| Summary: | 碩士 === 國立中央大學 === 化學研究所 === 98 === Abstract
Ionic liquid (IL) is a very popular medium which has been explored
in recent years. It has been widely employed in various research
fields. Nanoscale transition metal catalysts have also attracted increasing
intrests. It has been mainly the study of special physical and chemical
properties of ILs in order to make use of metal ions. Alternatively, ILs
can prevent the metal nanoparticles from aggregation.
Pd-nanoparticles and Au-nanoparticles were synthesized by UV
irradiation or microwave heating of respective metal halide anions PdBr2
and HAuCl4 in CDCl3 solution of 1-butyl-3-ethyl-1H-imidazol-3-ium
bromide ,chloride(4-2Br and 4-2Cl), respectively.
The 4-2 Br IL with 10 mol % metal salt in chloroform ionic liquid
clustering exhibits at increasing concentration of 4-2 Br. After UV or
microwave irradiation, the metal nanoparticles produced could serve as
the contrasting agent on the TEM images, to correlate the concentrations
of IL with the aggregation phenomena of IL. On a separate study,
fluorescent dyes of 3-hydroxy chromone derivatives
2-(6-diethylaminobenzo[b]furan-2-yl)-3-hydroxychromone (FA) and
2-(4-(dimethylamino)phenyl)-3-hydroxy-4H-chromen-4-one (CF) have
been used to extract structural information from the luminescence and
excitation spectra, which also reflect the the aggregation of ionic liquid in
chloroform.
The chloroform solution of 4-2 Br and 10% PdBr2 under UV or
microwave irradiation generated the Pd nanoparticles in IL layer of 4-2
Br which also protected the size of Pd nanoparticles from growing too fast. These Pd nanoparticles in IL were used in the Heck reactions.
Initially ionic liquid layer with Pd NPs was added with organic materials
for the two-phase catalytic Heck reactions, which could be carried out
under mild conditions. The combinations of Pd nanoparticles and the IL
conforms to goals of green chemistry in reducing environmental
damages.
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