Professor John Verkade of Iowa State University will investigate "atrane" coordination compounds with support from the Inorganic, Bioinorganic, and Organometallic Program. These are highly symmetrical compounds with polycyclic alkoxide and amide-type ligands. One class of compounds will place the metal center in a C3v environment with an axial amine. The other class will be similar, but with a C2v (quasi-fourfold) environment. Both transition metal and main-group metal centers will be used. The initial studies will focus on synthesis of these interesting species. Verkade will also conduct mechanistic studies of their transmetallations, axial ligand displacements, and other reactions. An unusual technique to be employed will be 119Sn, 51V, and 73Ge NMR spectroscopy. %%% "Atranes" are an interesting class of compounds in which a central metal atom is bound symmetrically to three or four oxygen atoms in a plane, while a nitrogen atom is bound axially. In such compounds the central metal can be systematically varied, as can other features of the molecules. Their high symmetry endows them with high volatility, which provides an unusual mechanism for transporting the central metal atom. The synthesis of such compounds, as well as a study of their reactivity is the subject of the present grant.