Chemistry, 2012

    Synthesis and Characterization of Thiol-Derivatized AgI Nanoparticles
    Cassady Allen, Megan Deeds, Alicia Tysl
    Mentor: Steven Clymer

    AgI nanoparticles are capable of being characterized because of their high ionic conductivity which is due to the compound’s unique transport properties. These properties have garnered recent attention because of the possibilities for using these nanoparticles in applications relating to solid-state battery and chemical sensing systems. A large-scale synthesis of nanometer-sized AgI powder particles is often used for ionic conductivity measurements as well as for other studies of physical properties including phase transformation. Some other potential applications of this technology involve catalysis methods and microelectronics. The synthetic route used in this study includes a thiolate compound. Thiolate anions are chosen because they play a significant role as growth moderators while exhibiting strong particle surface binding to a metal ion. The strong interaction observed between the thiolate and silver ions is useful in that the overall size of the silver iodide particles can be controlled, specifically in the nanometer range. Originally, the synthesized AgI nanoparticles were studied through optical absorption and photochemical means. However, UV-Vis spectroscopy and Fourier transform infrared spectroscopy (FT-IR) were used in the element analysis and product characterization for this experiment.


    Biochemistry of Ethanol: Here We Go!
    Harshesh Amin, Ashley Thorbahn
    Mentor: Tracey Murray

    The consumption of alcohol (ethanol) is a common practice among college students, yet one that can be potentially lethal. To better understand the physiological effects of alcohol consumption on the human body, the biochemistry of ethanol was studied through a literature review. Ethanol has well-known negative neurological, gastrointestinal, and cardiological effects on the body. One key enzyme is alcohol dehydrogenase, which plays a major role in the removal of toxins, such as ethanol, from the human body. Not only does this enzyme remove the ethanol from the body, the other products of the alcohol dehydrogenase reaction change the metabolism of carbohydrates, often causing weight gain. Since alcohol consumption is so common among the college students, it is important that students understand the effect of this compound on their bodies.


    Synthesis and Characterization of ZnO Nanoparticles
    Dustin Auble
    Mentor: Wayne J. Becktel

    Nanoparticles are small clusters of as few as one thousand atoms that function as semiconductors. Zinc oxide (ZnO) nanoparticles of different diameters from 3nm to 10nm are characterized as quantum dots. ZnO nanoparticle properties vary with synthetic methods. Formation occurs in several ways. Differences in solvent, time, and temperature have critical roles in quantum dot formation, affecting the size of the particle, technological use, and absorbance of light resulting in different colors. In the reported experiments, zinc oxide nanoparticles were formed by precipitation according to the following equation: Zn2+ + H2O +2OAc- → ZnO + 2HOAc. The kinetics behind the size of the particles formed was determined by ultraviolet spectroscopy. The radius of the particles was observed to grow with time at a fixed temperature. Observed radii of the particles ranged from roughly from 0.3 nm through 0.9 nm. A Chemistry 101 Lab has been designed around the synthesis of the zinc nanoparticles. Different fluorescent colors of particles were observed by adjusting the concentration of the precipitation conditions. Future experimentation will be carried out to determine if further differences in solvent affect particle size. This work is important in learning more about the characterization of nanoparticles and their formation and uses in modern science and technology.


    Characterization of a Novel Overexpression System in Haloferax volcanii
    Brian Huff, Jenna Hilty
    Mentors: Jens Hemmingsen, Margaret Ginn-Pease

    A novel inducible protein expression system has been developed in the halophilic archaea, Haloferax volcanii (Hvo.). The expression system is based on the histidine utilization (Hut) operon and can be induced by histidine or urocanate, a histidine metabolite. This study characterizes the 88 base promoter region between the gene that encodes a newly discovered Hut regulatory protein (Hut-R) and the first gene in the Hut operon, Hut-U. Plasmids have been constructed that contain the gene for Hut-R, the promoter region, the first three codons of Hut U and the gene for L7ae, an RNA binding protein, used as an expression reporter. The plasmid containing the wildtype promoter yields a high level of inducible gene expression when transformed into Hvo. Two specific mutations have been constructed in the promoter near the Hut U start sequence, deleting either 5 bases (Del 1) or 20 bases (Del 2) immediately upstream of the Hut U start codon. These mutants yield decreased gene expression as measured by Northern and Western analysis. The new system appears to be generally useful for overexpression of halophilic proteins and has the potential for protein overexpression from a variety of halophilic organisms.


    Metal Binding to Riboflavin Binding Protein
    Marissa Snyder
    Mentor: Tracey Murray

    Riboflavin binding protein (RBP) is a protein that is involved in the transportation of riboflavin in avian eggs. Because these eggs contain all of the essential nutrients for development, it is important that the embryo does not receive all of these nutrients at one time. This could result in poisoning of the embryo or deficient amount of nutrients later on in development. Recent studies have shown the binding of copper (II) to RBP in a 1:1 molar ratio after dialyzing the RBP against copper, suggesting that riboflavin transport may not be RBP’s only function. Dialysis of RBP against additional metals was used to test the binding of other divalent anions to RBP. The RBP concentration of the resulting samples was determined using UV-Vis spectrophotometry and the metal concentration was determined using atomic absorbance spectroscopy. Results show the binding of other metals, including zinc, to RBP. These results also suggest that RBP may have another function, such as the transport and storage of essential metals inside the egg.


    Synthesis of Triphenylchloromethane from Triphenylmethanol
    Derrick Ward
    Mentor: Nyenty Arrey

    The synthesis of triphenylchloromethane has been a challenge in years past. The synthetic issue is due to the high stability of the phenyl groups, which contributes to a relatively stable tertiary carbocation intermediate. The basis of the research involves a new approach to the synthetic route of triphenylchloromethane using triphenylmethanol and acetyl chloride as the starting reagents in an inert atmosphere. Due to the molecular properties of the starting reagents, it was believed that a SN1 mechanism would occur followed by the elimination of the hydroxyl functional group. Experimental analysis (FT-IR, H-NMR, Mass Spectroscopy, and MelTemp), confirmed the synthesis of triphenylchloromethane. More importantly, the synthesis of triphenylchloromethane signifies that a SN1 mechanism is possible with organic compounds that exhibit stable carbocation intermediates.