Electrochemical behaviour of titanium tetrachloride solutions in 1-butyl-2,3-dimethyl imidazolium azide (BMMImN(3)) at 65 degrees C has been examined. Ti(IV) reduction was studied with chronopotentiometry and cyclic voltammetry methods in melts with different concentrations of TiCl4. According to IR spectra, Ti(IV) exists in form of a hexaazidotitanate complex. The electrochemical reduction of this complex was found to proceed irreversibly to Ti(III) species only. Diffusion coefficients of Ti(IV) in this ionic liquid at temperature 65 degrees C were calculated based on the chronopotentiometry measurements at different TiCl4 concentrations (D-Ti(IV) = 1.3 +/- 0.6 x 10(-6) cm(2) s(-1)). (C) 2007 Elsevier Ltd. All rights reserved.