Synthesis, Electrochemical and Optical Properties of Stable Yellow Fluorescent Fluoranthenes

2015

New J. Chem.

In this study, fluoranthene-based derivatives with a high thermal stability were synthesized for applications in organic electroluminescent devices. The two derivatives synthesized in this study, bis(4-(7,9,10-triphenylfluoranthen-8-yl)phenyl)sulfane (TPFDPS) and 2,8-bis(7,9,10-triphenylfluoranthen-8yl)dibenzo[b,d]thiophene (TPFDBT), were characterized by cyclic voltammetry, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). TPFDPS exhibits a high T g of 210 1C while TPFDBT is crystalline in nature. Both the derivatives are thermally stable up to 500 1C. The charge transport studies reveal predominant electron transport properties. Subsequently, we fabricated blue OLEDs with 2-tert-butyl-9,10-bis-(b-naphthyl)-anthracene (TBADN) as the emitting layer to demonstrate the applications of these molecules as an electron transporting layer.

Section: Introductionmentioning

confidence: 99%

High T_g fluoranthene-based electron transport materials for organic light-emitting diodes

Kumar

2015

New J. Chem.

“…These results suggest that the IMR process of the TPE core has a strong influence on the excited states of the luminogen, rendering weak fluorescence. The observed emission in THF predominantly arises from the fluoranthene units . Thin films of TFPE show a hypsochromic shift of about 30 nm in comparison with spectrum in THF and show a blue emission at λ ≈493 nm with a quantum yield of 5.4 %.…”

Section: Resultsmentioning

confidence: 99%

Tetraphenylethene‐Based Conjugated Fluoranthene: A Potential Fluorescent Probe for Detection of Nitroaromatic Compounds

Chandrasekaran

Venkatramaiah

2016

Chemistry A European J

This study reports the synthesis and photophysical properties of a star-shaped, novel, fluoranthene-tetraphenylethene (TFPE) conjugated luminogen, which exhibits aggregation-induced blue-shifted emission (AIBSE). The bulky fluoranthene units at the periphery prevent intramolecular rotation (IMR) of phenyl rings and induces a blueshift with enhanced emission. The AIBSE phenomenon was investigated by solvatochromic and temperature-dependent emission studies. Nanoaggregates of TFPE, formed by varying the water/THF ratio, were investigated by SEM and TEM and correlated with optical properties. The TFPE conjugate was found to be a promising fluorescent probe towards the detection of nitroaromatic compounds (NACs), especially for 2,4,6-trinitrophenol (PA) with high sensitivity and a high Stern-Volmer quenching constant. The study reveals that nanoaggregates of TFPE formed at 30 and 70% water in THF showed unprecedented sensitivity with detection limits of 0.8 and 0.5 ppb, respectively. The nanoaggregates formed at water fractions of 30 and 70% exhibit high Stern-Volmer constants (Ksv=79,998 and 51,120 M(-1), respectively) towards PA. Fluorescence quenching is ascribed to photoinduced electron transfer between TFPE and NACs with a static quenching mechanism. Test strips coated with TFPE luminogen demonstrate fast and ultra-low-level detection of PA for real-time field analysis.

“…[35][36][37][38] The better thermal and electrochemical stability, wide band gap, high photoluminescence quantum yield (PLQY), and apparent resistance towards oxygen quenching of fluoranthene derivatives have led to the utilization in various optoelectronics devices. [38][39][40][41][42][43][44][45][46][47] Li et al reported the synthesis of heterocyclic fused fluoranthene derivatives, tetraazabenzodifluoranthne dimides, as potential electron acceptor materials in solar cells. 48 In our earlier report, we have observed very high thermal stability and predominant n-type character for fluoranthene derivatives, bis(4-(7,9,10-triphenylfluoranthen-8-yl)phenyl)sulfane (TPFDPS) and 2,8-bis (7,9,10- 49 We have explored these molecules as electron transport materials for OLEDs using 2-tert-Butyl-9,10-di(naphth-2-yl)anthracene (TBADN) as the active layer, N,N'-diphenyl-N,N'-bis (3-methylphenyl)(1,1'-biphenyl)-4,4'-diamine (TPD) as hole transport layer, in a tri-layer device configuration; and achieved moderate device efficiencies.…”

Section: Introductionmentioning

confidence: 99%

Fluoranthene-Based Molecules as Electron Transport and Blue Fluorescent Materials for Organic Light-Emitting Diodes

Kumar

2015

J. Phys. Chem. C

Herein, we report the synthesis, characterization and potential application of bis(4-(7,9,10-triphenylfluoranthen-8-yl)phenyl)sulfone (TPFDPSO2) and 2,8-bis(7,9,10-triphenylfluoranthen-8-yl)dibenzo[b,d]thiophene 5,5-dioxide (TPFDBTO2) as electron transport as well as light emitting materials. These fluoranthene derivatives were synthesized by oxidation of their corresponding parent sulphide compounds which were prepared via Diels-Alder reaction. These materials exhibit deep blue fluorescence emission in both solution and thin film, high PLQY, thermal and electrochemical stability over a wide potential range. Hole-only and electron-only devices were fabricated to study the charge transport characteristics and predominant electron transport property comparable with well-known electron transport material, Alq 3 , was observed. Further, bilayer electroluminescent devices were fabricated utilizing these fluoranthene derivatives as electron transport as well as emitting layer and device performance was compared with their parent sulphide molecules. The EL devices fabricated with these molecules displayed bright sky blue color emission and 5-fold improvement in EQE with respect to their parent compounds.