A novel pyrazino-fused TSeF donor molecule 1 was synthesized. The donor 1 s
howed two pairs of reversible redox waves (+0.85 and +1.18 V vs. Ag/AgCl in
PhCN). Many cation radical salts containing tetrahedral or octahedral anio
ns showed metallic conducting behavior down to low temperature. Among them,
the BF4- and ClO4- salts have unique donor arrangements, similar to the be
ta " -like structure and 2:1 donor-to-anion composition. These salts are tw
o-dimensional conductors with a strong intermolecular interaction along the
side-by-side direction of the donor molecule.