2 research outputs found
Fluorescence-Enhanced Chemosensor for Metal Cation Detection Based on Pyridine and Carbazole
A series
of donor–acceptor systems incorporating a carbazole
moiety as the donating unit and pyridine moiety as the accepting unit
have been designed and synthesized. The spectroscopic and electrochemical
behaviors of the carbazole derivatives demonstrate that the carbazole
unit interacts with the electron-accepting group through the π-conjugated
spacer, thus leading to the intramolecular charge transfer (ICT).
The pyridine-substituted carbazole derivatives show significant sensing
and coordinating properties toward a wide range of metal cations.
Compound <b>S2</b> exhibits fluorescence enhancement upon association
with transition metal cations, and compound <b>V3</b> shows
high selectivity for Cu<sup>2+</sup> among this series of materials.
DFT calculations indicate the different association abilities of the
dyes and the enhancement of ICT upon addition of the metal cations
AIE-Active Fluorene Derivatives for Solution-Processable Nondoped Blue Organic Light-Emitting Devices (OLEDs)
A series
of fluorene derivatives end-capped with diphenylamino
and oxadiazolyl were synthesized, and their photophysical and electrochemical
properties are reported. Aggregation-induced emission (AIE) effects
were observed for the materials, and bipolar characteristics of the
molecules are favored with measurement of carrier mobility and calculation
of molecular orbitals using density functional theory (DFT). Using
the fluorene derivatives as emitting-layer, nondoped organic light-emitting
devices (OLEDs) have been fabricated by spin-coating in the configuration
ITO/PEDOT:PSSÂ(35 nm)/PVKÂ(15 nm)/<b>PhN-OFÂ(</b><i><b>n</b></i><b>)-Oxa</b>(80 nm)/SPPO13Â(30 nm)/CaÂ(8 nm)/AlÂ(100
nm) (<i>n</i> = 2–4). The best device with <b>PhN-OFÂ(</b><b>2</b><b>)-Oxa</b> exhibits a maximum
luminance of 14 747 cd/m<sup>2</sup>, a maximum current efficiency
of 4.61 cd/A, and an external quantum efficiency (EQE) of 3.09% in
the blue region. Investigation of the correlation between structures
and properties indicates that there is no intramolecular charge transfer
(ICT) increase in these molecules with the increase of conjugation
length. The device using material of the shortest conjugation length
as emitting-layer gives the best electroluminescent (EL) performances
in this series of oligofluorenes