The electrochemical properties of the self-assembled monolayers of a tetrathiafulvalenyl-alkane monothiol (1) and the ether-substituted alkane monothiol (1-O) adsorbed onto gold electrodes showed no difference in their redox potentials and surface coverages. In contrast, the difference between the alkyl chain and the oxy-alkyl chain in the redox potentials and surface coverages was found in the self-assembled monolayers and the electropolymerized films of the tetrathiafulvalenyl-tetrathiol (2) and the ether-substituted tetrathiol (2-O) adsorbed onto gold electrodes.