Tetrathiafulvalene quinones, hydroquinones and esters

Article abstract of DOI:10.1016/S0040-4020(01)89885-9

Benzocyclohexa-2,5-diene-1,4-dione-1,3-thiole-2-thione (2) was synthesized starting with 2,3-dichloronapthoquinone (1). Compounds 3 and 4 were also obtained; however, the yield of 2 can be increased through control of the temperature and reaction time. Reaction of 2 with triethylphosphite gave 5 and the tetrathiafulvalene ester 6. The tetrathiafulvalenequinone (9) was obtained by hydrolysis of 6 followed by oxidation of 8. Compound 9 was obtained more directly by hydrogenation of 2 followed by coupling with triethylphosphite and oxidation. Chloranil was used to prepare the dithiafulvene quinone 12 which was reduced, coupled with triethylphosphite to form, presumably, polymer 13. The reactions were repeated using the hexanoic acid esters of the corresponding hydroquinone thiafulvalenes. The crystal structures of 2, 3, 4, 5, 6a and 10 were determined by X-ray diffraction. Cyclic voltammetry studies show the tetrathiafulvalene quinones reduce like quinones, but do not exhibit the oxidation properties of tetrathiafulvalenes.