Due to their square-planar geometry, platinum(II) complexes demonstrate an extraordinary and unique photophysical behavior. The photophysical properties of monometallic platinum(II) complexes depend on the concentration, while in bimetallic platinum(II) complexes they depend on the distance between the metal centers. In this study we reveal a correlation between the electronic and photophysical properties of monomeric monometallic platinum(II) complexes and their aggregates with the corresponding bimetallic complexes.