Emissive Annular Digold(I) Compounds Containing Diphosphine and Dithiolate Ligands

Abstract

AbstractMolecular structures of three emissive annular digold compounds [Au2(dmpm)(dtc)]Cl (dmpm = Me2PCH2PMe2,dtc = S2CNEt2), 1, [Au2(dppm)(dtc)]PF6, (dppm = Ph2PCH2PPh2),2,and [Au2(dppe)(dtc)]‐(PF2) (dppe = Ph2P(CH2)2PPh2), 3, were determined. All three compounds are dimetallacycles having two gold atoms bridged by a dithiolate ligand and a diphosphine ligand, the geometry around each gold atom being almost linear. All the dimetal lacy die rings are slightly distorted from planarity with intramolecular Au‐Au distances shorter than 3.0 Å. Compound 1 forms a polymeric chain through intermolecular Au‐Au contacts (3.061 − 3.135 Å). Compound 2 forms a tetramer through intermolecular Au‐Au interactions (Au‐Au distances ranging from 3.086 to 3.222 ). Compound 3 is monomeric. All of the compounds luminesce at 77 K in the solid state. Emissions originating from 3LMCT from dtc ligand to Au excited states are assigned. The emission maxima of 1 − 3 are at 541,535 and 520 nm respectively and are blue shifted as the number of Au‐Au interactions is decreased.