A chloride-doped Cu18 nanocluster: synthesis, bonding and nonlinear optical properties

Abstract

Atomically precise copper nanoclusters have emerged as an essential class of materials that have found applications in a wide range of fields. However, the design and development of copper cluster nanomaterials are still in their embryonic stages, with most of the focus being on those containing hydride atoms. In this report, we present the discovery of a copper nanocluster doped with other non-metallic atoms, which represents a new and promising type of material. A novel chloride-doped Cu₁₈ cluster, with the chemical composition of [ClCu₁₈(PET)₁₆(PPh₃)₄]⁺ (PET is 2-phenylethanethiol), was synthesized using a one-pot process. The molecular structure of the cluster, as determined by single-crystal X-ray diffraction analysis, reveals the stabilization of the ClCu₆ kernel by a Cu₁₂ cage, which is further passivated by thiolate and phosphine ligands. The cluster exhibits typical optical limiting effects, suggesting that copper nanoclusters doped with non-metallic atoms are a new family of advanced materials in the field of nonlinear optics.