Synthesis of Some New Electron π-Donors Containing Methoxy Groups

The synthesis of some new electron π-donors carrying four or two methoxy groups is described. The precursor 5,6-dimethoxy-5,6-dihydro[1,3]dithiolo[4,5-b] [1,4]dithiin- 2-thione was synthesized and by coupling reactions the symmetrical 5,6,5’,6’-tetramethoxy-5,6,5’,6’-tetrahydro- [2,2’]bi[[1,3]dithiolo[4,5-b][1,4]dithiinylidene] and unsymmetrical 5,6-dimethoxy-5,6,5’,6’-tetrahydro-[2,2’]bi[[1,3]- dithiolo[4,5-[1,4]dithiinylidene], 2-(5,6-dimethoxy-5,6-dihydro-[ 1,3]dithiolo[4,5-b][1,4]dithiin-2-ylidene)-5,6-dihydro-[ 1,3]dithiolo[4,5-b][1,4]-dioxine and (5,6-dimethoxy- 5,6-dihydro-[1,3]dithiolo[4,5-b][1,4]dithiin-2-ylidene)-6,7- dihydro-5H-[1,3]dithiolo[4,5-b][1,4]dithiepine donors were prepared. They have been characterized spectroscopically and their redox potentials determined using cyclic voltammetry.