Synthesis of osmium and ruthenium complexes bearing dimethyl (S,S)-2,2′-(pyridine-2,6-diyl)-bis-(4,5-dihydrooxazol-4-carboxylate) ligand and application to catalytic H/D exchange
Kenneth J. H. Young, Kapil S. Lokare, Chin Hin Leung, Mu-Jeng Cheng, Robert J. Nielsen, Nicos A. Petasis, William A. Goddard III, Roy A. Periana
Abstract
Using tridentate, neutral PyBox ligands, several new osmium and ruthenium complexes [M(PyBox)Cl_(2)(C_(2)H_(4)), where M = Ru, Os] have been prepared, all thermally stable. Some of these PyBox compounds are active for C–H activation of benzene. The Os(PyBox)Cl_(2)(C_(2)H_(4) complex was characterized by X-ray diffraction. DFT calculations (B3LYP and M06 including Poisson–Boltzmann solvation) corroborate that the Os/PyBox complex in acetic acid (ΔG‡ = 32.0 kcal/mol) is more reactive for benzene C–H activation than Ru/PyBox in basic conditions (ΔG‡ = 34.8 kcal/mol at pH = 13). The stability of hydroxide- and chloride-bridged dinuclear resting states determines calculated barriers.
Group Members
Young, K. J. H., Lokare, K. S., Leung, C. H., Cheng, M., Nielsen, R. J., Petasis, N. A., III, W. A. G., & Periana, R. A. (2011). Synthesis of osmium and ruthenium complexes bearing dimethyl (S,S)-2,2′-(pyridine-2,6-diyl)-bis-(4,5-dihydrooxazol-4-carboxylate) ligand and application to catalytic H/D exchange. *Journal of Molecular Catalysis A: Chemical*, *339*(1-2), 17-23.