BAUMANN FAMILY SCHOLARSHIP
2002 - 2003 Winners
Josh Waetzig and Trish Hoette
Josh Waetzig's Research Proposal (November, 2002):
We are investigating mixed hybridization state carbocyclic rings and their further uses in relation to their biological activity. We are synthesizing a molecule that looks similar to natural products made by various fungi that may be useful as antibiotics or in DNA signaling process. The molecule we are synthesizing will hopefully mimic that natural product and may be used in antibiotics and may also have uses in DNA alkylation, giving guidance to future cancer research. The molecule’s synthesis is shown in Figure 1 on the next page. Dr. Hulce and I have so far been able develop methods of the attachment of the trimethylsilyl group onto the cyclopentene ring, 1. Then, moving forward, we have developed ways into protect the keto group on the cyclopentene as an acetal, 2, to allow us to reach the step of the cyclopropanation, 3. Once we have solved the mystery of the cyclopropanation step we will move on to deprotect the keto group on the pentane ring, 4. Once this step has occurred we will remove the trimetylsilyl group, 5, and attempt addition of different nuleophiles, 6, validating the usefulness of this molecule as a model for an antibiotic. This will complete the investigation of this mixed hybridization state carbocycle.
Josh Waetzig's Research Report
Trish Hoette's Research Proposal (November, 2002):
Chlorine dioxide, also known as chlorine peroxide, is an "effective and powerful biocide, disinfectant and oxidizer under appropriate conditions" (Ibanez et al.). Chlorine dioxide is also preferred over other disinfecting agents because it has fewer by-products than the more common disinfectant, chlorine. Recently, the U.S. government used chlorine dioxide to rid government buildings and offices of anthrax. In addition, there are other applications for chlorine dioxide that make it more environmentally friendly than chlorine.
We, Dr. Anderson and I, plan on making chlorine dioxide using a small polypropylene pipette. The pipette is necessary because chlorine dioxide is known to be explosive as a gas ligand. Because of chlorine dioxide's explosive nature, we will work on a microscale gas level. Should the gas explode, no more than 0.1 mmol would ever be present in the pipette generator. To perform the reaction, the reagents will be introduced to the pipette generator via syringe. Any excess chlorine dioxide can be reacted with sodium hydroxide to form NaClO2 (aq). Normally we would use a 60-mL syringe to produce chlorine dioxide, but we are concerned that because of chlorine dioxide's oxidative properties, it would react with the rubber in a 60-mL syringe. We will create chlorine dioxide using the following reagents.
2 NaClO2 + NaOCl + H2O 2 ClO2 + 2 NaOH + NaCl
The appearance of yellow gas will show that chlorine dioxide was formed. In addition, UV light that decomposes chlorine dioxide into chlorine and oxygen gas can detect chlorine dioxide. Using Beer's Law or titrating chlorine dioxide with iodide, we can determine the concentration of chlorine dioxide
2 ClO2 + 8 H+ + 10 I- 5 I2 + 2 Cl- + 4 H2O
Chlorine dioxide is a powerful oxidizing agent and is useful in a number of reactions. For example, chlorine dioxide reacts with sulfur to form sulfuric acid. The formation of sulfuric acid will be observed with the change in pH of the solution. These results could be compared with the concentration determined in chlorine dioxide's reaction with iodide.
4 S + 6 ClO2 + 4 H2O 4 H2SO4 + 3 Cl2
Chlorine dioxide also reacts with Fe2+ to make Fe3+ in the following reaction.
4 H+ + ClO2 + 5 Fe2+ 5 Fe3+ + Cl-
We are alas thinking of ways that teachers might use this gas for demonstrational purposes. For example, we would like to use chlorine dioxide to kill microbes on a piece of bread. A "wheat" piece of bread would eventually mold in a ziplock bag. The piece of bread treated with chlorine gas should show no mold should be compared to the control that has mold.
7. Plans for presentation of research results (conference, publication, seminar, etc.)
We will present my findings at a seminar with the Creighton University Chemistry Department.
Ibanez, Jorge G.; et. al. Microscale Environmental Chemistry: Production of Chlorine Dioxide.
Cotton, F. Albert; Wilkinson, Geoffrey. Advanced Inorganic Chemistry: A Comprehensive Text. Interscience Publishers: New York, 1972.
Wood, C.W., Holliday, A.K., Inorganic Chemistry: An intermediate text. Butterworths: London, 1967.
Sidgwick, N.V. The Chemical Elements and their Compounds. Vol. II. Oxford University Press: London, 1962.
Trish Hoette's Research Report (available May, 2003)