A new tetrathiapentalene (TTP) donor 2-(4,5-dimethoxy-1,3-dithiol-2-ylidene)-5-(1,3-dithiol-2-ylidene)-1,3,4, 6-tetrathiapentalene (DMO-TTP) has been synthesized, and the PF6 and AsF6 salts have also been prepared by electrochemical crystallization. X-ray structure analyses have revealed that intermolecular and intramolecular CH center dot center dot center dot O hydrogen bondings are constructed in the neutral crystal and the cation radical salts, respectively. The PF6 and AsF6 salts have a so-called A-type arrangement of the donors and show metallic behavior down to around 10 K.