Alkoxy Chains Research Articles

Synthesis, mesomorphic and fluorescent properties of 1,3,4-oxadiazoles/thiadiazoles with a terminal 3-fluoro-4-cyanophenyl group

A series of new liquid crystalline 1,3,4-oxa/thiadiazoles with a terminal 3-fluoro-4-cyanophenyloxy group were synthesized, and their structures were characterized by nuclear magnetic resonance (NMR) and electrospray ionization mass spectrometry (ESI-MS). The liquid crystal properties were studied by differential scanning calorimetry (DSC) and polarizing optical microscopy (POM). All of the 1,3,4-oxadizoles exhibited only Nematic mesophase, while the 1,3,4-thiadiazole analogues displayed Smectic A (SmA) and Smectic C (SmC) over a wide temperature range. The fluorescent properties were investigated using ultraviolet–visible spectrophotometer (UV–Vis) and fluorescence spectrometer. The solutions of all final compounds in CH2Cl2 individually displayed one absorption band with λabs-max values at 319–340 nm, and exhibited an intense emission with λem-max values at 432–448 nm, and the photoluminescence quantum yields reached 0.52–0.66. The effects of the heterocyclic structural units, the terminal alkoxy chain length and the lateral fluorine atom on liquid crystalline and fluorescent properties were comparatively discussed.

Synergetic Alkoxy Side‐Chain and Chlorine‐Contained End Group Strategy toward High Performance Ultra‐Narrow Bandgap Small Molecule Acceptors

Comprehensive SummaryUltra‐narrow bandgap (ultra‐NBG) small molecule acceptors (SMAs) show great potential in organic solar cells (OSCs) due to the extended near‐infrared (NIR) absorption. In this work, a synergetic alkoxy side‐chain and chlorine‐contained end group strategy is employed to achieve A‐DA'D‐A type ultra‐NBG SMAs by introducing alkoxy chains with oxygen atom at the second position into the thiophene β position as well as replacing the F atoms with Cl atoms in the end group. As a result, the heptacyclic BZO‐4F shows a redshifted absorption onset (960 nm) compared with Y11 (932 nm) without oxygen atoms in the side chains. Then, the fluorinated end groups are substituted with the chlorinated ones to synthesize BZO‐4Cl. The absorption onset of BZO‐4Cl is further redshifted to 990 nm, corresponding to an optical ultra‐NBG of 1.25 eV. When blending with the polymer donor PBDB‐T, the binary devices based on PBDB‐T:BZO‐4F and PBDB‐T:BZO‐4Cl deliver power conversion efficiencies (PCEs) over 12%. Furthermore, ternary devices with the addition of BZ4F‐O‐1 into PBDB‐T:BZO‐4Cl system achieve the optimal PCE of 15.51%. This work proposes a synergetic alkoxy side‐chain and chlorine‐contained end group strategy to achieve A‐DA'D‐A type ultra‐NBG SMAs, which is important for future molecular design.

Unfused-ring acceptor based on a quinoxaline unit functionalized with meta-positioned alkoxy chains for efficient organic solar cells with high open-circuit voltage

Owing to the simple synthesis and flexible chemical modifiability of unfused-ring non-fullerene acceptors (UF-NFAs), they have gained great research attraction for fabricating organic solar cells (OSCs). However, UF-NFA-based devices still underperform fused-ring non-fullerene acceptor-based devices. Herein, a series of UF-NFAs based on a fluorinated quinoxaline (Qx) building block functionalized with meta-positioned alkoxy chains, namely FQxOC8-H, FQxOC8-F, and FQxOC8-Cl, are synthesized. Density-functional theory (DFT) calculations demonstrated that all UF-NFAs exhibited good backbone coplanarity, owing to the S⋯N and H⋯F nonbonding interactions. The resulting UF-NFAs showed broad absorption ranged from 500 to 900 nm as well as deep highest occupied molecular orbital (HOMO) levels. FQxOC8-Cl exhibited more red-shifted and greater absorption coefficient owing to the stronger molecular stacking caused by chlorine atoms of the end groups. Moreover, PM6:FQxOC8-Cl-based blended film exhibited reduced charge recombination, higher carrier mobilities, and suitable phase-separation domains. Accordingly, OSCs based on FQxOC8-Cl yielded a superior power conversion efficiency (PCE) of 10.52%. In contrast, FQxOC8-H-based device afforded a lower efficiency of 6.13%. Our work indicates that combining the fluorinated Qx motif functionalized with meta-positioned alkoxy chains with electron-withdrawing end-groups showed great potential to construct efficient UF-NFAs.

NIR-AIEgens nanospheres featuring high-fidelity dynamic lipid droplet targeting, expediting ferroptosis to annihilating tumor in hypoxia

Severe ferroptosis is a non-apoptotic iron-dependent cell death pathway, and extreme hypoxia and anomalous iron metabolism in tumors critically suppress the efficacy of ferroptosis therapy. Overcoming tumor hypoxia while facilitating ferroptosis is an extremely challenging task. Herein, the photosensitizer named BOTTQ with specific targeting of lipid droplet (LD) was synthesized by increasing the tail chain length of triphenylamine. The addition of alkoxy chains optimized the molecular structure and fostered inter-system crossing and type I reactive oxygen species (ROS) generation. Besides, BOTTQ yielded large amounts of type I ROS under light excitation oxidize efficiently polyunsaturated fatty acids in lipid monolayer of LD and contribute to the formation of ferroptosis substrate. Meanwhile, the generation of type I ROS accelerated the Fenton reaction, thus effectively boosting the occurrences of ferroptosis. Furthermore, the successful encapsulation of BOTTQ into DSPE-PEG-MAL material not only elevates the stable type of nanoparticle colloids, but the MAL moiety can deplete the functional thiols of glutathione in a mild environment, which leads to glutathione failure and facilitates ferroptosis. Thus tumor-specific ferroptosis-inducing strategy offers a universally applicable therapy with the capacity to enhance type I ROS production and effectively contain tumorigenesis.

Mesomorphic and computational evaluation of C[tbnd]N‧‧‧I halogen bonded complexes of 4-alkoxy-4′-cyanobiphenyls systems with 1,6- diiodoperfluorohexane

Thermotropic halogen bonded (XB) liquid crystalline complex (A-n XB) of 4-alkoxy-4′- cyano biphenyls (A-n) systems containing nitrile (-CN) group with variable alkoxy chain length (-CnH2n+1, where n = 3 to 10) acting as halogen bond acceptor with 1,6-diiodoperfluorohexane, (I-atom) acting as halogen bond donor were prepared by the liquid-assisted grinding method. The A-n XB complex formations, through CN‧‧‧I XB interactions, were established by the FTIR, Raman, PXRD, polarizing optical microscope (POM) with hot stage, DSC and TGA techniques. Further, POM study of these homologous XB complex series showed liquid crystalline phases with a alteration of (1–10 °C) compared to their respective parent mesogenic molecules. The computational study was carried out using Frontier Molecular Orbitals (FMOs), Molecular Electrostatic Potential (MEP), Non-covalent interactions (NCI) and Quantum theory of atoms in molecule (QTAIM) analysis to evaluate the reactivity parameters and strength of XB in the complexes.

The ferroelectric nematic phase: on the role of lateral alkyloxy chains

ABSTRACT The synthesis and characterisation of the 4-({[4’-nitro-(1,1’-biphenyl)−4-yl]oxy}carbonyl)phenyl 2-alkoxy-4-methoxybenzoates are reported: the 1O(m-On)PEPEBNO2 series. These materials include an additional phenyl ring compared to the extensively studied ferroelectric nematogen RM734, added to increase the liquid crystal transition temperatures. All members of the series exhibited both conventional nematic (N) phase and ferroelectric nematic (NF) phases; TNI and TNFN both decrease on increasing n, the length of the lateral alkoxy chain. The properties of this four-ring series are compared with analogous three-ring laterally substituted variants of RM734; the addition of the extra phenyl ring has a significantly more pronounced effect on the value of TNI than on TNFN. The increase in TNI may be attributed to the enhanced structural anisotropy and more favourable intermolecular interactions arising from the insertion of the phenyl ring, whereas the much weaker effect on TNFN may reflect a change in the shape of the molecule. We also report two materials with three-ring structures, the 4’-nitro-(1,1’-biphenyl)-4-yl 2-alkoxy-4-methoxybenzoates: 1O(m-On)PEBNO2 (n = 1 and 2). The removal of the ester linkage between RM734 and 1O(m-O1)PEPNO2 extinguishes the NF phase and this appears to be consistent with a model in which the molecules are described in terms of a longitudinal surface charge density wave.

Fluorene Thiophene α-Cyanostilbene Hexacatenar-Generating LCs with Hexagonal Columnar Phases and Gels with Helical Morphologies as Well as a Light-Emitting LC Display.

Two series of novel synthesized hexacatenars, O/n and M/n, containing two thiophene-cyanostilbene units interconnected by central fluorene units (fluorenone or dicyanovinyl fluorene) using a donor-acceptor-acceptor-donor (A-D-A-D-A) rigid core, with three alkoxy chains at each end, can self-assemble into hexagonal columnar mesophases with wide liquid crystal (LC) ranges and aggregate into organogels with flowerlike and helical cylinder morphologies, as revealed via POM, DSC, XRD and SEM investigation. Furthermore, these compounds were observed to emit yellow luminescence in both solution and solid states which can be adopted to manufacture a light-emitting liquid crystal display (LE-LCD) by doping with commercially available nematic LC.

Eco-Friendly Solvent-Processed Dithienosilicon-Bridged Carbazole-Based Small-Molecule Acceptors Achieved over 25.7% PCE in Ternary Devices under Indoor Conditions.

Terminal acceptor atoms and side-chain functionalization play a vital role in the construction of efficient nonfullerene small-molecule acceptors (NF-SMAs) for AM1.5G/indoor organic photovoltaic (OPV) applications. In this work, we report three dithienosilicon-bridged carbazole-based (DTSiC) ladder-type (A-DD'D-A) NF-SMAs for AM1.5G/indoor OPVs. First, we synthesize DTSiC-4F and DTSiC-2M, which are composed of a fused DTSiC-based central core with difluorinated 1,1-dicyanomethylene-3-indanone (2F-IC) and methylated IC (M-IC) end groups, respectively. Then, alkoxy chains are introduced in the fused carbazole backbone of DTSiC-4F to form DTSiCODe-4F. From solution to film absorption, DTSiC-4F exhibits a bathochromic shift with strong π-π interactions, which improves the short-circuit current density (Jsc) and the fill factor (FF). On the other hand, DTSiC-2M and DTSiCODe-4F display up-shifting lowest unoccupied molecular orbital (LUMO) energy levels, which enhances the open-circuit voltage (Voc). As a result, under both AM1.5G/indoor conditions, the devices based on PM7:DTSiC-4F, PM7:DTSiC-2M, and PM7:DTSiCOCe-4F show power conversion efficiencies (PCEs) of 13.13/21.80%, 8.62/20.02, and 9.41/20.56%, respectively. Furthermore, the addition of a third component to the active layer of binary devices is also a simple and efficient strategy to achieve higher photovoltaic efficiencies. Therefore, the conjugated polymer donor PTO2 is introduced into the PM7:DTSiC-4F active layer because of the hypsochromically shifted complementary absorption, deep highest occupied molecular orbital (HOMO) energy level, good miscibility with PM7 and DTSiC-4F, and optimal film morphology. The resulting ternary OSC device based on PTO2:PM7:DTSiC-4F can improve exciton generation, phase separation, charge transport, and charge extraction. As a consequence, the PTO2:PM7:DTSiC-4F-based ternary device achieves an outstanding PCE of 13.33/25.70% under AM1.5G/indoor conditions. As far as we know, the obtained PCE results under indoor conditions are one of the best binary/ternary-based systems processed from eco-friendly solvents.

AIE properties of blue-light-emitting molecules based on triazine derivatives

Novel star-shaped molecules of triazine with different terminal oxyalkyl chains were synthesized and systematically investigated by aggregation induced emission (AIE) studies, photophysical properties, and electrochemical properties. These triazine derivatives have a broad absorbance range and good intramolecular charge transfer (ICT) character. They have a non-planar structure with a triazine as an acceptor and a benzene ring attached by a carbon-carbon single bond. The existence of terminal alkoxy chains increases steric hindrance, which is beneficial for limiting intramolecular motion and achieving AIE effect. They exhibit positive solvatochromism effect, high stokes shift and good fluorescence quantum yield. They exhibit AIE properties in N,N-dimethylformamide (DMF)/H2O mixtures. Among them, the AIE properties of 3-5OBCT is the most excellent and fluorescence intensity of 3-5OBCT in DMF/H2O mixtures with water fraction of 40% is 26.7 times that in pure DMF. Purely organic luminescent materials with AIE features exhibit high efficiency in non-doped OLEDs. Therefore, these materials have broad application prospects in the field of OLEDs.

Organic Persistent RTP Crystals: From Brittle to Flexible by Tunable Self-Partitioned Molecular Packing.

Aiming to solve trade-off of "RTP-flexibility" in principle, organic room temperature phosphorescence (RTP) crystals with elastic/plastic deformation have been realized. These properties are mainly due to the divisional aggregation structures of aromatics and alkoxy chains, and can be modulated by the controllable molecular configurations. The longest RTP lifetime of 972.3ms has been achieved as the highest record for organic flexible crystals. The plastic crystals with persistent RTP were realized for the first time, which can be applied into biomedical optical technologies by afterglow delivery. Moreover, relationship among elastic/plastic deformation, RTP property and aggregated structures have been established. Elastic/plastic deformation is mainly determined by difference of interaction energies from aromatics and alkoxy chains. For BP-OR series with twisted configurations, the alkoxy chain with the middle length is favorable for RTP property, while the strength of π-π coupling is the cruical factor to RTP property of Xan-OR series with planar skeletons. It explored a new way to promote the development of flexible RTP crystals, by modulation of aggregated structures as well as rational distribution of intermolecular interactions. This article is protected by copyright. All rights reserved.

Design of unsymmetric coumarin chalcone derivatives with tunable self-assembling behavior

Unsymmetric coumarin chalcone derivatives were designed with unsymmetric alkoxy chain on both terminal of the molecules to find their effect on the overall mesomorphic properties. In the first homologous series, compounds with fixed octyloxy chain on chalcone end and varied alkoxy chain length at coumarin end of the molecule (n = 10,12,14,16,18) have been analyzed for their mesomorphic properties. In this series, all the Compounds showed stable enantiotropic SmC mesophase. In the second homologous series, compounds with fixed octyloxy chain on coumarin end and varied alkoxy chain length at chalcone end (n = 10,12,14,16,18) have been studied for their mesomorphic properties. In the second homologues series, compounds (n = 10,12) exhibited monotropic nematic mesophase. For higher analogues (n = 16,18), enantiotropic SmA mesophase was observed. Further, the powder X-ray diffraction analysis of the three compounds from both the series at 112 °C showed diffraction pattern quite close to identified mesophase type. To understand effect of variation of terminal chain, DFT theoretical study was carried out for both different series and tried to understand correlation between mesomorphic properties and structural parameters.

Cu(I)-catalyzed Synthesis of Symmetrical Perfluoroterphenyl Analogues; Fluorescence, Antioxidant and Molecular Docking studies.

Pentafluoroaryl analogues have been found to exhibit para specific nucleophilic aromatic substitution (SN Ar). Herein, we describe the use of SN Ar chemistry to create luminous perfluorinated symmetrical terphenyls. Both of SN Ar chemistry and Cu(I)-catalyzed decarboxylative cross-coupling were applied for the synthesis of those perfluorinated symmetrical terphenyls in high yields from the corresponding derivatives of aryl iodide and potassium salt of fluorobenzoate. A series of perfluorinated symmetrical terphenyls with different para alkoxy chains were synthesized. The synthesized perfluorinated terphenyl adducts were confirmed via elemental analysis, FT-IR, 1 H/13 C NMR, and 19 F NMR spectra. The absorbance and fluorescence spectra showed solvatochromic activities. The new synthesized fluoroterphenyl hybrids were screened against antioxidant inspection over DPPH performance, in assessment to Vitamin C and BHT as standard drugs exposed that fluoroterphenyl hybrid covering decyl hydrocarbons exhibited highest effectiveness through IC50 values 21.74 μg/mL. Additionally, molecular docking procedures of the synthesized fluoro-terphenyl hybrids were employed by using (PDB ID: 5IKQ) protein. The docking simulation was displayed convenient and recognized findings with the antioxidant examination.

The influence of core fluorination on the phase behaviour of rod-like mesogens

ABSTRACT The effect of core fluorination on the mesomorphic properties of rod-like Schiff base-derived liquid crystalline materials was reported. For this purpose, two new series of laterally fluorinated Schiff base liquid crystals are synthesised and investigated in detail. The two series differ from each other’s in the length of the terminal alkoxy chain attached to one end of the aromatic core, where in the first series an octyloxy chain is used and in the second series it is replaced by a longer dodecyloxy chain. At the other end in both series of compounds, in addition to the nonsubstituted end (X = H) four different substituents were used (X = CH3O, C6H13O, CH3 and F). The molecular structures of all synthesised compounds were confirmed using different spectroscopic techniques. The molecular self-assembly was investigated using differential scanning calorimetry (DSC) and polarised optical microscope (POM). Depending on the length of terminal alkoxy chain at one end and nature of the substituent X at the other end, different types of mesophases were observed, including nematic and two different types of smectic phases.

Molecular Shape, Electronic Factors, and the Ferroelectric Nematic Phase: Investigating the Impact of Structural Modifications.

The synthesis and characterisation of two series of low molar mass mesogens, the (4-nitrophenyl) 2-alkoxy-4-(4-methoxybenzoyl)oxybenzoates (NT3.m) and the (3-fluoro-4-nitrophenyl) 2-alkoxy-4-(4-methoxybenzoyl)oxybenzoates (NT3F.m), are reported in order to investigate the effect of changing the position of a lateral alkoxy chain from the methoxy-substituted terminal ring to the central phenyl ring in these two series of materials based on RM734. All members of the NT3.m series exhibited a conventional nematic phase, N, which preceded the ferroelectric nematic phase, NF , whereas all the members of the NT3F.m series exhibited direct NF -I transitions except for NT3F.1 which also exhibited an N phase. These materials cannot be described as wedge-shaped, yet their values of the ferroelectric nematic-nematic transition temperature, T , exceed those of the corresponding materials with the lateral alkoxy chain located on the methoxy-substituted terminal ring. In part, this may be attributed to the effect that changing the position of the lateral alkoxy chain has on the electronic properties of these materials, specifically on the electron density associated with the methoxy-substituted terminal aromatic ring. The value of TNI decreased with the addition of a fluorine atom ortho to the nitro group in NT3F.1, however, the opposite behaviour was found when the transition temperatures of the NF phase were compared which are higher for the NT3F.m series. This may reflect a change in the polarity and polarizability of the NT3F.m series compared to the NT3.m series. Therefore, it is suggested that, rather than simply promoting a tapered shape, the role of the lateral chain in inhibiting anti-parallel associations and its effect on the electronic properties of the molecules are the key factors in driving the formation of the NF phase.

Imine based Four-Ring Chalcone-Ester liquid Crystals: Synthesis, Characterization, mesomorphic behaviour and DFT approach

In this study, new imine-based chalcone-ester liquid crystals with symmetric and unsymmetrical alkoxy chains were synthesized and their mesomorphic behaviour was examined. The FT-IR, 1H NMR, 13C NMR, and mass spectral analysis have all been used to characterize new mesogens. From the study of mesophase behaviour, the compounds of CHE-(6–18) and 12-CHE-(6–18) series with different alkoxy chains at both the ends exhibited stable enantiotropic smectic C in addition to nematic mesophase for compounds with longer alkoxy chains. Whereas the three compounds of CHAE series were found to be non mesogenic. By comparing new compounds with structurally similar compounds, the impact of inclusion/replacement of various mesogenic units have been discussed. The theoretical calculations were performed to illustrate the mesomorphic behaviour of the studied compounds in terms of aromaticity and π–π stacking. Also, the experimental findings of the individual compounds were correlated with the calculated polarizability, dipole moment, and aspect ratio. Moreover, a projection of the molecular electrostatic potential and the frontier molecular orbitals has been considered to demonstrate the influence of the polarity of the terminal chains and the mesogenic cores on the energy gap of the FMOs and the distribution of electrostatic charges on the investigated compounds.

Efficient ternary organic solar cells enabled by asymmetric nonfullerene electron acceptor with suppressed nonradiative recombination

The open-circuit voltage (Voc) of organic solar cells (OSCs) is still far from the Shockley-Queisser limit due to the large non-radiative voltage loss (ΔVocnonrad). Reducing energy loss (Eloss) to obtain higher Voc without sacrificing Jsc and FF is the key to achieve further improvement in power conversion efficiency (PCE) of OSCs. In this work, we designed and synthesized a new asymmetric nonfullerene acceptor via a dual asymmetric strategy, named as SN-O. Under the synergistic effect of alkoxy chain and nitrogen atom substitution, the LUMO and HOMO energy levels of SN-O are significantly elevated compared to Y6, allowing SN-O to display a high open-circuit voltage with a reduced nonradiative energy loss (ΔEnonrad = 0.177 eV). The alkoxy side chain of SN-O brings an intramolecular conformational locking effect and the large dipole moment of asymmetric molecules facilitate the aggregation properties in thin films. The good miscibility allows Y6 and SN-O to form alloy acceptor attributing to the similar chemical structures. The addition of SN-O as the third component into the D18:Y6 system showed a significant reduction in the nonradiative energy loss and a favorable blend film morphology, thus improves exciton dissociation, charge transport and collection. Consequently, a high PCE of 18.3% was achieved for D18:Y6:SN-O ternary system with simultaneously enhancement of Voc, Jsc and FF, which is much higher than that of the binary devices.

Asymmetric perylene-diimide-based polymeric acceptor integrating alkoxy and alkyl side chains: Synthesis and application for all-polymer solar cell

Alkoxy side chain embodying the large electronegative oxygen played the critical role in tuning the optoelectronic and photovoltaic properties. However, few efforts devoted to incorporating the alkoxy side chain into perylene diimide (PDI) building block. In this contribution, one PDI-containing asymmetric polymeric acceptor PPDI-HD-OHD-T bearing 2-hexyldecyl (HD) and 2-hexyldecyloxy (OHD) side chains was developed. Also, two symmetric polymeric acceptors PPDI-HD2-T and PPDI-OHD2-T with identical HD and OHD side chains were prepared to systematically study the impact of bonding OHD side chain on light-harvesting and electrochemical property, molecular configuration, solar cell performance and morphology. Moving from alkyl to alkoxy chains resulted in at first a red-shifted and then a blue-shifted absorption maximum, gradually downshifted HOMO and LUMO energy levels, better molecular planarity, enhanced solution and film state aggregation, and improved photo-stability, these changes resulted from the N–O σ-inductive effect induced by the inserted oxygen, along with the increased number of alkoxy side chain of PDI ring. Furthermore, PPDI-HD-OHD-T acquired a more complementary absorption to PTB7-Th, increased electron mobility and benefited morphology. Thereupon, both improved JSC and FF in PPDI-HD-OHD-T-based device contributed to the boosted PCE of 2.08%, which was higher than those of symmetric side chains PPDI-HD2-T and PPDI-HD-OHD-T-based devices. To our knowledge, it is the first attempt to introduce the alkoxy side chain to N-position of PDI to construct asymmetric polymer acceptor and demonstrated that skillfully tuning the side-chain can effectively affect the electron distribution, molecular configuration, aggregation, charge mobility, and achieve improved device efficiency in all-polymer solar cell.

Synthesis and molecular structure of V-shaped liquid crystalline compounds: Spectroscopic, mesomorphic, DFT investigations, electrochemical and fluorescence studies

A series of V-shaped compounds consisting of a central phenyl core connected by two identical mesogenic units which possess the imine (C=N) and ester (COO) bonds along with the terminal alkoxy chain (-OCnH2n+1) where n = 6-12. The ultimate compounds were synthesised and characterized by CHN elemental analysis, Fourier-Transform Infrared (FT-IR), nuclear magnetic resonance (1H-NMR), and UV-Visible (UV-Vis) spectroscopic techniques. The mesomorphic properties, thermal behaviour and conformation of compounds were studied by using polarised optical microscopy (POM), and differential scanning calorimetry (DSC). It can be generalized from present study that the V-shaped compounds with odd n carbon number in alkoxy chains were non-mesogenic. Whilst the compounds with shorter alkoxy chains of n = 6 and 8 were monotropic nematic, the compounds which possess longer alkoxy chains (n = 10 and 12) exhibited enantiotropic nematic phase. The computational method Chem3D Pro suggests the molecular structures of all the compounds with even n carbon number in the alkoxy chain. The Gaussian calculation with B3LYP/6-31G+(d,p) condition was employed to further demonstrate the chemical reactivity for all target compounds based on HOMO-LUMO analysis, the energy difference between HOMO-LUMO and surface charges. The target molecules of which the member containing the even n parity along the mesogenic arms have shown the same trend of electrocatalytic behaviour particularly toward the detection of hydrogen peroxide via the cyclic voltammetry study. Furthermore, the member with n=12 has been validated as a remarkable fluorogenic probe for the detection of Zn2+ ion.

Luminescent liquid crystals: from supramolecular plant dyes to emissive flavylium salts

ABSTRACTInspired by the supramolecular architecture of cornflower blue we developed luminescent flavylium salts with lipophilic alkoxy or thioether side chains which self-assemble into liquid crystalline phases. The current account highlights some fundamental aspects of our biological ‘role model’ anthocyanine, the origin of the natural pigment cornflower blue, and our recent developments on novel liquid crystalline emissive dyes. Starting with the general synthesis of flavylium salts, other topics address variations of flavylium ILCs, including specific tuning of their mesomorphic and photophysical behaviour.

Synthesis and Computational Investigations of New Thioether/Azomethine Liquid Crystal Derivatives

Methylthio moiety was observed to alter the mesomorphic features of rod-like Schiff-base-derived liquid crystalline materials. For this purpose, a new series of (E)-4-(alkoxy)-N-(4-(methylthio)benzylidene)aniline (In) liquid crystals were synthesized and examined using experimental and computational approaches. The compounds in the series differ from each other in the terminal alkoxy chain length that is attached to one end of the aromatic core. Various spectroscopic methods were used to verify the molecular structures of the produced derivatives. All compounds were checked for correct chemical structures using elemental analysis, FT-IR, 1H-NMR, and 13C-NMR. Both a polarized optical microscope (POM) and a differential scanning calorimeter (DSC) were used in order to study the behavior of liquid crystals. Both tested compounds I6 and I8 have monotropic nematogenic properties while the longer chain derivative I16 shows non-mesomorphic behavior. Computational studies were carried out using density functional theory (DFT) calculations to validate the experimental results. All of the analyzed compounds had their reactivity characteristics, dipole moments, and polarizability explained. Finally, in order to determine the chemical shape–mesomorphic property relationship, the present examined series was compared to other structurally comparable homologues.