Spectroscopy and physicochemical properties of ruthenium(II) polypyridine complexes in free solutions and entrapped in zeolites

Thesis/Dissertation · Wed Jan 01 04:00:00 EST 1992

OSTI ID:5642910

Maruszewski, K

Ru(II) polypyridine complexes have attracted wide interest in view of their potential utility in solar energy conversion devices. The major goals of this experimental study are: increasing the lifetime of the excited electronic states, eliminating photodegradation and preventing rapid back-electron-transfer processes. To achieve these goals two routes can be followed. One involves modification of coordinated ligands while in the other investigated molecules are incorporated into organized media. Y-zeolites are particularly attractive because their large supercages can accommodate ruthenium tris-polypyridine complexes. Several zeolite-Y-entrapped homo and heteroleptic tris polypyridine complexes of Ru(II) have been synthesized. Several synthetic aspects, peculiar to the intra-zeolite chemistry, have been observed. These include ligand exchange and formation of the zeolite-bound ruthenium species. The electronic absorption and emission spectra of the free and zeolite-entrapped complexes have been obtained. To investigate possible structural alterations in ground and excited electronic states of the entrapped compounds, resonance Raman and time-resolved resonance Raman spectra have been acquired. Excited electronic state lifetimes have been measured and compared with the results for aqueous solutions. While relatively small electronic and structural perturbations are induced by zeolite supercages, substantial modifications of the excited state lifetimes in zeolite matrices have been observed. To investigate mechanisms of the excited state energy dissipation in the Ru(bpy)[sub 3][sup 2+] system the excited state lifetimes of several selectively deuteriated bypyridine analogues were obtained. These results indicate position-dependence of deuteration on the observed lifetimes. The changes in the excited state lifetimes observed upon deuteration of bpy in ru(bpy)[sub 3][sup 2+] were explained in terms of shifts of vibrational frequencies of the critical acceptor mode.

• Research Organization: Marquette Univ., Milwaukee, WI (United States)
• OSTI ID: 5642910
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
140505 -- Solar Energy Conversion-- Photochemical
Photobiological
& Thermochemical Conversion-- (1980-)
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201 -- Chemical & Physicochemical Properties
664200* -- Spectra of Atoms & Molecules & their Interactions with Photons-- (1992-)
74 ATOMIC AND MOLECULAR PHYSICS
ABSORPTION SPECTRA
AZINES
CHEMICAL PREPARATION
CHEMICAL PROPERTIES
COMPLEXES
CONVERSION
ELECTRONIC STRUCTURE
EMISSION SPECTRA
ENERGY CONVERSION
HETEROCYCLIC COMPOUNDS
INORGANIC ION EXCHANGERS
ION EXCHANGE MATERIALS
MATERIALS
MINERALS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHOTOSENSITIVITY
PYRIDINES
RAMAN SPECTRA
RUTHENIUM COMPLEXES
SENSITIVITY
SILICATE MINERALS
SOLAR ENERGY CONVERSION
SPECTRA
SYNTHESIS
TRANSITION ELEMENT COMPLEXES
ZEOLITES