Single-component molecular conductors based on zinc complexes with filled 3d shells and extended-TTF ligands, [ZnL2] (L = tmdt, dmdt, and dt) were prepared. The crystal structure of semiconducting [Zn(tmdt)(2)] (rho (rt) approximate to 50 Omega cm) was determined by the synchrotron radiation X-ray powder diffraction experiments. The molecule has a tetrahedral geometry and two ligand planes are almost perpendicular to each other.