Wiktionary
tetrathiafulvalene
n. An organosulfur compound related to the hydrocarbon fulvalene by replacement of four CH (carbon-hydrogen) groups with sulfur atoms.
Wikipedia
Tetrathiafulvalene
Tetrathiafulvalene is an organosulfur compound with the formula (HCSC). Studies on this heterocyclic compound contributed to the development of molecular electronics. TTF is related to the hydrocarbon fulvalene, (CH), by replacement of four CH groups with sulfur atoms. Over 10,000 scientific publications discuss TTF and its derivatives.