Exchange of Organic Radicals with Organo-Cobalt Complexes Formed in the Living Radical Polymerization of Vinyl Acetate

摘要: Exchange of organic radicals between solution and organo-cobalt complexes is experimentally observed the reaction pathway probed through DFT calculations. Cyanoisopropyl from AIBN (2,2′-azobisisobutyronitrile) enter solutions cobalt(II) tetramesityl porphyrin ((TMP)CoII•, 1) vinyl acetate (VAc) in benzene react to produce transient hydride (TMP)Co−H (•CH(OAc)CH2C(CH3)2CN (R1•)) that proceed on form (TMP)Co−CH(OAc)CH3 (4, Co−R2) (TMP)Co−CH(OAc)CH2C(CH3)2CN (3, Co−R1), respectively. Rate constants for cyanoisopropyl radical addition with hydrogen atom transfer (TMP)CoII• are reported kinetic studies formation transformation species this system. near-degenerate exchanges deduced 1H NMR modeling. computations revealed an unsymmetrical adduct ...