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

Abstract

The [Ag 3(μ 3-η 2-CCPh) 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.