A 2D layer network assembled from an open dendritic silver cluster Cl@Ag11N24 and an N-donor ligand

Abstract

Fruitful efforts have been made for the assembly of nanosized silver clusters, and the majority of which are protected by thiolates and alkynyl ligands. By comparison, the reported silver clusters or silver-cluster-based supramolecular networks protected by N-donor ligands are very rare because of the hard basicity of N-donor ligands with respect to the soft acid Ag(I). Here, by using an N-donor ligand, a 2D Cl@Ag₁₁N₂₄-based supramolecular network [Cl@Ag₁₁(L)₈X₂ ]_n (X = CF₃COO⁻ for 1, NO₃⁻ for 2 and CF₃SO₃⁻ for 3) has been constructed with a Ag–O bond as the linker. This high-nuclearity silver cluster Cl@Ag₁₁N₂₄ has an open dendritic structure with a high coordination ratio of the N atom, which is different from the well-established macrocycle, spheroidal cage and core–shell architectures based on silver–thiolate/alkynyl/phosphine clusters. The stability and assembly process of the 2D network has been studied by high-resolution electrospray mass spectrometry (HR-ESI-MS). Notably, 1 shows an intriguing dual-emission feature that is strongly influenced by different excitation wavelengths and temperatures. Significantly, this work sheds new light on the construction of novel silver clusters and supramolecular networks based on them and provides a kind of luminescent material.