ABSTRACT
Thermally activated delayed fluorescence-based organic light-emitting diodes (TADF-OLEDs) have recently attracted tremendous research interest as next-generation optoelectronic devices. However, there are a limited number of host materials with an appropriately high lowest-excited triplet energy (ET) and bipolar charge transport properties for high-efficiency TADF-OLEDs. Moreover, these host materials should have high thermal and morphological stabilities. In this study, we develop novel bipolar host materials consisting of an electron-donating 9-phenylcarbazole unit and an electron-accepting triphenylphosphine oxide, triphenylphosphine sulfide, or 2,4,6-triphenyl-1,3,5-triazine unit linked by a nonconjugated cyclohexane core. These bipolar host materials possess high glass-transition temperatures of over 100 °C and high ET values of approximately 3.0 eV. TADF-OLEDs employing these bipolar host materials could achieve high external electroluminescence quantum efficiencies of up to 21.7% together with reduced efficiency roll-off characteristics, because of expansion of the charge-recombination zone within the emission layer arising from the bipolar charge transport ability of these host materials.
ABSTRACT
Highly monodispersed electrophoretic particles of size ranging from 550 to 160 nm could be prepared through dispersion-polymerization of methyl methacrylate and ethylene glycol dimethacrylate in presence of pyrazoline nanoparticles in a methanol-water mixture. The size of the fabricated electrophoretic particles could be controlled by adjusting the concentration of surfactant. Stearic acid, used as surfactant during the polymerization process also acts as charge controlling additive to control the electrophoric mobility of the particles. Maximum electrophoric mobility (-7.513×10(-5) cm(2)/Vs) was obtained for the 400 nm electrophoretic particles prepared with 1.5 wt.% of stearic acid surfactant. The electrophoric display cells prepared with our electrophoretic particles reveal good current voltage characteristics and color change under applied bias voltage.
ABSTRACT
Libraries of 1-methyl-2,4-diaryl-3-azabicyclo[3.3.1]nonan-9-ones/oximes/O-methyloximes 1-14/15-28/29-42 and 7-methyl-2,4-diaryl-3-azabicyclo[3.3.1]nonan-9-ones/oximes/O-methyloximes 43-48/49-54/55-60 were synthesized and their stereochemistry was established by 1D/2D NMR spectral and single crystal XRD studies. All the synthesized oximes and oxime ethers were screened for their in vitro antimicrobial activity against a panel of pathogenic bacteria (Bacillus subtilis, Staphylococcus aureus, Klebsiella pneumoniae and Pseudomonas aeruginosa) and fungi (Candida albicans, Candida parapsilosis, Aspergillus niger and Cryptococcus neoformans) using Gentamicin and Fluconazole as standards, respectively. From the SAR profile, the lead molecules were identified.
Subject(s)
Anti-Infective Agents/chemical synthesis , Azabicyclo Compounds/chemical synthesis , Ethers/chemistry , Oximes/chemistry , Anti-Infective Agents/chemistry , Anti-Infective Agents/pharmacology , Antifungal Agents/chemical synthesis , Antifungal Agents/chemistry , Antifungal Agents/pharmacology , Azabicyclo Compounds/chemistry , Azabicyclo Compounds/pharmacology , Crystallography, X-Ray , Magnetic Resonance Spectroscopy , Microbial Sensitivity Tests , Molecular Conformation , Small Molecule Libraries , Stereoisomerism , Structure-Activity RelationshipABSTRACT
In the title compound, C(22)H(25)NO(3), the mol-ecule has a pseudo-mirror plane. The structure is a positional isomer of 2,4-bis(4-methoxy-phenyl)-3-aza-bicyclo-[3.3.1]nonan-9-one [Cox, McCabe, Milne & Sim (1985 â¶). J. Chem. Soc. Chem. Commun. pp. 626-628]. The 3-aza-bicyclo-[3.3.1]nonan-9-one moiety adopts a double chair conformation with equatorial orientations of both 2-methoxy-phenyl substituents on either side of the secondary amino group. The benzene rings are oriented at an angle of 33.86â (4)° with respect to each other and the meth-oxy groups point towards the carbonyl group. The crystal structure is stabilized by intermolecular N-Hâ¯π inter-actions.
ABSTRACT
In the mol-ecular structure of the title compound, C(20)H(19)Br(2)NO, the fused six-membered heterocyclic and cyclo-hexane rings adopt a twin-chair conformation with equatorial orientations of all the substituents. Both the ortho-bromo substituents of the benzene rings are oriented towards the carbonyl group; the dihedral angle between the ring planes is 29.13â (3)°. In the crystal structure, the N-H group does not participate in any hydrogen bonds.
