Metal stabilized carbanions XII. Intramolecular Cr(CO)3 migration from a phenyl to a cyclopentadienyl ring through a σ-bond

Ceccon, Alberto; Gambaro, Alessandro; Gottardi, Francesca; Santi, Saverio; Venzo, Alfonso; Lucchini, Vittorio

doi:10.1016/0022-328x(89)80026-9

Cited by 16 publications

(7 citation statements)

References 19 publications

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“…Apparently, this is due to steric interactions in the complex 64 existing between the bulky bromine atom, on the one hand, and the ortho-proton of the adjacent ring and the organometallic group, on the other hand, resulting in the appearance of a twisting angle (a nonzero dihedral angle) and distortion of conjugation of the phenyl rings (see, for example, Refs 132 and 133). Ceccon et al 134 also revealed the presence of the twisting angle and a noticeable degree of noncoplanarity of the five-and six-membered rings in the tricarbonylchromium complexes 29 and 30. For the thermodynamically more stable (and, correspondingly, more populated) conformation of the orthoderivatives of (Z 6 -biphenyl)tricarbonylchromium, the degree of noncoplanarity of the six-membered rings is higher than that in the corresponding para-derivatives.…”

Section: B Studies Of Rearrangements In Tricarbonylchromium Complexes...mentioning

confidence: 94%

Inter-ring haptotropic rearrangements in π-complexes of transition metals with polycyclic aromatic ligands

Oprunenko¹

2000

Russ. Chem. Rev.

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Illinois 601 15. USC M S . received 14th M a y 1970Ahtract. Starting from bare-ion pseudopotentials, net crystal potentials are evalutiied in direct space by (a) the usual linear screening technique and (b) the Thomas-Fermi method. For the metals considered (Na and AI), the potentials are quite similar, crossing outside the cores and never differing by more than 0.02 a.u. in the case of Na nor by more than 0.2 a.u. in the case of Al. The similarity of the results based on (a) and (b) suggest the use of the pseudopotential concept in conjunction with the rather general method (b) under conditions when (a) is questionable, that is whenever the zeroth order uniform electron gas solution is a poor physical approximation to the actual system under study (specific examples being molecules, insulating solids and interfaces).Methods (a) and (bj both yield shallower wells than those most often used as input information in band structure calculations and obtained by superposing atomic data.

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Section: B Studies Of Rearrangements In Tricarbonylchromium Complexes...mentioning

confidence: 94%

Inter-ring haptotropic rearrangements in π-complexes of transition metals with polycyclic aromatic ligands

Oprunenko¹

2000

Russ. Chem. Rev.

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“…[Cr-(CO) 3-phenyl]-cyclopentadiene 24 was converted into its anion by treatment of the THF solution with an excess of KH in the presence of 18-crown-6 ether at room temperature under argon. 25 The anion solution was added at room temperature to an equivalent amount of [Rh(µ-Cl)(COD)] 2 in THF. After 1 h the solution was cooled to -40 °C, the solvent pumped off, and the residue washed with cyclohexane and crystallized from diethyl ether-hexane to give a light brown powder.…”

Section: Methodsmentioning

confidence: 99%

Heterobimetallic Indenyl Complexes. Kinetics and Mechanism of Substitution and Exchange Reactions of trans-[Cr(CO)₃-indenyl-Rh(CO)₂] with Olefins

et al. 1996

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The trans coordination of the benzene ring of the indenyl-Rh(CO) 2 complex with tricarbonylchromium strongly enhances the rate of substitution of CO's with bidentate olefins, 1,5-cyclooctadiene (COD) and norbornadiene (NBD) ("extra-indenyl effect"). The activation parameters suggest an associative reaction pathway assumed to proceed via the intermediacy of a nonisolable low-hapticity species, η 1 -indenyl-Rh(CO) 2 (L 2 ). In addition, the rate of exchange of the Cr(CO) 3 group of the complexes trans-[Cr(CO) 3 -indenyl-Rh(CO) 2 ], 3, and trans-[Cr(CO) 3 -indenyl-Rh(COD)], 3a, and suitable acceptors (hexamethylbenzene and cycloheptatriene) is markedly increased with respect to that measured for the same reaction in the monometallic complex η-naphthalene-Cr(CO) 3 ("extra-naphthalene effect"). These mutual effects of the Cr(CO) 3 and RhL 2 units are transmitted through the 10 π electron indenyl framework, and the results obtained are in agreement with the existence of an haptomeric ground-state equilibrium between the two isomers trans-[Cr(CO) 3 -µ,η 6 :η 3 -indenyl-RhL 2 ], I, and trans-[Cr(CO) 3 -µ,η 4 :η 5 -indenyl-RhL 2 ], II.

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“…[16a] The 11 B signal of [1] 2À is comparable to that measured for h 5 -coordinated borole metal complexes, such as [CpFe(C 4 H 4 BPh)] (d = 13.8 ppm). [21] An X-ray structure analysis on bright red single crystals of [1] 2À (Figure 3) [25] unambiguously revealed an unusual reduction-induced [CpFe] migration from the C 5 H 4 ring to the borole ring. Compound [1][K(THF)] 2 crystallizes in the Scheme 1.…”

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confidence: 97%

“…[21] An X-ray structure analysis on bright red single crystals of [1] 2À (Figure 3) [25] unambiguously revealed an unusual reduction-induced [CpFe] monoclinic space group P2 1 /c as a potassium-bridged dimer.…”

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confidence: 98%

The Reduction Chemistry of Ferrocenylborole

et al. 2010

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Time to B radical: One‐electron reduction of 1‐ferrocenyl‐2,3,4,5‐tetraphenylborole results in a radical anion with 5 π electrons in the borole ring. Both EPR spectroscopic investigations and spin density calculations confirm the formation of a borol radical (see picture). Further reduction stimulates an intramolecular [(C5H5)Fe] migration from the cyclopentadienyl anion to the borole dianion.

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Metal stabilized carbanions XII. Intramolecular Cr(CO)3 migration from a phenyl to a cyclopentadienyl ring through a σ-bond

Cited by 16 publications

References 19 publications

Inter-ring haptotropic rearrangements in π-complexes of transition metals with polycyclic aromatic ligands

Inter-ring haptotropic rearrangements in π-complexes of transition metals with polycyclic aromatic ligands

Heterobimetallic Indenyl Complexes. Kinetics and Mechanism of Substitution and Exchange Reactions of trans-[Cr(CO)₃-indenyl-Rh(CO)₂] with Olefins

The Reduction Chemistry of Ferrocenylborole

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Metal stabilized carbanions XII. Intramolecular Cr(CO)3 migration from a phenyl to a cyclopentadienyl ring through a σ-bond

Cited by 16 publications

References 19 publications

Inter-ring haptotropic rearrangements in π-complexes of transition metals with polycyclic aromatic ligands

Inter-ring haptotropic rearrangements in π-complexes of transition metals with polycyclic aromatic ligands

Heterobimetallic Indenyl Complexes. Kinetics and Mechanism of Substitution and Exchange Reactions of trans-[Cr(CO)3-indenyl-Rh(CO)2] with Olefins

The Reduction Chemistry of Ferrocenylborole

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Heterobimetallic Indenyl Complexes. Kinetics and Mechanism of Substitution and Exchange Reactions of trans-[Cr(CO)₃-indenyl-Rh(CO)₂] with Olefins