Kineticresolution of racemic sulphoxides by chiralpoly[N-(1-phenylethyl)iminoalanes](PIA-PHETs) from (+)- or (–)-1-phenylethylamine is described. For p-tolyl mesityl sulphoxide in the temperature range between –25 and +85 °C, optical yields increase with temperature to an upper limit of between 55 and 70 °C, with enantiomeric enrichments up to ca. 75%. It is shown that, among the three molecular