19F, 1H-HOESY and PGSE NMR studies of neutral trinuclear complexes of AuI and HgII:: Evidence for acid-base stacking in solution

By combining the information from 19F, 1H-HOESY and PGSE NMR methodologies, unprecedented direct evidence has been obtained for the formation of supramolecular assemblies in solution between the trinuclear cyclic AuI basic compounds ([Au(μ-C2,N3-bzim)]3 (bzim = 1-benzylimidazolate), 1, and [Au(μ-C,N-C(OEt) = N-p-C6H4-CH3)]3, 2, on one hand, and the trinuclear cyclic HgII acid complex [Hg(μ-C,C-C6F4)]3, 3, on the other hand. HOESY experiments indicate that a stacking similar to that observed in the solid state occurs. PGSE studies demonstrate the presence of an equilibrium between the free trinuclear entities and adduct A in the case of 2/3 admixtures (see Sketch) while for 1/3 admixtures, adducts A and B are mainly present in solution. Copyright © 2002 American Chemical Society.