Coumarin substituted symmetric diaminopyridine molecules: Synthesis, mesomorphic characterizations and DFT studies

Mohammad, AbdulKarim‐Talaq; Al-Mohammed, Mohammad Hameed; Srinivasa, H. T.; Ameen, Wissam A.

doi:10.1016/j.molliq.2020.113782

Cited by 11 publications

(1 citation statement)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…3,5-Diarylisoxazoles synthesized by (3 + 2) 1,3-dipolar cycloaddition in two steps offers many opportunities to synthesize a collection of new isoxazole liquid crystals (ILCs) with a variety of substituents connected to the isoxazole ring. The stabilization of the smectic mesophase depends on some factors such as the out-of-layer fluctuations (OLFs), which is related to the nature and size of the substituents connected to the rigid core of LCs. − The performance of a device based on LC materials depends on several parameters . One of them is the molecular alignment in smectic-based material devices presenting the N-SmA-SmC transition.…”

Section: Introductionmentioning

confidence: 99%

Origin of the Monolayer and Bilayer Arrangement in Smectic A and C Mesophases and Nematic Cybotactic Domains: The Case Study of Benzyloxy-Terminated Isoxazole Liquid Crystals

Lopes

Pavan

Gonçalves

et al. 2023

Crystal Growth & Design

View full text Add to dashboard Cite

The synthesis and characterization of two benzyloxy-terminated isoxazole liquid crystals, (ILCs) 7a (n-octyl) and 7b (n-decyl), are described. The synthesis of the five-membered isoxazole ring was based on the (3 + 2) 1,3-dipolar cycloaddition to furnish the isoxazoline cycloadduct and the subsequent MnO2-oxidation. The liquid crystal (LC) behavior was accomplished by polarized optical microscopy (POM), differential scanning calorimetry, single-crystal X-ray diffraction, X-ray diffraction (XRD), 7-lithium nuclear magnetic resonance (7Li-NMR), and density functional theory (DFT) calculations. For both ILCs, the nematic cybotactic (Ncyb) and smectic A and C mesophases were characterized. Two organizational monolayer and bilayer regimes for the smectic A and C mesophases were characterized by the XRD pattern, and the Ncyb mesophase was assigned by the analysis of the low intensity of the peak at 2θ = 2.70°, suggesting some smectic character for the nematic mesophase. A correlation length (ξ) of around 20 layers and 7 layers was established by XRD for the monolayer and bilayer organization in the SmC mesophase. Single-crystal XRD, 7Li-NMR experiments, and DFT calculations were performed and are discussed in the context of the LC behavior influenced by the benzyloxy-terminated group. A model for the layering organization is presented as well as the organization in the Ncyb, SmA, and SmC mesophases.

show abstract