Coordinated o‐Dithio‐ and o‐Iminothiobenzosemiquinonate(1−) π Radicals in [MII(bpy)(L.)](PF6) Complexes

Ghosh, Prasanta; Begum, Ameerunisha; Herebian, Diran; Bothe, Eberhard; Hildenbrand, Knut; Weyhermüller, Thomas; Wieghardt, Karl

doi:10.1002/anie.200390162

Cited by 97 publications

(78 citation statements)

References 19 publications

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“…Delocalized π bonds are characterized for the aromatic ring of a catecholato dianion and a quinoid‐type pattern with localized π bonds is found in semiquinonato radicals 5c. 28d, 37 Another criterion is based on the specific values of the C4C5 bond length, which depends on the oxidation state of the catechol ligand (1.369–1.400 Å, for L = Cat 2− and 1.383–1.446 Å for L = SQ . − ).…”

Section: Resultsmentioning

confidence: 99%

Electronic, Vibrational, and Structural Properties of a Spin‐Crossover Catecholato–Iron System in the Solid State: Theoretical Study of the Electronic Nature of the Doublet and Sextet States

Simaan

Boillot

Carrasco

et al. 2005

Chemistry A European J

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As a functional model of the catechol dioxygenases, [(TPA)Fe(Cat)]BPh4 (TPA = tris(2-pyridylmethyl)amine and Cat = catecholate dianion) exhibits the purple-blue coloration indicative of some charge transfer within the ground state. In contrast to a number of high-spin bioinspired systems, it was previously shown that, in the solid state, [(TPA)Fe(Cat)]BPh4 undergoes a two-step S = 1/2 = S = 5/2 spin-crossover. Therefore, the electronic and vibrational characteristics of this compound were investigated in the solid state by UV/Vis absorption and resonance Raman spectroscopies over the temperature range of the transition. This allowed the charge-transfer transitions of the low-spin (LS) form to be identified. In addition, the vibrational progression observed in the NIR absorption of the LS form was assigned to a five-membered chelate ring mode. The X-ray crystal structure solved at two different temperatures, shows the presence of highly distorted pseudo-octahedral ferric complexes that occupy two nonequivalent crystalline sites. The variation of the molecular parameters as a function of temperature strongly suggests that the two-step transition proceeds by a successive transition of the species in the two nonequivalent sites. The thermal dependence of the high-spin fraction of metal ions determined by Mössbauer experiments is consistent with the magnetic data, except for slight deviations in the high temperature range. The optimized geometries, the electronic transitions, vibrational frequencies, and thermodynamic functions were calculated with the B3LYP density functional method for the doublet and the sextet states. The finding of a ground state that possesses a significant mixture of Fe(III)-catecholate and FeII-semiquinonate configurations is discussed with regard to the set of experimental and theoretical data.

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Section: Resultsmentioning

confidence: 99%

Electronic, Vibrational, and Structural Properties of a Spin‐Crossover Catecholato–Iron System in the Solid State: Theoretical Study of the Electronic Nature of the Doublet and Sextet States

Simaan

Boillot

Carrasco

et al. 2005

Chemistry A European J

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“…For example, the existence of S,S-coordinated o-dithiobenzosemiquinonate radical anions (rather than aromatic doublycharged dithiolate anions) has been proposed for many complexes, 65,66 but this fact has not been supported by experimental evidence. Later on, the presence of such radicals was confirmed for the paramagnetic square-planar [Pd(bipy)(L Bu )] + complex (where L Bu is 3,5-di-tert-butylbenzene-1,2-dithiol) 67 by UV-Vis and ESR spectroscopy.…”

Section: Complexes Of O-benzenedithiols and Their Deprotonated And Oxmentioning

confidence: 95%

Metal complexes with non-innocent ligands

Butin¹,

Белоглазкина²,

Зык³

2005

Russ. Chem. Rev.

123

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The review summarises data on transition metal com-The review summarises data on transition metal complexes with the so-called non-innocent ligands. The specific plexes with the so-called non-innocent ligands. The specific feature of these complexes is that the oxidation state of the central feature of these complexes is that the oxidation state of the central metal atom and the electronic structure of the ligands are metal atom and the electronic structure of the ligands are impossible to determine impossible to determine a priori a priori and unambiguously. The results and unambiguously. The results of experimental studies (spectroscopic, electrochemical, X-ray of experimental studies (spectroscopic, electrochemical, X-ray diffraction) of complexes with various non-innocent ligands are diffraction) of complexes with various non-innocent ligands are analysed. Particular attention is given to their structures and analysed. Particular attention is given to their structures and redox properties. The bibliography includes 208 references redox properties. The bibliography includes 208 references. .

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“…The EPR spectrum of [3] + is rhombic and centered at g ≈ 2.007, characteristic of ligandcentered radical (Figure 7), similar to [Pd II (tBu-salcn · )]. [6] The g anisotropy, ∆g = 0.030, is significantly larger than the anisotropy observed for free phenoxyls (∆g = 0.008), [17] such that despite the lack of any observable metal hyperfine ( 105 Pd, I = 5/2, 22.3 % natural abundance), which is not uncommon amongst paramagnetic palladium(II) complexes with radical ligands, [6,18] …”

Section: Electrochemistry and Epr Spectroscopymentioning

confidence: 96%

Polynuclear Complexes Containing the Redox Noninnocent Schiff Base Ligand 2‐[(E)‐2‐Mercaptophenylimino]methyl‐4,6‐di‐tert‐butylphenolate(2–)

et al. 2009

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The N,O,S-donor Schiff base ligand 2-[(E)-(2-mercaptophenylimino)methyl]-4,6-di-tert-butylphenolate(2-) (H 2 L) was deprotonated with triethylamine (2 equiv.) and treated with equimolar amounts of Cu (OAc) (4), all characterized by X-ray crystallography. Electronic structure calculations (DFT) on dimeric 1 show that the two singly occupied Cu d x 2 -y 2 orbitals are antiferromagnetically coupled, and the cal-

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Coordinated o‐Dithio‐ and o‐Iminothiobenzosemiquinonate(1−) π Radicals in [M^II(bpy)(L^.)](PF₆) Complexes

Cited by 97 publications

References 19 publications

Electronic, Vibrational, and Structural Properties of a Spin‐Crossover Catecholato–Iron System in the Solid State: Theoretical Study of the Electronic Nature of the Doublet and Sextet States

Electronic, Vibrational, and Structural Properties of a Spin‐Crossover Catecholato–Iron System in the Solid State: Theoretical Study of the Electronic Nature of the Doublet and Sextet States

Metal complexes with non-innocent ligands

Polynuclear Complexes Containing the Redox Noninnocent Schiff Base Ligand 2‐[(E)‐2‐Mercaptophenylimino]methyl‐4,6‐di‐tert‐butylphenolate(2–)

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