Narrowing the gap: A compactly fused π-conjugated molecule combines a high-lying HOMO with a low-lying LUMO (E_ox - E_red = 0.52 eV) and a fairly low-lying LUMO+1 on the bridging unit, giving rise to strong optical charge transfer transitions. A facile electron transfer has been observed by EPR and NMR spectroscopies.

This work was carried out in the group of Prof. Silvio Decurtins.

References:

• X. Guégano, A. L. Kanibolotsky, C. Blum, S. F. L. Mertens, S.-X. Liu, A. Neels, H. Hagemann, P. J. Skabara, S. Leutwyler, T. Wandlowski, A. Hauser, S. Decurtins;
  "Pronounced Electrochemical Amphotericity of a Fused Donor–Acceptor Compound: A Planar Merge of TTF with a TCNQ-Type Bithienoquinoxaline"
  Chem. Eur. J., 15, 63-66, (2009); doi:10.1002/chem.200802011.