Abstract
Temperature-jump experiments of the Cu(II)-phenylalanine and Cu(II)-dopa (amino acid end) systems have been interpreted according to the reaction CuL„-i + L ^ CuL„ (k„, forward; k-n, reverse), where L is the anionic form of the ligand and charges have been neglected. The results, at 250 and μ = 0.1 M, are: phenyl- alanine, ki = 1.2 X 109 M~l sec-1, k-\ = 22 sec-1, k2 = 3 X 108 M-1 sec-1, k-i = 30 sec-1; dopa, k\ — 1.1 X 10s M-1 sec-1, k~\ = 8.3 sec-1, k2 = 4.2 X 107 M-1 sec-1, k-¡ = 22 sec-1. The dissociative, water-loss mechanism appears to be operative, although the hydroxyl groups of the dopa may have a misorienting effect on this ligand’s reactivity.