Browsing Undergraduate Honors Thesis Collection by Subject "Chemistry"
Now showing items 1-2 of 2
The dangers of plasticBisphenol A (BPA) is used to make plastics and has been found to be a xenoestrogen. Planaria (Girardia tigrina), regenerating flatworms, were exposed to BPA and deuterated BPA (D8-BPA). Phenotypic effects of BPA on the planaria were recorded during exposure and BPA was then extracted to quantify the amount absorbed by the flatworms. Deuterated BPA (D8-BPA) was used to distinguish added BPA from BPA already present in the organism from supply-chain contamination. A control experiment tested whether the multiple washes performed after incubation removed physisorbed BPA from planaria. Additional analysis was performed using high performance liquid chromatography (HPLC, reverse phase). Improvements in HPLC method to analyze BPA and D8-BPA resulted in better separation between BPA and D8-BPA peaks. Gas chromatography mass spectroscopy (GCMS) was used to quantify BPA/D8 BPA. It is concluded that planarian regeneration is negatively affected by exposure to 20 M concentrations of BPA/D8-BPA, planaria absorbed BPA and D8-BPA from solution, the washing method removed most physisorbed BPA, and decreasing the HPLC pump flow rate improved peak separation. This section describes studies done by other researchers to explore detrimental effects of BPA on humans, including miscarriage, infertility, obesity, and sexual dysfunction. The detrimental environmental effects of excessive plastic use, plastic alternatives, and solutions to reducing the damage of plastic are also described.
Iridium complexes of quinone-based phosphine ligandsThis project was focused on the synthesis of iridium complexes containing Quinone-based phosphine ligands under dry and inert conditions. Iridium complexes with pincer-type ligands have been shown to serve as efficient catalysts in alkane dehydrogenation. However, to regenerate these compounds to their original states and maintain catalytic activity, a sacrificial hydrogen acceptor must be used which is costly and creates unnecessary by-products. Quinones may serve as a counter-balance to this inefficiency by acting as a catalytic hydrogen acceptor. Quinones may rapidly transition between their dehydrogenated and hydrogenated states through electron/proton transfers which may be driven electrochemically. The initial aim of this research was to produce iridium complexes bonded to a Quinone base in a pincer/tridentate framework. Two Quinone-based phosphine ligands (PCAQ and POAQ) were synthesized prior to being reacted with iridium-based catalysts. Synthesis reactions between Quinone-based ligands and iridium-based catalysts yielded a compound, which upon further investigation using 31P-NMR and 1H-NMR spectroscopy revealed a bidentate complex which was stabilized with a CO molecule. Further work is needed to characterize the compounds using X-ray crystallography and to compare the complexes to other iridium catalysts in efficiency of catalytic reactions.