Oxygen-oxygen bond homolysis in a novel titanium(IV) alkylperoxide complex, Cp2Ti(OOtBu)Cl.
Cp2TiCl2 reacts with NaOOtBu to form the new titanium peroxide complex, Cp2Ti(OOtBu)Cl (1), which has been characterized both in solution and in the solid state. This complex is surprisingly unreactive towards olefins and phosphines, as it does not directly transfer an oxygen atom. Instead, decomposition occurs via initial homolysis of the oxygen-oxygen bond, yielding a tert-butoxyl radical. Decomposition of 1 in the presence of phosphines yields either phosphine oxides (e.g., OPPh3) or phosphinites (e.g., tBuOPEt2), products that result from tBuO* + PR3. O-O bond homolysis is surprising because the Ti(IV) center is d0 and cannot be oxidized, where all previous clear examples of homolytic cleavage of metal peroxide complexes are facilitated by oxidation of the metal center.
DiPasquale
Antonio G
AG
Department of Chemistry, Campus Box 351700, University of Washington, Seattle, Washington 98195-1700, USA.
Kaminsky
Werner
W
Mayer
James M
JM
D007700:Kinetics; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry*; D010084:Oxidation-Reduction; D010545:Peroxides / Q000737:chemistry*; D014025:Titanium / Q000737:chemistry*; D020002:tert-Butyl Alcohol / Q000737:chemistry; D020122:tert-Butylhydroperoxide / Q000737:chemistry
D009942:Organometallic Compounds; D010545:Peroxides; C406884:titanocene; D020122:tert-Butylhydroperoxide; D014025:Titanium; D020002:tert-Butyl Alcohol