Tetrathiafulvalene-calix[4]pyrrole: a versatile synthetic receptor for electron-deficient planar and spherical guests

Org Biomol Chem. 2019 Mar 6;17(10):2594-2613. doi: 10.1039/c8ob02514b.

Abstract

The first tetrakis-tetrathiafulvalene-calix[4]pyrrole (TTF-C[4]P) was reported in 2004. Early on it and related π-extended TTF-C[4]Ps were found to function as both anion receptors and as hosts for planar electron deficient neutral guests, including nitroaromatic explosives. Anion binding was found to occur with a 1 : 1 binding stoichiometry and to stabilise the cone C[4]P conformation, whereas planar electron deficient guests were bound in a cooperative 1 : 2 fashion to the 1,3-alternate conformer. Addition of strongly complexing anions was found to trigger release of the electron deficient guests concurrent with a conformational change to the cone form. Subsequent studies led to the discovery of anion-induced complexation with C60, and the finding that the resulting complexes would support fast photoinduced electron transfer events. Synthetic advances then led to the preparation of nonsymmetric TTF-C[4]Ps where a single moiety organises the receptor in either the 1,3-alternate conformation or the partial cone conformation, thus modifying both selectivity and sensitivity. TTF-C[4]P-based stimulus responsive systems, that rely on anions and cations as controlling inputs, have also been developed and studied in recent years. This review provides a summary of TTF-C[4]P-related chemistry.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Review

MeSH terms

  • Calixarenes / chemistry*
  • Colorimetry / methods
  • Explosive Agents / analysis
  • Explosive Agents / chemistry
  • Fullerenes / chemistry
  • Molecular Conformation
  • Nitrobenzenes / analysis
  • Nitrobenzenes / chemistry
  • Pyrroles / chemistry*

Substances

  • Explosive Agents
  • Fullerenes
  • Nitrobenzenes
  • Pyrroles
  • Calixarenes