SYNTHESIS OF MACROCYCLIC COMPLEXES OF GOLD(III) BY CONDENSATION OF BIS(ETHYLENEDIAMINE)GOLD(III) CHLORIDE WITH BETA-DIKETONES

Bis(ethylenediamine)gold(III) chloride in aqueous base reacts with a variety of β-diketones via Schiff base condensation to form 14-membered, tetraaza ring, 12π macrocyclic complexes of gold(III). Reaction intermediates in which condensation of only one β-diketone has occurred can be isolated and condensed with a different β-diketone to provide variety in substituents on the macrocyclic ring. Oxidation of (5, 7, 12, 14-tetramethyl-l, 4, 8, ll-tetraazacyclotetradeca-4, 6, 1l, 13-tetraenato)gold(III) hexafluorophosphate, I, with trityl tetrafluoroborate introduces a double bond in one of the five-membered rings. Gold can be removed from macrocycle I by reduction with Zn in aqueous base, and the free ligand so obtained may be used to prepare macrocyclic complexes of other metal ions. No condensation products could be isolated upon treating [Au(en)2]Cl3 in aqueous base with l, l, l, 5, 5, 5-hexafluoropentane-2, 4-dione, 2, 2, 6, 6-tetramethylheptane-3, 5-dione, biacetyl, biguanide, acetone, or 1, 1, 3, 3-tetramethoxypropane. © 1979, American Chemical Society. All rights reserved.