ESR of homo- and heteroleptic mono- and dinuclear tris(. alpha. -diimine)ruthenium radical complexes

Journal Article · Wed Jan 03 04:00:00 EST 1990 · Journal of the American Chemical Society; (USA)

DOI:https://doi.org/10.1021/ja00157a028· OSTI ID:6652747

Kaim, W; Ernst, S; Kasack, V ^[1]

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1. Universitaet Stuttgart (West Germany)

A comprehensive ESR study of 11 mononuclear and 5 dinuclear singly reduced tris({alpha}-diimine)ruthenium(II) complexes of the general formulas ((L){sub 3}Ru){sup {sm bullet}+}, ((L)(bpy){sub 2}Ru){sup {sm bullet}+}, and ((bpy){sub 2}Ru({mu}-L)Ru(bpy){sub 2}){sup {sm bullet}3+} (bpy, 2,2{prime},-bipyridine; L, other {alpha}-diimine) shows a variety of g factors and spectral resolution. All paramagnetic species are true anion-radical complexes with little g anisotropy and relatively small but characteristically positive differences g(ligand radical) - g(complex). The variations correlate with the calculated properties of the ligands and with spectroscopic and electrochemical data for the diamagnetic precursor complexes. In particular, the g shifts depend (i) on the extent of metal-ligand interaction and (ii) on the energy differences between the singly occupied and neighboring unoccupied or completely filled orbitals. Virtually complete localization of the unpaired electron on the better {pi}-accepting ligand L has been established for the mono- and dinuclear heteroleptic systems, while fast spin exchange on the ESR time scale is evident from the ESR line width of all singly reduced homoleptic complexes.

• OSTI ID: 6652747
• Journal Information: Journal of the American Chemical Society; (USA), Journal Name: Journal of the American Chemical Society; (USA) Vol. 112:1; ISSN 0002-7863; ISSN JACSA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400102 -- Chemical & Spectral Procedures
400201* -- Chemical & Physicochemical Properties
COMPLEXES
DATA
DATA ANALYSIS
ELECTRON SPIN RESONANCE
EXPERIMENTAL DATA
INFORMATION
LIGANDS
MAGNETIC RESONANCE
MEASURING INSTRUMENTS
MEASURING METHODS
NUMERICAL DATA
RADICALS
RESONANCE
RUTHENIUM COMPLEXES
TRANSITION ELEMENT COMPLEXES