Self-Assembled Encapsulation of CuX2-(X = Br, Cl) in a Gold Phosphine Box-like Cavity with Metallophilic Au-Cu Interactions

Synthetic routes to the crystallization of two new box-like complexes, [Au6(Triphos)4(CuBr2)](OTf)5 center dot(CH2Cl2)3 center dot(CH3OH)3 center dot (H2O)4 (1) and [Au6(Triphos)4 (CuCl2)](PF6)5 center dot(CH2Cl2)4 (2) (triphos = bis(2-diphenylphosphinoethyl)phenylphosphine), have been developed. The two centrosymmetric cationic complexes have been structurally characterized through single-crystal X-ray diffraction and shown to contain a CuX2- (X = Br or Cl) unit suspended between two Au(I) centers without the involvement of bridging ligands. These colorless crystals display green luminescence (Aem = 527 nm) for (1) and teal luminescence (Aem = 464 nm) for (2). Computational results document the metallophilic interactions that are involved in positioning the Cu(I) center between the two Au(I) ions and in the luminescence.

Automated summary

Synthetic routes to two new box-like complexes, [Au6(Triphos)4(CuBr2)](OTf)5 center dot(CH2Cl2)3 center dot(CH3OH)3 center dot (H2O)4 (1) and [Au6(Triphos)4 (CuCl2)](PF6)5 center dot(CH2Cl2)4 (2), have been developed. Single-crystal X-ray diffraction confirmed that these centrosymmetric cationic complexes contain a CuX2- (X = Br or Cl) unit suspended between two Au(I) centers without any bridging ligands. These colorless crystals exhibit green luminescence (Aem = 527 nm) and teal luminescence (Aem = 464 nm), respectively. Computational analysis revealed the involvement of metallophilic interactions in the positioning of the Cu(I) center between the two Au(I) ions and in the luminescence phenomenon.