Kinetic Study of the Catalyzed Substitution Reaction of Benzal Chloride and Sodium Iodide in Acetone

Abstract

AbstractThe substitution reaction of benzal chloride (PhCHCl2) and sodium iodide in acetone needs a metal‐ion catalyst. Without considering the effects of solubility and the dissociation of salt, salts of Cr(III), Mn(II), Fe(II, III), Co(II), Ni(II), Cu(II)m Zn(II), Cd(II), Hg(I, II), and Sb(III) ions are used to study their catalytic reactivities. It is found that the Fe(II) ion exhibits acceptable catalytic effect. The overall Fe(II)‐catalyzed PhCHCl2‐NaI reaction can be described by the following competitive consecutive scheme: PhCHCl2 → PhCHCII → PhCHI2. Under suitable conditions, coupling products such as PhCH=CHPh and PhCHClCHClPh are also found. The rate of the first‐stage substitution of the PhCHCl2‐NaI reaction increases linearly with the PhCHCl2 concentration. It increases asymptotically with the FeCl2 concentration. However, there is an optimum concentration for Nal. The apparent activation energies are 104 ± 4 kJ/mol and 133 ± 4 kJ/mol for the Fe(II)‐catalyzed PhCHCl2‐NaI and PhCHCH‐NaI reactions, respectively.