Dr. Michael Heinekey, Chemistry Department, University of Washington, is supported by the Inorganic, Bioinorganic, and Organometallic Chemistry Program for studies of the synthesis and reactivity of transition metal hydrides. Synthetic methods will be developed for cationic dihydrogen complexes of iron and ruthenium. These complexes will be studied as models for the active site of hydrogenase. Tris-pyrazolyl and related ligands will be used to stabilize a series of cationic Ir and Rh hydrides that will be used to activate hydrocarbons. Structural and charge dependence of the quantum mechanical proton tunneling that occurs in polyhydride metal complexes will be investigated to increase the mechanistic understanding of the process. A significant portion of the study will involve the study of hydrides into which deuterium or tritium has been incorporated. Tritium nmr will be used to characterize the behavior of some of these systems. Exchange coupling will be developed as a probe of the solvation and ion-pairing that occurs in these systems. The occurrence of partial orientation of dihydrogen complexes in very high magnetic fields will investigated at 17.6 Tesla and these data will be used to determine the H-H distance in the complexes.
Hydrogen molecules may be activated when they interact with metal atoms. This behavior has tremendous utility in laboratory and industrial chemistry to increase the ability of hydrogen to undergo many reactions, including virtually all "hydrogenation" reactions. In another respect, the interactions between hydrogen and metals has become an important topic with the increased interest in hydrogen as a clean fuel. In this project the fundamental ways that hydrogen becomes attached to a metal will be investigated and the details of how hydrogen atoms interchange with each other and interact with the surrounding environment will be determined.
