Der einfluss zunehmender methylsubstitution auf die ladungsverteilung und molekülgeometrie in ferrocenen

Schmitz, D.; Fleischhauer, Jörg; Meier, Ursula; Schleker, Wolfgang; Schmitt, Günter

doi:10.1016/s0022-328x(00)82440-7

Cited by 16 publications

(10 citation statements)

References 33 publications

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“…Since the metal is low spin in the systems under study, occupation of the e 1g orbitals occurs only with d 7 and above. In some cases the order of the e 2g and a 1g orbitals is reversed. − According to Mossbauer, ESR spectra, and theoretical results, , the percentage of metal contribution to the HOMO orbitals of a 1g and e 2g in iron group sandwich complexes is more than 60%. Even in the e* 1g orbitals, metal contributions are as high as 55%, 50%, and 37% for FeCp 2 , CoCp 2 , and NiCp 2 complexes .…”

Section: Resultsmentioning

confidence: 99%

Electrochemical Parametrization in Sandwich Complexes of the First Row Transition Metals

et al. 1996

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Applying the ligand electrochemical parameter approach to sandwich complexes and standardizing to the Fe(III)/Fe(II) couple, we obtained E(L)(L) values for over 200 pi-ligands. Linear correlations exist between formal potential (E degrees ) and the summation operatorE(L)(L) for each metal couple. In this fashion, we report correlation data for many first row transition metal couples. The correlations between the E(L)(L) of the substituted pi-ligand and the Hammett substituent constants (sigma(p)) are also explored.

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Section: Resultsmentioning

confidence: 99%

Electrochemical Parametrization in Sandwich Complexes of the First Row Transition Metals

et al. 1996

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“…33,34 Instead, electronic communication between the iron atoms may be mediated by the bridging π-ligand. 2,35,36 Table 1 shows that for the two terminal Cp′ ligands in 2, Fe−C bond distances are close to the corresponding distances in free octamethylferrocene (Fe−C 2.048 Å, C−C 1.422 Å), 37,38 but for the bridging ligand, the average Fe−C bond is longer (2.071 Å), as are the C−C bonds within the Cp′ ring (average 1.460 Å). Moreover, the average perpendicular distance between each Fe and the center of the bridging Cp′ ring is slightly longer (1.658 Å) than the corresponding distance to the center of the outer rings (1.652 Å).…”

Section: ■ Results and Discussionmentioning

confidence: 80%

Synthesis and Structures of Triple-Decker Complexes with a Bridging Tetramethylcyclopentadienyl Ligand

et al. 2013

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New triple-decker complexes with bridging tetramethylcyclopentadienyl ligands were synthesized by the reaction of electrophilic metal fragments with octamethylferrocene, Cp′2Fe (Cp′ = C5Me4H). The reaction of coordinatively unsaturated ruthenium cations [(C5R5)Ru]+ (R = H, CH3) with Cp′2Fe afforded purple-colored heterometallic triple-decker complexes [(C5R5)Ru(μ-Cp′)FeCp′]+ by direct electrophilic addition. Surprisingly, the analogous reaction with the coordinatively unsaturated manganese cation [Mn(CO)3]+ and Cp′2Fe produced a blue homometallic triple-decker complex, [Cp′Fe(μ-Cp′)FeCp′]+, by ring abstraction and subsequent addition of the newly generated cation [Cp′Fe]+ to an equivalent of Cp′2Fe. Three air-stable triple-decker complexes, [Cp′Fe(μ-Cp′)FeCp′]+ (2), [CpRu(μ-Cp′)FeCp′]+ (3), and [Cp*Ru(μ-Cp′)FeCp′]+ (4), have been characterized by NMR spectroscopy, elemental analysis, and single-crystal X-ray diffraction.

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“…The two terminal rings in 1 are nearly eclipsed with torsion angles for C(1–5)–Ct′–Ct″–C(20–24) between 3.4 and 4.2° (Ct = ring centroid), whereas the bridging ring is rotated by approximately 33° for C(1–5)–Ct′–Ct–C(11–15) and 37° for C(11–15)–Ct–Ct″–C(20–24) . These cross-orientation angles differ from those in the solid-state structures of octamethylferrocene and decamethylferrocene in which the rings adopt a staggered geometry in accord with D 5 d molecular symmetry. − …”

Section: Resultsmentioning

confidence: 89%

“…The intramolecular Fe···Fe distance of 3.3207(6) Å exceeds the sum of their covalent radii (estimated at 2.6–3.0 Å), indicating the absence of any direct Fe–Fe bond. , While there is no solid-state structural information for nonamethylferrocene, the data in Table may be compared with corresponding Fe–C bond distances in octamethylferrocene (average 2.048 Å) , and decamethylferrocene (average 2.050 Å) . Such comparisons show that Fe–C bond distances for the terminal Cp* ligands in 1 are similar to bond lengths in Cp′ 2 Fe and Cp* 2 Fe, but for the bridging Cp′ ligand in 1 , the average Fe–C bond is considerably longer (2.075 Å) than in either metallocene.…”

Section: Resultsmentioning

confidence: 99%

“…24−27 The intramolecular Fe•••Fe distance of 3.3207(6) Å exceeds the sum of their covalent radii (estimated at 2.6−3.0 Å), indicating the absence of any direct Fe−Fe bond. 28,29 While there is no solid-state structural information for nonamethylferrocene, the data in Table 1 may be compared with corresponding Fe−C bond distances in octamethylferrocene (average 2.048 Å) 24,25 and decamethylferrocene (average 2.050 Å). 27 To the extent that bond length can be correlated with bond strength, these data suggest weaker Fe−C and C−C interactions for the bifacially coordinated bridging ring in comparison with the singly coordinated terminal rings.…”

Section: ■ Introductionmentioning

confidence: 88%

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Syntheses, Structures, and Mössbauer Effect Spectroscopy of Triple-Decker Complexes Incorporating Nonamethylferrocene

et al. 2015

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Three new triple-decker complexes were synthesized by the reaction of nonamethylferrocene, Cp′FeCp* (Cp′ = C5Me4H, Cp* = C5Me5), with coordinatively unsaturated transition-metal complexes. The reaction of ruthenium cations [(C5R5)Ru]+ (R = H, Me) with Cp′FeCp* afforded the purple heterometallic triple-decker complexes [(C5R5)Ru(μ-Cp′)FeCp*]+ by electrophilic addition of ruthenium to the Cp′ ring of nonamethylferrocene. The analogous reaction with the manganese cation [Mn(CO)3]+ produced the blue homometallic triple-decker complex [Cp*Fe(μ-Cp′)FeCp*]+ by abstraction of the Cp′ ring from Cp′FeCp* and subsequent addition of the newly generated cation [Cp*Fe]+ to 1 equiv of Cp′FeCp*. These experiments demonstrate that the asymmetry of Cp′FeCp* gives rise to a remarkable degree of regioselectivity such that ruthenium electrophiles add only to the Cp′ ring and never to the Cp* ring. In a similar way, [Mn(CO)3]+ abstracts only the Cp′ ring from Cp′FeCp* to produce [Cp*Fe]+, which in turn adds only to the Cp′ ring of Cp′FeCp* to produce [Cp*Fe(μ-Cp′)FeCp*]+. Three air-stable triple-decker complexes incorporating nonamethylferrocene, [Cp*Fe(μ-Cp′)FeCp*]+ (1), [CpRu(μ-Cp′)FeCp*]+ (2), and [Cp*Ru(μ-Cp′)FeCp*]+ (3), have been characterized by NMR spectroscopy, elemental analysis, single-crystal X-ray diffraction analysis, and temperature-dependent 57Fe Mössbauer spectroscopy.

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Der einfluss zunehmender methylsubstitution auf die ladungsverteilung und molekülgeometrie in ferrocenen

Cited by 16 publications

References 33 publications

Electrochemical Parametrization in Sandwich Complexes of the First Row Transition Metals

Electrochemical Parametrization in Sandwich Complexes of the First Row Transition Metals

Synthesis and Structures of Triple-Decker Complexes with a Bridging Tetramethylcyclopentadienyl Ligand

Syntheses, Structures, and Mössbauer Effect Spectroscopy of Triple-Decker Complexes Incorporating Nonamethylferrocene

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