Heterolytic CH Activation with a Cyclometalated Platinum(II) 6-Phenyl-4,4'-di-tert-butyl-2,2-Bipyridine Complex
Kenneth J. H. Young, Steven K. Meier, Jason M. Gonzales, Jonas Oxgaard, William A. Goddard III, Roy A. Periana
Abstract
The more electron-rich, thermally, air, and protic stable, cyclometalated Pt(II)(NNC) trifluoroacetate complex (3) (NNC = κ^3-6-phenyl-4,4'-di-tert-butyl-2,2'-bipyridine) was synthesized with the expectation that it would be less susceptible to H_2O inhibition than the Pt(bpym)(TFA)_2 system (bpym = κ^2-2,2'-bipyrimidine) for the catalytic oxidation of hydrocarbons. Complex 3 was found to catalyze the H/D exchange between benzene and trifluoroacetic acid via CH activation but at a rate slower than the Pt(bpym) complex. Experimental and theoretical studies show that while the use of the more electron-rich NNC ligand motif lowered the ΔH for substrate coordination relative to the Pt(bpym) system, a larger increase in the barrier for CH cleavage led to an increase in the overall barrier for CH activation.
Group Members
Young, K. J. H., Meier, S. K., Gonzales, J. M., Oxgaard, J., III, W. A. G., & Periana, R. A. (2006). Heterolytic CH Activation with a Cyclometalated Platinum(II) 6-Phenyl-4,4'-di-tert-butyl-2,2-Bipyridine Complex. *Organometallics*, *25*(20), 4734-4737.