Synthesis and Photophysics of Dendronized Nanomaterials

With luminescence quantum efficiencies ranging from
5 to 15%, Cadmium selenide (CdSe) quantum dots (QDs)
are stronger emitters than many organic fluorescent
dyes. Inorganic coated ODs such as (CdSe)ZnS further
increase quantum yield by fully coordinating free
unbound surface electrons by reducing the occurrence
of nonradiative transitions. The electron hole is
confined to the QD core, while the electrons are
delocalized throughout the core/shell structure.
Surface modification of QDs with covalently attached
dendrons offers a means to not only modify
luminosity of the quantum dot, but to also modify
its soluibility. In this dissertation, the synthesis
of CdSe QDs with covalently bound thiol dendrons is
presented. While covalently bonding the dendrons to
the QD did not increase the quantum efficiency or
emission lifetime, the dendrons did effect the
morphology of the quantum dot by replacing the
surface Selenium with Sulfur from the dendron
attachment effectively creating an organically
coated core/shell QD. Elemental analysis is
presented amongst other data as evidence for the
composition of the (CdSe)CdS-Dendron compounds.

Autorentext

Born in Germany, Dr. Hodel is a US citizen and resident of Cameroon. She received the Astellas USA Foundation humanitarian award which carries a US$ 30,000 price. She received her Ph D in Organic Chemistry from the City University of New York; Nat. Tour Speaker for the American Chemical Society speaking on "Drug Production in Africa".

Klappentext

With luminescence quantum efficiencies ranging from 5 to 15%, Cadmium selenide (CdSe) quantum dots (QDs) are stronger emitters than many organic fluorescent dyes. Inorganic coated ODs such as (CdSe)ZnS further increase quantum yield by fully coordinating free unbound surface electrons by reducing the occurrence of nonradiative transitions. The electron hole is confined to the QD core, while the electrons are delocalized throughout the core/shell structure. Surface modification of QDs with covalently attached dendrons offers a means to not only modify luminosity of the quantum dot, but to also modify its soluibility. In this dissertation, the synthesis of CdSe QDs with covalently bound thiol dendrons is presented. While covalently bonding the dendrons to the QD did not increase the quantum efficiency or emission lifetime, the dendrons did effect the morphology of the quantum dot by replacing the surface Selenium with Sulfur from the dendron attachment effectively creating an organically coated core/shell QD. Elemental analysis is presented amongst other data as evidence for the composition of the (CdSe)CdS-Dendron compounds.