Pt(bph)(CO)(2), where bph is the biphenyl dianion, displays multiple emission by altering the temperature, solvent, or its state. Emission spectra and emission quantum yields are concentration and excitation wavelength dependent. In dilute 4:1 ethanol/methanol at room temperature, a structured emission at high energy ( approximately 500 nm) occurs, but in the solid state a nonstructured emission centered at ( approximately 750 nm) is found. Between these extremes, two other emissions located at approximately 540 and approximately 650 nm are observed. Emissions from high energy to low energy are attributed to the following: triplet emission centered on the bph ligand, emission from a dimer (exciplex), emission from an aggregate, and emission from "stacked" platinum(II) crystals.