Synthesis and Structure of η<sup>4</sup>‐Enone Complexes of Ruthenium(0)

Marcuzzi, A.; Linden, Anthony; Philipsborn, W. Von

doi:10.1002/hlca.19930760220

Cited by 14 publications

(4 citation statements)

References 48 publications

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“…The coupled ligand forms one more five-membered oxaruthenacycle Ru(1)C(7)C(27)C(26)O(4), which contains two saturated carbon atoms (C(7) and C(27)) and a formally double C(26)O(4) bond that is π-coordinated to the Ru(2) atom. Due to additional coordination of the O(4) atom to the Ru(1), the C(26)O(4) bond is elongated to 1.364(9) Å, which exceeds the normal values of 1.306−1.320 Å for π-coordinated carbonyl groups. , The remaining olefin bond of the second DBA molecule is also π-coordinated to the Ru(2) atom, which makes it possible to describe this moiety of complex 8 as a η 4 -coordinated oxadiene fragment. Bond lengths in the C(24)C(25)C(26)O(4) chain are equalized; thus the π-coordination to the Ru(2) atom is nearly symmetrical.…”

Section: Resultsmentioning

confidence: 94%

Reaction of Ru₃(CO)₁₂ with Dibenzylideneacetone

et al. 2005

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The thermal reaction of Ru 3 (CO) 12 with dibenzylideneacetone PhCHdCHCOCHdCHPh (1) was studied. From the solution, the trinuclear complexes Ru 3 (CO 7) were isolated, and the precipitate was found to contain the tetranuclear complex Ru 4 (CO 8). The organic ligand in complexes realizes different coordination modes forming five-membered oxaruthenacycle, η 3 -coordinated dihydropyran cycle, η 4 -coordinated diene, or oxadiene fragments. Complex 7 is unstable and undergoes chemical transformations yielding complex 8. Reversible changes occur with complex 8 upon dissolution in acetone, and binuclear complex Ru 2 (CO) 4 (η-Od CMe 9) is formed. The central Ru 2 O 2 cycle in complex 8 is cleaved and the formed vacant coordination site is occupied by an acetone molecule in complex 9. Complexes 6-9 were characterized by IR and 1 H NMR spectroscopy, and their structures were determined by single-crystal X-ray diffraction analysis. The structural and spectroscopic features and possible pathways of the complexes' transformations are discussed.

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Section: Resultsmentioning

confidence: 94%

Reaction of Ru₃(CO)₁₂ with Dibenzylideneacetone

et al. 2005

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“…Representative complexes 2g and 2l are illustrated in Figures and . The chalcone ligands exhibit the expected s-cis (single-bond geometry connecting the enone) conformation, and the bond lengths within the C−C−C−O framework exhibit the changes that are predicted on the basis of the bonding models described above; namely, the O 1 −C A and C B −C C bonds show significant lengthening on coordination to the metal, whereas C A −C B exhibits shortening, compared to the free ligand. ,− An examination of the bond angles around the iron indicates that the complexes are best considered to be six-coordinate octahedral species with three coordination sites occupied by the carbonyl ligands, with the remaining position occupied by O 1 , C C , and the center of the C A −C B bond. The mean bond angles around the iron for all six complexes are shown in Figure .…”

Section: Resultsmentioning

confidence: 95%

A Rationale for the Linear Correlation of Aryl Substituent Effects in Iron(0) Tricarbonyl Complexes Containing α,β-Unsaturated Enone (Chalcone) Ligands

et al. 2007

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A library of iron(0) tricarbonyl complexes containing η4-bound α,β-unsaturated enone ligands [Fe(CO)3(η4-RCHCH−C{Ph}O)] has been prepared to facilitate comprehensive correlation of the electronic withdrawing/donating properties of the substituent, R, with the strength of the metal−ligand interaction. The IR and NMR spectroscopic data proved invaluable in aiding a comprehensive correlation and global understanding of the aryl substituent effects. The frequency of the M−CO bands in the infrared spectra of these species exhibits a linear correlation with the Hammett parameters for the substituents. The coordination shifts in both the 1H and 13C NMR spectra for the ligands exhibit a similar linear relationship. The largest coordination shifts are observed when more electron-withdrawing groups are present, implying that the organic ligand is primarily acting as a π-acid. The structures of six complexes of this type have been determined by single-crystal X-ray diffraction.

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“…Red oil. IR (CH,Cl,) (an-'): 3055-2855, 1995 s, 1935 [q4-Hexa-(2E,4E)dieneIFe(CO),P(OEt), (20). 13C NMR (150.9 MHz, 180 K, acetone-d,): (apical conformer) 215 …”

Section: Compoundsmentioning

confidence: 99%