On the emission of bis-arylacetylide trinuclear Cu(I) complexes

A combination of computational techniques was used to study the phosphorescent emission of complexes with general formula [Cu3(μ-dppm)3(μ3-η1-C≡CAr)2]BF4, with Ar = aryl. The calculated S0–T1 transition energies are in good agreement with the experimental emission maxima. Natural Transition Orbital analysis of the lowest triplet states indicates that the emission largely originates from a π → π* excitation on one of the two acetylide ligands with only a marginal participation of the trinuclear copper(I) cluster, unlike previously proposed.