Acid-catalysed decomposition of 2-isopropylnaphthalene hydroperoxide (2-IPNHP), which is of industrial importance for the productions of 2-naphthol and acetone Simultaneously, proceeds through a complex ionic reaction mechanism. Since two steps of the ionic reactions in series are nucleophilic reactions, the presence, character and concentration of nucleophile reagents in the decomposition reaction medium are important. In the present study, the effects of the neutral oxygen nucleophiles: H2O2, water, 2-IPNHP and dimethyl-2-naphthylcarbinol (DMNQ were investigated. 2-IPNHP is the reactant of the process, water is another reactant of the nucleophilic addition reaction, DMNC is the by-product of the preceding 2-IPNHP production process and H2O2 is initially added into the medium to oxidise the DMNC to 2-IPNHP. Among the neutral oxygen nucleophiles, H2O2, water and DMNC decreased, but 2-IPNHP increased the production rate of 2-naphthol in accordance with the mechanism and with the following descending order of the strength of nucleophiles: DMNC > 2-IPNHP > H2O2 > water. The influence of nucleophile characters of aprotic solvents of low dielectric constant (propyl acetate and acetone), aprotic solvents of high-dielectric constant (acetonitrile and nitrobenzene), protogenic solvent (acetic acid) and amphiprotic solvent (methyl alcohol) on the 2-IPNHP decomposition were also discussed in the paper. (c) 2005 Elsevier B.V. All rights reserved.