Intrazeolitic photoinduced redox reactions between Ru(bpy){sub 3}{sup 2+} and methylviologen

Journal Article · Thu Nov 12 04:00:00 EST 1992 · Journal of Physical Chemistry

DOI:https://doi.org/10.1021/j100202a064· OSTI ID:563417

Dutta, P K; Turbeville, W ^[1]

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1. Ohio State Univ., Columbus, OH (United States)

This study examines the photoinduced redox reactions between Ru(bpy){sub 3}{sup 2+} and methylviologen in the supercages of hydrated zeolite Y. The size of the Ru(bpy){sub 3}{sup 2+} molecules ensures that it is trapped within the supercages, yet it can interact with molecules in the neighboring cages through the 7-{angstrom} ring openings. Methylviologen, on the other hand, can migrate through the zeolite network. Evidence for photoelectron transfer from entrapped Ru(bpy){sub 3}{sup 2+} to methylviologen in neighboring cages is provided by time-resolved resonance Raman spectroscopy. Two pathways are observed for the fate of the transferred electron. Rapid back electron transfer from MV{sup {sm_bullet}+} to Ru(bpy){sub 3}{sup 3+} is observed via a second-order process on the microsecond time scale. A slower process, that occurs on a longer time scale and is observed by steady-state photolysis, leads to charge separation and stabilization of the redox pairs for extended periods. The authors have proposed that as the MV{sup 2+} diffuse through the cages, particular orientations of the molecules are established which lead to electron hopping along adjacent molecules leading to charge separation. The kinetics of this process is also influenced by diffusion of the cocation, necessary to balance the charge as the photoelectron migrates. 28 refs., 10 figs.

• Sponsoring Organization: USDOE
• DOE Contract Number: FG02-90ER14105
• OSTI ID: 563417
• Journal Information: Journal of Physical Chemistry, Journal Name: Journal of Physical Chemistry Journal Issue: 23 Vol. 96; ISSN JPCHAX; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
40 CHEMISTRY
BIPYRIDINES
ELECTRON TRANSFER
PHOTOCHEMICAL REACTIONS
PYRIDYL RADICALS
REDOX REACTIONS
RUTHENIUM COMPOUNDS
SOLAR ENERGY CONVERSION
ZEOLITES