Tetrathiafulvalene derivative precursors, tetrathiafulvalene derivatives, and processes for producing them

A tetrathiafulvalene derivative precursor represented by formula (1), a tetrathiafulvalene derivative represented by formula (6), and processes for producing the tetrathiafulvalene derivative precursor and the tetrathiafulvalene derivative: <IMAGE> (1) <IMAGE> (6) wherein R1 and R2 may be the same or different and represent organic groups that may be linked together to form a ring.