Studying divalent ytterbium chemistry as challenging undergraduate research projects


Gregory M. Ferrence,, Kathleen E. Stull,, Kristin V. Geary, Samantha M. Robinson, Anthony K. Hofer,, and Amanda S. Burwell, Department of Chemistry, Illinois State University, Campus Box 4160, Normal, IL 61790-4160
Stable divalent ytterbium complexes of the general formula (TptBu,Me)Yb(OAr)(thf) n (n = 0,1) may be readily prepared using the sterically demanding hydrotris(3-tert-butyl-5-methylpyrazolyl)borate (TptBu,Me) ligand. The aryloxide complexes may be formed from a range of precursors including [(TptBu,Me)Yb(-H)]2; (TptBu,Me)Yb(CH2SiMe3)(thf), (TptBu,Me)YbN(SiMe3)2, and (TptBu,Me)YbI(thf). Currently we are investigating the reactivity of the (TptBu,Me)Yb(OAr)(thf)n complexes and their precursors towards 3,5-disubstituted pyrazoles and 3,5 disubstituted 1,2,4-triazoles. Our investigations have been followed primarily by multinuclear NMR spectroscopy and X-ray crystallography. This research provides challenging research experiences for undergraduate researchers (ugrs) while at the same time investigating chemistry at the cutting-edge of lanthanide coordination chemistry. Beginning ugrs learn the relatively forgiving synthesis protocols for pyrazole, triazole, and pyrazolylborate ligands. Intermediate ugrs learn to manipulate air-sensitive lanthanide complexes as they prepare the known divalent lanthanide precursors. Advanced ugrs learn to successfully prepare and study new, previously unknown, complexes.

General Inorganic Chemistry
9:00 AM-1:00 PM, Sunday, April 6, 2008 Morial Convention Center -- Rm. 219, Oral

Division of Inorganic Chemistry

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008