Notizen: Zur Kenntnis der Bildungsweisen von Chrom(0)-Komplexen mit Bipyridyl(2.2′), 1.10-Phenanthrolin und Tripyridyl(2.2′.2″) <sup>1</sup>

Behrens, H.; Meyer, K.; Müller, Alexius

doi:10.1515/znb-1965-0115

Cited by 26 publications

(1 citation statement)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…5) and [W(tpy) 2 ] (6) were synthesized from M(CO) 6 (M = Mo, W) and 2 equiv of tpy at 180 °C. 31,43 From room temperature magnetic measurements 27 it was established that the dication possesses an S = 1 ground state (μ eff = 2.80 μ B ), the monocation possesses an S = 1 / 2 ground state (μ eff = 1.85 μ B ), and all three neutral species (4−6) were reported to be diamagnetic. 27,31 Here, we synthesized the neutral complexes 4, 5, and 6 from the corresponding hexacarbonyl starting material M(CO) 6 (M = Cr, Mo, W) and 2 equiv of tpy in refluxing mesitylene (M = Cr) or n-pentadecane (M = Mo, W) under an argon-blanketed atmosphere.…”

Section: ■ Introductionmentioning

confidence: 99%

Experimental Fingerprints for Redox-Active Terpyridine in [Cr(tpy)₂](PF₆)_n (n = 3–0), and the Remarkable Electronic Structure of [Cr(tpy)₂]^1–

et al. 2012

View full text Add to dashboard Cite

The molecular and electronic structures of the four members, [Cr(tpy)(2)](PF(6))(n) (n = 3-0; complexes 1-4; tpy = 2,2':6',2″-terpyridine), of the electron transfer series [Cr(tpy)(2)](n+) have been determined experimentally by single-crystal X-ray crystallography, by their electro- and magnetochemistry, and by the following spectroscopies: electronic absorption, X-ray absorption (XAS), and electron paramagnetic resonance (EPR). The monoanion of this series, [Cr(tpy)(2)](1-), has been prepared in situ by reduction with KC(8) and its EPR spectrum recorded. The structures of 2, 3, 4, 5, and 6, where the latter two compounds are the Mo and W analogues of neutral 4, have been determined at 100(2) K. The optimized geometries of 1-6 have been obtained from density functional theoretical (DFT) calculations using the B3LYP functional. The XAS and low-energy region of the electronic spectra have also been calculated using time-dependent (TD)-DFT. A consistent picture of the electronic structures of these octahedral complexes has been established. All one-electron transfer processes on going from 1 to 4 are ligand-based: 1 is [Cr(III)(tpy(0))(2)](PF(6))(3) (S = (3)/(2)), 2 is [Cr(III)(tpy(•))(tpy(0))](PF(6))(2) (S = 1), 3 is [Cr(III)(tpy(•))(2)](PF(6)) (S = (1)/(2)), and 4 is [Cr(III)(tpy(••))(tpy(•))](0) (S = 0), where (tpy(0)) is the neutral parent ligand, (tpy(•))(1-) represents its one-electron-reduced π radical monoanion, (tpy(2-))(2-) or (tpy(••))(2-) is the corresponding singlet or triplet dianion, and (tpy(3-))(3-) (S = (1)/(2)) is the trianion. The electronic structure of 2 cannot be described as [Cr(II)(tpy(0))(2)](PF(6))(2) (a low-spin Cr(II) (d(4); S = 1) complex). The geometrical features (C-C and C-N bond lengths) of these coordinated ligands have been elucidated computationally in the following hypothetical species: [Zn(II)Cl(2)(tpy(0))](0) (S = 0) (A), [Zn(II)(tpy(•))Cl(NH(3))](0) (S = (1)/(2)) (B), [Zn(II)(tpy(2-))(NH(3))(2)](0) (S = 0 or 1) (C), and [Al(III)(tpy(3-))(NH(3))(3)](0) (S = (1)/(2) and (3)/(2)) (D). The remarkable electronic structure of the monoanion has been calculated and experimentally verified by EPR spectroscopy to be [Cr(III)(tpy(2-))(tpy(••))](1-) (S = (1)/(2)), a complex in which the two dianionic tpy ligands differ only in the spin state. It has been clearly established that coordinated tpy ligands are redox-active and can exist in at least four oxidation levels.

show abstract

Section: ■ Introductionmentioning

confidence: 99%

Experimental Fingerprints for Redox-Active Terpyridine in [Cr(tpy)₂](PF₆)_n (n = 3–0), and the Remarkable Electronic Structure of [Cr(tpy)₂]^1–

et al. 2012

View full text Add to dashboard Cite

show abstract

Bis(η⁶‐naphthalin)chrom(0)

Elschenbroich¹,

Möckel²

1977

Angewandte Chemie

View full text Add to dashboard Cite

show abstract

Bis(η⁶‐naphthalene)chromium(0)

Elschenbroich¹,

Möckel²

1977

Angew. Chem. Int. Ed. Engl.

View full text Add to dashboard Cite

I 11 P. Debye, Trans. Electrochem. SOC. 82, 265 (1942).[12] These results suggest that the faster isomerization of ally1 anions in the 270-MHz spectra. 1972, 4729. VOl. I, pp. 37ff. the presence of catalytic amounts of oxygen (personal communication, Prof. H. Ahlbrecht, Universitat Giessen, and Prof. M . Schlosser, Univer-sit6 de Lausanne; G. Boche, A. Bieberbach, unpublished results) is attributable to a reversible electron transfer with intermediate formation of configurationally more labile allyl radicals. G. Boche, A. Bieberbach, H . Weber, Angew. Chem. 87, 550 (1975); Angew. Chem. Int. Ed. Engl. 14, 562 (1975); Tetrahedron Lett. 1976, 1021. Note added in prooJ (October 26, 1977): Ah itiitio 4-3143 calculations also indicate that the rotational barrier of the ally1 radical (21.2 kcal/mol) is smaller than that of the allyl anion (27.6kcal/mol); G. Boche, H. U .Wagner, unpublished results.

show abstract

Notizen: Zur Kenntnis der Bildungsweisen von Chrom(0)-Komplexen mit Bipyridyl(2.2′), 1.10-Phenanthrolin und Tripyridyl(2.2′.2″) ¹

Cited by 26 publications

References 0 publications

Experimental Fingerprints for Redox-Active Terpyridine in [Cr(tpy)₂](PF₆)_n (n = 3–0), and the Remarkable Electronic Structure of [Cr(tpy)₂]^1–

Experimental Fingerprints for Redox-Active Terpyridine in [Cr(tpy)₂](PF₆)_n (n = 3–0), and the Remarkable Electronic Structure of [Cr(tpy)₂]^1–

Bis(η⁶‐naphthalin)chrom(0)

Bis(η⁶‐naphthalene)chromium(0)

Contact Info

Product

Resources

About

Notizen: Zur Kenntnis der Bildungsweisen von Chrom(0)-Komplexen mit Bipyridyl(2.2′), 1.10-Phenanthrolin und Tripyridyl(2.2′.2″) 1

Cited by 26 publications

References 0 publications

Experimental Fingerprints for Redox-Active Terpyridine in [Cr(tpy)2](PF6)n (n = 3–0), and the Remarkable Electronic Structure of [Cr(tpy)2]1–

Experimental Fingerprints for Redox-Active Terpyridine in [Cr(tpy)2](PF6)n (n = 3–0), and the Remarkable Electronic Structure of [Cr(tpy)2]1–

Bis(η6‐naphthalin)chrom(0)

Bis(η6‐naphthalene)chromium(0)

Contact Info

Product

Resources

About

Notizen: Zur Kenntnis der Bildungsweisen von Chrom(0)-Komplexen mit Bipyridyl(2.2′), 1.10-Phenanthrolin und Tripyridyl(2.2′.2″) ¹

Experimental Fingerprints for Redox-Active Terpyridine in [Cr(tpy)₂](PF₆)_n (n = 3–0), and the Remarkable Electronic Structure of [Cr(tpy)₂]^1–

Experimental Fingerprints for Redox-Active Terpyridine in [Cr(tpy)₂](PF₆)_n (n = 3–0), and the Remarkable Electronic Structure of [Cr(tpy)₂]^1–

Bis(η⁶‐naphthalin)chrom(0)

Bis(η⁶‐naphthalene)chromium(0)