5111
J . Phys. Chem. 1987, 91, 51 11-51 12
+
whether the preequilibration proceeds predominantly via Ni L H F= Ni-LH or via L H F= L 2 Ni-L Ni-LH. Consequently, the authors cannot differentiate between the two limiting cases which they consider. In the end both limiting cases lead to a rate constant for the reaction of Ni2+ with L2- (of DNSA) of k = 3.3 X lo4 M-' s-l (in their notation, k43k35/k34 for the first limiting case and k4, for the second limiting case). This value agrees very well with ours, k l = 3.1 X lo4 M-I s-I for DNSA. For the reaction with HL- results from their evaluation (both This value, too, is consistent limiting cases) k
