Electron spin resonance study of iron(III) and ruthenium(III) in a trinuclear complex of tris(2-mercaptoethylamine)cobalt(III)

Abstract

The new heteronuclear complexes Rum(CoL3)2X3 (L = 2-mercaptoethylamine( 1 -); X = I~, BPha") have been prepared and characterized and found to be analogous to the previously prepared Fe(III) complexes. A study of the electron spin resonance of these unique Fe(III) and Ru(III) species indicates that they are severely distorted from octahedral geometry, a fact responsible in part for their room-temperature spectra and that substantial metal-metal interaction occurs via direct metal orbital-metal orbital overlap. Ffyperfine structure from two equivalent Co nuclei indicates that the unpaired electron is delocalized over all three metal ions in the complex. A comparison with other systems is given.

PEG-modified Copper Cysteine for Photodynamic Therapy in Alzheimer's Disease

“…As shown in Figure 1e, the XRD pattern of Cu-Cy-PEG showed a very sharp and intense peak which could indicate the high crystallinity of this material. The oxidation state of copper is Cu + instead of Cu 2+ [20,21] . Because this is an entirely new compound, the measured XRD pattern couldn't match any Cu compounds in the current database.…”

Polymer‐Supported Optically Active fac(S)‐Tris(thiotato)rhodium(III) Complex for Sulfur‐Bridging Reaction With Precious Metal Ions

“…Such characteristics of the CD spectra are of great advantage to selective or simultaneous determinations for mixtures of analytes because a change in concentration of one analyte can be detected at λ Δε =0 for the other analytes. Recently, the inherent property of the CD spectra and the optical and chemical properties of the S ‐bridged complexes were applied to the selective and simultaneous CD spectropolarimetric determination of some metal ions using Δ LLL ‐ fac ( S )‐[Rh(L‐cys‐ N , S ) 3 ] 3− and optically resolved Λ ‐[Rh(aet) 3 ] …”

“…[5][6][7][8][9] Since fac(S)-[M(aet) 3 ] exists as a racemic mixture, we successfully carried out the optical resolution of sparingly soluble fac(S)-[Rh(aet) 3 ], 10 which is quite stable compared with the corresponding cobalt(III) complex without decomposition or racemization. The above fac(S)-tris(thiolato) complexes readily form the stable S-bridged linear-type trinuclear complexes with various metal ions such as Cr(III), 11 Fe(III), [12][13][14] Co, (III), 9,[15][16][17][18][19] and Ni(II) [20][21][22] and their optically active isomers, ΔΔ or ΛΛ, exhibit quite strong circular dichroism (CD) spectra attributed to the μ-thiolato sulfur-to-metal charge transfer characteristic of the bridged central metal ions (Fig. 2).…”

“…Recently, the inherent property of the CD spectra and the optical and chemical properties of the S-bridged complexes were applied to the selective and simultaneous CD spectropolarimetric determination of some metal ions using Δ LLL -fac(S)-[Rh(L-cys-N,S) 3 ] 3À and optically resolved Λ-[Rh(aet) 3 ]. [10][11][12][13][14] The above application of the S-bridging reactions are expected to extend to so-called precious metal ions such as gold(III), platinum(II), and palladium(II). Furthermore, if the S-bridged reaction can be performed on the polymersupported fac(S)-tris(thiolato)rhodium(III) complexes, it may be useful for extraction of the precious mete ions into the solid polymer phase.…”

Kinetic Effect of Zinc(II) and Cadmium(II) Ions on Configurational Inversion of ΔLLL-fac(S)-Tris(l-cysteinato-N,S)cobalt(III) Complex

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14] These S-bridged complexes are usually rather stable in solution and their optically active isomers exhibit quite strong circular dichroism (CD) spectral bands attributed to µ-thiolato sulfur-to-metal charge-transfers. While these S-bridged trinuclear complexes exhibit broad intense absorption bands in the whole spectral region characteristic of the S-bridged structure, the CD spectra exhibit positive and negative Cotton effects for each component of the electronic transitions.…”