Octanuclear Bis(triple-helical) Metal(II) Complexes

Saalfrank, Rolf W.; Löw, Norbert; Trümmer, Stefan; Sheldrick, George M.; Teichert, Markus; Stalke, Dietmar

doi:10.1002/(sici)1099-0682(199805)1998:5<559::aid-ejic559>3.0.co;2-m

Cited by 74 publications

(40 citation statements)

References 33 publications

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“…Although a series of transition metal complexes containing tetraketones with structures similar to 3b are known,11,12 this is the first structure determination of an uncoordinated compound of this type. The 1,3‐diketo moieties are both found in the enol structure.…”

Section: Resultsmentioning

confidence: 98%

“…3a was transformed into the dipyrazolyl derivative 4a in high yield by ring closure with hydrazine 10 . 3b 11 was treated with formamide in the presence of ammonium carbonate and sodium sulfate to give the dipyrimidinyl derivative 5 in moderate yield (Scheme ). Experiments on the ring closure to pyrimidines with substituents other than tert ‐butyl resulted in very poor yields of the desired products.…”

Section: Resultsmentioning

confidence: 99%

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Iron and Cobalt Complexes of Tridentate N‐Donor Ligands in Ethylene Polymerization: Efficient Shielding of the Active Sites by Simple Phenyl Groups

et al. 2008

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Tridentate 2,6-bis[3(5)-pyrazolyl]pyridines and 2,6-bis(4-pyrimidinyl)pyridine were synthesized and characterized spectroscopically and by single-crystal X-ray structure analysis. The derived complexes with FeCl 2 and CoCl 2 were investigated for their activity in the ethylene polymerization in the presence of methylalumoxane (MAO). Iron and cobalt catalysts bearing the ligand 2,6-bis[5-butyl-1-(4-nitrophenyl)pyrazol-3-yl]pyridine showed moderate catalytic activity and

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Section: Resultsmentioning

confidence: 98%

Section: Resultsmentioning

confidence: 99%

Iron and Cobalt Complexes of Tridentate N‐Donor Ligands in Ethylene Polymerization: Efficient Shielding of the Active Sites by Simple Phenyl Groups

et al. 2008

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“…Wie empfindlich die Bildung metallosupramolekularer Strukturen auf die Oxidationsstufen der beteiligten Metallionen reagiert, zeigt sich eindrucksvoll bei der Reaktion der topologisch äquivalenten Liganden (L 1 ) 2− und (L 2 ) 2− mit Mangan‐, Zink‐ und Cadmiumsalzen14 anstelle von Eisen(III)‐chlorid. Während mit Eisen(III)‐chlorid der Komplex [K⊂{Fe 2 (L 2 ) 3 }]PF 6 ( 17 ) entsteht (Abschnitt 3.1), isoliert man bei der Umsetzung von H 2 L 1 oder H 2 L 2 mit Cadmium(II)‐ oder Mangan(II)‐chlorid mit wässrigem Ammoniak oder einer wässrigen Zinkacetatlösung die Komplexe 20 – 22 (Schema ).…”

Section: Ligand‐ Und Metallgesteuerte Synthese Von {2}‐metallocrypunclassified

Supramolekulare Koordinationschemie – Synergie von Zufallsentdeckung und rationalem Design

2008

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Supramolekulare Koordinationsverbindungen haben mehrere Vorteile gegenüber ihren organischen Pendants: Sie sind in Eintopf‐Reaktionen in hohen Ausbeuten zugänglich und weisen physikalische Eigenschaften auf, die organischen Molekülen in der Regel fehlen. Darüber hinaus ermöglichen ihre schwachen, reversiblen nicht‐kovalent bindenden Wechselwirkungen die Behebung von Fehlverknüpfungen durch Selbstreparaturmechanismen. Dieser Aufsatz beschreibt Entwicklungen in der supramolekularen Koordinationschemie, die ausgehend von Zufallsentdeckungen mithilfe rationalen Designs gemacht wurden. Das Auffinden von Parallelen bei der Entstehung verschiedener supramolekularer Architekturen ermöglicht eine Vorhersage von Ergebnissen in ähnlichen Fällen. Die supramolekulare Synthese verläuft in etwa nach Regeln, wie sie das “lead sheet” zur Improvisation in einem kleinen Jazz‐Ensemble vorgibt, und kann daher zu unvorhergesehenen Resultaten führen. Detaillierte Symmetriebetrachtungen haben basierend auf den Grundregeln der Koordinationschemie jüngst die Entwicklung rationaler Strategien für den Aufbau der verschiedensten Nanostrukturen mit geplanter Größe und Gestalt ermöglicht.

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“…There are few examples of cluster helicates, in which metal clusters define the helical axis 6. However, Saalfrank and co‐workers have introduced [M 3 O] 4+ (M=Mn II , Zn II , or Cd II ) clusters into helicates 6c. This result prompted us to synthesize a cluster helicate with a similar cluster core.…”

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confidence: 99%

An [Fe^II₃O]⁴⁺ Core Wrapped by Two [Fe^IIL₃]⁻ Units

et al. 2006

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The spontaneous self-organization of coordination compounds has been studied intensively over the last few decades.[1] One area of particular interest is the assembly of multistranded helicates. [2][3][4][5] As most strategies for the synthesis of helicates with high nuclearities make use of long and flexible organic ligands, many linear helicates have been prepared. [3, 5] Because of their unique physical and chemical properties, helicates have been used as components of functional materials and devices. [6, 7] These applications could experience remarkable development if clusters with novel properties were introduced into the helicates.There are few examples of cluster helicates, in which metal clusters define the helical axis.[ [9] The Mössbauer spectrum of 1 at 78 K consists of three quadrupole doublets with relative peak areas of 2:1:2, which correspond to two types of high-spin iron(II) ions (isomer shift (IS) = 1.03 mm s À1 , quadrupole splitting (QS) = 3.34 mm s À1 ; IS = 1.03 mm s À1 , QS = 2.81 mm s À1 ) and one type of low-spin iron(II) ion (IS = 0.46 mm s À1 , QS= 0.26 mm s À1 ), respectively (Figure 1).[10] These Mössbauer data are consistent with the structure determined by X-ray diffraction.

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Octanuclear Bis(triple-helical) Metal(II) Complexes

Cited by 74 publications

References 33 publications

Iron and Cobalt Complexes of Tridentate N‐Donor Ligands in Ethylene Polymerization: Efficient Shielding of the Active Sites by Simple Phenyl Groups

Iron and Cobalt Complexes of Tridentate N‐Donor Ligands in Ethylene Polymerization: Efficient Shielding of the Active Sites by Simple Phenyl Groups

Supramolekulare Koordinationschemie – Synergie von Zufallsentdeckung und rationalem Design

An [Fe^II₃O]⁴⁺ Core Wrapped by Two [Fe^IIL₃]⁻ Units

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Octanuclear Bis(triple-helical) Metal(II) Complexes

Cited by 74 publications

References 33 publications

Iron and Cobalt Complexes of Tridentate N‐Donor Ligands in Ethylene Polymerization: Efficient Shielding of the Active Sites by Simple Phenyl Groups

Iron and Cobalt Complexes of Tridentate N‐Donor Ligands in Ethylene Polymerization: Efficient Shielding of the Active Sites by Simple Phenyl Groups

Supramolekulare Koordinationschemie – Synergie von Zufallsentdeckung und rationalem Design

An [FeII3O]4+ Core Wrapped by Two [FeIIL3]− Units

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An [Fe^II₃O]⁴⁺ Core Wrapped by Two [Fe^IIL₃]⁻ Units