connected by a central crown ether (12-crown-4 and 18-crown-6), provide interesting structural and electronic properties. The inter- and intra-columnar structure was investigated by small and wide angle X-ray scattering. The electronic and ionic transports were studied by temperature dependent photoconductivity and impedance spectroscopy, respectively. Besides a strong increase of the stability and the width of the columnar phases the presence of soft anions (iodide, thiocyanate, tetrafluoroborate) leads to an improved intra-columnar order. The hereby shortened stacking-distance of the triphenylene cores leads to a significant increase of the photoconductivity in the columnar mesophase. Furthermore, the ionic conductivity of the new materials was investigated on macroscopically aligned thin films. The existence of channels for fast cation transport formed by the stacked crown ether moieties in the centre of each column can be excluded. The cations are coordinated strongly and therefore contributing only little to the conductivity. The ionic conductivity is dominated by the anisotropic migration of the non-coordinated anions through the liquid, like side chains favouring the propagation parallel to the columns. Iodide migrates about 20 times faster than thiocyanate and 100 times faster than tetrafluoroborate.

Crown ethers and their derivatives are versatile building blocks for the design of supramolecular materials. They can be functionalized at will and are well known for their abilities to complex with alkali cations. Here, we show that emissive lanthanide free hybrid materials can be generated by using such building blocks. The organic tribenzo[18]crown-6 central core was functionalized via six-fold Suzuki cross-coupling as a key reaction with three o-terphenyl units which could be converted into their corresponding triphenylenes by the Scholl reaction, leading to novel liquid-crystalline columnar materials. Selected tribenzo[18]crown-6 o-terphenyls could interact with emissive ternary metal cluster compound salts to generate hybrid materials combining the properties of both moieties. Due to synergistic effects and despite the anisometry of the cluster compounds, individual properties such as liquid-crystalline phase stability of the organic part and emission abilities of its inorganic counter-part are enhanced in the hybrid compounds.

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ILCs consisting of cationic head group–spacer–fluorenone central core–side chain show de Vries-like behaviour.

Fischer indole reaction of Weiss diketone with 4‐bromophenylhydrazine provided the 2,8‐dibromo‐hexahydropentaleno[2,1‐b:5,4‐b’]diindole key intermediate, which was converted to the target compounds by N‐protection/Suzuki cross‐coupling. Variation of protecting groups, mesogenic units, and their alkoxy substitution gave calamitic diindole mesogens. Both N‐protection and alkoxy chain influenced the mesomorphic properties of phenyl diindoles. Among the differently N‐protected derivatives only ethylcarbamate‐protected ones formed enantiotropic mesophases. Mesophase range and type were controlled by the chain lengths: chains≤C12 gave nematic (N) phases, diindoles with side chains≥C14 formed additional lower temperature smectic (SmA) phases. Irrespective of the chain lengths 4′‐alkyloxybiphenyl diindoles formed N and SmA phases upon first heating but tended to decomposition below their clearing points. X‐ray crystal structure analysis of bis(4′‐decyloxy)biphenyl diindole reveals that in the solid‐state the folding angle of the hydropentalene core caused an almost perpendicular orientation of the two indole/biphenyl parts with respect to each other.

Aiming at merocyanine dyes with good linear optical and self-assembly properties, a series of rigid mono-, bi- and tricyclic merocyanines with O- and N-donor units as well as keto or...

In this work, the synthesis, X-ray crystal structure analysis, studies on mesomorphism and luminescence spectroscopy of 2,7-diphenyl-4,5-diazafluorenones carrying 2, 4 or 6 peripheral alkoxy side chains of different lengths in the mesogenic unit are reported. The latter was attached to starting 2,7-dibromo-4,5-diazafluoren-9-one via Suzuki cross coupling of the respective 2-(alkoxyphenyl)-tetramethyl-1,2,3-borolane. The liquid crystalline properties were found to depend on both the number of side chains and their lengths. Derivatives with two short alkoxy chains (C6-C8) in the periphery formed nematic (N) and smectic C (SmC) mesophases while for the higher homologues only SmC mesophases were observed. Compounds carrying six alkoxy side chains with a minimum length of C8 assembled into columnar hexagonal phases. Homologues with C14 and C16 chain length displayed additionally two columnar rectangular mesophases. Four peripheral alkoxy chains, however, led to the loss of mesomorphism. Crystal structure data of a series of rod-shaped diazafluorenones helped to rationalize their liquid crystalline self-assembly and to understand geometry and thermal stability. Temperature-dependent luminescence spectra of diazafluorenone with two C12 chains revealed aggregation-induced emission (AIE) depending on the supramolecular order of the bulk phase. These studies suggested that AIE requires a lower degree of aggregation as compared to mesophase formation.