Novel Luminescent Diazafluorenone Liquid Crystals - Université de Rennes Accéder directement au contenu
Article Dans Une Revue Crystal Growth & Design Année : 2019

Novel Luminescent Diazafluorenone Liquid Crystals

Résumé

In this work, the synthesis, X-ray crystal structure analysis, studies on meso-morphism and luminescence spectroscopy of 2,7-diphenyl-4,5-diazafluorenones carrying 2, 4 or 6 peripheral alkoxy side chains of different lengths in the mesogenic unit are reported. The latter was attached to starting 2,7-dibromo-4,5-diazafluoren-9-one via Suzuki cross coupling of the respective 2-(alkoxyphenyl)-tetramethyl-1,2,3-borolane. The liquid crystalline properties were found to depend on both the number of side chains and their lengths. Derivatives with two short alkoxy chains (C6-C8) in the periphery formed nematic (N) and smectic C (SmC) mesophases while for the higher homologues only SmC mesophases were observed. Compounds carrying six alkoxy side chains with a minimum length of C8 assembled into columnar hexagonal phases. Homologues with C14 and C16 chain length displayed additionally two columnar rectangular mesophases. Four peripheral alkoxy chains, however, led to the loss of mesomorphism. Crystal structure data of a series of rod-shaped diazafluorenones helped to rationalize their liquid crystalline self-assembly and to understand geometry and thermal stability. Temperature-dependent luminescence spectra of diazafluorenone with two C12 chains revealed aggregation-induced emission (AIE) depending on the supramolecular order of the bulk phase. These studies suggested that AIE requires a lower degree of aggregation as compared to mesophase formation.
Fichier principal
Vignette du fichier
Bader et al-2019-Novel Luminescent Diazafluorenone Liquid Crystals.pdf (2.59 Mo) Télécharger le fichier
Origine : Fichiers produits par l'(les) auteur(s)
Loading...

Dates et versions

hal-02278403 , version 1 (11-10-2019)

Identifiants

Citer

Korinna Bader, Angelika Baro, Philipp Ehni, Wolfgang Frey, Rafet Guendemir, et al.. Novel Luminescent Diazafluorenone Liquid Crystals. Crystal Growth & Design, 2019, 19 (8), pp.4436-4452. ⟨10.1021/acs.cgd.9b00211⟩. ⟨hal-02278403⟩
35 Consultations
155 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More