Intramolecular C−H Activation of a Bisphenolate(benzene)-Ligated Titanium Dibenzyl Complex. Competing Pathways Involving α-Hydrogen Abstraction and σ-Bond Metathesis

Golisz, Suzanne R.; Labinger, Jay A.; Bercaw, John E.

doi:10.1021/om100253u

Cited by 36 publications

(40 citation statements)

References 31 publications

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“…55 ). 46 The presence of the two Li counterions in 3 renders the Fe1−Cl2 (2.4252(15) Å) distance 0.1152 (19) Å longer than the Fe1−Cl1 bond (2.3100(11) Å). The Li atoms are coplanar with the basal plane, and each distorted tetrahedral Li interacts with an oxygen atom from the pincer ligand, two THF molecules, and the same Cl atom (Cl2).…”

Section: ■ Results and Discussionmentioning

confidence: 99%

Synthesis, Characterization, and Reactivity of Iron(III) Complexes Supported by a Trianionic ONO^3– Pincer Ligand

Pascualini¹,

Russo²,

Quintero³

et al. 2014

Inorg. Chem.

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Synthetic and characterization results of a new family of Fe(III) compounds stabilized by a trianionic [CF3-ONO](3-) pincer-type ligand are reported. The ligand possesses three negatively charged donors constrained to the meridional positions that provide sufficient electron density to stabilize high-valent metal complexes. Using the redox-insulated [CF3-ONO](3-), pentacoordinated square-pyramidal {[CF3-ONO]FeCl2}{LiTHF2}2 (3), dimeric μ-DME{[CF3-ONO]FeDME}2 (4), trigonal bipyramidal [CF3-ONO]Fe(bpy) (5), and octahedral [CF3-ONO]Fe(bpy)H2O (5·H2O) complexes are synthesized. An interesting feature of the [CF3-ONO](3-) pincer-type ligand is its ability to coordinate the metal center in both the more common meridional positions or occupying a face of a trigonal bipyramidal complex. The molecular structure of 3 contains structural features similar to those of a rare square-planar high-spin Fe(II) complex, and the important role of the counterions in stabilizing a square-plane is emphasized. SQUID magnetometry measurements of 3 reveal its high-spin character, and cyclic voltammetry measurements indicate high oxidation state species are unstable. However, all compounds can be reduced, and in particular 5 displays a reversible reduction event at -2255 mV versus ferrocene (Fc(+)/Fc) that can be assigned to either the Fe(I)/Fe(0) couple or 2,2'-bipyridine reduction.

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Section: ■ Results and Discussionmentioning

confidence: 99%

Synthesis, Characterization, and Reactivity of Iron(III) Complexes Supported by a Trianionic ONO^3– Pincer Ligand

Pascualini¹,

Russo²,

Quintero³

et al. 2014

Inorg. Chem.

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“…Besonders interessant sind OCO‐Pincerkomplexe, die strukturell auf meta ‐Terphenyl‐2,2′′‐diolen basieren. Als Metalle können Cr, Mo, W, Ti, Zr, Ta, Sm und Yb genutzt werden. Erfolgreiche Anwendungen der meta ‐Terphenyl‐2,2′′‐diole als Pincerliganden wurde bereits für Sauerstoff‐ und Stickstoffübertragungsreaktionen, Polymerisation von Acetylenen und Olefinen, Alkenisomerisation, Nitren‐ und Carbengruppenübertragungen, O 2 ‐ und C‐H‐Aktivierung, Disulfidreduktionen und aerobe Oxidationen nachgewiesen.…”

Section: Methodsunclassified

Synthese von meta‐Terphenyl‐2,2′′‐diolen durch anodische C‐C‐Kreuzkupplungen

et al. 2016

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Die anodische C‐C‐Kreuzkupplung ist eine vielseitig einsetzbare Transformation, die eine gezielte Synthese von Biphenolen und arylierten Phenolen ermöglicht. Wir berichten über einen ebenfalls elektrosynthetischen, metallfreien Ansatz, der einen Zugang zu symmetrischen und nichtsymmetrischen meta‐Terphenyl‐2,2′′‐diolen in guten Ausbeuten und hoher Selektivität ermöglicht. Symmetrische Derivate können durch eine direkte Synthese in einer ungeteilten Zelle gewonnen werden, wohingegen nichtsymmetrische meta‐Terphenyl‐2,2′′‐diole zwei elektrochemische Stufen benötigen. Die milde Methode ist einfach durchzuführen und skalierbar. Außerdem konnte erstmalig eine breite Substratvariabilität aufgezeigt werden, die eine Vielzahl funktioneller Gruppen toleriert. Die erhaltenen Strukturen könnten als [OCO]3−‐Pincerliganden genutzt werden.

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“…The luminescence quantum yields were determined in dichloromethane solutions using quinine sulfate in aerated 0.05 M H 2 SO 4 as a luminescence standard (Φ em = 0.55). 41 The luminescence decays were collected by a time-correlated singlephoton-counting technique. The excitation source was a NanoLED-370 electroluminescent diode (Horiba Jobin Yvon) emitting at 375 nm and operated at a 1 MHz repetition rate.…”

Section: ■ Experimental Sectionmentioning

confidence: 99%

Redox and Luminescent Properties of Robust and Air-Stable N-Heterocyclic Carbene Group 4 Metal Complexes

et al. 2014

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Robust and air-stable homoleptic group 4 complexes of the type M(L)2 [1-3; M = Ti, Zr, Hf; L = dianionic bis(aryloxide) N-heterocyclic carbene (NHC) ligand] were readily synthesized from the NHC proligand 1,3-bis(3,5-di-tert-butyl-2-hydroxyphenyl)imidazolinium chloride (H3L,Cl) and appropriate group 4 precursors. As deduced from cyclic voltammetry studies, the homoleptic bis-adduct zirconium and hafnium complexes 2 and 3 can also be oxidized, with up to four one-electron-oxidation signals for the zirconium derivative 2 (three reversible signals). Electron paramagnetic resonance data for the one-electron oxidation of complexes 1-3 agree with the formation of ligand-centered species. Compounds 2 and 3 are luminescent upon excitation in the absorption band at 362 nm with emissions at 485 and 534 nm with good quantum yields (ϕ = 0.08 and 0.12) for 2 and 3, respectively. In contrast, the titanium complex 1 does not exhibit luminescent properties upon excitation in the absorption band at 310 and 395 nm. Complexes 2 and 3 constitute the first examples of emissive nonmetallocene group 4 metal complexes.

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Intramolecular C−H Activation of a Bisphenolate(benzene)-Ligated Titanium Dibenzyl Complex. Competing Pathways Involving α-Hydrogen Abstraction and σ-Bond Metathesis

Cited by 36 publications

References 31 publications

Synthesis, Characterization, and Reactivity of Iron(III) Complexes Supported by a Trianionic ONO^3– Pincer Ligand

Synthesis, Characterization, and Reactivity of Iron(III) Complexes Supported by a Trianionic ONO^3– Pincer Ligand

Synthese von meta‐Terphenyl‐2,2′′‐diolen durch anodische C‐C‐Kreuzkupplungen

Redox and Luminescent Properties of Robust and Air-Stable N-Heterocyclic Carbene Group 4 Metal Complexes

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Intramolecular C−H Activation of a Bisphenolate(benzene)-Ligated Titanium Dibenzyl Complex. Competing Pathways Involving α-Hydrogen Abstraction and σ-Bond Metathesis

Cited by 36 publications

References 31 publications

Synthesis, Characterization, and Reactivity of Iron(III) Complexes Supported by a Trianionic ONO3– Pincer Ligand

Synthesis, Characterization, and Reactivity of Iron(III) Complexes Supported by a Trianionic ONO3– Pincer Ligand

Synthese von meta‐Terphenyl‐2,2′′‐diolen durch anodische C‐C‐Kreuzkupplungen

Redox and Luminescent Properties of Robust and Air-Stable N-Heterocyclic Carbene Group 4 Metal Complexes

Contact Info

Product

Resources

About

Synthesis, Characterization, and Reactivity of Iron(III) Complexes Supported by a Trianionic ONO^3– Pincer Ligand

Synthesis, Characterization, and Reactivity of Iron(III) Complexes Supported by a Trianionic ONO^3– Pincer Ligand