New symmetrical tetrathiafulvalene π-donors containing nine- and ten-membered dithiaheterocycles

Abstract

Reactions of disodium 2-thioxo-1,3-dithiole-4,5-dithiolate (DMIT)5 with 1,5-dibromopentane, 1,6-dibromohexane and (±)-1,2-dibromopropane yielded the thiones 6, 7 and 8 respectively in good yields. Coupling of these thiones with triethyl phosphite afforded π-donors 9, 10 and 11 respectively in moderate yields. The π-donors and their precursors have been characterised by elemental analysis, mass spectrometry, UV–VIS, IR and NMR spectroscopy. The oxidation potentials of donors 9, 10 and 11 are reported. Preparation of the charge-transfer complexes of the donors with acceptors TCNQ and CuCl₂ and their solid state conductivity and ESR data is also presented.