Methoxy Benzylidene Research Articles

Electric Response of a Negative Dielectric Anisotropy Nematic Liquid Crystal Doped with Ionic Dopant

The electrical properties measurements have been performed in a homogeneous alignment parallelepiped cell containing 4-methoxy benzylidene- 4-butylaniline (MBBA) liquid crystal doped with 0.02%wt tetrabutylammonium bromide (TBAB). The measurement of the complex permittivity was conducted in the nematic phase, covering a frequency range of 42 Hz to 5 MHz. A new relaxation mode was observed in the low-frequency region, which was not present in pure MBBA. The obtained dielectric dispersion could be fitted using the double Cole–Cole formula to determine the relaxation frequencies. The steady-state current exhibited a nonlinear dependence on the applied voltage, and hysteresis was observed in the transient current-voltage characteristic curve.

Distribution of Nine Organic UV Filters along the Shore Next to the Harbor Canals in the Middle Pomeranian Region (Northern Poland)

Spatiotemporal changes in the concentration of UV filters were investigated along the shore according to increasing distance from breakwaters, from the shoreline, as well as according to seasonality in three locations of different anthropogenic pressures, involving those from cosmetic products being released during touristic activity. Nine organic UV filters (benzophenone-1 (BP-1), benzophenone-2 (BP-2), benzophenone-3 (BP-3), octocrylene (OCR), 4-methoxy benzylidene camphor (4-MBC), ethylhexyl methoxycinnamate (EHMC), ethylhexyl salicylate (EHS), homosalate (HMS), and butyl methoxydibenzoylmethane (BMDM)) were determined in core sediments, and the range of determined concentrations above the limit of quantification was between 19.2 ng·kg−1 d.w. (HMS) and 539.5 μg·kg−1 d.w. (4-MBC). Unexpectedly, contrary to the level of anthropogenic pressure, the concentrations of four (BP-1, BP-2, BP-3, OCR) UV filters decreased in the following order: Darłówko > Ustka > Rowy. Higher concentrations of BP-1, BP-2, BP-3, and OCR were determined in spring than in summer and autumn. The maximal concentration of HMS and EHMC/EHS was found in the summer and in the autumn, respectively. BMDM was determined occasionally only in two samples collected in Ustka. The higher maximal concentration range of all UV filters was determined in core sediments taken from the eastern (539.5 μg·kg−1 d.w.) rather than from the western (11.3 μg·kg−1 d.w.) parts of the beaches. According to increasing distance from the breakwaters, higher concentrations of UV filters were determined in sites located up to 100 m away in all locations and seasons. Spatial variation in the concentration of UV filters was observed in profiles perpendicular to the water line. Typically, higher concentrations were determined at sites having contact with water, although incidentally, high concentrations were also noticed at sites located further into the beach. The Polish coast of the Baltic Sea is not free from organic UV filters, and expectations concerning the abundance of UV filters in a given location are far from recorded data due to the impact of hydro-technical treatments (i.e., stony and wooden breakwaters, artificial reefs, nourishment) and coastal littoral drift.

Acute toxicity assessment of nine organic UV filters using a set of biotests

UV filters in environmental compartments are a source of concern related to their ecotoxicological effects. However, little is known about UV filters’ toxicity, particularly those released into the environment as mixtures. Acute toxicity of nine organic UV filters benzophenone-1, benzophenone-2, benzophenone-3, 4-methoxy benzylidene camphor, octocrylene, ethylhexyl methoxycinnamate, 2-ethylhexyl salicylate, homosalate, and butyl methoxydibenzoylmethane was determined. UV filter solutions were tested as single, binary, and ternary mixtures of various compositions. Single solutions were tested using a set of bio tests, including tests on saline crustaceans (Artemia franciscana), freshwater crustaceans (Daphnia magna), marine bacteria (Aliivibrio fischeri), and freshwater plants (Lemna minor). The tests represent different stages of the trophic chain, and hence their overall results could be used to risk assessment concerning various water reservoirs. The toxicity of binary and ternary mixtures was analyzed using the standardized Microtox® method. Generally, organic UV filters were classified as acutely toxic. Octocrylene was the most toxic for Arthemia franciscana (LC50 = 0.55 mg L–1) and Daphnia magna (EC50 = 2.66–3.67 mg L–1). The most toxic against freshwater plants were homosalate (IC50 = 1.46 mg L–1) and octocrylene (IC50 = 1.95 mg L–1). Ethylhexyl methoxycinnamate (EC50 = 1.38–2.16 mg L–1) was the most toxic for marine bacteria. The least toxic for crustaceans and plants were benzophenone-1 (EC50 = 6.15–46.78 mg L–1) and benzophenone-2 (EC50 = 14.15–54.30 mg L–1), while 4-methoxy benzylidene camphor was the least toxic for marine bacteria (EC50 = 12.97–15.44 mg L–1). Individual species differ in their sensitivity to the tested organic UV filters. An assessment of the toxicity of mixtures indicates high and acute toxicity to marine bacteria after exposition to a binary mixture of benzophenone-2 with octocrylene, 2-ethylhexyl salicylate, or homosalate. The toxicity of mixtures was lower than single solutions predicting antagonistic interaction between chemicals.Graphical abstract

Computational and Molecular Docking Studies of New Benzene Sulfonamide Drugs with Anticancer and Antioxidant Effects.

The studies on the potential usage of benzene sulfonamide derivatives as anticancer agents are limited. benzene sulfonamide derivatives are currently used as anticancer agents against different breast cancer cell lines, such as MCF-7, lung cancer cells (A549), prostate cancer cells (Du-145), and cervical cells (HeLa). A series of new sulfonamide drugs are synthesized by reacting aldehydes thio-semi-carbazones derivatives with benzene sulphonyl chloride to form benzylidene-N-(phenylsulfonyl) hydrazine-1-carbothioamide derivatives. Studying the anticancer effects against MCF-7 breast carcinoma cell lines and the antioxidant activities of these newly synthesized compounds. Studying the anticancer effects against MCF-7 breast carcinoma cell lines and the antioxidant activities of these newly synthesized compounds. To study the anti-breast cancer activity of the newly synthesized compounds, a molecular docking study is used to analyze the binding energy for the nonbonding interactions between the ligands (studied compounds) and receptor (4PYP (pdb code: 4FA2)) against human breast cancer (MCF-7) cells. The bioavailability of all studied compounds is confirmed by pharmacological investigations using Mol inspiration and absorption, distribution, metabolism, excretion, and toxicity online servers. The two derivatives, 2-(4- methoxy benzylidene)-N-(phenylsulfonyl) hydrazine-1-carbothioamide (4c) and 2-(4-dimethylamino) benzylidene)-N-(phenylsulfonyl) hydrazine-1-carbothioamide (4e) show the most potent anticancer effects against MCF-7 breast carcinoma cell lines. Meanwhile, these two derivatives show the lowest antioxidant activities. The different spectral techniques were used to confirm the structure of the novel synthesized compounds. Further, 2-(4-(dimethyl amino) benzylidene)-N- (phenylsulfonyl)hydrazine-1-carbothioamide (4e) and 2-(4- methoxy benzylidene)-N-(phenylsulfonyl) hydrazine-1 carbothioamide (4c) were the most potent anticancer derivatives against MCF-7 breast carcinoma cell lines. Furthermore, they exhibited the most potent antioxidant activities. Meanwhile, the 2-benzylidene-N-(phenylsulfonyl) hydrazine-1-carbothioamide (4a) and 2-(4-chloro benzylidene)-N-(phenylsulfonyl) hydrazine-1-carbothioamide (4d) had the lowest antioxidant potentials. The estimated binding energies, inhibition constant, intermolecular energies, and reference RMSD produced from docking for all studied compounds were reported. These values showed that all studied compounds formed stable complexes with the receptor with high binding affinity. It was further noted from the ADMET analysis that compounds 4c, 4d, and 4e have good absorption, low toxicity in the human liver, and medium BBB penetration. Hence, these studied compounds (4c-4e) may be suggested as potential compounds against human breast cancer MCF-7 cells.

Synthesis and characterization of copolymer Poly [(Thiophene-2, 5-diyl)-co-para methoxy benzylidene] doped with Cobalt acetate using Oxidative polymerization

A one pot oxidative polymerization technique is used to synthesize copolymer Poly [(thiophene-2, 5-diyl)-copara methoxy benzylidene]. In this technique we used catalyst POCl3 and 1, 4 dioxane solvent for copolymerization of para methoxy benzaldehyde with thiophene. One pot method takes around 24 hours. Doped copolymer was synthesized in presence of 0.2gm cobalt acetate. Catalyst is removed using ammonia. Products are obtained using menthol. UV–Vis, FTIR, 1HNMR, 13CNMR, XRD, FE-SEM, EDX, BET and TGA are used to analyze physical properties of undoped and doped copolymers. The polycrystalline phase is confirmed using structural analysis. Interconnected nonoporous structure is indicated by surface morphology. The nano crystalline sizes of undoped and doped forms are 44 nm and 55 nm respectively. The surface area changed due to cobalt doping of copolymer from 3000 to 47900cm2/g. Both copolymers are thermally stable up to 280oC confirmed by thermogravimetric analysis. Optical absorption studies proved that band gap changed from 2.93 to 2.83 eV after doping and two-probe method was used to calculate conductivity values as 1.34 x 10-9to 7.54 x 10-8 S/cm for undoped and doped copolymers. Both undoped and doped copolymers have several uses like semiconducting material and energy storage in the field of conducting polymers.

Facile TiO2 NPs catalysed synthesis of substituted-4-Hydroxy/methoxy benzylidene derivatives as potent antioxidant and anti-tubercular agents

In this work, we report a facile synthesis of a series of substituted-4-hydroxy/methoxy benzylidene derivatives ( 3a-i ) via Knoevenagel condensation reaction of different active methylene compounds ( 1 ) with 4-hydroxy/methoxy benzaldehyde ( 2 ) under reflux condition in aq. EtOH using catalytic amount of TiO 2 NPs. The structures of all the obtained compounds were confirmed by analytical and spectroscopic methods and screened for their antioxidant and anti-tubercular activities. Antioxidant activity results revealed that, the compound 3e with IC 50 value 105.48 µg/mL showed very effective DPPH scavenging activity and compound 3h with IC 50 value 129.72 µg/mL exhibited most effective nitric oxide radical scavenging activity compared to the reference standard BHT and ascorbic acid respectively. From the results of anti-TB activity, compound 3b displayed a more sensitivity at 25 µg/mL. Furthermore, synthesized compounds were assessed for molecular docking studies on the target enzymes Human peroxiredoxin 5 and enoyl-ACP reductase and they were emerged has an active antioxidant and anti-TB agents with least binding energy -5.8 and -8.0 kJ mol −1 respectively.

Synthesis, Characterization and Antiioxidant Activity of Schiff Base Compounds Obtained Using Green Chemistry Techniques

The objective was to implement green chemistry methodologies in the synthesis of Schiff bases. Natural berry fruit juice freeze-dried extract was employed as natural acid catalyst for the synthesis of N-(4-methoxy benzylidene) aniline from anisaldehyde and aniline, N-salicylideneaniline from salicylaldehyde and aniline, and N-benzylaniline from benzaldehyde and aniline. The Schiff base thus synthesized from natural berry fruit juice freeze-dried extract was characterized by FT-IR and NMR spectral techniques. The antioxidant skin efficacy of these Schiff bases was tested by application on the healthy human skin. The proposed green chemistry methods are convenient, affordable, simple, provide more efficient extraction, and show maximum efficiency.

Benzidine-based Schiff base compounds for employing as corrosion inhibitors for carbon steel in 1.0 M HCl aqueous media by chemical, electrochemical and computational methods

The inhibiting performance of three benzidine derivatives named Bis (4(dimethylamino)benzylidene)biphenyl-4,4′-diamine (DBB), Bis(4-methoxy benzylidene)biphenyl-4,4′-diamine (MBB) and Bis(4-chlorobenzylidene)biphenyl-4,4′-diamine (CBB) for carbon steel (CS) corrosion in 1.0 M HCl aqueous media was evaluated using weight loss and electrochemical techniques. The affinity of tested compounds towards the steel surface was investigated using Density Functional Theory (DFT) and Molecular Dynamics (MD) simulations. Compounds revealed a good inhibition action in tested medium even at low concentrations and the inhibition efficiency increases with increasing concentration of inhibitors. Polarization curves show that they act as mixed-type inhibitors and their adsorption process obeyed the Langmuir adsorption model. SEM, AFM and EDX studies were used to confirm the presence of the protective film formed on the carbon steel surface by observing the corrosion attack morphologies and elemental composition of the corrosion products, respectively. DFT and MD results complement experimental studies and demonstrate that Schiff base moieties and functional groups are responsible for corrosion inhibitive performances of investigated compounds.

Synthesis And Characterization Of Novel Pyrimidine-4,5-Diamine As Anticancer Agent

Unlike latent cells, cancer cells supply deoxyribonucleoside triphosphates to cells continuously and thereby, prop up the uncontrolled cancer growth. Pyrimidine has been concerned in the separation of leukemic cells, known as adenine bioisosteres, as well as its biological activities, especially its anticancer properties. In this context, a novel series of N5-(3-substituted benzylidene)-N4-phenyl pyrimidine-4,5-diamine [5A-5F] / N5-(2-substituted benzylidene)-N2,N2-dimethyl-N4-phenyl pyrimidine-2,4,5-triamine [5a-5f] were synthesized by using the starting ingredient formimidamide/4-(dimethylamino) benzimidamide and sodium ethoxide. The synthesized compounds were characterized by IR, 1H NMR, and Mass spectral analyses and screened for their biological studies. In the present study, pyrimidine derivatives and their insilico modeling were done by using c-Src kinase and p38 MAP kinase complex followed by the evaluation of their anticancer activity. The screening of synthesized scaffolds possessed significant activity against HeLa cell lines and showed similar activity compared to standard Cisplatin. Among all the synthesized compounds, N5-(4-hydroxybenzylidene)-N4-phenyl pyrimidine-4,5-diamine 5A, N5-benzylidene-N4-phenylpyrimidine-4,5-diamine 5C, N5-benzylidene-N2, N2-dimethyl-N4-phenyl pyrimidine-2,4,5-triamine 5c, and N5-(4-methoxy benzylidene)-N4-phenyl pyrimidine-4,5-diamine 5E showed the highest significant anticancer activity. Based on the study, it was observed that substituents such as 4-hydroxy, 4-fluoro, 4-nitro, 4-methoxy, and 4-methyl are important to produce a biological effect. Moreover, among these substituents, N5-(4-hydroxybenzylidene)-N4-phenyl pyrimidine-4,5-diamine exhibited the highest anticancer activity followed by unsubstituted derivative N5-benzylidene-N4-phenylpyrimidine-4,5-diamine, which delivered significant anticancer activity.

A new spectrophotometric study with ortho hydroxy schiff base for the determination of aluminum in drug

In this study, a Schiff base called (E)-2-((2- hydroxy -3- methoxy benzylidene)amino)-5- methylphenol (L) was used as a ligand. Spectrophotometric properties of the ligand have been defined and the optimum conditions for determining aluminium by complex by UV-Vis. spectrophotometry. The absorbance of Al(III)-L complex obeys Beer’s law between 1.4 µg mL–1 and 13.5 µg mL–1 for the aluminium in the optimum conditions. Under optimum conditions, the determination of aluminium in Kompensan® drug was done successfully. The LOD and LOQ values of the developed method were 0.01139 μg mL-1 and 0.0345 μg mL-1, respectively for the ligand.

Tailor made biheterocyclic pyrazoline-thiazolidinones as effective inhibitors of Escherichia coli FabH: Design, synthesis and structural studies

In the present study, a new series of biheterocycles pyrazoline-thiazolidinones derivatized at fifth position with substituted arylidene groups were developed as potent inhibitors of Escherichia coli FabH (PDB: 5BNS) an antimicrobial target. These compounds are conveniently synthesized from 3,5-substituted pyrazolinyl carbothioamide precursor. The virtual inhibition assay and pharmacokinetic profiling were carried out based on in vitro antimicrobial assay on pathogenic microbes. Amongst, the compound with 4-methoxy benzylidene substituent emerged as effective against all tested bacterial strains. The compound binds very effectively to the active site of the target with minimum glide score = −8.400 kcal/mol. The structure of newly synthesized derivatives was confirmed by several spectroscopic techniques and some of the hybrids by single crystal XRD studies. The compounds 3, 4a and 4g were crystallized in monoclinic crystal system with P21/c, P21/n and Cc space group respectively. The intermolecular contacts in the crystal structure were elucidated by Hirshfeld computational methods and molecular electrostatic potential maps illustrated the charge distribution of the molecules.

Microwave-Assisted Organic Reactions: Eco-friendly Synthesis of Dibenzylidenecyclohexanone Derivatives via Crossed Aldol Condensation

The synthesis of dibenzylidenecyclohexanone derivatives via environmentally friendly Microwave Assisted Organic Synthesis (MAOS) crossed aldol condensation had been carried out. The condensation reaction to synthesize the dibenzylidenecyclohexanone 8b was performed by reacting benzaldehyde 4 and cyclohexanone 2 (mole ratio of 2:1) with NaOH as catalyst for 2 min under microwave irradiation. The benzaldehyde derivatives used in this study were 4-methoxybenzaldehyde and 3,4-dimethoxybenzaldehyde and gave of (2E,6E)-bis(4-methoxy benzylidene)cyclohexanone 8a and (2E,6E)-bis(3,4-dimethoxybenzylidene)cyclohexanone 8c, respectively. The study was commenced by searching the optimum concentration of NaOH. The reaction yield was determined by TLC scanner and the structure was elucidated by FTIR and NMR spectrometers. For the comparison, the reaction was also carried out by using stirring method. The results showed that optimum concentration of NaOH was 5 mmole. By using the optimum condition via MAOS method, the compounds 8a, 8b and 8c were obtained in 100, 98 and 93%, respectively. The research also proved that the method of dibenzylidenecyclohexanones (8) synthesis using MAOS was more efficient than stirring method.

Physico-chemical studies of the experimental and theoretical properties of organic nonlinear optical material 4-chloro-4'methoxy benzylideneaniline

The FT-IR, FT-Raman and UV–visible spectral analysis of 4-chloro 4’-methoxy benzylidene aniline were done experimentally and interpreted with the aid of normal coordinate analysis based on density functional theory (DFT) at the B3LYP/6–311++G (d, p) level of theory. Natural Bond orbital analysis was performed to understand the charge transfer interactions and reactive sites within the system. HOMO-LUMO analysis and first static and dynamic hyperpolarizability calculations were carried out in order to confirm the NLO activity of CMOBA. Photophysical characterization was done to understand the fluorescence emission and lifetime of CMOBA leading to application in blue OLEDs. The Molecular Electrostatic Potential Map was simulated to identify the active sites for electrophilic and nucleophilic attack or the active sites of the molecule which can bind to proteins. Molecular docking analysis revealed its potential as an inhibitor for different proteins which are responsible for cancer and many inflammatory diseases such as rheumatoid arthritis, inflammatory bowel disease, Crohn's disease and psoriasis. Experimental studies of invitro antiproliferative effect by MTT assay verified the anticancer properties of CMOBA.

Theoretical evaluation of corrosion inhibition performance of three antipyrine compounds

Corrosion inhibition performance of three antipyrine derivatives namely, 4-amino-antipyrine (AAP), 4-[(4-hydroxy benzylidene)-amino]-antipyrine (SAAP) and 4-[(4-methoxy benzylidene)-amino]-antipyrine (AAAP), for metal surface corrosion was studied by using quantum chemistry, molecular mechanics and molecular dynamics simulation methods. Correlations between the quantum chemical parameters (EHOMO, ELUMO, the energy gap, global hardness, global softness and Fukui index) and experimentally determined inhibition efficiency have been carried out and discussed. The adsorption behavior of AAP, SAAP and AAAP on metal surface was studied using molecular dynamics simulation methods, through which the binding energy was obtained. The order is as follows: AAAP>SAAP>AAP, which is well accorded with the result (inhibition efficiencies) obtained from the experiments.

Synthesis, biological evaluation, and molecular docking studies of N-(α-acetamido cinnamoyl) aryl hydrazone derivatives as antiinflammatory and analgesic agents

A series of acyl hydrazone derivatives were synthesized and screened for antiinflammatory and analgesic activities. The N-acylarylhydrazone compounds described herein were designed by combining the pharmacophoric features of hydrazones and styryl ketones in order to identify the pharmacophoric contribution of the N-acylarylhydrazone moiety and to study the structure–activity relationships. In carrageenan-induced paw edema test, N′-(4-hydroxy benzylidene)-2-acetamido-3-phenyl propenohydrazide (6j) reduced edema by 74 % which is comparable to the standard reference drug, phenylbutazone at equidose. N′-(4-methoxy benzylidene)-2-acetamido-3-phenyl propenohydrazide (6g) showed analgesic activity (68 %) which is equipotent to the standard drug, aspirin (64 %). Molecular docking studies further confirmed that 6j showed better binding affinity with COX-2 and LOX-5 with reduced gastric ulcerogenic effect when compared to phenylbutazone.

Inhibiting effects of 4-amino-antipyrine based schiff base derivatives on the corrosion of mild steel in hydrochloric acid

The inhibiting action of 4-amino-antipyrine (AAP) and its schiff bases 4-[(benzylidene)-amino]-antipyrine (BAAP), 4-[(4-hydroxy benzylidene)-amino]-antipyrine (SAAP) and 4-[(4-methoxy benzylidene)-amino]-antipyrine (AAAP) which are derived from 4-amino-antipyrine with benzaldehyde, salicylaldehyde and anisaldehyde, toward the corrosion behavior of mild steel in 1 M HCl solution was studied using weight loss, potentiodynamic polarization, electrochemical impedance and FT-IR spectroscopic techniques. Although AAP was found to retard the corrosion rate of mild steel, the synthesized schiff base compounds were seen to retard the corrosion rate very effectively. The inhibitor efficiencies calculated from all the applied methods were in good agreement and were found to be in the order: AAAP > SAAP > BAAP > AAP.

Vibrational assignment of the normal modes of 2-phenyl-4-(4-methoxy benzylidene)-2-oxazolin-5-one via FTIR and Raman spectra, and ab inito calculations

Raman and FTIR spectra of 2-phenyl-4-(4-methoxy benzylidene)-2-oxazolin-5-one were recorded in the regions, 100–3300 and 400–4000 cm −1, respectively. Vibrational frequencies and intensities of the fundamental modes of this hetrocyclic organic molecule were computed using ab initio as well as AM1 semiempirical molecular orbital methods. Ab initio calculations were carried out with basis set up to RHF/6-311G. Conformational studies regarding the effect of moving the methoxy group in the 2-phenyl-4-(4-methoxy benzylidene)-2-oxazolin-5-one molecule to a different position on the ring was also carried out. Observed vibrational wavenumbers were found to be mostly consistent with ab initio values. The most intense mode of vibration observed at 1250 cm −1 in Raman spectra, also observed as a strong band in FTIR, was assigned as C–O stretching vibration in the methoxy group. Asymmetric stretching vibrations between C C and C N bonds was predicted as most intense mode by our ab initio calculation.

Synthesis of potassium pentagamavunonat-0 using potassium hydroxyde and solvent tertrahydrofuranethanol

Pentagamavunon-0 (PGV-0) (2,5-bis(4’-hydroxy-3’-methoxy benzy-lidene) cyclopentanone) is a curcumin analogue. To improve its bioavailability it has been succesfully synthesized the Na-salt of this compound. However, sodium may disturb the electrolyte liquid-balance in the body which in turn hypertension. Therefore, the synthesis of potassium pentagamavunonat-0 is attempted. Synthesis has been done using potassium hydroxide as a potassium source, in tetrahydrofuran-ethanol solvent, with molar variations. The result is dipotassium pentagamavunonate-0 (elucidated with IR, 1H-NMR, 13C-NMR and MS spectra), which is more soluble in water and has better stability at high pHs. Molar variations did not show correlation with its yield. The yields are more than 100 %, may be caused by water crystals that contaminate the compound. Key words : pentagamavunon-0, dikalium pentagamavunonat-0, synthesis

Crystal growth and characterization of 4-nitro-4′-methoxy benzylidene aniline (NMOBA)

We report the crystal growth studies of 4-nitro-4′-methoxy benzylidene aniline (NMOBA). NMOBA was synthesized by the condensation of the corresponding aniline and aldehyde. Formation of the product was confirmed from the FTIR and NMR spectral analyses. Powder second harmonic generation analysis of the crystal showed that its efficiency is 1.24 times than that of KDP. The solubility of NMOBA was determined in toluene at different temperatures. Single crystals were grown from toluene by restricted evaporation and slow cooling methods. The structural characterization of the grown crystal was carried out by X-ray diffraction method and the thermal properties were studied by TGA, DTA and DSC experiments and optical transparency of the sample was determined by UV–VIS–NIR spectroscopy.

Investigation of the nematic-ferroelectric interface under a strong magnetic field

The behaviour of methoxy benzylidene butyl aniline (MBBA) nematic liquid crystal on the cleavage surface of triglycine sulphate under a strong magnetic field has been investigated. With the saturation regime obtained for the liquid crystal cell in fields up to 100 kOe, for the first time the possibility appears to determine not only the ordinary anchoring coefficient W 2, but the effective anchoring energy W ∗ without any fitting procedure. Considerable difference in these parameters (two orders of magnitude) disagrees with “electrical” corrections of the Rapini-Papoular approximation. This discrepancy is connected with the surface polarization caused by spontaneous ordering of longitudinal components of MBBA molecular dipoles on interface. The form of the anisotropic interaction potential for such interfaces has to take into account polar effects in near-surface layers of the liquid crystal.