ЖУРНАЛ ФИЗИЧЕСКОЙ ХИМИИ, 2009, том 83, № 9, с. 1747–1752 1747 INTRODUCTION Pushpull alkenes are defined as substituted olefins containing one or two electrondonating substituents (D) on one end of a C=C double bond and one or two electronaccepting substituents (A) at the other end. Electronic D–A interactions via the C=C bond result in a polarization of the “pushpull” system [l]. Conse quently, an increase of the pushpull character is asso ciated with a decrease of the πbond character of the polarized C=C bond. In turn, the corresponding π bond orders of the C–D and C–A bonds are in creased. The pushpull effect has major impact on both, the dynamic behavior and the chemical reactiv ity of these compounds: Stereodefined 2alkylidene4oxothiazolidines (1), which have been previously characterized by 1 H NMR, 13 C NMR, IR, UV, MS spectroscopy and Xray structural analysis [2], exemplify typical push S N H R O EWG H (1) EWG = COPh, CONHPh, CN R = Me, CH 2 CO 2 Et, H, =CHCO 2 Et pull compounds. They exist in different configuration al and conformational forms. One of the characteristic processes of pushpull alkenes 1, based on a lowering of the rotational barrier of the C=C bond at the C2 posi tion, is configurational isomerization which can be followed, under proper experimental conditions, by dynamic 1 H NMR spectroscopy [3]. Herein, we report an extension of our study on electrochemical behavior of pushpull alkenes, that is the functionalized 4oxothiazolidine 1a (R: =CHCO 2 Et; EWG: CONHPh), having two exocyclic C=C bonds at C2 and C5 positions. In addition, the configurational isomerization at the C2 double bond, occurring during the electrochemical reduction in wet DMSO, has been examined. EXPERIMENTAL Cyclic voltammetry (CV) experiments were per formed on a VOLTALAB40 electrochemical device using thermostated onecompartment electrolytic cell with stationary PtEDI 101 of 2 mm diameter as work ing electrode, Pt counter electrode and Agquasi refer ence electrode. Tetranbutylammonium hexafluoro phosphate (TBAHFP) 0.1M was employed as support ing electrolyte. The solution in the electrochemical cell was deaerated with highpurity Ar before starting the CV experiments and an atmosphere of Ar was main tained over the solution in the cell during measure COLLOID CHEMISTRY AND ELECTROCHEMISTRY CYCLIC VOLTAMMETRY STUDY OF (5ETHOXYCARBONYLMETHYLIDENE4OXOTHIAZOLIDIN2 YLIDENE)NPHENYLETHANAMIDE © 2009 I. Ceki Laskovi * , **, D. M. Mini * , **, M. BaranacStojanovi ** , ***, R. Markovi ** , ***, E. Volanschi**** *Faculty of Physical Chemistry, University of Belgrade, Studentski trg 12, Belgrade, Serbia **Center for Chemistry ICTM, P.O. Box 473, 11001 Belgrade, Serbia ***Faculty of Chemistry, University of Belgrade, Studentski trg 16, 11001 Belgrade, Serbia ****Department of Physical Chemistry, University of Bucharest, Blvd Elisabeta 412, RO030018, Bucharest, Romania Abstract – As a continuation of our ongoing project on electrochemical properties of pushpull 5substituted 2alkylidene4oxodiiazolidines (1a), differing in substituent R at C5position and electron withdrawing group (EWG), we have investigated the electrochemical behaviour of (5etoxycarbonylmethylidene4 oxothiazolidin2ylidene)Nphenylethanamide 1a (R: =CHCO 2 Et; EWG: CONHPh), consisting as a (2E, 5Z)/(2Z, 5Z) mixture, by cyclic voltammetry in polar as well as nonpolar solvent (0.1 M TBAHFP in DMSO and CHCl 3 , respectively). Cyclic voltammetry at stationary electrode was employed to characterize the ele clron transfer steps. Based on electrochemical criteria and correlation with the DigiSim simulations, an ECE mechanism, involving two electrochemical steps and one isomerisation step, was suggested. c  c  c  c  c  УДК 541.13 10*