2003 - 2005 HEUER Research Fellows Program in the Chemical Sciences for First & Second Year Students

A generous grant from the Russell Pearce and Elizabeth Crimian Heuer Foundation enabled the chemistry department to inaugurate this new summer research opportunity. Fellows will spend 8 weeks working with a faculty mentor carrying out original research. Selected students will receive a stipend, room & board, plus travel to attend National ACS Meeting. There are 2 positions: To apply, first submit a short letter to Dr. Larry French indicating your desire to be considered. Include a list of relevant coruse work you will have completed and some ideas about how chemistry might relate to your longer term educational and professional aspirations. Preliminary application should be received by February 15. The dept will then nominate a group of students to formally apply for the fellowship. At this point you will be asked to speak to potential faculty research mentors and submit a general project plan. A review committee with representatives from the department and the Academic Dean's office will then select the two fellows. (To print out this information separately, click here.)

SUMMER 2005 HEUER FELLOWSHIPS

DNA Binding Studies of Two New Classes of Metal Complexes
Ariel Riezenman, Heuer Fellow; and Dr. S. Glazier, Advisor

Past research has shown that some molecules bind to DNA usually by one or more mechanisms such as electrostatic interactions, groove binding or intercalation.1, 2 Compounds that have the ability to bind specific regions of DNA alter the functionality of DNA in a specific way. Medical applications include pharmaceuticals that inhibit replication, for example, the growth of cancerous cells. The series of complexes shown in figure 1 are of interest because they include transition metal polypyridyl complexes which are water soluble, luminescent, and stable. The ligand is a terpyridinyl derivative capable of forming complexes with ruthenium, cobalt and iron which are referred to as chiral monsters. Employing two different linkers, one rigid and the other flexible, dimers and polymers complexes can be isolated. Dimer complexes have the potential to become irreversibly threaded between DNA base pairs. The binding mechanisms of dimers are not well understood. Viscosity, fluorescence spectroscopy and Uv-Visible absorbance spectroscopy were used to characterize the binding mechanisms and relative binding strengths of compounds from the chiral monster series. From this work we hope to better understand the effects of linker rigidity, type of metal ion and chain length.
The DNA binding potential of the relatively planar and charged copper and manganese based metallacrowns currently being synthesized by Neil Law's group is intriguing, particularly because of the absence of research in this area. Preliminary DNA binding studies suggest a complicated interaction and the need for new experimental methods. Research by Robert F. Pasternack3 and others show that porphyrins, which are structurally similar to metallcrowns, form complexes with DNA and we expect to discover associated behavior for metallcrowns.

Figure 1: Schematic representation of the 2,2':6',2''-terpyridine complexes of ruthenium CM, CD and RCD and the corresponding ligands [ctpy-X-ctpy] and [ctpy-B-ctpy].

(1) Foye, W. O., Ed.; In Cancer Chemotherapeutic Agents; 1995; , pp 698.
(2) Metcalfe, C.; Thomas, J. A. Chem. Soc. Rev. 2003, 32, 215-224.
(3) Pasternack, R. F.; Goldsmith, J. I.; Szep, S.; Gibbs, E. J. Biophys. J. 1998, 75, 1024-1031.

HEUER FELLOWSHIPS RESEARCH REPORT - SUMMER 2004
(click on a title below to view the abstract)

Effects of Aggregation of T-Cell Receptors on the Presence and Insolubility of Lipid Rafts in Human Jurkat T-Cells
Jane W. Mutoru '06 with Dr. N. Marano, Advisor

An Exploratory Study on Agrochemical Cycling on-off SLU Golf Course.
Jonathan French '06 withDr. N. Gao, Advisor

HEUER FELLOWSHIP - SUMMER 2003

Synthesis of Isobenzo Furans and their Epoxide Rearrangements
Joseph Jablonski (Heuer Fellow) and Larry French

Presented at National American Chemical Society Meeting, March 2004, Anaheim CA.

Abstract

A series of phenyl-substituted 1,4-dihydro-1,4-epoxynaphthalenes were produced using Diels-Alder reactions of 1,3-diphenylisobenzofuran and several dienophiles. Epoxidation of these cycloadducts was a prelude to study of their rearrangement chemistry. Through the reaction of diphenyl acetylene as the dienophile, a stable cycloadduct was obtained in 85% yield. Upon epoxidation of the cycloadduct with MCPBA under standard conditions, the presumed epoxide was not isolated. The acidic reaction conditions allowed for it to rearrange via a Grob fragmentation pathway to afford an isochromene in 81% yield. Phase transfer oxidation conditions allowed for the epoxide to be isolated. This product could then be rearranged, although slowly, upon treatment with lithium perchlorate in refluxing toluene. With the other dienophiles studied, the Diels-Alder cycloadducts were unstable and underwent aromatizing ring opening rearrangements

SUMMER STUDENT RESEARCH funded by the Russell Pearce and Elizabeth Crimian Heuer Foundation, 2005
We gratefully acknowledge financial support from the Heuer Fellowship.