Direct methanol fuel cells (DMFCs) could provide an alternative energy source for mobile applications.  A DMFC uses the energy from the oxidation of methanol to perform work.  Catalytic materials used in DMFCs include platinum or platinum/ruthenium electrodes.  We are interested in the cooperation between platinum and ruthenium atoms in the oxidation of alcohols.  To that end we are synthesizing platinum-rich heterometallic clusters such as the cluster below and investigating their reactivity with alcohols.

We are currently investigating new synthetic routes to clusters with two platinum and one ruthenium atoms related to the cluster above.  Julia Riggs (junior Chemistry major) is also utilizing theoretical studies to investigate the stabilities of possible products in conjunction with Dr. Pounds.  There are opportunities for additional students to work on the synthesis, characterization and investigations of the reactivity of platinum-rich heterometallic complexes.

    Two students have presented posters at the Regional ACS meeting from our work on this project.

“Investigations of a Platinum-Rich Heterometallic Complex”  Riggs, J. C.^*, Dopke, N. C.  American Chemical Society 55^th Southeast Regional Meeting, Undergraduate Poster Session, Atlanta, Georgia, November 2003.

“Synthesis and Characterization of a Platinum-Rich Heterometallic Complex”  Hunter, R. E., Jr.*;  Nash, J.*;  Dopke, N. C.  American Chemical Society 54^th Southeast Regional Meeting, Undergraduate Poster Session, Charleston, South Carolina, November 2002.

    Undergraduate student presenter's names are underlined.  The names of undergraduate students who contributed to the posters are marked with asterisks.

2.  Mass Spectrometry in Education

Mass spectrometry is a widely used technique in research labs.  In the last twenty years soft ionization techniques have been introduced that allow the analysis of intact non-volatile molecules such as proteins or clusters.   One of the particularly successful soft ionization techniques is matrix-assisted laser desorption/ionization (MALDI).  In 2002 a bench-top MALDI time-of-flight mass spectrometer (Bruker Daltonics Omniflex) was installed in Mercer's Department of Chemistry and is being used by students in laboratory classes and for research projects.  This instrument was purchased with funds from a NSF CCLI grant.

Students in the Advanced General Chemistry class use the MALDI to investigate the relationship between isotopes and average mass, and utilize the molecular mass from a MALDI experiment in conjunction with elemental analysis data to determine the formula of a peptide.  Students in Organic Chemistry utilize the MALDI to determine the degree of bromination of a synthesized product.  Students in the Problems in Chemistry laboratory during Spring 2003 utilized the MALDI to investigate aqueous zinc clusters and molybdenum blue solutions.

Students in my lab are developing experiences for biochemistry and advanced labs.  The two most recent projects involve the adaptation and expansion of a published laboratory experience for biochemistry students, and the investigations of plant components with the MALDI.

3.  The Use of MALDI Mass Spectrometry in Inorganic Chemistry

One value of mass spectrometry in inorganic chemistry is its use in synthetic projects.  The usefulness lies in its ability to provide information on either the molecular species or fragments to assist in identification or confirmation of a product.  Only with sufficient data to help define the relationship between mass spectral data and the identity of an analyte can the full potential be realized.  One of the questions that we are addressing concerns the ability to predict ligand loss from inorganic complexes during the MALDI experiment. 

I am currently interested in d⁸ metal complexes with and without phosphines.  Complexes with different phosphine ligands and different metal cations are being investigated under varying conditions.  There are opportunities to participate in this project.

Students interested in conducting research in any of these areas should come talk to Dr. Dopke.  Students who work on any of these projects will learn to independently use the MALDI mass spectrometer.