Akademik Veri Yönetim Sistemi
APPLIED CATALYSIS A-GENERAL, cilt.183, sa.2, ss.377-393, 1999 (SCI-Expanded)
Decomposition of 2-isopropylnaphthalenehydroperoxide (2-IPNHP) proceeds through either ionic or radical reaction mechanism. 2-Naphthol and acetone are produced by ionic reactions, however, dimethyl-2-naphthylcarbinol and 2-acetonaphthone productions through radical reactions cannot be avoided because of induced decomposition effects. In this work, we performed the acid-catalysed decomposition of 2-IPNHP for 2-naphthol and acetone production in the presence of eight different solvents and three different acid catalysts. The results were discussed in combination with the ionic reaction mechanism to evaluate the solvent-catalyst interactions. Dodecane, isopropylnaphthalene, propyl acetate, acetone (aprotic solvents of low dielectric constant); acetonitrile, nitrobenzene (NB) (aprotic solvents of high dielectric constant), acetic acid (AcOH) (protogenic solvent) and methyl alcohol (MeOH) (amphiprotic solvent) were used separately with oxyacids HClO4 and H2SO4, and hydroacid KCl. 2-IPNHP decomposition and 2-naphthol production rates increased with increasing dipole moment of aprotic solvents. The highest reaction rates were obtained in the protogenic solvent AcOH and in the aprotic solvent NE where the reactions in the amphiprotic solvent MeOH resulted in the lowest reaction rates. In addition to characters of the solvent and catalyst of the decomposition medium, the composition of the reactant mixture also affected the reaction mechanism and decomposition yield. According to the experimental results, AcOH and HClO4 are the favourable solvent and catalyst for 2-naphthol production, respectively. 61% yield of 2-naphthol was achieved in the presence of AcOH by 0.114 mol dm(-3) HClO4 with the medium concentrations of 1.078 mol dm(-3) 2-IPNHP, 0.222 mol dm(-3) DMNC, 8.680 x 10(-3) mol dm(-3) AN and 0.255 mol dm(-3) H2O2. (C) 1999 Elsevier Science B.V. All rights reserved.