Hierarchical self-assembly of a radical naphthalenediimide-based N-heterocyclic carbene-Au(i) macrocycle

Abstract

Here, we show that a naphthalenediimide skeleton can facilitate the hierarchical assembly of a derived metal N-heterocyclic carbene (NHC) macrocycle into diverse supramolecular architectures. The macrocycle exhibited solvent-dependent supramolecular isomerization, and two polymorphs with different stacking modes grown in DMF and MeCN were obtained. The coprecipitation of the obtained macrocycle and a cuprous bromide anion led to the formation of a tertiary structure. Through the donor–acceptor interactions between the electron-deficient macrocycle and electron-rich pyrene/naphthalene, two cocrystal complexes with different supramolecular systems were successfully fabricated. Moreover, the solid-state structure of the corresponding radical macrocycle unambiguously confirmed the existence of an ordered linear array extending from the discrete mononuclear NHC-Au(I) macrocycle via multiple noncovalent interactions. Such a radical NHC-Au(I) macrocycle can be readily generated upon a one-electron reduction.