Synthesis and structure of bimetallic complexes with σ,π-bridged monocarbene ligands

Terblans, Yvette M.; Lotz, Simon

doi:10.1039/a700229g

Cited by 18 publications

(8 citation statements)

References 26 publications

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“…The Cr(CO) 3 fragment exhibits a piano‐stool coordination environment, clarified by almost ideal carbonyl C–Cr–C angles of 86.9(4)–91.1(10) °. One carbonyl is directed antiperiplanar towards the sulfur atom by 172.8(10)–174.1(10) °, which is in accordance to literature reported solid‐state structures of Cr(CO) 3 complexed thiophenes . The cyclopentadienyls of one of each ferrocenyl substituent in 3a , b adopts an ecliptic conformation [1.6(10) to 8.9(7) °], whereas the other one reveals a rather staggered positioning [18.6(6)–31.6(12) °].…”

Section: Resultssupporting

confidence: 89%

“…[10a] This approach is contrary to literature reported procedures, where a post‐functionalization of the η 5 ‐thiophene Cr(CO) 3 compounds is realized , ,. [10b], [10c], , Thiophenes 1a – g are accessible by cross‐coupling protocols that were recently reported by our group. [1a], [1c], [2c], , The complexation reactions of thiophenes 1a – g with 2 were performed in dibutyl ether at 90 °C for 15 h to give the respective Cr(CO) 3 compounds 3a – e in up to 65 % yield (Scheme ).…”

Section: Resultsmentioning

confidence: 99%

“…Within this family of compounds, η 5 ‐thiophene chromium tricarbonyl was first prepared by Fischer and Öfele as early as 1958 in a solvothermal metathesis reaction of thiophene and Cr(CO) 6 . Up to date, only a few Cr(CO) 3 complexes with η 5 ‐bonded thiophenes bearing additional organometallic fragments have been reported, including titanocene structures, Pt complexes, silyl groups, –M(CO) 5 (M = Mn/Cr,W). Although, basic knowledge of their reaction behavior and NMR properties were investigated, electrochemical studies are still pending.…”

Section: Introductionmentioning

confidence: 99%

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Ferrocenyl‐Functionalized η⁵‐Thiophene Cr(CO)₃ Half‐Sandwich Compounds

et al. 2018

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The synthesis of η 5 -Cr(CO) 3 complexed 2,5-Fc 2 -(3a), 3,4-Fc 2 -(3b), 2,3-Fc 2 -(3c) and 2-Fc-3,4,5-Me 3 -thiophenes (3d) [Fc = Fe(η 5 -C 5 H 4 )(η 5 -C 5 H 5 )] is described. These half-sandwich compounds are accessible by the reaction of Cr(CO) 3 (MeCN) 3 with the appropriate substituted thiophenes. The compounds were analyzed by NMR spectroscopy, where a highfield shift for the ring-carbons and substituted hydrogen atoms of the thiophene core occurred. The 2,5-and 3,4-derivatives could be characterized structurally by single-crystal X-ray diffraction analysis, demonstrating that a low bending of the sulfur atom out of the thiophene plane of up to 9.95(17)°and an anti-arrangement of the ferrocenyl and Cr(CO) 3 fragments is characteristic. Electrochemical measurements showed that each ferro- [a]

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Section: Resultssupporting

confidence: 89%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Ferrocenyl‐Functionalized η⁵‐Thiophene Cr(CO)₃ Half‐Sandwich Compounds

et al. 2018

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“…26 A similar reaction leading to THF ring opening has been observed in our laboratories with p-coordinated thienyl chromium tricarbonyl substituents. 27 The THF insertion is initiated by a nucleophilic attack of the metal acyllate on the a-carbon of the THF leading to ring cleaving and the formation of the butoxy(methoxy) carbene complexes (Scheme 2).…”

Section: Synthesis Of Carbene Complexesmentioning

confidence: 99%

Synthesis and reactivity of metal carbene complexes with heterobiaryl spacer substituents

et al. 2009

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“…The yield of 1 was increased to 0.16 g (20%) by using 2 equivalents of [Cr(η , 26%]. 1 H NMR [(CD 3 ) 2 CO, 0 ЊC]: δ 6.83 (d, H 3 , 3 J HH = 3.9, platinum satellites, 3 J PtH = 37.2), 7.17 (td, H 4 , 3 J HH = 3.9, 5 J PH = 0.9), 7.69 (d, H 5 , 3 J HH = 4.2), 5.82, 5.79 (m, ηthienyl, H 3 -H 5 ) and 1.60 (d, 9 H, 2 J PH = 11.2, platinum satellites, 3 J PtH = 38.7 Hz); see also Table 2.…”

Section: Preparationsmentioning

confidence: 99%

Synthesis and structure of bimetallic complexes with σ,π-bridging thienyl and benzothienyl ligands

Toit¹,

Landman²,

Lotz³

1997

J. Chem. Soc., Dalton Trans.

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The ligand properties of the organometallic fragment (η 5 -SC 4 H 3 )Cr(CO) 3 were studied in the new σ,π-bimetallic complexes [Cr{(η 5 -SC 4 H 3 )PtL 2 (SC 4 H 3 )}(CO) 3 ] with L = CO and PMe 3 1 or L 2 = dppe [1,2-bis(diphenylphosphino)ethane] 2, [Cr{(η 5 -SC 4 H 3 )Au(PPh 3 )}(CO) 3 ] 3 and [Cr(η 5 -SC 4 H 3 SnMe 3 )(CO) 3 ] 4. Whereas the intermediates [Cr{(η 5 -SC 4 H 3 )PtL 2 Cl}(CO) 3 ] (L = PMe 3 or dppe) and [Pt{(SC 4 H 3 )Cr(CO) 3 } 2 L 2 ] were too unstable to isolate and characterize, 4 slowly converted into [Cr{η 5 -SC 4 H 2 (SnMe 3 ) 2 }(CO) 3 ] 5. By contrast, the reaction of lithiated [Cr(η 6 -SC 8 H 6 )(CO) 3 ] with [Pt(dppe)Cl 2 ] afforded the stable trinuclear complex, [Pt{(η 6 -SC 8 H 5 )Cr(CO) 3 } 2 (dppe)] 6.Studies of the activation of organic substrates by more than one transition metal in dinuclear organometallic complexes are increasingly being reported. 2 The interest in such complexes stems not only from their intriguing structural diversities 2,3 but also from their potential catalytic activity, 4 their possible importance in materials with conducting properties 5 and their role in bioinorganic chemistry. 6 Furthermore, metal-ligand activation in dinuclear complexes has not yet been studied systematically and an improved understanding of the scope and extent of such activations is very relevant. Two metals in close proximity sharing a common unsaturated ligand can cooperatively activate and assist in novel reactions, unique transformations and can cause severe structural deformations. 7 Examples are carbon-carbon bond-cleavage and coupling reactions, 8 sterically and/or electronically controlled sites of activity, 9 stabilization of reactive intermediates via co-ordination 1,10 and migratory movements of ligands or metal fragments. 11In our laboratories studies relating to heterobimetallic complexes with σ,π-bridged phenyl and thienyl ligands are of particular interest. 12 Recently we discovered an interesting activation mechanism surrounding a shared thienyl ligand which was π bonded to Cr(CO) 3 and σ bonded to Mn(CO) 5 in the 2 position. The two metal fragments irreversibly, and according to an intramolecular mechanism, exchanged σ,π co-ordination sites. 13 This novel conversion was a direct result of the metals being in electronic contact through the bridging thienyl ligand. These results prompted us further to investigate the extent of activation by σ-bonded early and late transition-metal substituents and their influence on thienyl ligands which are π bonded to Cr(CO) 3 . In this paper we describe the synthesis and characterization of dinuclear complexes with σ-bonded platinum() and gold() fragments in the 2 position of a bridging π-coordinated thienyl ligand.The platinum group metals show very high hydrodesulfurization (HDS) activity 14 and Maitlis and co-workers 15 recorded an oxidative insertion of Pt 0 into the C᎐S bond of thiophenes. Unfortunately for HDS purposes the reverse reaction, regenerating thiophene, is favoured. Efforts to prepare platinum() complexes of 2-(2...

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Synthesis and structure of bimetallic complexes with σ,π-bridged monocarbene ligands

Cited by 18 publications

References 26 publications

Ferrocenyl‐Functionalized η⁵‐Thiophene Cr(CO)₃ Half‐Sandwich Compounds

Ferrocenyl‐Functionalized η⁵‐Thiophene Cr(CO)₃ Half‐Sandwich Compounds

Synthesis and reactivity of metal carbene complexes with heterobiaryl spacer substituents

Synthesis and structure of bimetallic complexes with σ,π-bridging thienyl and benzothienyl ligands

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Synthesis and structure of bimetallic complexes with σ,π-bridged monocarbene ligands

Cited by 18 publications

References 26 publications

Ferrocenyl‐Functionalized η5‐Thiophene Cr(CO)3 Half‐Sandwich Compounds

Ferrocenyl‐Functionalized η5‐Thiophene Cr(CO)3 Half‐Sandwich Compounds

Synthesis and reactivity of metal carbene complexes with heterobiaryl spacer substituents

Synthesis and structure of bimetallic complexes with σ,π-bridging thienyl and benzothienyl ligands

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Ferrocenyl‐Functionalized η⁵‐Thiophene Cr(CO)₃ Half‐Sandwich Compounds

Ferrocenyl‐Functionalized η⁵‐Thiophene Cr(CO)₃ Half‐Sandwich Compounds