Thermally Stable Homogeneous Catalysts for Alkane Dehydrogenation S.O. thanks the German Academic Exchange Service (DAAD) for financing a research stay with W.C.K. in the USA. This work was supported by the National Science Foundation (CHE 9800184 to M.B.H.), by the University of California Energy Institute and University of California Santa Barbara (to W.C.K.), and by the German Research Association (DFG, to M.W.H). We thank Dr. R. Mynott and Mrs. C. Wirtz, MPI für Kohlenforschung, for NMR spectroscopic investigations.