Intramolecular excimers based on rigidly-linked platinum(II) complexes: intense deep-red triplet luminescence in solution.

By linking together two cyclometallated, N--C--N-coordinated platinum(II) complexes through a xanthene core, intense luminescence in the red region of the spectrum is achieved in solution at room temperature (lamda max = 690 nm, phi(lum) = 0.20, tau = 1.7 micros in CH2Cl2) due to the efficient formation of an intramolecular excimer.