Research Activities
The Department of Chemistry, Geosciences, and Environmental Science at Tarleton State University is fortunate to be the recipient of a Chemistry Departmental Research Grant from The Robert A. Welch Foundation of Houston, Texas. A portion of these funds is used to provide undergraduate students with stipends to assist in this research.
Five faculty members are currently involved in basic chemical research projects sponsored by this grant. They are Dr. Peter Bell (Organic Chemistry), Dr. Stephen Field (Geochemistry), Dr. Arthur Low (Theoretical Chemistry), Dr. Harold Rathburn (Biochemistry), and Dr. Linda Schultz (Inorganic Chemistry).
Recent Research Articles Published or Submitted
A.K. Charlton, R.S. Sevcik, D.A. Tucker, and L.D. Schultz, “A Colorimetric Analysis Experiment Not Requiring a Spectrophotometer: Quantitative Determination of Albumin in Powdered Egg White,” J. Chem. Educ., 84 (2007) 826.
Stephen W. Field, "Diffusion, discontinuous precipitation, metamorphism, and metasomatism: The complex history of South African upper-mantle symplectites”. American Mineralogist, 93, (2008) 618-631.
Richard S. Sevcik, Ragan L. McGinty, Susan V. Alexander, and Linda D. Schultz, “Periodic Table Target: A Game That Introduces the Biological Significance of Chemical Element Periodicity”, J. Chem. Educ., 85 (2008) 514.
Richard S. Sevcik, O’dell Hicks, Susan V. Alexander, and Linda D. Schultz, “Elements -A Card Game of Chemical Names and Symbols”, J. Chem. Educ., 85 (2008) 516.
Perez, Lisa M.; Webster, Charles Edwin; Low, Arthur A.; Hall, Michael B. Theoretical study of the biologically important dioxo diiron diamond core structures. Theoretical Chemistry Accounts (2008), 120(4-6), 467-478.
Richard S. Sevcik, Rex Gamble, Elizabet Martinez, Susan V. Alexander, and Linda D. Schultz, “Ionic Blocks”, J. Chem. Educ. – proofs accepted, will appear in November, 2008.
Peter T. Bell, Alyssa D. Adkins, Rex J. Gamble, and Linda D. Schultz, “Enthalpy Costs of Making and Breaking Bonds: A Game of Generating Molecules with Proper Lewis Structures”, J. Chem. Educ. – revised manuscript submitted.
Regina A. Oliver, Jeremy R. Andreatta, Richard S. Sevcik, Clifford E. Terrel, Laura B. Rogers, and Linda D. Schultz, “An Undergraduate Kinetics Lab Experiment Using the Blue Bottle Demonstration “, J. Chem. Educ. – under review.
Research Presentations Presented by Tarleton State University Welch Undergraduate Scholars in 2003
Jeremy R. Andreatta, J.L. McAfee, and Linda D. Schultz, "Potassium Polytellurides in Nonaqueous Solvents" presented at 225th ACS National Meeting, New Orleans, LA, March 24, 2003.
Research Presentations Presented by Tarleton State University Welch Undergraduate Scholars in 2004
J.R. Andreatta, E.T. Davis, R.A. Oliver, and Linda D. Schultz, "Raman Spectroscopy of Potassium Polytellurides in Nonaqueous Solvents," presented at 227th ACS National Meeting, Anaheim, CA, March 29, 2004.
A.A. Low, "Nature of Metal-metal Bonds in Complexes with p-acid Ligands," presented at 227th ACS National Meeting, Anaheim, CA, March 31, 2004.
R.A. Oliver, J.R. Andreatta, and A. Charlton, "Chemvention: Detecting Increases and Decreases of Oxygen in the Atmosphere," presented at 227th ACS National Meeting, Anaheim, CA, March 29, 2004.
Research Presentations Presented by Tarleton State University Welch Undergraduate Scholars in 2005
A.K. Charlton, R.O. Glenn, J.R. Andreatta, and L.D. Schultz, "The Blue Bottle: New Applications of an Old Demonstration," presented at 229th ACS National Meeting, San Diego, CA, March 14, 2005.
A.A. Low, "Bimetallic Complexes with Bridging p-acid Ligands," presented at 60th Southwest Regional ACS Meeting, Ft. Worth, TX, September 30, 2004.
A.K. Charlton and R.S. Sevcik, "Chemvention: Colorimetric Determination of Albumin in Powdered Egg Whites with Bromophenol Blue," presented at 229th ACS National Meeting, San Diego, CA, March 14, 2005.
A.K Charlton and H.B. Rathburn, "Development of a Purification Scheme for a Trypsin Inhibitor from a Native Texas Legume", presented at 2nd Annual TAMUS Pathways Research Symposium, Texas A&M University--Corpus Christi, TX, October 15-16, 2004.
Research Presentations Presented by Tarleton State University Welch Undergraduate Scholars in 2006
O’dell Hicks and Peter T. Bell, "Abnormal Buffer Region Observed for Silica Attached to 3-aminopropyl-trimethoxysilane," Abatracts of 231st ACS National Meeting, Atlanta, GA, March 27, 2006.
Richard S. Sevcik, Jeremy R. Andreatta, and Linda D. Schultz, "Comparison of Potassium Polytellurides in Liquid Ammonia and Dimethylformamide Solution," Abstracts of 231st ACS National Meeting, Atlanta, GA, March 27, 2006.
O’Dell Hicks, Elizabet Martinez, Ragan L. McGinty, and R.S. Sevcik, "Chemvention: Toys for Chemical Education," Abstracts of 231st ACS National Meeting, Atlanta, GA, March 27, 2006.
Amanda K. Charlton and Harold B. Rathburn, "Development of a Purification Scheme for a Trypsin Inhibitor from a Native Texas Legume", Abstracts of 3rd Annual Texas A&M System Pathways Research Symposium, Texas A&M University-Kingsville, November 4, 2005.
Research Presentations Presented by Tarleton State University Faculty and/or Welch Undergraduate Scholars in 2007
“A Green Quantitative NMR Experiment: Acetone and Ethyl Alcohol in D2O,” Peter T. Bell and Linda D. Schultz, 232nd ACS National Meeting, San Francisco, CA, September 10, 2006.
“Equilibrium Among Potassium Polytellurides in Dimethylformamide Solution,” Richard S. Sevcik, Peter D. Poulsen, and Linda D. Schultz, 62nd ACS Southwest Regional Meeting, Houston, TX, October 20, 2006.
“Analysis of Purity of Common Solvents using Quantitative NMR,” Peter T. Bell, Alyssa D. Adkins, and Linda D. Schultz, 233rd ACS National Meeting, Chicago, IL, March 26, 2007.
“Recycled Paper as a Plywood Component,” Adrian Dunson, O’dell Hicks, Elizabet Martinez, and Ragan McGinty, 233rd ACS National Meeting, Chicago, IL, March 26, 2007. This was a finalist in an American Chemical Society national competition.
Research Presentations Presented by Tarleton State University Faculty and/or Welch Undergraduate Scholars in 2008
“A College Chemistry Lab Experiment Developed from a Classic Demonstration,” Laura B. Rogers, Clifford E.Terrel, and Linda D. Schultz, 5th Annual TAMUS Pathways Student Research Symposium, Tarleton State University, Stephenville, TX, Nov. 3, 2007.
“A Quantitative NMR Experiment: Determination of Solvent Purity,” O’dell Hicks, Peter T. Bell, and Linda D. Schultz, 5th Annual TAMUS Pathways Student Research Symposium, Tarleton State University, Stephenville, TX, Nov. 3, 2007.
“DMSO as an Internal Standard for the Analysis of Solvent Mixtures by qNMR,” Peter T. Bell, O’dell Hicks, Alyssa Adkins, and Linda D. Schultz, 235th ACS National Meeting, New Orleans, LA, April 7, 2008
Michalewicz T, Castaneda J, Laney R, Brady J and Rathburn H. “Analysis of Dehydrin Genes from Fescue.” 235th ACS National Meeting, New Orleans, LA, April 7, 2008
Laney R, Castaneda J, King J, Rathburn H, Mitchell F and J Brady. “Labeling Xylella fastidiosa with autofluorescent proteins.” Texas Pierce's Disease Research Symposium, Driftwood, Texas, April 30, 2008.
Castaneda J, King J, Laney R, Rathburn H, Mitchell F and J Brady. “Multilocus Melt Typing of Xylella fastidiosa subspecies using Real Time PCR.” Texas Pierce's Disease Research Symposium, Driftwood, Texas, April 30, 2008.
Current Chemistry Faculty Research Projects - July 2008
Dr. Peter Bell (Organic Chemistry)
I) Solid Supported O-alkyl isourea: One of our research projects involves the development of a mild, environmentally friendly solid supported medium for alkylation of carboxylic acids to afford esters. This methodology can be extended to alkylation of other suitable species such as amines, sulfur and phosphorous nucleophiles among others
In order to enhance the incorporation levels of ligand attachment to the solid support as well as flow and processing efficiency our group successfully synthesized silicious mesocellular foams (MCF) and reacted it with I as illustrated in scheme 1.
Elemental analysis revealed a modest increase in incorporation levels of the ligand. In addition, the flow properties were much superior to that of silica gel.
Future work will involve attachment of a variety of organic reagents to the MCF solid support matrix and evaluation of the regent’s effectiveness compared to that of the equivalent homogeneous reactions.
II) Quantitative NMR Experiment Development: In conjunction with Dr. Linda Schultz, we have developed and implemented quantitative 1H-NMR experiments to assess the purity/composition of common organic solvents in D2O. Solvents studied include acetone, ethanol, methanol, isopropanol, dimethylformamide, and tetrahydrofuran. The best internal standard studied has been dimethylsulfoxide.
Significant improvements have also been obtained after optimizing the NMR parameters for data acquisition and processing of integral values of solvent peaks.
Dr. Arthur Low (Inorganic/Theoretical Chemistry)
During the summer of 2007, I collaborated with Dr. Tom Cundari of University of North Texas performing solid state theoretical calculations on models of TCNQ complexes of platinum using the Crystal software package.
I have also begun work on a paper involving the dimetallic complexes of cyclopentadienyl metal complexes with bridging nitrosyls and carbonyls. The focus of the paper will be the nature of the direct metal-metal interaction in these complexes using the theory of atoms in molecules (AIM) and difference density plots. I am currently working with an undergraduate student (Owen Howard) on producing the difference density plots.
Publication for the past year:
Perez, Lisa M.; Webster, Charles Edwin; Low, Arthur A.; Hall, Michael B. Theoretical study of the biologically important dioxo diiron diamond core structures. Theoretical Chemistry Accounts (2008), 120(4-6), 467-478.
Dr. Stephen Field (Geochemistry)
This year a research article titled "Diffusion, discontinuous precipitation, metamorphism, and etasomatism: The complex history of South African upper-mantle symplectites was completed. It was published in the Journal American Mineralogist, Volume 93, pages 618-631, 2008.
I am currently writing a research article on a symplectite in an eclogite recovered from the Roberts Victor Mine in South Africa. The paper's title is "A corundum-kyanite-garnet symplectite and the growth of garnet in an aluminous eclogite from the Roberts Victor Kimberlite, South Africa". The paper will be submitted to the Journal "Geology" in September or October of 2008.
Analytical work on Ascension Island peridotites continues. Bulk major and trace element analyses have been completed.
Work on the amphibolite suite from Kimberley, South Africa also continues. Currently, studies are being done on iron, magnesium, and calcium chemical maps showing chemical zonation of the amphiboles in the rock. This work is being done on a scanning electron microprobe at Tarleton State University.
Dr. Harold Rathburn (Biochemistry)
Since Green and Ryan (1972) first suggested a defensive function for trypsin inhibitors (TI) found in plants, a body of evidence has indicated that this relationship does indeed exist. Studies have assayed TI as a component in artificial diets against insect larvae, resulting in reduced larval weight. Transformation of crops with TI genes from other plants has been successful (Hilder et al.,1987; Johnson et al., 1989), favoring the hypothesis of Green and Ryan (1972). Sesbania vesicaria (Jacq.) Ell. (Leguminosae), a legume native to the coastal states, including Texas, has been reported to be toxic to livestock (Kingsbury, 1964). The existence and possible role of TI in Sesbania sp. toxicity has never been explored.
Research completed in my laboratory at Tarleton State University strongly indicates the existence of proteinaceous TI in the seeds of S. vesicaria. Several crude aqueous extracts of S. vesicaria seeds have been prepared by undergraduate students that inhibit 5µg bovine trypsin by 50% in a spectrophotometric assay modified from Houseman et al. (1985).
To further purify the TI, contaminating proteins must be removed from the crude extract by various simple biochemical techniques. Some techniques are more successful than others. Ammonium sulfate precipitation (55% saturation) removes contaminating proteins as does the addition of HCl to pH 4.5. Techniques that result in loss of TI activity are temperatures above 50C and acetone precipitation.
The goal for the next Welch research scholar to work on this project (Benjamin Kaster) will be to accomplish TI purification with ion exchange chromatography employing a DEAE-cellulose matrix.
Poster Presentations in 2007-2008:
Michalewicz T, Castaneda J, Laney R, Brady J and Rathburn H. “Analysis of Dehydrin Genes from Fescue.” 235th ACS National Meeting, New Orleans, LA, April 7, 2008
Laney R, Castaneda J, King J, Rathburn H, Mitchell F and J Brady. “Labeling Xylella fastidiosa with autofluorescent proteins.” Texas Pierce's Disease Research Symposium, Driftwood, Texas, April 30, 2008.
Castaneda J, King J, Laney R, Rathburn H, Mitchell F and J Brady. “Multilocus Melt Typing of Xylella fastidiosa subspecies using Real Time PCR.” Texas Pierce's Disease Research Symposium, Driftwood, Texas, April 30, 2008.
Dr. Linda Schultz (Inorganic Chemistry/Analytical Chemistry)
Research in my lab has involved several different projects, as detailed below.
1) Alkali Metal Polytellurides in Nonaqueous Solvents
A manuscript entitled “Comparison of Potassium Polytellurides in Liquid Ammonia and N,N’-dimethylformamide Solution” by Jason L. McAfee, Jeremy R. Andreatta, Richard S. Sevcik, and Linda D. Schultz is almost complete and will be submitted to Inorganica Chimica Acta this fall. The gist of the article is that the mechanism of reaction of potassium with tellurium in liquid ammonia is different that that in N,N’-dimethylformamide (DMF) because the solvated electron is not present in the latter solvent. Instead, reaction occurs when elemental potassium comes in physical contact with tellurium powder in the solvent as the mixture is stirred, rather than when tellurium reacts with solvated electrons in a sequential process. The monotelluride ion is not measurably soluble in liquid ammonia, but it is soluble in DMF. This factor results in formation of a complex equilibrium mixture of polytelluride species in dimethylformade, which is contrasted with the spectrocsopically identifiable materials formed in liquid ammonia solution.
2) Alkali Metal Polyselenides in Nonaqueous Solvents
This project is an extension of the polytelluride study described above. Several differences have previously been noted in the behavior of sodium polytellurides (Schultz and Koehler, Inorg. Chem., 26, 1987,1989) and sodium polyselenides (Sharp and Koehler, Inorg. Chem., 16, 1977, 2258) in liquid ammonia solution. The highest sodium polyselenide is a hexaselenide, compared to the tritelluride, and polyselenides demonstrate equilibria among the mono-, di- and tri- species which is lacking in the polytellurides in liquid ammonia.
Our initial study of the reaction of potassium and selenium in DMF indicates that the elements react together in DMF in a manner similar to that of the polytellurides described above. The elements cannot combine initially, because potassium floats and selenium sinks to the bottom of the reaction flask. However, as the mixture is stirred, a yellowish color forms, which darkens to a pine green, then progresses to a spinach color. It should be noted that the triselenide is green inl liquid ammonia, the tetratelluride is red, the pentaselenide does not form, and the hexasellenide is reddish brown.,Spectra are shown below.
When the spectra are submitted to peak resolution, the following trends are noted.
Tentative peak assignments are monoselenide - 290 nm, diselenide – 345 nm, triselenide – 461 and 400 nm, and tetraselenide – 400 nm. However, much more study needs to be made of this system.
3) Determination of solvent purity using quantitative NMR (QNMR)
This project is a cooperative effort between myself and Dr. Peter Bell to develop a useful and rapid technique for determining the purity of common solvents, such as acetonitrile, DMF, ethanol, methanol, and tetrahydrofuran (THF). Our initial investigations used acetone and ethanol as internal standards because they are readily available in ultrapure (99.9+%) form, inexpensive, and relatively nontoxic. However, the volatility of these solvents made preparation of stable solutions difficult and resulted in poor reproducibility of results. We are currently investigating dimethylsulfoxide, (DMSO) as an internal standard with promising results and have added isopropyl to our list of solvents studied. While we obtained excellent results (error < 1%) for some solvents, others gave errors in excess of 10%. We have been changing our instrument operating parameters, especially pulse sequence times and number of pulses, and our results are much improved.
Poster presentation: “DMSO as an Internal Standard for the Analysis of Solvent Mixtures by qNMR,” Peter T. Bell, O’dell Hicks, Alyssa Adkins, and Linda D. Schultz, 235th ACS National Meeting, New Orleans, LA, April 7, 2008
4) Submission of Student Projects for Publication to Journal of Chemical Education
Chemical Education is not a research activity directly funded by the Welch Foundation, but student recipients of Welch Undergraduate Research Stipends have participated in the American Chemical Society “Chemvention” competition for the past five years. This is a national competition to solve some chemical problem in an original manner and within a limited budget. The Tarleton State University Student Affiliate Chapter has been a finalist each year, and their submissions have been presented at National ACS Meetings, where they have been very well received, and many attendees encouraged us to develop them into a format suitable for publication in the Journal of Chemical Education. This has been very challenging, as the development of a simple demonstration into an activity suitable for an entire class or lab section is not unlike development a small chemical synthesis into a commercial process.
Because some student participants in the projects were receiving financial support from the Welch Foundation at the time the work was done, Welch Foundation support has been acknowledged for these publications.
This page was last updated on September 24, 2008, by Jared Ross.
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