Redox-state-dependent preferential solvation of ruthenium(II) and ruthenium(III) ammine complexes. Implications for electron-transfer processes in mixed solvents

Journal Article · Wed Aug 12 04:00:00 EDT 1987 · Inorg. Chem.; (United States)

DOI:https://doi.org/10.1021/ic00263a022· OSTI ID:5648585

Ennix, K S; McMahon, P T; de la Rosa, R; Curtis, J C

Preferential solvation of the asymmetric binuclear complex (bpy)/sub 2/Ru/sup II/Cl(pyz)Ru/sup II/III/(NH/sub 3/)/sub 4/py/sup 3+/4+/ by Me/sub 2/SO in acetonitrile has been studied via UV-vis, near-IR, and electrochemical techniques. It is found that the strong donor Me/sub 2/SO preferentially solvates the mixed-valence 4+ form of the dimer to a greater degree than the fully reduced 3+ form due to the relatively higher Lewis acidity of the ammine protons when coordinated to Ru(III). As one index of this, the equisolvation point of the II,II dimer is found at chi/sub Me2SO/ = 0.104 whereas that for the II,III form is at chi/sub Me2SO/ = 0.003. The degree of solvent re-sorting that must occur upon a change in redox state at the ruthenium ammine moiety as a function of chi/sub Me2SO/ is quantified and found to go through a maximum at chi/sub Me2SO/ approx. = 0.019. It is concluded that a solvent trapping barrier arising from nonequilibrium preferential solvation must be considered in situations involving electron-transfer processes of preferentially solvated solutes.

• Research Organization: Univ. of San Francisco, CA
• OSTI ID: 5648585
• Journal Information: Inorg. Chem.; (United States), Journal Name: Inorg. Chem.; (United States) Vol. 26:16; ISSN INOCA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
400400 -- Electrochemistry
ACETONITRILE
AMMINES
CHEMICAL REACTIONS
CHEMISTRY
COMPLEXES
DATA
ELECTROCHEMISTRY
ELECTRON TRANSFER
ELEMENTS
EXPERIMENTAL DATA
INFORMATION
INFRARED SPECTRA
METALS
NITRILES
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PLATINUM METALS
REDOX REACTIONS
RUTHENIUM
RUTHENIUM COMPLEXES
SOLVATION
SOLVENT PROPERTIES
SPECTRA
TRANSITION ELEMENT COMPLEXES
TRANSITION ELEMENTS
ULTRAVIOLET SPECTRA
VISIBLE SPECTRA