Synthesis and characterization of a nanocluster-based silver(I) tert-butylethynide compound with a large second-harmonic generation response

A new nanocluster-based silver(I) tert-butylethynide compound, namely, (^tBuCCAg)₂(Ag₄SiW₁₂O₄₀)(DMSO)₆ (HT-1), has been synthesized and structurally characterized by X-ray crystallography. The two kinds of nanocluster synthons (a silver aggregate named [(^tBuCC)₂Ag₆(DMSO)₆] and a SiW₁₂ polyoxoanion) are assembled into a three-dimensional coordination network, which has a non-centrosymmetric crystal lattice. Powder second-harmonic generation (SHG) measurements reveal that HT-1 belongs to the phase-matchable class with a moderately strong SHG response of about 3 times that of the KH₂PO₄ (KDP) sample. HT-1 represents the first example of a Ag(I) alkynyl cluster compound with a SHG response. The present study not only extends the application fields of Ag(I) alkynyl clusters but also demonstrates a new paradigm for understanding the Ag(I) alkynyl structural chemistry.