Cage escape yields in the quenching of *Ru(bpy) sub 3 sup 2+ by methylviologen. Presence of triethanolamine as a sacrificial electron donor

Journal Article · Thu Oct 03 04:00:00 EDT 1991 · Journal of Physical Chemistry; (United States)

DOI:https://doi.org/10.1021/j100173a031· OSTI ID:7273656

Georgopoulos, M; Hoffman, M Z ^[1]

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1. Boston Univ., MA (United States)

Continuous and pulsed laser flash photolysis techniques have been used to determine the efficiency ({eta}{sub cd}) with which the redox products are released into the bulk upon the oxidative quenching of *Ru(bpy){sub 3}{sup 2+} by MV{sup 2+} in the absence and presence of TEOA as a sacrificial electron donor in aqueous solution. The value of {eta}{sub ce} is diminished as the ionic strength ({mu}) of the solution increases, although the extent of the effect depends on whether or not TEOA is present: in the absence of TEOA, {eta}{sub ce} = (3.8 + 4.8{mu}{sup 1/2}){sup {minus}1}; in the presence of 0.1 M TEOA in alkaline solution, {eta}{sub ce} = (3.8 + 9.0{mu}{sup 1/2}){sup {minus}1}. TEOA is an effective scavenger of Ru(bpy){sub 3}{sup 3+} at concentrations {ge} 0.05 M and in the pH 8.5-11.5 range. In less alkaline solution, its protonation diminishes its reducing ability; in more alkaline solution, reactions between its degradation products and MV{sup 2+} yield additional equivalents of MV{sm bullet}{sup +}. The value of {eta}{sub ce} is also a function of (Ru(bpy){sub 3}{sup 2+}) with a transition at 20-50 {mu}M between upper and lower plateau values.

• OSTI ID: 7273656
• Journal Information: Journal of Physical Chemistry; (United States), Journal Name: Journal of Physical Chemistry; (United States) Vol. 95:20; ISSN 0022-3654; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400400* -- Electrochemistry
400500 -- Photochemistry
AMINES
AQUEOUS SOLUTIONS
AZINES
BINDING ENERGY
BIPYRIDINES
CATIONS
CHARGED PARTICLES
CHEMICAL REACTIONS
COMPLEXES
DATA
DECOMPOSITION
DISPERSIONS
ELECTROLYTES
ELECTROMAGNETIC RADIATION
ELECTRONS
ELEMENTARY PARTICLES
ENERGY
ENERGY LEVELS
EXCITED STATES
EXPERIMENTAL DATA
FERMIONS
HETEROCYCLIC COMPOUNDS
INFORMATION
IONS
LASER RADIATION
LEPTONS
MIXTURES
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PH VALUE
PHOTOCHEMICAL REACTIONS
PHOTOLYSIS
PYRIDINES
QUENCHING
RADIATIONS
REDOX REACTIONS
REDUCTION
RUTHENIUM COMPLEXES
SOLUTIONS
TRANSITION ELEMENT COMPLEXES
VALENCE