Hydroxyphenyl substituted tetrathiafulvalene vinylogues affording stable cation radical salts with unusual crystal structures

TTF vinylogues containing hydroxyphenyl groups were newly prepared. They are stronger electron donors than BEDT-TTF and afforded their cation radical salts as single crystals upon electrochemical oxidation. X-Ray structure analysis has revealed their unusual crystal structures, where π-overlapping and hydrogen bonding play a crucial role in constructing them.