Quimica

Since the discovery of a thin-film organic electroluminescent
device by the team at Kodak,1a organic light emitting
diodes (OLED) have become the most promising new
optoelectronic devices forpractical industrial applications.
Electroluminescent thin films of organic molecules have
been extensively investigated because of their low operating
voltage, tunable red-green-blue output colors,high brightness,
mechanical flexibility and ease of fabrication.1b
Although polymeric as well as small organic molecules
are well established electroluminescent materials used in
fabricating thethin film devices, smaller organic units were
realized to be advantageous with facile emission color
control and the easy fabrication of multilayer devices.2
Investigations on synthesizing new blueluminous materials
for applications in electroluminescent (EL) display have
attracted great attention recently, but there are very few
single component deep blue- and pure red-emitting dyes.2Recently, Wudl et al. reported pyrrolopyridazine derivatives
as a new class of blue organic luminophors. They
demonstrated the possibility of tuning colors and energy
levels by modifying the structuresof these luminophors.3
Herein, we report the synthesis of new pyrrolopyridazine
derivatives, along with the optical properties of these new
compounds. To study the relationship between opticalproperties and the effect of conjugation and substitution, we
systematically designed and synthesized a series of
luminophors containing a core pyrrolo[1,2-b]pyridazine-
5,6,7-tricarboxylic acidtrimethyl ester moiety. Three
different classes of pyrrolopyridazine derivatives were
synthesized, for example, aryl groups directly connected
to the core PPY(pyrrolo[1,2-b]pyridazine-5,6,7-tricarboxylic
acid trimethyl ester) moiety, aryl groups
connected to the PPY via a vinylene linker and aryl groups
connected to the PPY via an acetylene linker. Their
comparative optical and electrochemical...