russellp@leland.stanford.edu Graduate Student... Please, no. No longer... I just graduated! Note: He looks happy on the picture :-) Check our forthcoming papers on galacose oxidase models.     Born in 1976, Canadian. B.Sc. (Chemistry), University of British Columbia,  Vancouver, BC, Canada (1998)

Interests in the StackLab: Galactose Oxidase Models

Our goal is to mimic the reactivity of the mononuclear copper enzyme galactose oxidase. This enzyme couples the oxidation of primary alcohols to aldehydes with the reduction of oxygen to hydrogen peroxide, using a single copper atom and a modified tyrosine cofactor as the electron transfer agents for these 2-electron reactions. Our model complexes are based on derivatives of the classic "salen" ligand, taking advantage of the simple and modular synthesis. Small changes in the ligand structure have displayed interesting changes in structural and redox properties in the copper complexes.
We have been able to stabilize and study one-electron oxidized forms of the model complexes, which mimic the oxidized resting state of the enzyme. However, the model complexes have so far only behaved as single-electron oxidants, so that two equivalents are required for the oxidation of a primary alcohol substrate. Part of our current efforts is to create complexes with accessible copper(I) states with the aim of promoting two-electron processes.
 

Publications: (click on the number to get the pdf file)

(5) Mechanistic Insights from Reactions between Copper(II)-Phenoxyl Complexes and Substrates with Activated C-H Bonds
Pratt R.C., Stack T.D.P.
Inorg. Chem. 2005, 44, 7, 2367-2375.

(4) Snapshots of a Metamorphosing Cu(II) Ground State in a Galactose Oxidase-Inspired Complex
Pratt R.C., Mirica L.M., Stack T.D.P.
Inorg. Chem. 2004, 43, 25, 8030-8039.

(3) Intramolecular charge transfer and biomimetic reaction kinetics in galactose oxidase model complexes
Pratt R.C., Stack T.D.P.
J. Am. Chem. Soc. 2003, 125, 29, 8716-8717.

(2) Oxidatively robust monophenolate-copper(II) complexes as potential models of galactose oxidase
Klein Gebbink R.J.M, Watanabe M., Pratt R.C., Stack T.D.P.
Chem. Commun. 2003, 5, 630-631.

(1) Porphyrins incorporating heterocyclic N-oxides: (oxidopyridyl)porphyrins, porphyrin-N-oxides, and a tirapazamine-porphyrin conjugate
Posakony J.J., Pratt R.C., Rettig S.J., James B.R., Skov K.A.
Can. J. Chem. 1999, 77, 2, 182-198.

Oral Presentations:

R.C. Pratt; T.D.P. Stack: "Characterization and reactivity of Cu(II)-phenoxyl complexes: models of galactose oxidase" Oral presentation, CSC Conference 2002, Vancouver, BC.