Colh Phase Research Articles

Ion‐Pairing Chromonic Liquid Crystals via Alternately Stacked Assembly of Amphiphilic Charged π‐Electronic Systems

In this study, a new assembly strategy for lyotropic chromonic liquid crystals (LCLCs) is proposed using iπ–iπ interactions, mainly comprising electrostatic and dispersion forces, between charged π‐electronic systems to form stacking structures supported by the hydration of triethylene glycol (TEG) units. Meso‐TEG‐aryl‐substituted porphyrin AuIII complex, an amphiphilic π‐electronic cation, showed diverse states and assembly modes in ion pairs depending on the coexisting counteranions. The PCCp– ion pair formed a hexagonal columnar (Colh) LC phase based on a charge‐by‐charge assembly, suggesting the formation of an ordered arrangement of charged p‐electronic systems through iπ–iπ interactions, with reduced interactions between the TEG chains. Furthermore, in the presence of water, LCLC behaviors in the Colh and nematic columnar phases according to the amount of water were observed for the PCCp– ion pair via iπ–iπ interactions. Magnetic‐field‐induced orientation of the charge‐by‐charge columnar structures upon dehydration was observed. Furthermore, single‐stranded charge‐by‐charge columnar structures, as components of the LCLCs, were observed using transmission electron microscopy (TEM).

Triphenylene diimides: A new class of discotic liquid crystals

Unlike the well-explored perylene diimides and naphthalene diimides, the synthesis and characterization of triphenylene diimides have not been reported to date. In this study, several di(decyloxy)-substituted triphenylene 2,3,6,7-tetracarboxyldiimides with various imide substituents were synthesized and comprehensively analyzed for their photochemical properties and mesophase behavior. It was observed that different imide substituents significantly affect self-assembly in both solution and the liquid-crystalline state. Specifically, diimide 2–1, with two n-octyl chains at the imide nitrogens, exhibits a tendency to self-assembly at relatively high concentrations in CDCl3 and displays a hexagonal columnar (Colh) phase near room temperature. Remarkably, its isomer, diimide 2–2, with two branched 2-ethylhexyl chains, exhibits an enatiotropic Colh phase with an unusually large range of 292 °C, extending from 7 °C to 299 °C. Furthermore, the study also reports two triphenylene monoimide diesters as room temperature liquid crystals, each composed of one imide, two alkoxycarbonyl, and two alkoxy side chains. These findings not only enrich the diversity of aromatic diimides but also highlight the potential applications of these novel diimides in the field of liquid crystals.

Tailoring Chiral Discotic Liquid Crystals: Mesophase Engineering through Alternative Approaches and Chain Lengths.

Hydrogen (H)-bonding is crucial in constructing superstructures in chemical (such as chiral discotic liquid crystals (DLCs)) as well as in biological systems due to its specific and directional nature. In this context, we achieved the successful synthesis of two branches of heptazine-based H-bonded complexes using distinct strategies. Hpz*-Es-Cn , we incorporated chiral alkyl tails (Hpz-chiral) onto the central C3 symmetric heptazine core, connected to achiral benzoic acid derivatives (Es-Cn acid) through H-bonding. In Hpz-Es-Cn -acid*, we used an achiral heptazine derivative (Hpz-Es-Cn ) linked to a chiral acid via H-bonding. On the other hand, based on the DSC results, we observed that Hpz*-Es-Cn complexes exhibited three distinct phases, whereas Hpz-Es-Cn -acid* complexes displayed only a single mesophase. In polarized optical microscopy (POM) observations, all the complexes displayed birefringence at room temperature, with the color of the POM images changing as the temperature varied. X-ray diffraction (XRD) studies at lower temperatures confirmed that Hpz*-Es-C8 exhibited the columnar rectangular (Colr ) phase, while Hpz*-Es-C10/12 exhibited the columnar oblique (Colob ) phase. However, all the H-bonded complexes exhibited the columnar hexagonal (Colh ) phase at higher temperatures. The chiroptical spectra recorded by Circular dichroism (CD) highlight the specific observations in the columnar phase of two complexes, Hpz*-Es-C10 and Hpz*-Es-C12 . This behavior has potential applications in various fields, including sensors, displays, and responsive materials.

Thermophilic artificial water channels of a lipid-like dendron stabilized by water-containing hydrogen-bonded network

Nature modulates the non-covalent interaction of biomolecules to strengthen their structural integrity against various extreme environments. Water, as the key component in living systems, can provide the H-bonded connectivity to readily stabilize the thermophilic proteins toward thermal adaption. However, this brilliant strategy has seldom been utilized in molecular design since the role of water is less explored in synthetic systems. In this study, we design the lipid-like dendron (LD) to form the hydrated hexagonal columnar (Colh) phase in water-induced self-assembly (WISA). Our findings suggest that the amount of embedded water molecules affects the phase stability of the hydrated Colh phase. The characterization further reveals that remarkable enhancement of phase stability is attributed to the extensive water-containing H-bonded network of the bulk-like core water and interfacial water within the Colh phase. The water-containing H-bonded network prevents artificial water channels (AWCs) in the Colh phase from the destruction of thermal perturbation at temperature higher than the boiling point of water. Moreover, the weakened H-bonded network at high temperatures further accelerates water flow through the AWC of the LD and resulted in the water permeability of an individual AWC (PAWC) of 1.33 × 107 H2O·channel−1·s−1 at 80 °C. This transporting feature in the weak H-bonded network of the bulk AWCs of the LD is similar to the water transport in the hydrophobic channels such as Aquaporin and other single-molecule AWCs. The study suggests that just like how it does to the thermophilic proteins, water can also use its H-bonded network to enhance the thermal stability of synthetic matter and allow them to perform better functions at higher temperatures.

Organic electronic applications and charge transport mechanism in novel discotic liquid crystals

ABSTRACTTriphenylene-based pentaalkynylbenzene dyads and naphthophenanthridine derivativediscotic mesogens have been proven a backbone-like utility for modern optoelectronic applications. Herein, we present the charge transport and organic electronic applications of naphthophenanthridine derivatives and a dimer composed of pentaalkynylbenzene (PA) and triphenylene (TP) discotic liquid crystals (DLCs). Naphthophenanthridine derivatives exhibit a hexagonal columnar (Colh) phase; whereas, triphenylene-pentaalkynylbenzene dyads show a columnar centred rectangular (Colr) phase and transform into Colh phase on doping the pure compounds with an electron-acceptor 2,4,7-trinitrofluorenone (TNF) in a 2:1 TNF/compound ratio. The ambipolar charge transport behaviour of the compounds mentioned above has been investigated by the time-of-flight technique. Naphthophenanthridine derivative renders an ambipolar charge transport, showing temperature-independent electron and hole mobility of the order of 3 × 10−4 cm2/Vs; whereas, TP-PA dimer yields an ambipolar charge carrier mobility of order 10−3 cm2/Vs. The phenazine-fused triphenylene DLC shows unipolar hole mobility of the order of 10−4 cm2/Vs; whereas, hydrogen-bonded Hpz-C9-TP DLCs exhibit ambipolar charge mobility of the order of 10−2 cm2/Vs. The high ambipolar charge carrier mobility in the investigated DLC compounds makes them suitable for fabricating organic semiconducting electronic devices.

Large-Area Uniaxially Oriented Sub-5 nm Line Patterns of Hybrid Liquid Crystals Constructed by Perylene Diimide and Oligo(Dimethylsiloxane).

Construction of sub-5 nm long-range ordered structures through self-assembly has received increasing attention. Herein, a series of ODMS-based thermotropic liquid crystals (LCs) containing perylene diimide (PDI) were designed and synthesized. These LCs can form ordered nanostructures with periodic sizes around 5 nm including smectic J (SmJ), oblique columnar (Colob ), and hexagonal columnar (Colh ) phases with change in the volume fraction of ODMS, where the layer spacing of the SmJ phase is less than 5 nm. Thin films with parallel oriented nanolines with line width less than 5 nm can be obtained on PDMS-modified silicon substrates by spin-casting and simple thermal annealing processes. Moreover, owing to the strong π-π interaction between PDI cores, these nanolines are long-range ordered with uniaxial orientation in relatively large areas (1.5×1.5 μm2 ) with over 300 continuous microdomains without pre-patterning. These nanostructures provide the possibility of preparing nanotemplates by oxygen plasma etching.

Soft nanostructures out of star-shaped triazines with flexible amide spacers: liquid crystals with a cubic to columnar transition with memory effect, gels and supramolecular chirality

This work reports the synthesis and characterization of a new family of star-shaped tricarboxamides with C3-symmetry that have flexible amide spacers linking a tris(triazolyl)triazine core with three trialkoxyphenyl groups. The presence of amide groups allows the formation of intermolecular hydrogen bonds that reinforce π-stacking and van der Waals interactions, promoting liquid crystalline behavior, and self-assembly in solvents leading to organogels. As determined by polarized optical microscopy, differential scanning calorimetry and X-ray diffraction on powder samples, all the three reported molecules present a hexagonal columnar (Colh) phase stable at room temperature. Interestingly, they show a transition to a cubic micellar mesophase (BCC) at high temperatures. A mechanism for this transition, which is consistent with the fragmentation of columns to form supramolecular spheres, was elucidated from X-ray studies on aligned samples. Moreover, on cooling from the BCC to the columnar phase a preferential orientation of columns occurs, according to which each cubic domain gives rise to four hexagonal domains. The ability of the synthesized structures to aggregate in solvent media was studied in a variety of organic solvents, and all of them were able to gel 1-octanol at low concentrations. X-ray studies of gels and xerogels were carried out and showed a molecular organization consistent with Colh order. FTIR studies were carried out to analyze the formation of hydrogen bonds and the influence of the length of the flexible spacer in the liquid crystalline state and in the organogels. Furthermore, the presence of a stereogenic center in the flexible amide spacer leads to macroscopic chirality in the liquid crystal state and the organogels in 1-octanol as demonstrated by circular dichroism spectroscopy.

Hydrogen-bonding stabilized columnar mesophases in hexasubstituted triphenylene 2,3-Dicarboxamides

A series of new mixed tail triphenylene derivatives having four β-alkoxy and two adjacent β-carboxamide side chains have been prepared and characterized. The synthesis was carried out by amidation of the triphenylene 2,3-dicarboxylic methyl ester with various primary amine. All the dicarboxamides exhibit an enantiotropic Colh phase, except compound TPC6-(CONHC6H13)2 bearing the shortest hexyloxy chains. Effects of variation in lengths of alkoxy and N-alkyl chains on mesogens were also studied and the pronounced influence of lengths of alkoxy chains turned out to be more important than that of N-alkyl chains. Furthermore, the intermolecular hydrogen bonding induced by amide functions in TPC8-(CONHC4H9)2 does indeed enhance the mesophase stability in comparison to the non-hydrogen bonding ester TPC8-(COOC4H9)2, as reflected by higher clearing temperatures and evidenced by temperature-dependent FT-IR studies. Although the compound TPC6-(CONHC6H13)2 was found to decompose to imide compound on the hot stage before clearing in the course of the POM experiment, only it shows good gelation property in single toluene, indicating that the intermolecular hydrogen bonding is not the only factor responsible for the formation of gel in these molecules.

Synthesis, Mesomorphism, Photophysics, and Device Properties of Liquid-Crystalline Pincer Complexes of Gold(III) Containing Semiperfluorinated Chains.

Gold(III) complexes of C∧N∧C-coordinating 2,6-diphenylpyridine pincer ligands with arylacetylide co-ligands are known triplet emitters at room temperature. We have reported previously that by functionalizing both the pincer ligand and the phenylacetylene with alkoxy chains, liquid crystallinity may be induced, with the complexes showing columnar mesophases. We now report new derivatives in which the phenylacetylene incorporates one, two, or three 1H,1H,2H,2H-perfluoroalkyl chains. In terms of intermolecular interactions, solution 1H NMR experiments suggest that the semiperfluoroalkyl chains promote a parallel, head-to-head arrangement of neighboring molecules relative to one another, rather than the anti-parallel, head-to-tail orientation found for the all-hydrocarbon materials. In terms of the liquid crystal properties, the complexes show columnar phases, with the addition of the more rigid fluorocarbon chains leading to a stabilization of both the crystal and liquid crystal mesophases. Mesophase temperature ranges were also wider. Interestingly, the amphiphilic nature of these complexes is evident through the observation of a frustrated columnar nematic phase between a Colr and a Colh phase, an observation recently reported in detail for one compound (Liq. Cryst., 2022, doi: 10.1080/02678292.2021.1991017). While calculation shows that, despite the “electronic insulation” provided by the dimethylene spacer group in the semiperfluoroalkyl chains, a small hypsochromic shift in one component of the absorption band is anticipated, experimentally this effect is not observed in the overall absorption envelope. Complexes with substituents in the 3,3′,4,4′-positions of the phenyl rings of the pincer ligand once more show higher-luminescence quantum yields than the analogues with substituents in the 4,4′-positions only, associated with the lower-energy-emissive state in the former. However, in contrast to the observations with all-hydrocarbon analogues, the luminescence quantum yield of the complexes with 3,3′,4,4′-substitution on the pincer increases as the number of semiperfluoroalkyl chains on the phenylacetylide increases, from 20% (one chain) to 34% (three chains). External quantum efficiencies in fabricated OLED devices are, however, low, attributed to the poor dispersion in the host materials on account of the fluorinated chains.

Synthesis and mesomorphism of 3,4-dialkoxyphenylpyridine complexes of silver(I)

3,4-Dialkoxyphenylpyridine complexes with silver dodecyl sulfate or silver triflate are liquid crystalline. The complexes are polycatenar and show one or both of a cubic and a columnar hexagonal phase depending on the chain length of the dialkoxyphenylpyridine and the anion associated with the silver. Their mesomorphism is compared both with the analogous and very well-studied silver complexes of dialkoxystilbazole ligands as well as closely related N-phenylpyridinium analogues. The slightly shorter nature of the dialkoxyphenylpyridines is important in determining the mesomorphism when compared to the dialkoxystilbazole complexes, whereas there are appreciable differences with the N-phenylpyridinium salts. The notable stabilisation of the Colh phase remains a feature of all three families of materials.

Chasing Self‐Assembly of Thioether‐Substituted Flavylium Salts in Solution and Bulk State

Two series of flavylium triflates carrying alkoxy side chains in the A‐ring (benzo unit of chromylium salt) and thioethers in the B ring (phenyl unit) (On ‐Fla‐Sm ) as well as thioethers at both A and B ring (Sn ‐Fla‐Sm ) were synthesized in order to understand the effect of thioether functionalization on their self‐assembly and electronic properties. Concentration‐dependent and diffusion ordered (DOSY) NMR experiments of O1 ‐iV‐Fla‐S3 indicate the formation of columnar H‐aggregates in solution with antiparallel intracolumnar stacking of the AC unit (chromylium) of the flavylium triflate, in agreement with the solid state structure of O1 ‐V‐Fla‐S1 . Thioether substitution on the B ring changes the linear optical properties in solution, whereas it has no effect on the A ring. According to differential scanning calorimetry, polarizing optical microscopy and X‐ray diffraction bulk self‐assembly of these ionic liquid crystals (ILCs) depends on the total number of side chains, yielding SmA and LamCol phases for ILCs with 2–3 chains and Colro, Colh phases for ILCs with 3–6 chains. Thus, we demonstrated that thioethers are a useful design tool for ILCs with tailored properties.

Dual-Axis Alignment of Bulk Artificial Water Channels by Directional Water-Induced Self-Assembly.

Approaching single-crystal-like morphology has always been important in driving materials toward their optimal properties. With only orientational order, liquid crystal (LC) materials require dual-axis orientational control to optimize their structural order in the bulk phase. However, current external guiding fields such as electrical, magnetic, and mechanical guiding fields are less effective in aligning amphiphilic LCs. In this study, water is developed as an excellent structural stabilizer and orientation-directing agent of an amphiphilic discotic molecule (AD) in the water-induced self-assembly (WISA) process. Thermal analysis and structural characterization results show that water increases the stability and domain sizes of the hexagonal columnar (Colh) phase of the AD by co-assembling with the ADs to form bulk artificial water channels (AWCs). Moreover, through control over the nucleation conditions (degree of supercooling and location of nucleation), dual-axis alignment in both the planar and vertical growth of the AWCs is achieved by applying water as the guiding field in the directional WISA. With precise control over the hierarchical structures, the bulk AWC array of the AD delivers excellent salt rejection properties and water permeability. Considering that all the amphiphilic LCs have hydrophilic segments, these new roles of water in the WISA process could launch the further development of functional amphiphilic LCs by providing a dynamic interaction and a readily available guiding field.

Chiral columns forming a lattice with a giant unit cell.

Mesogenic materials, quinoxaline derivatives with semi-flexible cores, are reported to form a new type of 3D columnar phase with a large crystallographic unit cell and Fddd lattice below the columnar hexagonal phase. The 3D columnar structure is a result of frustration imposed by the arrangement of helical columns of opposite chiralities into a triangular lattice. The studied materials exhibit fluorescence properties that could be easily tuned by modification of the molecular structure; for compounds with the extended π electron conjugated systems the fluorescence is quenched. For molecules with a flexible structure the fluorescence quantum yield reaches 25%. On the other hand, compounds with a more rigid mesogenic core, for which the fluorescence is suppressed, show effective photogeneration of charge carriers. For some materials bi-polar hole and electron transport was observed.

Molecular ordering dependent charge transport in [formula omitted]-stacked triphenylene based discotic liquid crystals and its correlation with dielectric properties

We investigate the charge transport in triphenylene core based homologous series of discotic mesogens (HATn) by the time-of-flight method. HAT5, HAT6 and HAT8 exhibit Colh phase whereas HAT4 shows Colhp phase. For the investigated homologous series, we have observed a single transit in the transient photocurrent curves corresponding to positive charge carriers having the mobility in order of 10-2 to 10-4 cm2/vs. The hole mobility decreases with increasing the number of carbon atoms (n) in the alkyl chain attached to the triphenylene core, which follows the empirical exponential relationship: μ≈a.exp(-b/n). Furthermore, the dielectric measurement has been done on these compounds to bring a correlation between the molecular ordering by varying the alkyl chain of the HATn compounds. In the light of structure-property correlation, we have noticed that the hole mobility and permittivity vary according to the length of alkyl chain attached to the triphenylene core. The molecular ordering is also discussed via phase behaviour of compounds and confirmed by polarized optical textures. The change in entropy also decreases with increasing alkyl chain length of the HATn compounds rendering an agreement with that of the mobility and dielectric measurements. The HATn compounds show their potential applications in opto-electronics and could serve as organic semiconductors; however, the poor conductivity remains as a futuristic challenge.

Liquid Crystals Based on the N-Phenylpyridinium Cation-Mesomorphism and the Effect of the Anion.

Families of symmetric, ionic, tetracatenar mesogens are described based on a rigid, N-phenylpyridinium core, prepared as their triflimide, octyl sulfate and dodecyl sulfate salts for a range of terminal chain lengths. The mesomorphism of the individual series is described before a comparison is drawn between the different families and then more broadly with (i) neutral tetracatenar materials and (ii) related bis(3,4-dialkoxystilbazole)silver(I) salts. For the octyl and dodecyl sulfates and the related triflates reported earlier, a SmA phase is seen at shorter chain lengths, giving way to a Colh phase as the terminal chain lengthens. For the alkyl sulfate salts, an intermediate cubic phase is also seen and the terminal chain length required to cause the change from lamellar to columnar mesophase depends on the anion. Furthermore, there is an unexpected and sometime very large mesophase stabilisation seen on entering the columnar phase. All of the triflimide salts show a rectangular columnar (ribbon) phase.

Self‐Assembly and Molecular Electrical Switching Property of Phthalocyanine‐Based Liquid‐Crystalline Poly(Styrene Sulfonic Acid) Compounds

AbstractA series of phthalocyanine‐based liquid‐crystalline poly(styrene sulfonic acid) compounds (LCPCs) are synthesized using cholesterol, dicarboxylic acid, amino‐ zinc phthalocyanine, and polystyrene sulfonic acid. The chemical structure, thermal property, liquid‐crystalline behavior, direct current conductivity, and temperature‐controlled molecular electronic switch property are investigated by use of various techniques. The LCPCs show both columnar phase (Colh) induced by the phthalocyanine moieties and nematic discotic (Nd) phase formed by the collapse of the columnar phase structure. The temperature‐dependent conductivity of the LCPCs is associated with the activation energy evaluated by Broido's graphical procedure according to the thermogravimetric analytical curves. The LCPCs show low conductivity derived from 1D charge migration through phthalocyanine cores in the colh phase, but exhibit high conductivity due to 3D ionic charge transport in the Nd phase. A temperature‐controlled molecular electronic switch is fabricated on the basis of the temperature‐dependent conductivity property, which can be useful for some potential applications.

Exceptional dual fluorescent, excited-state intramolecular proton-transfer (ESIPT) columnar liquid crystals characterized by J-stacking and large Stokes shifts

Excited-State Intramolecular Proton-Transfer (ESIPT) fluorophores are emerging as promising future materials for electronic and biotechnological applications. ESIPT columnar (Col) liquid crystals (LCs) have been especially projected as the apt materials for advanced technological endeavors. But, there are hardly any explorations in this direction and thus, needing immediate attention. Herein we report on the synthesis, characterization, and ESIPT activity of a homologous series of novel phasmidic bis(N-salicylideneaniline) Col LCs. Optical microscopic, calorimetric and powder X-ray diffraction (XRD) studies evidence the occurrence of hexagonal columnar (Colh) phase having p6mm symmetry where the constituent slices result from the self-assembly of a pair of mesogens in a side-by-side manner facilitated by intense longitudinal π-π interactions. X-ray data confirm the absence of both directionally correlated tilting of the slices and transverse core-core interactions within the columns. Fluorescence probing clearly evidence the ESIPT occurring not only in DCM solution of the mesogens but also in their three-condensed states viz., solid, liquid crystal, and isotropic liquid phase; in general, two archetypal emission bands at ~430 nm (weak) and ~ 630 nm (strong) with large Stokes shifts (250–275 nm) of ESIPT phenomenon have been observed. The slow shift of emission maxima of the ESIPT fluorescence as a function of decreasing temperature without photoluminescence quenching coupled with the estimated tilt angle (ϴ) of the slices normal to the columnar axis (37 to 42o), from the XRD data, confirm the formation of so-called Scheibe or J-aggregates. The redox activity, metal ion sensing ability, and solvatochromism of the mesogens have also been investigated. The study suggests that these ESIPT Col LCs with band-gap of about 3 eV can be regarded as wide-bandgap semiconducting materials having the electronic characteristics falling between those of conventional semiconductors and insulators.

Room-Temperature, Deep-Red/NIR-Emissive, C 3-Symmetric (n,π-conjugated) Columnar Liquid Crystals: C 3h -Tris(keto-hydrazone)s.

The first examples of deep-red/near-infrared (NIR) photoluminescent, (n,π-conjugated) discotics, namely, C3h-tris(keto-hydrazone)s, which are the tautomers of tris(azo-enol)s, have been synthesized via a facile one-step triple azo-coupling and characterized. The n,π-resonance-assisted intramolecular H-bonding, rendering planarity and shape persistence to the central core, facilitates their self-assembly into either a hexagonal columnar (Colh) phase (p6mm lattice) or a columnar rectangular (Colr) phase (p2mm lattice), over an extended thermal range including room temperature, fluorescing in the deep-red/NIR-I region. The low band gap with deep-red/NIR emission makes them ideal candidates for NIR-organic light-emitting diodes (OLEDs) and bioimaging.

An electron-deficient tris(triazole)-based discotic liquid crystal that exhibits fast electron transport

Fast electron transport of 1.61 × 10−2 cm2 V−1 s−1 using an electron-deficient tris(triazole)-based discotic liquid crystal.

Ion polarisation-assisted hydrogen-bonded ferroelectrics in liquid crystalline domains.

An alkylamide-substituted (−NHCOC10H21) hydrogen-bonded dibenzo[18]crown-6 derivative (1) was prepared to stabilise the ionic channel structure in a discotic hexagonal columnar (Colh) liquid crystal. The introduction of simple M+X− salts such as Na+PF6− and K+I− into the ionic channel of 1 enhanced the ionic conductivity of the Colh phase of the M+·(1)·X− salts, with the highest ionic conductivity reaching ∼10−6 S cm−1 for K+·(1)·I− and Na+·(1)·PF6− at 460 K, which was approximately 5 orders of magnitude higher than that of 1. The introduction of non-ferroelectric 1 into the ferroelectric N,N′,N′′-tri(tetradecyl)-1,3,5-benzenetricarboxamide (3BC) elicited a ferroelectric response from the mixed Colh phase of (3BC)x(1)1−x with x = 0.9 and 0.8. The further doping of M+X− into the ferroelectric Colh phase of (3BC)0.9(1)0.1 enhanced the ferroelectric polarisation assisted by ion displacement in the half-filled ionic channel for the vacant dibenzo[18]crown-6 of (3BC)0.9[(M+)0.5·(1)·(X−)0.5]0.1.