Ruthenium tris chelates with O,S-siderophores: synthesis, oxidation state, and electronic structure

Journal Article · Wed Sep 25 00:00:00 EDT 1985 · Inorg. Chem.; (United States)

DOI:https://doi.org/10.1021/ic00214a027· OSTI ID:5981049

Bhattacharya, S; Ghosh, P; Chakravorty, A

N-methylthiohydroxamic acids (RC(S)N(OH)Me), abbreviated HmeR (R = pH, p-C/sub 6/H/sub 4/OMe, CH/sub 2/Ph), react with RuCl/sub 3/ x 3H/sub 2/O in aqueous ethanol affording the green tris chelates Ru/sup III/(meR)/sub 3/. Cerium(IV) oxidation of these complexes in perchlorate media furnishes reddish pink Ru/sup IV/ (meR)/sub 3/ClO/sub 4/ x H/sub 2/O. The ruthenium(IV)-ruthenium(III) formal potential (E/sup 0//sub 298/) determined cyclic voltammetrically is approx. 0.4 V vs SCE. E/sub 298//sup 0/ of the ruthenium(III)-ruthenium(II) couple is approx. -1.0 V. Both redox couples are nearly reversible, suggesting the same gross stereochemistry for the three oxidation states. On the basis of comparative X-ray powder and IR data it is concluded that Ru(meR)/sub 3/ has facial stereochemistry. The Ru(meR)/sub 3/ complexes are low spin (S = 1/2; t/sub 2//sup 5/) and have rhombic EPR spectra. The EPR spectrum of Ru(ph)/sub 3//sup 3 -/ is rhombic but the three g values are closely spaced near 2 compatible with large net distortion. Two descriptions, viz. the ruthenium(IV)-stabilized ligand radical complex Ru/sup IV/(ph)/sub 2/(ph.)/sup -/ and the ruthenium(V) complex Ru/sup V/(ph)/sub 3//sup -/, are examined. The EPR spectrum is not incompatible with either description, but the Ru/sup v/(ph)/sub 3//sup -/ description has more favorable features. The thiohydroximate ligand appears to be able to span all oxidation states of ruthenium from +2 to +5. 58 references, 4 figures, 5 tables.

• Research Organization: Indian Association for the Cultivation of Science, Calcutta
• OSTI ID: 5981049
• Journal Information: Inorg. Chem.; (United States), Vol. 24:20
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
OXYGEN COMPLEXES
CHEMICAL PREPARATION
ELECTRONIC STRUCTURE
REDOX REACTIONS
STEREOCHEMISTRY
VALENCE
RUTHENIUM COMPLEXES
SULFUR COMPLEXES
CHELATES
EXPERIMENTAL DATA
LIGANDS
RADICALS
CHEMICAL REACTIONS
COMPLEXES
DATA
INFORMATION
NUMERICAL DATA
SYNTHESIS
TRANSITION ELEMENT COMPLEXES
400301* - Organic Chemistry- Chemical & Physicochemical Properties- (-1987)