Gold(i)–carbenes derived from 4-pyridylisocyanide complexes: supramolecular macrocycles supported by hydrogen bonds, and luminescent behavior

Abstract

Monomeric gold(I) carbenes of the type [AuR{C(NR¹R²)(NHPy-4)}] (Py-4 = 4-pyridyl) have been prepared with R = C₆F₅, Fmes (2,4,6-tris(trifluoromethyl)phenyl) by reaction of the corresponding isocyanide compounds [AuR(CNPy-4)] with primary or secondary amines. The single crystal X-ray diffraction structures of [Au(C₆F₅){C(NEt₂)(NHPy-4)}]·OH₂, [Au(Fmes){C(NEt₂)(NHPy-4)}], and [Au(Fmes){C(NHMe)(NHPy-4)}] show that the presence of the NHPy-4 moiety formed induces the formation of supramolecular macrocycles only supported by hydrogen bond interactions, either with N–H groups of other molecules (tetrameric macrocycles), or with water molecules (dimeric macrocycles). Dimeric gold(I) carbenes were also produced using a diamine to form a bridging carbene, or using octafluorobiphenyl to form a Au–C₆F₄–C₆F₄–Au bridge, but the solid state structures of these dimers could not be solved. Most of the complexes herein described display luminescent properties.