Effect of NaOH concentration on a sequential phosphazene reaction by phase-transfer catalysis

The effect of NaOH concentration of the substitution reaction of hexachloro cyclotriphosphazene, N3P3Cl6, with phenol was performed to synthesize the p artially substituted (phenoxy) chlorocyclotriphosphazenes, N3P3Cl6-i(OC6H5) (i), i = 1-6 by phase-transfer catalysis (PTC) in an organic phase/alkaline solution. The reaction system was controlled by both chemical kinetics and mass-transfer effects. The relationship between the functions of NaOH in a PTC reaction such as (i) salting out the intermediate product of catalyst QY to the organic phase and (ii) reducing the solvation between the catalys t and water to enhance the reactivity of active catalyst in the organic pha se, and the mass transfer capability of the catalyst between both phases wa s clarified. In addition, the corresponding energies, enthalpies and entrop ies of activation of the series substitution were also estimated. (C) 1998 Elsevier Science Ltd. All rights reserved.