the second-order reaction rate constant of o2- with the mn ( iii ) porphyrins , which governs the catalytic efficiency of the metalloporphyrins upon the disproportionation of the superoxide radical , was 5.1 x 10 ( 7 ) to 4.0 x 10 ( 5 ) dm3 mol-1 s-1 , depending on the ph and the nature of the metalloporphyrin .
C0032712
porphyrins
C0025541
metalloporphyrin