The First Tetrathiafulvalene− σ−Polynitrofluorene Diads: Low HOMO−LUMO Gap, Amphoteric Redox Behavior, and Charge Transfer Properties

The synthesis, solution redox behavior, EPR, and intramolecular charge transfer properties of novel donor−acceptor diads of TTF−σ−A type (TTF = substituted tetrathiafulvalene, σ = saturated spacer, A = polynitrofluorene acceptor) are reported. The HOMO−LUMO gap for compound 6 is as small as 0.3 eV, and spectroelectrochemical experiments reveal its electrochromic behavior in the near-IR region.