Blue electroluminescence of novel pyrazoloquinoline and bispyrazolopyridine derivatives in doped polymer matrices

Thin-layer photoluminescence and electroluminescence observed from pyrazoloquinoline-doped polymer matrices

“…[2] and the structure is shown in Scheme 1. Photoluminescence was measured from solid films prepared either by solution casting or by spin coating from suitable solvents.…”

“…PAQ4 and a few other pyrazoloquinoline and bispyrazolopyridine derivatives were found to have field-dependent electron mobilities in the range of 10 À6 -10 À4 (cm 2 V À1 s À1 ) when dispersed in a polystyrene matrix. [3,4] Coupled with their carrier transporting properties, pyrazoloquinoline and bispyrazolopyridine derivatives have been investigated to use in electroluminescent devices [2,5,6]. Copolymers with pyrazol moieties as main chains or side chains were also prepared [7].…”

“…Early work indicated that pyrazolo [3,4-b]quinolines emitted in the blue spectral range when excited optically [1] when doped in a range of polymer matrices or electronically [2] in a poly(N-vinyl carbozole) (PVK) host. The emissions from 1,3-bisphenyl-4-methyl-pyrazolo [3,4-b]quinoline (PAQ4) were often found to have their peak maxima around 440-460 nm with a half-peak width around 65 nm.The photoluminescent quantum efficiencies are generally high in solution.…”

A new blue light-emitting terphenyl-bridged bisbenzimidazolium salts: Synthesis, crystal structure, and photophysical properties

“…Compounds 5ae5h were synthesized by alkylation and quaternization of compounds 4ae4c with excess alkyl bromides in DMF at 110 C [40,41]. The 1 H NMR spectra, 13 C NMR spectra, MS spectra, and elemental analysis of 5ae5h…”

“…Efficient bright electroluminescence of the three primary colors-red, green, and blue is essential to achieve full color displays. After two decades of active research, many new blue-emitting materials, such as anthracene derivatives [9,10], fluorene derivatives [11,12], pyrazoloquinolines [13], pyrene derivatives [14], and others, have been exploited for the construction of blue OLEDs. However, these compounds often do not have good solubility in common organic solvents and easily aggregate in the solid state due to the strong intermolecular interactions [15e21].…”