Synthesis, photophysics, and electrochemistry of hexanuclear silver(I) chalcogenolate complexes. X-Ray crystal structures of [Ag6(μ-dppm)4(μ3-SC6H4Me-p)4](PF6)2 and [Ag6(μ-dppm)4(μ3-SeC6H4Cl-p)4](PF6)2

Abstract

A series of unprecedented hexanuclear silver(I) chalcogenolate complexes with bridging dppm ligands, [Ag₆(μ-dppm)₄(μ₃-EAr)₄](PF₆)₂ (EAr = SPh 1, SC₆H₄Me-p2, SePh 3, SeC₆H₄Cl-p4), have been synthesized and characterized. The X-ray crystal structures of 2 and 4 have been determined. The complexes were found to exhibit luminescence at 77 K and the orange-red emission was tentatively attributed to originate from excited states of an admixture of metal-centred (MC) and metal⋯metal-bond-to-ligand charge-transfer (MMLCT) character. The complexes were also found to exhibit interesting fluxional behaviour in solution and the weak Ag⋯Ag interaction is believed to play an important role in governing their fluxional properties.