exo-Methylene-BEDT-TTF and alkene-functionalised BEDT-TTF derivatives: synthesis and radical cation saltsCCDC 1051494-1051496. For crystallographic data in CIF or other electronic format see DOI: 10.1039/c5ra03921e

Hydroxymethyl-BEDT-TTF is converted by tosylation and elimination into exo -methylene-BEDT-TTF whose exocyclic double bond leads to a small increase in the oxidation potential, and from which radical cation salts with perchlorate and triiodide have been prepared, the latter showing semiconductor properties. Allyloxymethyl- and allylthiomethyl-BEDT-TTF, the first BEDT-TTF derivatives with an alkene in the side chain, have been prepared, along with a 1 : 2 radical cation perchlorate salt of the former, an insulator which contains a donor dication. The syntheses of novel BEDT-TTF donors with either an exo -alkene group or a terminal alkene side chain are described along with the crystal structures of their first radical cation salts which include a new semiconductor.