Catalytic activities of dismution reactions of Cu(bpy)Br(2) compound and its derivatives as SOD mimics: a theoretical study.

摘要: The systematical investigations on the catalytic mechanisms of dismutation reactions for superoxide dismutase (SOD) mimics Cu(bpy)Br(2) and its derivatives Cu(L(1))Br(2) Cu(L(2))Br(2) (bpy=2,2'- dipyridyl, L(1)=5,5'- di[1- (triethylammonio)methyl]- 2,2'- dipyridyl cation L(2)=5,5'- di [1- (tributylammonio)methyl]- cation) have been carried out by DFT/UB3LYP method. reaction each these compounds is confirmed to be a redox cycle consisting two half-reactions. In first half-reaction, proton transferred from hydroperoxide neutral radical (*OOH) one nitrogen atom pyridinic ring with Cu(II) being reduced Cu(I) in meantime. second back another form hydrogen peroxide molecule, oxidizing initial state. Our results show that half-reaction all rate-controlling step forward barrier values 6.61, 4.84, 3.79 kcal x mol(-1) Cu(bpy)Br(2), Cu(L(1))Br(2), Cu(L(2))Br(2), respectively. Consequently, SOD-like activities three are order < Cu(L(2))Br(2). effect factors activity studied also discussed.