There are several classes of compounds which are able to bind and recognize fullerenes, e.g., covalent or self-assembled macrocycles or molecular tweezers. They usually contain extended π-systems which bind the fullerene. One such system is the butterfly-shaped π-extended tetrathiafulvalene (exTTF). While it has been used in macrocycles, few molecular tweezers with exTTF have been developed.

Sébastien Goeb, Marc Sallé, and colleagues, Université d’Angers, France, have synthesized an exTTF bis-acetylide platinum(II) complex which can be used for C₆₀ recognition. The team prepared monoacetylide exTTF and coupled two equivalents of this alkyne to a square planar 4,4′-di(tert-butyl)-2,2′-bipyridine (dbbpy) platinum(II) complex in a CuI-catalyzed reaction.

The binding abilities of the resulting molecular tweezer for fullerene C₆₀ were measured by UV−vis titration in chlorobenzene. The results show that 1:1 host−guest complexes with high binding constants and good affinities for C₆₀ are formed. According to the researchers, the simple assembly approach of these platinum complexes could lead to new families of molecular tweezers.

• C₆₀ Recognition from Extended Tetrathiafulvalene Bis-acetylide Platinum(II) Complexes,
  Guillaume Bastien, Paul I. Dron, Manon Vincent, David Canevet, Magali Allain, Sébastien Goeb, Marc Sallé,
  Org. Lett. 2016.
  DOI: 10.1021/acs.orglett.6b02915