Charge ordering state of mixed-valence (TP-EDTT)3(PF6)2

4,5-Ethylenedithio-2-(thiopyran-4-ylidene)-1,3-dithiole (TP-EDTT) and its radical cation salts were prepared. Conventional galvanostatic electrocrystallization gave (TP-EDTT)2SbF6, (TP-EDTT)GaCl4, (TP-EDTT)ReO4, and (TP-EDTT)3(PF6)2. The variation of bond lengths upon the charge of each molecule was examined based on 0, +0.5, and +1.0-charged TP-EDTT molecules. Applying the relationship between the charge and the bond lengths to the donor molecules, (TP-EDTT)3(PF6)2 was proved to be a charge ordering system.