Electrochemically synthesised polymers of long, 2-oxaalkyl chain derivatives of 3,4-ethylenedioxythiophene (EDOT) have been studied using in situ EPR spectroelectrochemistry. Originally developed as promising candidates for preparation of soluble PEDOT derivatives, their polymers themselves reveal interesting spectroelectrochemical properties, in some cases even superior to their family's parent. Our results indicate notable differences in potential dependencies of concentration of spins and Delta B-pp width between the two polymers, indicating a major influence of the alkyl side chain length on specific properties of paramagnetic charge carriers appearing in these polymers in the course of their redox processes. Certain features of their spectroscopic response however, like the hysteresis of potential dependence of concentration of spins and Delta B-pp widths, point to similarities of their doping dedoping mechanism with the one of PEDOT. (C) 2009 Elsevier B.V. All rights reserved.