COMPLEX OF NICKEL (II) ION WITH TRYPTOPHAN AS A HOMOGENEOUS CATALYST IN THE DECOMPOSITION REACTION OF CUMENE HYDROPEROXIDE IN AQUEOUS SOLUTION

Abstract

The formation of Ni²⁺:Tryptophan (Trp) 1:1 complex, which acts as a model catalyst for decomposition of cumene hydroperoxide (ROOH) in Ni²⁺+Trp+ROOH+H₂O system, has been confirmed via kinetic study in aqueous solution at pH>7. The kinetic expression of a single catalytic decomposition reaction of ROOH under the influence of [NiTrp]⁺ complex was brought out. The temperature dependence of the effective rate constant of ROOH decay (K_eff=K_cat[Ni²⁺]₀[Trp]₀=const) in the temperature range from 323 to 343 K can be expressed by Arrhenius equation (E_eff is in kJ/mol): K_eff=(1.87±0.02)·10⁶exp[–(49.8±0.3)/RT], min ^–1.