Luminescent Liquid Crystals Derived from 9,10-Bis(Phenylethynyl)anthracene

Abstract

Liquid crystalline behavior has been found in a series of low-molecular-weight 9,10disubstituted anthracenes. In particular, nematic mesomorphism is displayed by derivatives bearing at least a 4′-pentylbiphenyl-4-ylethynyl group, showing that the presence of this substituent induces a mesophase despite the broad central core of the anthracene skeleton. These compounds can also be seen as derived from the known fluorescent material 9,10bis(phenylethynyl)anthracene (BPEA) with a p-pentylphenyl substituent (among others) along its long axis. A comparison of the optical properties of the compounds relative to the parent compound BPEA is presented in order to evaluate their applications in emissive devices. A study of a nematic compound in solution, PMMA film, and pure state in the different phases shows high fluorescence in solution in the green region that slightly shifts to higher wavelengths in PMMA films, but it is clearly red-shifted in pure state.

A Stimuli‐Responsive, Photoluminescent, Anthracene‐Based Liquid Crystal: Emission Color Determined by Thermal and Mechanical Processes

“…A number of anthracene derivatives have been reported to show LC properties. [15,16,34,35] For the present molecular design, a Fréchet type dendron [2,36,37] was attached to the fluorophore. The dendritic moieties [37] introduced into 1 are known to induce LC properties.…”

“…Our aim has been the development of a new class of photofunctional liquid crystals that change the emission properties on order-order phase transitions through external stimuli. [14] Recently, intensive work has been focused on photoluminescent liquid crystals [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33] as they may be used for materials such as polarizing electroluminescent materials and laser devices. However, a change of the photoluminescent color based on the dynamic change of the LC assembled structures has not been observed, except for a few examples.…”

Dicyanovinyl end-capped 9,10-bis (phenylethynyl) anthracenes for organic solar cells

“…Besides, they have been used for the synthesis of luminescent liquid crystals [22], sensors [23,24], organic semiconductors [25,26], useful fluorescent dyes for DNA labelling [27] and for the production of organic light-emitting diodes (OLEDs) [28,29]. The combination of anthracene with strong acceptors to form an acceptor-donor-acceptor (A-D-A) system seems also to be an opportunity to enhance its optoelectronic properties and apply it in the dye-sensitised solar cells.…”

Highly efficient blueish-green fluorescent OLEDs based on AIE liquid crystal molecules: from ingenious molecular design to multifunction materials

“…[9][10][11][12][13][14][15][16][17][18] Kato and co-workers have developed many luminescent mesogens formed by a rigid, π-conjugated core (such as pyrene and anthracene) functionalised with peripheral alkoxy chains. [19][20][21][22] Although this strategy can effectively generate liquid crystallinity, the emission quantum yield (Φ PL ) is often rather low, probably due not only to non-radiative transitions via intramolecular vibration caused by the periphery flexible chains, but also the aggregation-induced quenching of the rigid π-conjugated core.…”