Thermotropic Liquid Crystal Behavior Research Articles

Isothermal Phase Transitions in Liquid Crystals Driven by Dynamic Covalent Chemistry.

The dynamic nature of calamitic liquid crystals is exploited to perform isothermal phase transitions driven by dynamic covalent chemistry. For this purpose, nematic (N) arrays based on aldehyde 1 were treated with different amines (A-E) in an on-surface process, which resulted in different isothermal phase transitions. These phase transformations were caused by in situ imination reactions and are dependent on the nature of the added amine. Transitions from the N to crystal (1A, 1E), isotropic (1B), and smectic (Sm) (1C, 1D) phases were achieved, while the resulting materials feature thermotropic liquid crystal behavior. A sequential transformation from the N 1 to the Sm 1C and then to the N 1B was achieved by coupling an imination to a transimination processes and adjusting the temperature. All of these processes were well characterized by microscopic, spectroscopic, and X-ray techniques, unlocking not only the constitutional but also the structural aspects of the phase transitions. This work provides new insights into designing constitutionally and structurally adaptable liquid crystal systems, paving the way toward the conception of programable evolutive pathways and adaptive materials.

Isothermal Phase Transitions in Liquid Crystals Driven by Dynamic Covalent Chemistry

AbstractThe dynamic nature of calamitic liquid crystals is exploited to perform isothermal phase transitions driven by dynamic covalent chemistry. For this purpose, nematic (N) arrays based on aldehyde 1 were treated with different amines (A–E) in an on‐surface process, which resulted in different isothermal phase transitions. These phase transformations were caused by in situ imination reactions and are dependent on the nature of the added amine. Transitions from the N to crystal (1A, 1E), isotropic (1B), and smectic (Sm) (1C, 1D) phases were achieved, while the resulting materials feature thermotropic liquid crystal behavior. A sequential transformation from the N 1 to the Sm 1C and then to the N 1B was achieved by coupling an imination to a transimination processes and adjusting the temperature. All of these processes were well characterized by microscopic, spectroscopic, and X‐ray techniques, unlocking not only the constitutional but also the structural aspects of the phase transitions. This work provides new insights into designing constitutionally and structurally adaptable liquid crystal systems, paving the way toward the conception of programable evolutive pathways and adaptive materials.

Synthesis, Self-Assembly and Photoresponsive Behavior of Liquid Crystals Based on Azobenzene

A new amphiphilic surfactant (C4-Azo-C5-HDA) was formed by liquid crystals (LCs) based on azobenzene, whose structures were characterized by 1H-NMR spectroscopy. The reversible hydrogelation upon changes in temperature and light exposure was also studied. Under the irradiation of UV light, the trans-isomer of C4-Azo-C5-HDA rapidly photoisomerized to the cis-isomer, resulting in rapid disruption of the gel. The thermotropic liquid crystal behavior of the gelator was investigated via Differential Scanning Calorimetry (DSC) and Polarizing Optical Microscopy (POM). The biocompatibility experiment of multi-stimulus response of the liquid crystal provides a potential driving force for the development of biomaterials.

Synthesis of aromatic liquid crystal π-conjugated copolymers bearing three-ring pyrimidine-based mesogens, and optical texture observations

Poly(thiophene-co-phenylene) type π-conjugated polymers having two mesogens in monomer repeat unit were synthesized using the Migita–Kosugi–Stille coupling reaction. Thermotropic liquid crystal behavior of the series of polymers was examined with polarizing optical microscopy observations and differential scanning calorimetry. The produced polymers showed unique optical textures of smectic liquid crystal.

Self-assembly of ionic-liquid-type imidazolium gemini surfactant with polyoxometalates into supramolecular architectures for photocatalytic degradation of dye

In this article, ionic liquid-type imidazole gemini surfactants with different spacer length ([C14-n-C14im]Br2, n = 2, 4, 6) were synthesized and 3D nanostructures were constructed by using a novel Preyssler-type POM (K12.5Na1.5[NaP5W30O110]∙15H2O, abbreviated as P5W30) and [C14-n-C14im]Br2 through the ionic self-assembly (ISA) strategy. Hybrid nanostructures were fully characterized by various characterization methods, such as transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM), Fourier transform infrared (FT-IR) spectroscopy, X-ray small-angle scattering, X-ray diffraction (XRD), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). By changing the spacer length of [C14-n-C14im]Br2, the rigidity and space volume of the gemini surfactants can change, which can affect the behavior of [C14-n-C14im]Br2/P5W30, such as the size of the nanostructures, the behavior of thermotropic liquid crystals, d spacing of SAXS, spatial displacement and decomposition temperature. In addition, the calcined [C14-6-C14im]Br2/P5W30 nanostructures exhibit excellent degradation efficiency for methyl orange dyes (MO), which maybe have outstanding application prospects for wastewater treatment. The nanostructure formed by self-assembly not only realizes heterogeneous catalysis, but also solves the problem of water solubility of P5W30 which was easy to recycle. Moreover, the active sites of nanostructures formed by ion self-assembly increase, and the degradation rate was nearly 3 times higher than that of pure P5W30. Our work confirmed that POM and gemini surfactants can construct functional nanostructures through ISA strategy, which can be the perfect candidate for photocatalysis and biomedical.

Highly fluorescent liquid-crystal based on biomolecule and dye self-assembly and their luminescence behavior in solvents for the detection of Fe3+

Hierarchical self-assembly provides a new strategy for the bottom-up fabrication of functional materials with ordered structures. In this article, ionic self-assembly (ISA) of an anionic biological surfactant sodium deoxycholate (NaDC) and a cationic dye Rhodamine B (RhB) in NaOH solution were performed and three-dimensional spherical microcrystals consisting of symmetric nanorods which show similar architectural structure of sea urchin, were obtained. The urchin-like microcrystals possess highly ordered thermotropic liquid crystal behavior and it is interesting to find that the NaDC/RhB/NaOH microcrystals also possess highly enhanced solid emission which is in sharp contrast to nearly no photoluminescence of RhB. Moreover, they exhibited remarkably different morphologies and luminescence behaviors in mixed organic solvents which depended on the mixing ratio of the solvents, i.e., the fraction of n-propanol, due to the polarity of the solvent and the hydrophobic effect. Our NaDC/RhB/NaOH microcrystals in n-propanol show a superior fluorescent sensing capability for the detection of Fe3+ with a limit of detection (LOD) low to 4.40 μM through fluorescence quenching caused by donor–acceptor electron transfer mechanism. The supramolecular nanostructures developed herein open up new opportunities for practical applications in optoelectronics and sensors.

Mesoscopic simulations of temperature-dependent anchoring and wetting behavior at aqueous-liquid crystal interfaces in the presence of a rod-coil amphiphilic monolayer.

Dissipative particle dynamics simulations have been applied to study the temperature dependent anchoring and wetting behavior of thermotropic liquid crystals (LCs) in the presence of a rod–coil amphiphilic monolayer at the aqueous–LC interface. Upon cooling in the nematic phase, a thermally-induced anchoring transition from homeotropic through tilted to planar has been observed. The growth and propagation of smectic order from the interfaces to the bulk nematic LCs are demonstrated to be mainly responsible for this novel transition sequence. In particular, when a complete smectic layer in the amphiphile monolayer is induced around the bulk transition of nematic–smectic-A, the propagation of homeotropic alignment fails instantly and a unique planar anchoring configuration is formed instead. While heating towards the isotropic phase, simulation results show that the nematic–isotropic transition of confined LCs is slightly shifted to a higher temperature, and a nematic wetting layer with homeotropic alignment appears in the rod block monolayer when the bulk LCs is isotropic. Our systematic simulations throughout the whole phase regimes of LCs provide important molecular-level insight into how the coupling between the ordering of LCs and adsorbents and their temperature dependencies affect the anchoring behavior in this complex system, which should be instrumental in the rational design and application of advanced LC-based biosensors with optimal operating temperature range.

Bifunctional dipyridylpyrazole silver complexes with tunable thermotropic liquid crystal and luminescent behaviour

Five new series of alkyloxyphenyl-substituted dipyridylpyrazole silver(I) complexes [Ag(pypzR(n)py)]2[A]2 (R(n) = C6H4OCnH2n+1, n = 1, 12, 14, 16, 18; [A] = NO3−, BF4−, ReO4−, PF6−, CH3-p-C6H4SO3−) have been prepared by reaction of the corresponding pyrazoles pypzR(n)py with different silver salts AgA. The coordination of the non-mesomorphic ligands to the silver(I) metal ion induces mesomorphism in the new complexes. Most of them show smectic A mesophases in accordance with the textures observed by polarised light optical microscopy, and the lamellar arrangements established by temperature-dependent powder X-ray diffraction experiments. Additionally, all compounds behave as fluorescent materials in dichloromethane solution at room temperature. The ability of the pyrazole ligands as chemosensors for the detection of toxic and heavy metal ions such as Hg2+, Zn2+, Cd2+ and Pb2+ has also been proved. On the other hand, the luminescence properties of the silver compounds are improved through the in situ formation of polymetallic derivatives in solution. The effect of the counter-ions on both the liquid crystal and the luminescence behaviour is discussed.

Self-assembly, aggregates morphology and ionic liquid crystal of polyoxometalate-based hybrid molecule: From vesicles to layered structure

Polyoxometalate anions [SiW12O40]4- were encapsulated by four 1, 3-dioctadecylimidazolium cations (labeled as L+) driven by electrostatic interaction to obtain hybrid molecule L4[SiW12O40]. The composition and ingredients of L4[SiW12O40] were confirmed by infrared spectroscopy (IR) and elemental analysis. In mixedsolvent (chloroform/methanol volume of 4:1), the self-assembled aggregates of L4[SiW12O40] appear at multilamllar vesicles under optical microscopy and the micron-size bulky flower-like aggregates in scanning electron microscopy (SEM). However, Transmission electron microscopy (TEM) images and small-angle X-ray diffraction (XRD) of L4[SiW12O40] demonstrate that spherical aggregations in mixed-solvent are densely packed by flakes, which can self-assembly into ordered one dimension layered structure. In addition, L4[SiW12O40] shows typical thermotropic liquid crystal behavior similar to imidazole cations. The ordered self-assembly hybrid molecule materials based on organic-polyoxometalate ionic liquids would be exciting branch of nanostructure functional materials.

Dependence of thermotropic mesomorphism on lateral nitro group

ABSTRACTA novel homologous series RO-C6H4-COO-C6H3-(NO2)-CO-CH˭CH-C6H4OC18H37(n) para of chalconyl ester derivatives have been synthesized and studied with view to understanding the effect of an ortho substituted nitro group on thermotropic liquid crystal (LC) behavior. The novel homologous series consists of thirteen homologues (C1 to C18). The C1 to C4 homologues are nonliquid crystal (NLC) and the rest of the homologues (C5 to C18) homologues are enantiotropically nematogenic without exhibition of a smectic phase even in the monotropic condition. Transition temperatures were determined by an optical polarizing microscope (POM) equipped with a heating stage. Texture of nematic phase are threaded or Schlieren. Analytical, thermal and spectral data supported molecular structure of homologues. Thermal stability for nematic is 147.1°C whose mesophase lengths vary between 16.0 and 32.0°C the C7 and C18 homologues, respectively, and their mesogenic exhibition range between 96.0 and 166.0°C. Thus, the present novel series is middle ordered melting type, Group efficiency order is derived from comparative study of structurally similar series. The transition curves of a phase diagram behaved in normal manner except C10 and C16 homologues. Odd-even effect is observed for N-I transition curve. Group efficiency order derived is: -OC12H25 (n) > -OC18H37 (n) > -OC18H37 (n).

Effect of an n-Alkoxy-2,4-hexadiene Polymerizable Tail System on the Mesogenic Properties and Cross-Linking of Mono-Imidazolium-Based Ionic Liquid Crystal Monomers.

We demonstrate that an ether-based n-alkoxy-2,4-hexadiene polymerizable tail system is an effective and modular alternative to traditional ester-based polymerizable tail groups (i.e., acrylate, methacrylate, sorbate) and alkyl-1,3-diene tails for the design of radically polymerized ionic liquid crystal (ILC) monomers. Several series of nonsymmetric 1-vinylimidazolium-bromide-based ILC monomers containing these different polymerizable tail systems were synthesized and compared for their ability to form thermotropic liquid crystal (TLC) phases and to be photo-cross-linked with TLC phase retention. The n-alkoxy-2,4-hexadiene tail system was found to be more favorable/conducive to TLC phase formation than acrylate, methacrylate, and sorbate tails. It was more similar to the alkyl-1,3-diene tail system in terms of its more favorable effect on TLC behavior; however, it is more modular/easier to synthesize, more resistant to thermal Diels-Alder side reaction, and more isomerically pure, making it better for ILC monomer design. Also, the n-alkoxy-2,4-hexadiene tail system was found to be very amenable to radical photo-cross-linking with TLC phase retention. To demonstrate this feature, an example cross-linkable ILC monomer with this tail system was synthesized and polymerized in the smectic A TLC phase, and the monomer and polymerized material were characterized for their ionic conductivity behavior.

Hexadecyl-β-D-Glucopyranoside: A Liquid Crystal with Surfactant Properties for Stabilization of Microemulsions

Lyotropic liquid crystals (LLC) having amphiphilic properties are promising materials as co-surfactants in emulsion formulations. A carbohydrate lyotropic liquid crystal, hexadecyl-β-D-glucopyranoside, was synthesized by linking D-glucose to cetyl alcohol via acetylated glucoside and its ability to stabilize microemulsions was investigated. The synthesized compound was characterized by using Nuclear Magnetic Resonance Spectroscopy (NMR) and Fourier Transform Infrared Spectroscopy (FTIR). Both acetylated and deacetylated compounds were found to exhibit thermotropic and lyotropic liquid crystal behavior. The critical micelle concentration (CMC) value of 1.53 × 10−5mol dm−3 obtained for hexadecyl-β-D-glucopyranoside from both UV-visible spectroscopic and turbidity methods suggests its non-ionic surfactant properties. Calculated HLB value of 8.86 indicates that it is suitable for making self-emulsifying oils and water in oil (W/O) emulsions. By introducing optimum amount of 0.05 wt% of newly synthesized hexadecyl-β-D-glucopyranoside as a co-surfactant, macro emulsions formulated with olive oil, water and non-ionic lipophilic surfactant sorbitan monostearate (Span 80) was successfully converted into microemulsions.

On the Mesophase Formation of 1,3-Dialkylimidazolium Ionic Liquids

A series of seven different 1,3-dialkylimidazolium-based ion-pair salts with the same molecular weight and size but different symmetries was synthesized. For all salts, bromide was chosen as the counterion, giving the series ([CnIMCm][Br]), where IM = imidazolium and Cn and Cm are varying N-alkyl substituents with n + m = 13. Thus, the effect of symmetry on the physicochemical properties, such as thermal transitions, densities and viscosities and particularly mesophase formation, is investigated herein. All salts are fully characterized by NMR spectroscopy and mass spectrometry, and their physicochemical properties such as thermal transitions, densities, and viscosities are reported. Single crystal X-ray structure analysis is reported for 1-tridecylimidazolium bromide ([C0IMC13][Br]) and 1-ethyl-3-undecylimidazolium bromide ([C2IMC11][Br]). Salts 1-tridecylimidazolium bromide ([C0IMC13][Br]) and 1-dodecyl-3-methylimidazolium bromide ([C1IMC12][Br]) exhibit thermotropic liquid crystal behavior, confirmed by differential scanning calorimetry, polarized optical microscopy, and small-angle X-ray diffraction to be the SmA mesophase. A structure with interdigitation of alkyl chains is observed for all of [C0IMC13][Br], [C1IMC12][Br], and [C2IMC11][Br], despite the absence of thermotropic liquid crystalline behavior for the latter (and all other isomers with an alkyl chain length less than 12 carbon atoms). This allows us to draw the conclusion that for the liquid crystal phase of an ionic liquid to exist, not only are the calamitic shape and integral length of a molecule important but a minimal alkyl chain length of n = 12 is also required. Therefore, a dodecyl group could be considered as the functional group responsible for liquid crystalline behavior.

New ionic organic compounds containing a linear tris(imidazolium) core and their thermotropic liquid crystal behaviour

Imidazolium-containing thermotropic ionic liquid crystals (TILCs) are of interest because of their structural similarity to imidazolium-based ionic liquids (ILs), allowing them to exhibit some IL-like properties in addition to the LC order. More imidazolium units are important for increasing the IL character; however, the effect of multiple imidazolium units on LC behaviour is not well known. Most reported imidazolium TILCs contain one imidazolium unit; only a handful containing multiple imidazolium units is known. The only examples of TILCs with multiple imidazolium units sequentially linked with a flexible spacer are based on an alkyl- or oligo(ethylene oxide)-bridged bis(imidazolium) core with an n-alkyl tail at each end. Herein, a series of 10 new symmetric compounds containing three hexyl-bridged imidazolium bromide units as the core and two terminal n-alkyl chains was synthesised and analysed. Thermotropic LC phases were generally not observed for homologues with even-numbered tails less than 16 carbons. However, after initial annealing, the homologues containing 16-, 18- and 20-carbon tails, all form a smectic A phase in the 25–137°C range, with the latter two also forming a higher-order smectic phase. This indicates that with sufficiently long n-alkyl tails to counterbalance the poly(ion) core, these tris(imidazolium) salts can exhibit thermotropic mesomorphism.

Thermotropic liquid crystals built from organic–inorganic hybrid polyoxometalates and a simple cationic surfactant

By ion metathesis reactions, the dimethyldioctadecylammonium (DODA+) was used as the surfactant to encapsulate organic–inorganic hybrid polyoxometalates (POMs) (NH4)6{Mo2VO4[(Mo2VIO6)NH3CH2CH2CH2C(O)(PO3)2]2}·10H2O (POM-1) and (NH4)8{Mo2VO4[(Mo2VIO6)CH3C(O)(PO3)2]2}·14H2O (POM-2), resulting in two surfactant-encapsulated clusters (SECs) with characteristic thermotropic liquid-crystalline behavior. The chemical composition of the obtained SECs was determined by IR spectra, elemental analysis, TG analysis and NMR spectra. Also, polarized optical microscopy, differential scanning calorimetry (DSC), variable temperature X-ray diffraction (VT-XRD) and TEM of the samples were also performed, which revealed that both SECs show thermotropic liquid crystal behavior.

Self-Assembly of Hekates-Tris(N-salicylideneaniline)s into Columnar Structures: Synthesis and Characterization

Two series of new, photoluminescent star-shaped discotic liquid crystals, recently termed as "hekates", derived from tris(N-salicylideneaniline)s (TSANs), were synthesized by the facile threefold condensation of 3,4-bis(alkoxy)phenyl 4-aminobenzoates/3,4,5-tris(alkoxy) phenyl 4-aminobenzoates with 1,3,5-triformylphloroglucinol and characterized. These two series of discotics with six and nine peripheral n-alkoxy tails were especially designed and accomplished to understand the relation between mesomorphic/photophysical properties and molecular structure. Proton NMR spectral analysis revealed their existence as an inseparable mixture of two keto-enamine tautomeric forms featuring C(3h) and C(s) rotational symmetries. A systematic study into the thermotropic liquid crystal behavior using polarizing optical microscopy, differential scanning calorimetry, and X-ray scattering confirmed the presence of columnar (Col) phase in vast majority of the TSANs prepared. The two-dimensional (2D) lattices of these fluid columnar phases were found to be characteristic of hexagonal Col (Col(h)), rectangular Col (Col(r)), or oblique Col (Col(ob)) phases depending on the number/length of the peripheral flexible chains. The stabilization of the Col(ob) phase, a less commonly found fluid columnar structure, and the first of its kind in TSAN systems, implies very intensive intermolecular (face-to-face) interactions among the TSAN cores within the column. The photophysical properties were investigated both in solution and the columnar states by UV-vis absorption and photoluminescence; markedly, the solution state emits light in the blue region. The light-emitting ability of the Col phase is particularly significant given the possibility that, in such cores, the protons and electrons interact with each other through the H-bonding environment.

The phase behavior, structure, and dynamics of rodlike mesogens with various flexibility using dissipative particle dynamics simulation

We present a systematic dissipative particle dynamics (DPD) study on the phase behavior, structure, and dynamics of rodlike mesogens. In addition to a rigid fused-bead-chain model with RATTLE constraint method, we also construct a semirigid model in which the flexibility is controlled by the bending constant of k(φ). Using this notation, the rigid model has an infinite bending constant of k(φ)=∞. Within the parameter space studied, both two kinds of models exhibit the nematic and smectic-A phases in addition to the isotropic and solid phases. All of the phase transitions are accompanied by the discontinuities in the thermodynamical, structural, and dynamical quantities and the hysteresis around the transition points, and are therefore first order. Note that the obtained solid state exhibits an in-layer tetragonal packing due to the high density. For the rigid model, the simulations show that the liquid crystal phases can be observed for mesogens with at least five beads and the nematic phase is the first one to appear. More importantly, the phase diagram of seven-bead-chain models is obtained as a function of k(φ) and temperature. It is found that decreasing the value of k(φ) reduces the anisotropy of molecular shape and the orientational ordering, and thereby shifts the liquid crystal phases to the lower temperature end of the phase diagram. Due to the different k(φ) dependence of phase transition temperatures, the nematic phase range exhibits a more marked narrowing than the smectic-A phase as k(φ) is reduced, implying that the flexibility has a destabilizing effect on the nematic and smectic-A phases. We also have investigated the anisotropic translational diffusion in liquid crystal phases and its temperature and flexibility dependence. In our study, we find that the phases formed, their statical and dynamic properties, as well as the transition properties are in close accord with those observations in real thermotropic liquid crystals. It is clear that both the rigid and semirigid models we used are valuable models with which to study the behavior of thermotropic liquid crystals using DPD algorithm.

Using liquid crystals to detect DNA hybridization on polymeric surfaces with continuouswavy features

In this study, we examined the orientational behavior of thermotropic liquid crystals (LCs)supported on a film of DNA that was chemically immobilized on a nanostructure surface.The surface was comprised of gold film deposited onto a polymer substrate that had asinusoidal distortion normal to the surface, leading to a parallel array of peaks and troughs.The sinusoidal structures were produced by treating a polydimethylsiloxane (PDMS)substrate with oxygen plasma and buckled on a cylindrical surface. This patterned PDMSwas then used to create replicas of the associated relief structures on another polymersurface, poly(urethaneacrylate), where a film of gold was deposited. The gold films werefunctionalized with thiol-modified DNA, and then used as substrates for the hybridizationof a complementary strand of DNA (cDNA). The orientation of nematic 4-cyano-4′-pentylbiphenyl (5CB) was found to be parallel to the plane of the surface-immobilizedDNA before incubation with a solution of cDNA. However, the hybridization of DNAinduced a random orientation of 5CB, indicating that the DNA complexes disturbed thesinusoidal structure of the surface. These results demonstrate that LC can be used todetect the hybridization of DNA by manipulating the response of LC to the DNAdecorated surfaces.

Liquid Crystal-based Imaging of Biomolecular Interactions at Roller Printed Protein Surfaces

In this study, the orientational behavior of thermotropic liquid crystals (LC) supported on a film of protein receptors was examined. Avidin was roller printed and covalently immobilized onto the surface of gold using NHS/EDC chemistry. The orientation of nematic 4-cyano-4'-pentylbiphenyl (5CB) was found to be parallel to the plane of the printed avidin surface before incubation with a solution of biotin. However, protein-receptor complexation induced a random orientation of 5CB, where protein-receptor complexes disturbed the nanoscale topography of the printed protein surface. Atomic force microscopy and ellipsometry was used to confirm printing and the specific interaction of proteins. These results demonstrate that the combination of LC and roller printing can be used to detect specific interactions between biomolecules by manipulating the orientational behavior of LC to the printed protein surfaces.

Behavior of Liquid Crystals Confined to Mesoporous Materials as Studied by 13C NMR Spectroscopy of Methyl Iodide and Methane as Probe Molecules

The behavior of thermotropic nematic liquid crystals (LCs) Merck Phase 4 and ZLI 1115 confined to mesoporous controlled pore glass materials was investigated using 13C nuclear magnetic resonance spectroscopy of probe molecules methyl iodide and methane. The average pore diameters of the materials varied from 81 to 375 A, and the temperature series measurements were performed on solid, nematic, and isotropic phases of bulk LCs. Chemical shift, intensity, and line shape of the resonance signals in the spectra contain lots of information about the effect of confinement on the state of the LCs. The line shape of the 13C resonances of the CH3I molecules in LCs confined into the pores was observed to be even more sensitive to the LC orientation distribution than, for example, that of 2H spectra of deuterated LCs or 129Xe spectra of dissolved xenon gas. The effect of the magnetic field on the orientation of LC molecules inside the pores was examined in four different magnetic fields varying from 4.70 to 11.74 T. The magnetic field was found to have significant effect on the orientation of LC molecules in the largest pores and close to the nematic-isotropic phase transition temperature. The theoretical model of shielding of noble gases dissolved in LCs based on pairwise additivity approximation was utilized in the analysis of CH4 spectra. For the first time, a first-order nematic-isotropic phase transition was detected to take place inside such restrictive hosts. In the larger pores a few degrees below the nematic-isotropic phase transition of bulk LC the 13C quartet of CH3I changes as a powder pattern. Results are compared to those derived from 129Xe NMR measurements of xenon gas in similar environments.