Star-shaped Compounds Research Articles

Improvement of the Conductive Ability of Polymer Electrolytes

In current applied research, traditional electrolytes face significant challenges. The emergence and application of polymer electrolytes provide effective solutions to these problems. This paper will introduce the types and characteristics of polymer electrolytes based on three aspects. The star-shaped compound based on PEGMA, i.e., poly(ethylene glycol) methacrylate, can significantly enhance the mechanical and electrical properties of polymer electrolytes; the gel electrolyte prepared by compounding highly polar β-polyvinylidene fluoride (β-PVDF) with nylon 6 shows significant application potential in improving ion conduction efficiency and enhancing battery safety. Brush-shaped polymers have good performance in avoiding the crystallization of linear polymers and inhibiting the growth of lithium dendrites and improving mechanical strength. These three types of polymer electrolytes each have their characteristics and good application prospects. Still, they all face problems such as high cost and difficulties in industrialization at the present stage and need further development to better benefit human society. This paper aims to provide those who want to explore and do some decent research on this topic with some basic information as well as fundamental advice.

Effect of alkyloxy substituents on mesomorphic and photophysical properties of star-shaped tristriazolotriazines

ABSTRACTTwo series of tristriazolotriazine (TTT) derivatives with different length of aliphatic substituents have been synthesised in order to study the influence of peripheral substitution on mesomorphism and fluorescent properties of these star-shaped compounds. Homologues with methoxy and alkyloxy substituents (series 1) are non-mesogenic, in contrast to homologues with two alkyloxy substituents (series 2) exhibiting columnar mesophase. The results obtained by quantum-chemical calculations for the monomers and dimers of non-mesogenic TTT series and their comparison with truxenone derivatives having identical substituents made it possible to establish the reasons that deprive series 1 of mesogenity. Compounds of both TTT series possess good solubility in organic solvents and capable of specific interactions with solvents in the ground and excited states. They form fluorescenting floating layers and thin films. An analysis of the fluorescence spectra showed a high potential for their application, in particular, in the field of molecular sensing and precise non-invasive control.

2-{3,5-Bis-[5-(3,4-didodecyloxyphenyl)thien-2-yl]phenyl}-5-(3,4-didodecyloxyphenyl)thiophene

Star-shaped compounds are widely recognized as emerging materials for optical and electrical applications and as scaffolds of discotic liquid crystal. While the C3-symmetrical tri(phenylthienyl)benzene is the core for several electroopotical materials, no liquid crystal with this scaffold has yet been reported. Acid-catalyzed cyclocondensation of bromoacetylthiophene gives a C3-symmetrical star, threefold Suzuki coupling results in extension of the conjugated system. With 3,4-didodecylocyphenyl boronic acid, a star with a large rigid conjugated system and flexible aliphatic periphery is obtained. Differentials scanning calorimetry and polarized optical microscopy reveal an enantiotropic mesophase from 66 °C to 106 °C.

Impact of Substitution Pattern and Chain Length on the Thermotropic Properties of Alkoxy-Substituted Triphenyl-Tristriazolotriazines.

Tristriazolotriazines (TTTs) with a threefold alkoxyphenyl substitution were prepared and studied by DSC, polarized optical microscopy (POM) and X-ray scattering. Six pentyloxy chains are sufficient to induce liquid-crystalline behavior in these star-shaped compounds. Thermotropic properties of TTTs with varying substitution patterns and a periphery of linear chains of different lengths, branching in the chain and swallow-tails, are compared. Generally, these disks display broad and stable thermotropic mesophases, with the tangential TTT being superior to the radial isomer. The structure–property relationships of the number of alkyl chains, their position, length and structure were studied.

Star-Shaped Compounds with Oxadiazole Fragments. III. Informativity of Molecular Parameters Developed for Columnar Mesomorphism Prediction of Star-Shaped Compounds Towards Polycatenar Molecules

Star-Shaped Compounds with Oxadiazole Fragments. III. Informativity of Molecular Parameters Developed for Columnar Mesomorphism Prediction of Star-Shaped Compounds Towards Polycatenar Molecules

Synthesis of novel star-shaped molecules based on a 1,3,5-triazine core linked to different heterocyclic systems as novel hybrid molecules.

The synthesis of novel star-shaped compounds based on an s-triazine core and linked to hexahydroacridinediones, pyrimido[4,5-b]quinolones, 1H-isoquinolino[2,1-a]quinolines, tetrahydro-4H-chromenes, dihydropyrano[2,3-c]pyrazoles, thiazole, or benzothiazole as new hybrid molecules through Michael and Hantzsch reactions is reported. For this purpose, 2,4,6-tris(4-formylphenoxy)benzaldehyde was used as a versatile precursor.

Star-Shaped Compounds with Oxadiazol Fragments. II. Influence of Polycatenar Compound Structure on Ability of Columnar Mesomorphism Formation by Prediction Data

Star-Shaped Compounds with Oxadiazol Fragments. II. Influence of Polycatenar Compound Structure on Ability of Columnar Mesomorphism Formation by Prediction Data

Acetylene-bridged triazine-conjugated structures: synthesis and liquidcrystalline properties

We report the synthesis and liquid crystalline properties of a new type of tribranched compound built up from triazine as the central core and electron-rich triazine rings as peripheral groups. An equimolar mixture of the star-shaped compound based on the 1,3,5-triazine core with 4-dodecyloxybenzoic acid produced an organic salt exhibiting a columnar mesophase with a dendritic growing texture at low temperatures. The liquid crystalline properties of the triazine-based compound and organic salt were investigated by differential scanning calorimetry and polarizing optical microscopy.

Star-Shaped Compounds with Oxadiazole Fragments. I. Influence of Molecular Structure Variation of Azo-Diphthalic Acids Derivatives on their Mesomorphism According to Prognosis Data

Star-Shaped Compounds with Oxadiazole Fragments. I. Influence of Molecular Structure Variation of Azo-Diphthalic Acids Derivatives on their Mesomorphism According to Prognosis Data

Blue Luminescent Organic Light Emitting Diode Devices of a New Class of Star-Shaped Columnar Mesogens Exhibiting π–π Driven Supergelation

Five new, star-shaped compounds containing a central oligo(phenylenevinylene) core carrying six alkoxy chains were synthesized, and with varying alkyl chains the changes in their supramolecular ass...

Synthesis and Photophysical Properties of C 3-Symmetric Star-Shaped Molecules Containing Heterocycles Such as Furan, Thiophene, and Oxazole.

We report simple strategies to synthesize star-shaped molecules containing different heterocycles integrated with a number of variations. Here, cyclotrimerization, Vilsmeier–Haack reaction, Suzuki–Miyaura cross-coupling, and Van Leusen oxazole synthesis have been used as key steps to introduce diverse five-membered heterocycles such as furan, thiophene, and oxazole. More importantly, readily available starting materials such as thiophene, 2-formyl furan, and 2-acetyl furan were utilized. Also, the fluorescent behavior of these π-conjugated systems was studied. C3-Symmetric molecules containing furan moieties show a stronger fluorescence than thiophene-containing star-shaped compounds.

Synthesis of Star-Shaped Aromatic Derivatives with Chirality Predetermined by Bicyclo[3.3.1]nonane Framework

Star-shaped aromatic derivatives of bicyclo[3.3.1]nonane with predetermined chirality were synthesized by employing the Suzuki and Sonogashira reactions. The C 3-symmetric trifunctional aromatic derivatives based on the lateral bicyclo[3.3.1]nonene moiety possess unique molecular structures. The chiroptical properties of the star-shaped compounds and the corresponding monomeric derivatives were studied, and the absolute configuration was confirmed by using the empirical octant rule for the carbonyl chromophore and the sector rule for the aromatic chromophore.

The Effect of Star-Shaped Oligothiophenes with a Carbazole Core on Their Structural and Optical Properties

A comparative analysis of the structure and properties of donor–acceptor star-shaped compounds based on oligothiophene with electron-withdrawing dicyanovinyl groups and a different electron-donating branching center—planar 9-phenyl-9H-carbazole and propeller-shaped triphenylamine—has been carried out. It is shown that the absorption maxima in the spectra of 9-phenyl-9H-carbazole derivatives shift to shorter wavelengths, the HOMO energy decreases, and the LUMO energy increases. Moreover, in contrast to propeller-shaped triphenylamine-based compounds, which do not form ordered states, the T-shaped branched molecules based on carbazole form highly ordered crystal structures with different symmetry.

Synthesis, characterization, and nonlinear optical (NLO) properties of truxene-cored diphenylamine derivatives

Three star-shaped compounds based on a truxene core (FS11, FS12 and FS13) were prepared. The truxene core is incorporating with asymmetric diphenylamines, including one phenyl of diphenylamine substituted by methoxy group and the other phenyl substituted by tolyl, fluorophenyl and phenylethynyl for FS11, FS12 and FS13, respectively. Their one-photon, two-photon absorption, geometric structures, electrochemical behavior and thermal properties were investigated. The absorption maxima of charge transfer band for FS11, FS12 and FS13 are 375nm, 373nm and 383nm, and the corresponding molar extinction coefficients of FS11, FS12 and FS13 is 79,950M−1cm−1, 67,220M−1cm−1 and 108,780M−1cm−1. The “pull-push” structure promotes charge transfer between asymmetric diphenylamine branches and the truxene core. Their two-photon absorbtion property is measured by two-photon induced fluorescence. The maximum two-photon cross-sections values of FS11, FS12 and FS13 are excited at 750nm, which are 260 GM, 204GM and 367 GM, respectively.

Spirotriphenylamine based star-shaped D-A molecules meeting AIE chromophore for both efficient solution-processed doped and nondoped blue organic light-emitting diodes

To explore the structure-property of donor-acceptor (D-A) type blue emitter, in this contribution, four star-shaped compounds of p-TPA, m-TPA, p-TPA-TPE and m-TPA-TPE using spirotriphenylamine as the donor unit and triazine as the acceptor core were designed and prepared. The tetraphenylethene (TPE) unit was introduced into the D-A molecules to enhance the emission efficiency in solid state. The photophysical properties of all compounds were comparatively studied through experimental and theoretical methods. All these D-A compounds displayed blue emission (443–487 nm) both in solution and neat film. Compared to p-TPA and m-TPA, p-TPA-TPE and m-TPA-TPE possessed clear aggregated-induced emission (AIE) property and higher emission efficiency in the solid state. Both the doped and non-doped organic light-emitting diodes (OLEDs) based on m-TPA and m-TPA-TPE were fabricated by solution-processable approach. The m-TPA-TPE based non-doped device showed a satisfying performance with a high current efficiency of 4.2 cd/A and an external quantum efficiency of 1.8% in the bluish-green region. This research demonstrates that integrating AIE unit into D-A molecule is an effective strategy for design high efficient blue emitter in non-doped OLEDs.

Solvatochromic effect in absorption and emission spectra of star-shaped bipolar derivatives of 1,3,5-triazine and carbazole. A time-dependent density functional study

A series of three star-shaped compounds containing both donor (carbazole) and acceptor (2,4,6-triphenyl-1,3,5-triazine) moieties linked through various linking bridges was studied theoretically at the linear response TD-DFT level of theory to describe their absorption and fluorescence spectra. The concept of a localized charge-transfer excited state has been applied successfully to explain the observed strong solvatochromic effect in the emission spectra of the studied molecules, which can be utilized for the fabrication of color tunable solution-processable OLEDs. The concept is in particularly applicable to donor–acceptor species with a C3 symmetry point group where the static dipole moment changes dramatically upon electronic excitation. An important peculiarity of the studied molecules is that they are characterized by non-zero values of the HOMO and LUMO orbitals in the same common part of molecular space that provides a large electric dipole transition moment for both light absorption and emission.Graphical abstractStar-shaped C3 symmetry point group derivatives for color tunable OLEDs

Efficient synthesis and structural effects of ambipolar carbazole derivatives

A new class of carbazole derivatives, with varying degree of core substitution was synthesized and characterized. The presented synthetic route requires mild conditions, starts from low-cost substrates and leads to the formation of the target products with good yields. The optical and electronic properties of the synthesized materials were estimated and supported by DFT calculations. Investigated compounds emit violet light with quantum efficiency reaching 18.2%. Electrochemical and electron photoemission spectroscopy revealed that ionization potentials are in range of 5.10–5.30eV. Time-of-flight measurements revealed that those compounds have balanced hole and electron mobility in range of 4.27·10−6–8.42·10‐5 cm2/Vs for star-shaped compound and 6.2×10−7–6.2×10−6cm2/Vs for linear derivatives. Electroluminescence spectra of the OLED device prepared using the newly synthesized compounds were characterized by broad emission in visible range, resulting in white light generation.

Effect of the Nature of the Core on the Properties of the Star-Shaped Compounds Containing Bicarbazolyl Moieties

Three star-shaped compounds containing bicarbazolyl side arms and various core moieties are described. Bicarbazolyl moiety proves to be a stronger donor than single carbazolyl group, providing lower ionization potential and superior thermal and electrochemical stability. The influence of the central core, that is, 2,4,6-triphenyl-1,3,5-triazine, 1,3,5-triphenylbenzene, and 9-phenylcarbazole fragments, on the properties of the compounds is investigated and supported by DFT calculations. The dependence of photophysical properties on the rigidity and polarity of the media is discussed. Owing to the differences in molecular architecture, tuning of singlet and triplet energy values can be achieved. The synthesized compounds showed good hole-transporting properties with the mobility values exceeding 10–3 cm2 V–1 s–1.

Triazine-core-containing star-shaped compounds as cathode interlayers for efficient inverted polymer solar cells

Star-shaped conjugated compounds containing 1,3,5-triazine cores and fluorene arms are efficient cathode interlayers in inverted polymer solar cells.

Pentacyclic triterpenes grafted on CD cores to interfere with influenza virus entry: A dramatic multivalent effect

Multivalent effect plays an important role in biological processes, particularly in the specific recognition of virus with its host cell during the first step of infection. Here we report the synthesis of multivalent pentacyclic triterpene grafted on cyclodextrin core and potency of against influenza entry activity. Nine star-shaped compounds containing six, seven and eight pentacyclic triterpene pharmacophore on cyclodextrin scaffold were prepared by way of copper-catalyzed azide-alkyl cycloaddition reaction under microwave activation. Some of the multimers exhibited much potent antiviral activity against H1N1 virus (A/WSN/33), even equivalent or superior to oseltamivir. The most active compound 31, a heptavalent oleanolic acid-β-cyclodextrin conjugate, shows an up to 125-fold potency enhancement by its IC50 value over the corresponding monovalent conjugate and oleanolic acid, disclosing a clear multivalent effect. Further studies show that three compounds 31–33 exhibited broad spectrum inhibitory activity against other two human influenza A/JX/312 (H3N2) and A/HN/1222 (H3N2) viruses with the IC50 values at 2.47–14.90 μM. Most importantly, we found that compound 31, one of the best representative conjugate, binds tightly to the viral envelope hemagglutinin with a dissociation constant of KD = 2.08 μM, disrupting the interaction of hemagglutinin with the sialic acid receptor and thus the attachment of viruses to host cells. Our study might establish a strategy for the design of new pharmaceutical agents based on multivalency so as to block influenza virus entry into host cells.