A computational and experimental investigation of deep-blue light-emitting tetraaryl-benzobis[1,2-d:4,5-d′]oxazoles

Abstract

In an effort to design deep-blue light emitting materials, the optical and electronic properties of a series of tetraarylbenzobis[1,2-d:4,5-d’]oxazole (BBO) cruciforms were evaluated using density functional theory (DFT) and time-dependent...

Global Search for Stable C4H5NO Compounds—Guinness Molecules and Stability Islands

“…Oxazoles are important heterocycles found in numerous natural compounds and they are biologically active themselves [ 16 ]. Several quantum-chemical studies of compounds containing an oxazole ring have been published [ 17 , 18 , 19 ], but we are unaware of any computations of oxazoles with the formula C 4 H 5 NO.…”

Evaluating the Effect of Extended Conjugation and Regioisomerism on the Optoelectronic Properties and Device Efficiencies of Blue Light-Emitting Benzobisoxazoles

“…We used DFT calculations to aid our molecular selection and design and provide insight into their geometric and optoelectronic properties. In particular, we frequency-optimized the ground geometries of the four BBOs (Figure ), followed by an excited state generation using TD-DFT at the mPW3PBE/SV level (see Supporting Information for details on the computational methods), a functional basis set previously benchmarked by our group. , Table summarizes the computationally derived properties in chloroform through the conductor polarizable calculation model (CPCM), which shows the closest correlation to the experimental data; see Supporting Information for a comparison of the experimental and theoretical data in the gas phase and in chloroform. The geometric trends indicated very little difference between the carbazole linkage and the identity of the 2,6 aryl group.…”

“…We have previously designed deep blue and near UV light-emitting BBO cruciforms with EL λ max ≈ 417 nm; CIE y < 0.10. 41,42 These molecules had EQEs of <1% and were theoretically limited to maximum efficiencies of 5% when considering their outcoupling and charge recombination losses. 27,43 Few highly efficient, purely organic deep-blue and blue-emitting molecules have been successfully fabricated into devices.…”

Carbazole-substituted benzobisoxazoles: near-UV fluorescent emitters and ambipolar hosts for organic light-emitting diodes

“…[10][11][12][13] Moreover, many aryl-substituted BBOs are highly fluorescent materials that are stable under ambient atmosphere and at high temperatures, making them ideal candidates for use in OLEDs. 14,15 Lastly, many aryl-BBOs possess spatially segregated frontier molecular orbitals (FMO)s, which is favorable for achieving a small DE ST . [13][14][15][16] Previously, we reported a series of small-molecule BBO dopants which were used in host-guest OLEDs that exhibited deep-blue electroluminescence (EL) ( EL l max E 440 nm; CIE y o 0.10), albeit with external quantum efficiencies (EQE)s less than 3%.…”

“…14,15 Lastly, many aryl-BBOs possess spatially segregated frontier molecular orbitals (FMO)s, which is favorable for achieving a small DE ST . [13][14][15][16] Previously, we reported a series of small-molecule BBO dopants which were used in host-guest OLEDs that exhibited deep-blue electroluminescence (EL) ( EL l max E 440 nm; CIE y o 0.10), albeit with external quantum efficiencies (EQE)s less than 3%. 14 The low efficiency of the devices was attributed in part to the traditional fluorophore character of the BBO dopants where B75% of the excitons created were lost to various non-radiative pathways.…”