| Summary: | 博士 === 國立中央大學 === 化學工程與材料工程研究所 === 91 === A series of distyrylbenzene (DSB) derivatives, as oligo(para-phenylene-
vinylene) (OPV), were synthesized and assessed as the emitter in organic light
emitting diode (OLED) fabrication. The presence of electron-withdrawing cyano
group and electron-donating methoxy group at various positions in the molecule to
evaluate their influence on the photophysical property and the electroluminescent
behavior of these derivatives in OLED were studied. Bright blue emissions were
achieved with these materials as a dopant. There were not much difference in the
absorption and emission spectra of the compounds containing n-hexyloxy and
2-ethylhexyloxy groups. However, 2-ethylhexyloxy groups produce more saturated
blue color in their EL. The compounds with higher fluorescent quantum yield did not
result in higher EL quantum efficiency in this multiplayer OLED fabrication as that of
compounds with lower fluorescent quantum yield. DSB derivatives with cyano and
alkoxy groups grew epitaxially on the friction-transferred poly(tetrafluoroethylene)
(PTFE) layer. DSBs/PTFE double layers indicated the remarkable anisotropic feature
in absorption and emission properties. We concluded that trans,trans-1,4-
di(2-ethyl-hexyloxy)-2,5-bis[2-(4-cyanophenyl)ethenyl]benzene molecules take two
kinds of orientations on the PTFE layer in which the long axes of
trans,trans-1,4-di(2-ethyl-hexyloxy)-2,5-bis[2-(4-cyanophenyl)ethenyl]benzene are
parallel and normal to the substrate surface. On the other hand, the long axes of
trans,trans-1,4-di(2-ethylhexyloxy)-2,5-bis[2-(2-cyanophenyl)ethenyl]- benzene and
trans,trans-1,4-di(2-ethyl-hexyloxy)-2,5-bis[2-(3-cyanophenyl)-ethenyl]benzene ori-
ent inclined and parallel to the substrate, respectively. Treatment of conjugated
alkynone with NaI, TMSCl, and water in acetonitrile gave deconjugated
(Z)-3-iodo-3-alken-1-one in good yield and with high stereoselectivity (≥95%).
Mechanistic study showed that HI, generated from NaI, TMSCl and water, underwent
regioselective addition to the conjugated ynone, e.g. 3-decyn-2-one, to form
(E)-4-iodo-3-decen-2-one and (Z)-4-iodo-3-decen-2- one. Then, TMSCl catalyzed the
deconjugation reaction to form deconjugated (Z)-4-iodo-4-decen-2-one. The
application of the above deconjugation reaction was demonstrated by the
stereoselective synthesis of (Z)-α-phenoxy-methylene- γ-butyrolactone and its
hydrofuran analogues. DNA cleavage study also showed that γ-butyrolactone with
(Z)-configuration at α-alkylidene gave better result than its analogue even at 10µM
for only 10 min. The development of an efficient method for the preparation of
(Z)-α-phenoxy-methylene-γ-butyrolactone and (Z)-α-phenylthiomethyl-γ-butyro-
lactone derivatives from 2-propynyoxybenzene and 2-propynylthiobenzene were
described.
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