Synthesis, thermal and optical properties of a novel bis(2-(4-dicyanovinylphenyl) pyridinato-N, C2) iridium(acetylacetonate)

Bis(2-(4-formylphenyl) pyridinato-N, C2) iridium(acetylacetonate) (5) was subjected to a Knoevenagel reaction with malononitrile in dichloromethane in the presence of catalytic amount of pyrrolidine. This gave successfully a novel bis(2-(4-dicyanovinylphenyl) pyridinato-N, C2) iridium(acetylacetonate) (6) in good yield (83%). Complex 6 was fully chracterised by H-1, C-13 NMR, FT-IR, elemental analysis. Complex 6 showed a strong ligand centred (LC) absorption band at 355 nm (epsilon 56490 L mol (1) cm (1)) and weak metal-to-ligand charge transfer (MLCT) bands at 445 (epsilon 4154 L mol (1) cm (1)) and 535 nm (epsilon 2606 L mol (1) cm (1)). Complex 6 loses its acac moiety between 248 and 336 Alpha degrees C (under N-2 atmosphere) and emits a red light at 695 nm with a large Stokes shift (160 nm). (C) 2015 Elsevier B.V. All rights reserved

Extreme enantiomeric discrimination of fluoroalkanes using deuterium NMR in chiral liquid crystalline media

The enantiomeric assay of fluoroalkanes using H-2-NMR in a chiral liquid crystalline medium is demonstrated, and at its limit the enantiomers of [5-H-2]-5-fluorodecane were successfully resolved.</p

Practical syntheses of N-hexylcarbazol-2-yl- and -3-yl-boronic acids, their cross-coupled products and a derived tris-cyclometalated (pyridin-2-yl)carbazole iridium(III) complex

The syntheses of N-hcxylcarbazol-2-yl- and -3-yl-boronic acids (1 and 2) are described on a ca. 7 g scale, starting from commercially available 2,5-dibromonitrobenzene (4) and carbazole (11), respectively. Compounds I and 2 underwent efficient palladium-catalyzed cross-coupling reactions under Suzuki-Miyaura conditions to yield products 17, 18 and 20. Compound 18 reacted with IrCl3 to give the tris-cyclometalated (pyridin-2-yl)carbazole iridium(III) complex 21, the X-ray crystal structure of which is reported

Extreme enantiomeric discrimination of fluoroalkanes using deuterium NMR in chiral liquid crystalline media

The enantiomeric assay of fluoroalkanes using H-2-NMR in a chiral liquid crystalline medium is demonstrated, and at its limit the enantiomers of [5-H-2]-5-fluorodecane were successfully resolved.</p

White polymeric light-emitting diode based on a fluorene polymer/Ir complex blend system

Efficient white-polymeric light-emitting diodes (PLED) were fabricated as a single active layer containing blue-emitting poly(9,9-bis(2-ethylhexyl)fluorene-2,7-diyl) endcapped with bis(4-methylphenyl)phenylamine; (PF2/6am4), and yellow-orange-emitting iridium [tri-fluorenyl] pyridine complex [Ir(Fl(3)Py)(3)]. The fluorene-like ligands in the blended device prevent phase segregation and also enhance energy transfer from the polymer host to the guest due to efficient overlap of wave function (Dexter process) and host singlet emission and guest absorption bands (Forster process) which reduces the loading level required to produce white emission. The two emitted colors complement each other and doping levels of 2%-3% produce white emission. Above a certain current density, depending on the doping level, the device Commission Internationale de L'Eclairage (CIE) coordinates become bias independent and a stabilized white emission can be obtained. A white-emitting PLED (coordinates 0.348, 0.367) of peak external quantum efficiency of 2.8%, and luminance of 16000 cd/m(2) at applied voltage of 5 V (i.e., 4.57 cd/A) was obtained. (C) 2005 American Institute of Physics