Dithia-crown-annelated tetrathiafulvalene disulfides: Synthesis, electrochemistry, self-assembled films, and metal ion recognition

The synthesis and electrochemistry of a series of tetrathiafulvalene (TTF) and dithia-crown-TTF derivatives attached with one or two disulfide group(s ) 7a-f are reported. The self-assembled monolayers (SAMs) of these TTF disu lfides on gold were prepared and characterized by reflection-absorption inf rared spectroscopy. The SAMs are extremely stable under a wide variety of c onditions and over extended periods of time and show remarkable electrochem ical stability upon repeated potential scans. SAMs of the crown-TTF disulfi des 7c,d,f can recognize alkali metal ions, and the process can be monitore d following the electrochemical potential shift of the surface-confined TTF group.