Mechanism of anation of chromium (Ⅲ) by L-lysine

摘要

The kinetics of L-lysine anation of aquachromium(Ⅲ) ions have been investigated in the acidity range 5.6 ≤ 10~5[H~+] ≤ 31.6mol dm~(-3). The reaction takes place with outer-sphere association between Cr~(3+)/CrOH~(2+) and H_2L~+ (L = ~+HGCH (~+NH_3)(CO_2~-), G being the side chain) followed by transformation of the outer- into an inner-sphere complex by slow interchange. The results are discussed in relation to the data of analogous systems and it is concluded that anation of [Cr(H_2O)_6]~(3+) follows an I_a path whereas that of [Cr(H_2O)_5OH]~(2+) follows an I_d path.