Discotic mesogens containing the benzo[e][1,2,4]triazinyl radical as the central unit exhibit a Colh phase below 80 °C. Depending on the substituent at the N(1) position, they show different modes of thermal expansion and magnetic behavior, presumably due to differences in molecular organization. Thus, for 1-phenyl (1a) and 1-PhF-m (1b) derivatives, the Colh phase has positive thermal expansion coefficient κ and antiferromagnetic interactions, while for the 1-(3,4,5-(C12H25X)3C6H2) derivatives 1c (X = O) and 1d (X = S), κ is negative and weak ferromagnetic interactions in the crystalline phase are observed for 1c (J/kB = +4.76 K). Compounds 1a and 1c exhibit photoinduced hole transport (μ ≈ 1.3 × 10(-3) cm(2) V(-1) s(-1)) in the Colh phase.
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http://dx.doi.org/10.1021/jacs.6b06444 | DOI Listing |
Chem Sci
October 2024
Institute of Organic Chemistry, University of Stuttgart Pfaffenwaldring 55 D-70569 Stuttgart Germany
Creating (room temperature) liquid crystalline TADF materials that retain the photophysical properties of the monomolecular TADF emitters remains a formidable challenge. The strong intramolecular interactions required for formation of a liquid crystal usually adversely affect the photophysical properties and balancing them is not yet possible. In this work, we present a novel host-guest approach enabling unperturbed, narrowband emission from an MR-TADF emissive core from strongly aggregated columnar hexagonal (Col) liquid crystals.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Department of Applied Chemistry, College of Life Sciences, Ritsumeikan University, Kusatsu, 525-8577, Japan.
Dent Mater
November 2024
Institute of Biomaterials, University of Erlangen-Nuremberg, Cauerstraße 6, 91058 Erlangen, Germany. Electronic address:
Objective: Calcium silicate cements (CSCs) are often used in endodontics despite some limitations related to their physical properties and antibacterial efficacy. This study aimed to develop and demonstrate the viability of a series of CSCs that were produced by sol-gel method and further modified with mesoporous bioactive glass nanoparticles (MBGNs) and collagen, for endodontic therapy.
Methods: Calcium silicate (CS) particles and MBGNs were synthesized by the sol-gel method, and their elemental, molecular, and physical microstructure was characterized.
Chem Asian J
January 2024
Department of Chemical Science, Indian Institute of Science Education and Research (IISER) Mohali, Punjab, 140306, India.
Hydrogen (H)-bonding is crucial in constructing superstructures in chemical (such as chiral discotic liquid crystals (DLCs)) as well as in biological systems due to its specific and directional nature. In this context, we achieved the successful synthesis of two branches of heptazine-based H-bonded complexes using distinct strategies. Hpz*-Es-C , we incorporated chiral alkyl tails (Hpz-chiral) onto the central C symmetric heptazine core, connected to achiral benzoic acid derivatives (Es-C acid) through H-bonding.
View Article and Find Full Text PDFJ Am Chem Soc
August 2023
Shaanxi International Research Centre for Soft Matter, State Key Laboratory for Mechanical Behaviour of Materials, Xi'an Jiaotong University, Xi'an 710049, China.
The recently discovered orthorhombic liquid crystal (LC) phase of symmetry is proving to be widespread. In this work, a chiral hydroxybutyrate linkage is inserted into the molecular core of hexacatenar rodlike compounds, containing a thienylfluorenone fluorophore. In addition to more usual tools, the methods used include grazing-incidence X-ray scattering, modulated differential scanning calorimetry (DSC), flash DSC with rates up to 6000 K/s, and chiro-optical spectroscopies using Mueller matrix method, plus conformational mapping.
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