Chromium Sandwich Complexes of Polycyclic Aromatic Hydrocarbons: Triphenylene and Fluoranthene as η6 Ligands

Elschenbroich, Christoph; Möckel, Reinhart; Vasil’kov, A. Yu.; Metz, Bernhard; Harms, Klaus

doi:10.1002/(sici)1099-0682(199810)1998:10<1391::aid-ejic1391>3.0.co;2-6

Cited by 26 publications

(12 citation statements)

References 31 publications

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“…The formation of the (g 6 -SWNT)Cr(g 6 -SWNT) bond at the SWNT junctions is expected to be kinetically favorable because the van der Waals gap of 3.15 Å within SWNT bundles is close to the separation of 3.23 Å between the benzene rings in the (g 6 -C 6 H 6 ) 2 Cr parent compound. 32,33 The chromium atom possesses 6 valence shell electrons and by covalent coordination with two g 6 -benzenoid ligands shares a total of 18-electrons, which exactly fill the 3d 4s 4p first row transition metal valence shell and it is known to lead to a very stable electronic configuration. 18 Gold has a filled outer d-orbital and is unable to participate in hexahapto bonding and thus cannot provide a conducting pathway at the carbon nanotube junctions; the conductivity increase during gold deposition is ascribed to the parallel conductance of a continuous gold metal film formed over the SWNTs.…”

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confidence: 99%

Effect of first row transition metals on the conductivity of semiconducting single-walled carbon nanotube networks

Wang

Itkis

Bekyarova

et al. 2012

Applied Physics Letters

111

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confidence: 99%

Effect of first row transition metals on the conductivity of semiconducting single-walled carbon nanotube networks

Wang

Itkis

Bekyarova

et al. 2012

Applied Physics Letters

111

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“…A similar effect has also been observed for non-symmetric (CF 3 C 6 H 5 )Cr[p-(CH 3 ) 2 C 6 H 4 ]. Earlier, the sandwich chromium -complexes with polycyclic aromatic hydrocarbons (PAH), such as naphthalene (Kü ndig et al, 1985;Bush et al, 1987), triphenylene and fluoranthene (Elschenbroich et al, 1998), also exhibited an increase in Cr-C R distances compared with Cr-C H , where C R are the C atoms of the 6coordinated ring forming the C-C bonds with the noncoordinated part of the PAH ligand. The shift of the C atoms from the plane of the aromatic ring was found for the C atoms of the substituent groups.…”

Section: Resultsmentioning

confidence: 99%

Substituent effects in bis(arene)chromium compounds containing a CN group in the aromatic ring

Khrustalev

Vasil’kov

Antipin

2005

Acta Crystallogr Sect B

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The crystal structures of Cr(PhCN)(2) (2), (PhCN)Cr(PhCH(3)) (3) and (PhCN)Cr(PhCF(3)) (4) prepared by means of the Metal Vapor Synthesis (MVS) technique have been determined. Compounds (2), (3) and (4) crystallize as discrete sandwich complexes having intrinsic C(2v)(mm2), C(s)(m) and C(1)(1) symmetries, respectively. The X-ray diffraction study has revealed a synperiplanar conformation for (2) and (3), and a synclinal conformation for (4) with a torsion angle (C(ipso)1-Centroid1-Centroid2-C(ipso)2) of phi = 63.5 degrees . The angles between the ligand planes are 2.2, 3.9 and 1.8 degrees , respectively. The Cr atom is slightly (by 0.04-0.06 A) displaced towards the substituents from the line connecting the centers of the opposite aromatic rings. The Cr-C(ipso) distances are 2.115 (2)-2.137 (2), 2.112 (2) and 2.185 (3) A for CN, CF(3) and CH(3) groups, respectively. The CN groups as well as the H atoms lie out of the C(6) ring planes and are bent towards the Cr atom, but the C atom of the CH(3) group also lying out of the C(6) ring plane is bent away from the Cr atom. The C atom of the CF(3) group is essentially coplanar to the C(6) ring plane. There are no unusual intermolecular contacts in the structures of (2)-(4).

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“…Cr(CO) 3 ‐labeled diarylalkenes provide examples for metal migrations across one or two sp2‐hybridized carbon atoms 34. Haptotropic isomerizations of fluoranthene chromium complexes were studied for both the sandwich35 and the half‐sandwich system 36…”

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“…33 Cr(CO) 3 -labeled diarylalkenes provide examples for metal migrations across one or two sp 2 -hybridized carbon atoms. 34 Haptotropic isomerizations of fluoranthene chromium complexes were studied for both the sandwich 35 and the half-sandwich system. 36 Our group investigated haptotropic metal migrations of Cr(CO) 3 complexes of tri-, tetra-and pentacyclic fused arenes.…”

Section: Extended Fused Arenesmentioning

confidence: 99%

Tunable haptotropic metal migration in fused arenes: towards organometallic switches

Dötz

Jahr

2004

The Chemical Record

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Tricarbonyl chromium complexes of naphthalene derivatives are synthesized by chromium-templated [3 + 2 + 1]-benzannulation and subjected to thermally induced haptotropic rearrangement experiments. Thermodynamic and kinetic parameters for the metal shift demonstrate the influence of the arene substitution pattern. In turn, the chromium template may be tuned as well by phosphorus coligands which allow to accelerate or slow down the isomerization process; this effect quantitatively reflects the steric and electronic properties of the coligand sphere. Proper adjustment of the template allows for a photo-induced reverse migration of the chromium moiety which results in a switchable organometallic device. Experiments with enantiopure arene chromium complexes indicate a stereospecific metal migration. The rearrangement proceeds by an intramolecular mechanism in both directions. Haptotropic isomerization reactions are not limited to bicyclic arenes and can be extended from naphthalenes to phenanthrene or tetra- and pentacyclic heteroarene systems.

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Chromium Sandwich Complexes of Polycyclic Aromatic Hydrocarbons: Triphenylene and Fluoranthene as η6 Ligands

Cited by 26 publications

References 31 publications

Effect of first row transition metals on the conductivity of semiconducting single-walled carbon nanotube networks

Effect of first row transition metals on the conductivity of semiconducting single-walled carbon nanotube networks

Substituent effects in bis(arene)chromium compounds containing a CN group in the aromatic ring

Tunable haptotropic metal migration in fused arenes: towards organometallic switches

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