SQUARE-WAVE VOLTAMMETRY OF 4,4'-DIISOPROPYL-2,2'-BITHIAZOLINE AND ITSCOMPLEX WITH COPPER(II)

(4S)-4'-diisopropyl-2,2'-bithiazoline (DPT) is an electroactive organi c chiral compound giving two reduction responses in square-wave voltam mograms at potentials about -0.2 and -0.4 V by forming a complex with mercury which deposits at the electrode surface. Xy the addition of co pper(rr) ion to the solution of DPT a third peak appears between them at about -0.3 V, which corresponds to the reduction of adsorbed Cu-DPT complex. Optimal pH for the investigation of those redox processes wa s found to be 2.8. By square-wave voltammetric measurements it was int erpreted that these redox reactions were quasireversible with immobili zed reactants. By plotting i(p)/f vs. frequency a quasierversible maxi mum was obtained, and the apparent standard reaction rate constants we re calculated: log (k(s),)(DPT)=(0.91+/-0.9) and 1 < k(s) < 65 s(-1), log (k(s))(CuDPT)=(0.35+/-0.9) and 0.3 < k(s) < 18 s(-1) in 0.55 M NaC l.