Synthesis and properties of dimethoxy-substituted unsymmetrical TTF derivatives

Preparation of a series of unsymmetrical tetrathiafulvalenes substituted with two methoxy groups (2a-f), and their electrochemical properties are described. X-Ray crystal structure analysis of methylenedithio derivative 2c reveals that there are side-by-side S…S contacts shorter than the sum of the van der Waals radii (3.70 å). The TCNQ complex of ethylendithio-2 (2d) and I3 salt of 2c showed low conductivity of 10−5 S cm−1 at room temperature.