Luminescent silver(I) cluster, synthesis, spectroscopic properties and X-ray crystal structure of [Ag 3CPh) 2(dppm) 3]Cl · 4Et 2O · H 2O {dppm = bis(diphenylphosphino)methane}

Abstract

The [Ag 3(μ 3-η 2-C≡CCPh) 2(dppm) 3] + complex {dppm = bis(diphenylphosphino)methane} was prepared by reacting [(RC≡C)Ag]∞ with dppm in CH 2Cl 2. The X-ray crystal structure of [Ag 3(μ 3-η 2-C≡CPh) 2(dppm) 3]Cl · 4Et 2O · H 2O has been determined. The complex has an isosceles triangular array of Ag atoms and with two asymmetric phenylacetylide caps. The intramolecular Ag (I) ⋯ Ag (I) separations are 2.866(2) and 2.983(1) Å. Extended-Hückel molecular-orbital calculation reveals that the HOMO comprises of contributions from Ag(I) and phenylacetylide whereas the LUMO is largely the π* of phenylacetylide. The complex shows a solid-state emission at 555 nm with a lifetime of 0.4 μs at room temperature.