Fluorescent liquid crystals with rod-shaped π-conjugated hydrocarbon core

ABSTRACT

Calamitic fluorophores are presented possessing either two phenylethylene or phenylacetylene fragments which are connected via an aromatic entity. The new compounds exhibit smectic C and/or nematic liquid crystalline phases. The chromophores show fluorescence in the blue spectral region. Grafting acrylate functional groups to the termini of naphthalene centred members of the rod-shaped dyes provides new luminescent reactive mesogens. Uniaxial orientation of mixed systems of the acrylate fluorophores with non-emissive reactive benzoate nematogens was achieved by surface-assisted alignment on polyimide orientation layers. The photocrosslinked oriented films display linear polarised photoluminescence upon isotropic excitation.

GRAPHICAL ABSTRACT

KEYWORDS:

• Phenylenevinylene
• phenylacetylene
• calamitc liquid crystal
• fluorescence

Acknowledgment

We are grateful to Tatjana Egorov-Brening, Fraunhofer IAP, for performing the FT-IR measurements.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The financial support of the Bundesministerium für Bildung und Forschung (BMBF) (FKZ: 03WKQ04B) is gratefully acknowledged.