Electrochemical oxidation of some diamine derivatives (1H(+)-411(+)) has been investigated both experimentally and theoretically. Experimental results were obtained using cyclic voltammetry and controlled potential coulometry and the theoretical results were calculated at DFT (B3LYP and BP86) levels of theory and 6-311+G (p,d) basis set. The calculated result indicates that oxidation potential of 1H(+)-4H(+) is directly dependent on the Delta G(tot) and species with more positive oxidation potential (E-pA1) have larger Delta G(tot), values. Also in this paper electrochemical oxidations of N,N-diethyl-p-phenylenediamine (3) were studied in the absence and in the presence of some nucleophiles. Mechanistic study of the electrochemical oxidation of 3 indicates that its electrochemical oxidation proceed in the thermodynamically favored direction. (C) 2015 The Electrochemical Society. All rights reserved.