New symmetrical and unsymmetrical tetrathiafulvalene π-donors containing the dithiinoquinoxaline ring system

Abstract

2,3-Dichloroquinoxaline when treated with the multi-sulphur dithiolate (1) gave the thione (2), which was coupled using neat triethyl phosphite to give the bisquinoxalinodithiin-fused tetrathiafulvalene, BQDT-TTF (3). Cross-coupling of thione (2) with 4,5-bis(methylthio)-1,3-dithiole-2-thione and 5,6-dihydro-1,3-dithiol[4,5-b][1,4]dithiin-2-thione afforded the unsymmetrical donors (4) and (5) respectively. The oxidation potentials of donors (4) and (5) are reported along with the preparation and electrical conductivity measurement of a tri-iodide cation-radical salt of BQDT-TTF (3).