Synthesis of new torands and new uses for old torands

Abstract

Known torands 1 and 2 are preorganized host compounds having macrocyclic perimeters comprised of fully fused rings. Torand 1 was previously found to form strong 1:1 complexes with alkali metal ions. Spectroscopic studies now show that 1 also binds alkaline earth ions, transition metals, heavy metals, lanthanides and actinides. Triaryltri-n-butyl torands (4) have now been synthesized and are attractive precursors to novel materials. Torand 5, an “expanded porphyrin,” has been synthesized by Piloty rearrangement of azines; macrocycle 6 binds Li+ or Mg2+ with tautomerization to the bis(azine) form, producing dramatic UV-visible spectroscopic changes. © 1993 IUPAC