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@PHDTHESIS{Schmid:60068,
author = {Schmid, Sören},
othercontributors = {Albrecht, Markus},
title = {{L}umineszierende zweikernig dreisträngige {H}elicate},
address = {Aachen},
publisher = {Publikationsserver der RWTH Aachen University},
reportid = {RWTH-CONV-121798},
pages = {154 S. : Ill.,graph. Darst.},
year = {2005},
note = {Aachen, Techn. Hochsch., Diss., 2005},
abstract = {Luminescent triple-stranded dinuclear helicates The
building of systems showing a special function or a property
that makes them suitable for the preparation of functional
materials will become more and more important in the next
years. Based on the "bottom-up approach" supramolecular
chemistry can play an important part on this field. This
work deals with the building and examination of
triple-stranded dinuclear helicates. By using special ligand
systems and metals, it its possible to give these aggregates
a special property. In the centre of the investigations is
the use of lanthanoids. One of their properties is their
luminescence, which makes them already suitable for the
building of laser systems or colour displays. This
luminescene should be enhanced by the coordination with
special ligands. Also the energy transfer processes from the
ligands to the metal centres will be investigated. Three
different ligand systems will be prepared in this work. One
of those is based on 8-hydroxyquinoline. By connecting two
of these metal coordinating units, ligands will be received,
which are used in the building of neutral triple-stranded
dinuclear helicates. By reaction of those ligands with
aluminium(III)- and gallium(III)-ions, materials can be
obtained with a special luminescence property. Another
ligand motif is based on ß-diketones. Connecting two
ß-diketone moieties with a chiral spacer leads to a chiral
ligand tetraketone ligands, which can be used in
self-organizing processes with gallium(III)- and
iron(III)-ions to build neutral triple stranded dinuclear
helicates. The evidence, that only on enantiomer is present
is given in solution by NMR-investigation and in the solid
state via X-ray-analyses. Because of a cavity inside of the
helicates it is possible to include in a heterogeneous
reaction selectively lithium cations. This process can be
seen by NMR-experiments. Based on these experiments several
chiral ligands based on ß-diketones were synthesized and
used in self-assembly processes with lanthanoids. Some of
the resulting helicates were investigated for their
luminescence. Especially the europium-, terbium- and
holmium-helicates show a measurable luminescence. The
different ligands showed different properties in the energy
transfer from the ligands to the metal centres depending on
the substituents on the ß-diketon-moyeties. It can be
shown, that the presence of an aromatic system in the ligand
enhances the energy transfer. Is there also a halogen at the
aromatic substituent, the energy transfer will be more
enhanced. In cooperation with the working group of Z.
Pikramenou of the university of Birmingham, it was possible
to synthesize a quadruple-stranded dinuclear helicate and to
investigate this for the luminescence properties. In the
last part mixed N/O-donor-systems based on picolinates are
synthesized and characterized. These ligands should also be
used in the formation of triple-stranded dinuclear
helicates.},
cin = {100000},
ddc = {540},
cid = {$I:(DE-82)100000_20140620$},
typ = {PUB:(DE-HGF)11},
urn = {urn:nbn:de:hbz:82-opus-12331},
url = {https://publications.rwth-aachen.de/record/60068},
}
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