Abstract: The colorless complexes [Cu(py)I], and [Cu(mor)I], (py = pyridine; mor = morpholine) were shown to be
photoluminescent in noncoordinating solvents such as benzene, CH2Cl2, or acetone at room temperature. The red emission
( λmax= 698 nm) of the pyridine complex in benzene is quite intense (φ= 0.04) and decays with a lifetime of τ = 0.9 X
s. The red photoluminescence (λmax= 654 nm) of the morpholine complex is much weaker (φ= 0.004) and decays with τ
= 0.3 X 10” s. It is suggested that the emitting state of both complexes is a metal-centered 3d94s1 excited state of Cu(I),
but this state is strongly modified by copper-copper interaction in the tetramer which consists of a [CUI], cubane core.