Synthesis and Characterization of a Novel Thiophene Ligand and its
Incorporation in Low-Dimensional Platinum(II) Complexes
Autumn Krug (Dr. William
Wacholtz)
Electronically communicating polymers with transition metal centers
incorporated directly into the polymer backbone, possess properties
which could be useful in a wide variety of optoelectronic applications.
Platinum(II) is of particular interest due to its ability to fully
conjugate with ethynylenic groups, which can be attached to a number of
organic spacer ligands. Previous work on benzene-based organic spacers
has shown the excited state electron to be localized, rather than
delocalized, throughout the system. Use of a thiophene-based diethynyl
ligand should lower the energy barriers to facile electron transfer,
and still exhibit similar photophysical characteristics to that of the
benzene-based platinum(II) complexes. Ligand and platinum(II) complex
preparation, characterization and photophysical properties will be
presented and discussed.
Characterization of Marigold Dye
Catherine Polster (Dr. Jennifer
Mihalick)
Dyes created from marigolds (tagetes) are yellow, but when metal
mordants are added the color can shift. Three colored molecules in the
dye were separated using chromatography and extractions. The molecular
structures were analyzed using thin layer chromatography and UV-Visible
spectroscopy. The least polar molecule appears to be a flavone, while
the two more polar molecules appear to be flavonols. Reactions with
metal mordants were also characterized with UV-Visible spectroscopy.
Investigations of Columnar Photomechanically Active Rhodium (I)
Complexes
Alexsia Richards (Dr. William
Wacholtz; Ryan Davis and James Brozik, University of New Mexico,
Albuquerque)
Low-dimensional materials are compounds whose properties are dominated
by physical behaviors along primarily one axis. Crystals of the complex
Rh(CO)2(3,6-DTSQ) where Rh is rhodium(I) and 3,6-DTSQ is
3,6-di-tert-butylsemiquinone have been shown to bend reversibly when
exposed to near IR light. This property has been attributed in the
literature to a metal to ligand charge transfer (MLCT) transition.
Theoretical calculations of this compound and an analogous compound
employing 3,6-di-tert-butylnaphthaquinone (3,6-DTNQ) indicate that the
actual excited state transition appears to be a ligand to metal charge
transfer (LMCT). Implications of this study and confirmatory
experiments employing excited state IR and time resolved IR
spectroscopy will be discussed.
Thermochemistry of Cadmium Chloride Binding to Polysaccharides
Amber Schultz (Dr. Jennifer
Mihalick)
It has been shown that polysaccharides such as alginate and the capsule
layer of Microcystis flos-aquae C3-40, which resides in alkaline
lakes such as Lake Winnebago, are able to bind cadmium and other
divalent metals with varying affinities. Using an isothermal
microcalorimeter we measured the changes in enthalpy of reactions
between cadmium chloride and polysaccharides. These results were then
compared with reactions of manganese and lead with the polysaccharides.
Peaks in the data sets for lead and a polysaccharide have been linked
to a change in viscosity of the solution, and may also hold true for
cadmium and polysaccharide reactions.
Involvement of Protein Phosphatase Enzymes in Exit From Mitosis in
the Budding Yeast, Saccharomyces
cerevisiae
Benjamin Workman, Jason Keaton
(Dr. James Paulson, Dr. Linfeng Xie)
The first objective of this research was to test the hypothesis that
inactivation of Mitosis Promoting Factor (MPF) is sufficient to induce
exit from mitosis. We used strains of the budding yeast S. cerevisiae
containing the mutation cdc28-as1, in which Cdk1 (Cdc28) the protein
kinase subunit of MPF, is uniquely sensitive to the ATP analog
4-amino-1-tert-butyl-3-(1'-naphthylmethyl) pyrazolo [3,4-d] pyrimidine
(ANapthylmethyl-PP1"). S. cerevisiae cells were arrested in metaphase
by treatment with the spindle poison nocodazole and subsequently
treated with naphthylmethyl-PP1to inhibit MPF. As predicted by the
hypothesis, cells exited mitosis based on four criteria: (1)
Reinitiation of budding; (2) Stabilization of Sic1 protein (in a
Sic1-GFP strain); (3) Degradation of the mitotic cyclin Clb2 (using
western blotting); and (4) Susceptibility to induction of Ashmooing@ by
treatment with α-factor. These changes were not seen with wild-type or
mock-treated cells.
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Last updated: April 27, 2007