Design and characterization of ruthenium(II) complexes for advanced photonic applications.

다국어 초록 (Multilingual Abstract)

Polypyridyl ruthenium(II) complexes have found a widespread applicability for a variety of processes and technologies. The unique combination of their physical and chemical properties is valuable for various photon-driven applications. This thesis describes the use of several ruthenium(II) complexes for three diverse areas of photonics research.
The first part describes the properties of a series of ruthenium(II) trisbipyridyl complexes with covalently attached conjugated pyrenyl chromophores. The photophysical behavior of these compounds was contrasted with structurally related model systems. The study revealed that the resulting properties of the pyrene containing complexes were dominated by triplet intra-ligand excited states. These complexes possess structured emission spectra at room temperature and have long luminescence lifetimes, characteristics of the triplet nature of the excited states.
In the second part, the photoluminescence intensity of the ruthenium(II) trisdiphenylphenanthroline chromophore was modulated photochemically using an organic photochromic material. In the described intermolecular system, good luminescence intensity contrast in addition to the excellent switching performance was achieved. The luminescence intensity switching was described in terms of resonance energy transfer theory enhanced by diffusion. Also, for the first time, the new concept of luminescence lifetime binary discrimination for optical memory data storage was demonstrated.
The final chapter illustrates the concept of anti-Stokes delayed fluorescence observed in a metal-organic bichromophore. Upon excitation of the presented compound into the metal-to-ligand charge transfer band, intersystem crossing and energy transfer processes populate the triplet energy level of the appended organic chromophore. Since this triplet has a long lifetime, the efficient mutual annihilation of two organic triplets in fluid solution is possible. This process creates molecules in the excited singlet state that decay radiatively with the emission of a photon, and, moreover, the emitted light is of higher energy than the original excitation light.