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I have several areas of interest related to the environment.  Some of the projects, such as the synthesis of Ru-S complexes, involves ongoing research.  Others are ideas I would like to pursue with the appropriate graduate students.  The Ru project is briefly described below:

Organometallic Ruthenium/ Sulfur Complexes: Interest in the synthesis and preparation of new organometallic sulfur compounds stems from the Hydrodesulfurization (HDS) process.  In this industrial process, fossil fuel feedstocks are pretreated with a catalyst in the presence of hydrogen gas at elevated temperatures.  The HDS process converts the fossil fuels into usable hydrocarbons and eliminates hydrogen sulfide as a by-product (see Scheme).  The hydrogen sulifde can be converted to elemental sulfur by the Klaus process.

The HDS process is important for two main reasons:  1) removal of sulfur from the feed stock prevents poisoning of expensive reforming catalysts used later in the refining process and 2) sulfur removal reduces sulfur dioxide emissions which leads eventually to acid rain formation.

Commercially, a sulfided MoCo catalyst is employed due to the economics involved in using platinum metals for large scale catalytic processes.  Ruthenium disulfide is the best catalyst for the removal of sulfur from dibenzothiophene (Chianelli; et al., J. Catal., 1984 86, 226-230).  By studying the interactions of sulfur-containing ligands with a ruthenium metal center, information may be gained on how the catalytic HDS process works.

Our projects focus on the preparation and structural characterization of new organometallic compounds with sulfur ligands.  In conjunction with Prof. Thomas Cundari, University of North Texas, computational studies have been undertaken on the energetics of the ring conformers upon coordination to a metal center.

The importance of coal pretreatment is demonstrated in the DOE'sHealy Clean Coal Project

Other areas of interest:

Catalytic conversion of SO₂ to SO₃.

Synthesis of main group element thiomolybdates - models for support/ catalyst interactions in the HDS process.

Arsenate/arsenite removal from drinking water.

Ice removal by salt - are current methods the best?

Pressure treated wood - safer alternatives to CCA?

Mark Draganjac Department of Chemistry and Physics Arkansas State University State University, AR 72401 Office: (870) 972-3087 ex. 206 Fax: (870) 972-3089 mdraganj@astate.edu

or contact the ASU Environmental Sciences Program

Revised 5/12/03