Prof G.B. Deacon, Prof. A.M. Bond, Prof. D.R. MacFarlane, Dr. L. Spiccia and Dr. P.C. Junk

Rare Earths - and Exciting Emerging Chemistry

3 Li Lithium 6.941 4 Be Beryllium 9.012   Group 3 (Rare Earths) 11 Na  Sodium 22.99 12 Mg Magnesium 24.13 19 K Potassium 39.10 20 Ca Calcium 40.08 21 Sc Scandium 44.96 22 Ti Titanium 47.90 37 Rb Rubidium 85.47 38 Sr Strontium 87.62 39 Y Yttrium 88.91 40 Zr Zirconium 91.22 55 Cs Cesium 132.9 56 Ba Barium 137.3 57-71 La-Lu 72 Hf Hafnium 176.5 Figure. 1: Rare Earth Elements and their Place in the Periodic System

Figure 2. Yb2(Odpp)3+ A complex with only bridging donor atoms

Rare earths are a major but neglected Australian resource with large deposits as close as Horsham. In recent years, these elements which are normally hidden in Periodic Tables (Fig. 1) and neglected in text books have begun to hit the headlines with their remarkable chemistry. We are interested in high reactivity rare earth organometallics (Ln-C), organoamides (Ln-NR2) and aryloxides (Ln-OAr), and have developed unique synthetic methods to obtain them (Scheme). These methods may also be developed for Ca, Sr, Ba. Features of these compounds include unusual stereochemistry, low coordination numbers and unusual bonding of groups such as p-Ph....Ln coordination (Fig. 2). To prepare and structurally characterize the compounds represents a major challenge and provides an opportunity to work at a chemical frontier. The program involves extensive international collaboration.

Recent References

C.M. Forsyth and G.B. Deacon. Organometallics , 2000, 19 , 1205-1207.

G.B. Deacon, A. Gitlits, P.W. Roesky, M.K. Bürgstein, B.W. Skelton and A.H. White, Chemistry A European Journal , 2002, 7, 127-138.

P.C. Andrews, G.B. Deacon, C.M. Forsyth and N.M. Scott, Angew. Chem., 2002, 113 , 2166-2169; Angew. Chem., Int. Ed. , 2002, 40 , 2108-2111.