Associate Professor, Inorganic Chemistry

B.S. 1991, Indiana University of Pennsylvania
Ph.D. 1996, Purdue University
Postdoctoral: University of Alberta, Los Alamos National Laboratory

Email: ferrence@ilstu.edu
Phone: (309)438-7971
Office: 305 Science Laboratory Building

The chemistry of rare-earth organometallic complexes has undergone a remarkable renaissance over the last two decades. Once viewed as no more than curiosities, they have since demonstrated their critical importance as novel organic reagents and highly active catalysts, and challenged our understanding of bonding through the diverse structures they display. Rare-earth chemistry using cyclopentadienyl (C₅H₅^-, Cp^-) (I) ligands has been at the forefront of this development, as exemplified by numerous examples of trivalent lanthanide complexes comprising two Cp^- ligands and another anionic ligand (II).

My group seeks to expand rare-earth organometallic chemistry in new directions. Since it is anticipated that the reactivities of such non-cyclopentadienyl complexes will be different and novel, they have strong potential impact in influencing organic synthetic methods and catalysis.

The approach involves preparation of new complexes of yttrium, Y, lanthanum, La, and lutetium, Lu (collectively Ln) through variation of the supporting ligand environment. Described below are three independent thrusts, sharing a common foundation, which exemplify the research focus of my group.

1. Modification of ligand donor properties by replacement of two cyclopentadienyl with nitrogen donor ligands such as a series of tetraazaannulenes. Tetra- or octa-methyldibenzotetraazaannulene ligands (Me₄taa^2- and Me₈taa^2-, respectively)(III) will yield (Me_xtaa)LnL complexes (IV).

2. Optimizing ligand binding to metals of variable ionic radius through incorporation of a series of tropocoronand ligands (TC-n) (V) containing variable cavity sizes will yield the series (TC-n)LnL (VI, n=3;VII, n=5).

3. Replacement of two cyclopentadienyl ligands with one sterically tunable hydrotrispyrazolyl-borato (Tp^-) (VIII) ligand will provide availability of two reactive anionic ligands for further chemical transformation. Transformations of such trivalent lanthanide complexes, TpLnL₂, (IX-XI) include aminolysis and hydrogenolysis.

The significance for these thrusts hinges on a systematic investigation of the factors (strength, size, and number of ligands) that will influence the reactivity of these complexes.

SELECTED PUBLICATIONS

Jernigan, F. E. III; Sieracki, N. A.; Taylor, M. T.; Jenkins, A. S.; Engel, S. E.; Rowe, B. W.; Jové, F. A.; Yap, G. P. A.; Papish, E. T.; Ferrence, G. M. "Sterically bulky tris(triazolyl)borate ligands as water-soluble analogues of tris(pyrazolyl)borate," Inorg. Chem. 2007, 46, 360-362. doi:link

Beitelman, A. D.; Sieracki, N. A.; Zeller, M.; Ferrence, G. M. "3,4,5-Trimethyl-1,2,4-triazole trihydrate," Acta Cryst. 2007, E63, o2739-o2741. doi:link

Ferrence, G.M.; Arduengo, A.J. III; Jockisch, A.; Kim, H-J.; McDonald, R.; Takats, J. "Reaction of Tetramethylimidazol-2-ylidene with (Tp^tBu,Me)YbE(thf) (E = I, CH₂SiMe₃): Simple Adduct and a Hydrocarbyl Tethered Carbene Ligand," Journal of Alloys and Compounds 2006, 418, 184-188. doi:link

Squire, M.D.; Davis, R.A.; Chianakas, K.A.; Ferrence, G.M.; Standard, J.M.; Hitchcock, S.R. "Synthesis, X-ray crystallography and computational studies concerning an oxadiazinone derived from D-camphor: a structural limitation of oxadiazinones as chiral auxiliaries," Tetrahedron: Asymmetry 2005, 16, 1047-1053. doi:link

Antunes, M. A.; Ferrence, G. M.; Domingos, Â.; McDonald, R.; Burns, C.J.; Takats, J.; Marques, N. "Uranium (III) scorpionates: synthesis and structure of [(Tp^Me2)₂U{N(C₆H₅)₂}] and [(Tp^Me2)₂U{N(SiMe₃)₂}]," Inorganic Chemistry 2004, 43, 6640-6643. doi:link

Morissette, M.; Haufe, S.; McDonald, R.; Ferrence, G.M.; Takats*, J. "Steric saturation of the ytterbium coordination environment: (Tp^tBu,Me)Yb(OMes), a four coordinate, monomeric, base-free divalent lanthanide complex, its solvation with tetrahydrofuran, and comparison to the β-diketonate complex, (Tp^tBu,Me)Yb(dpm)," Polyhedron 2004, 23, 263-271. doi:link

Colby, D.A.; Ferrence, G.M.; Lash, T.D. "Regioselective oxidative metalation of azuliporphyrins with copper(II) salts: Formation of a porphyrin analogue system with a unique fully conjugated nonaromatic azulene subunit," Angewandte Chemie, Int. Ed. 2004, 43, 1345-1349. doi:link

Hitchcock, S.R.; Casper, D.M.; Vaughn, J.F.; Finefield, J.M.; Ferrence, G.M.; Esken, J.M. "Intramolecular chiral relay at stereogenic nitrogen. Synthesis and application of a new chiral auxiliary derived from (1R,2S)-norephedrine and acetone," Journal of Organic Chemistry 2004, 69, 714-718. doi:link

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