New divalent samarocenes for butadiene polymerisation: influence of the steric effect and the electron density on the catalytic activity

Bonnet, Fanny; Visseaux, Marc; Barbier‐Baudry, D.

doi:10.1016/j.jorganchem.2003.10.011

Cited by 23 publications

(21 citation statements)

References 18 publications

(23 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…[4]). It is confirmed that the more bulky the Cp R ligand, the higher the trans-stereospecificity [4], whereas the activity of the catalyst decreases with the electronic richness of the cyclopentadienyl ligand, as already observed [33].…”

Section: Isoprene Polymerisationsupporting

confidence: 76%

“…In the unsubstituted C 5 H 5 series, half-lanthanidocenes of the larger lanthanides are exceptional [6,10], whereas 3a is the first structurally characterized lanthanide complex featuring the bulky but electron-withdrawing C 5 H 2 Ph 3 ligand [33]. It is worth to be noted that the corresponding neutral half-sandwich could not be isolated pure by ionic metathesis [24].…”

Section: Stability Of Early Half-lanthanidocenesmentioning

confidence: 99%

See 1 more Smart Citation

New ionic half-metallocenes of early lanthanides

Visseaux

Zinck

Terrier

et al. 2008

Journal of Alloys and Compounds

Self Cite

View full text Add to dashboard Cite

International audienceWe present in this study a new and one-step method allowing the preparation of an unprecedented family of stable half-lanthanidocenes. X-ray analysis shows that the isolated compounds all display the same ionic Ln–Mg bimetallic structure consisting of two anionic (CpR)Ln(BH4)3 species and one cationic Mg(THF)6 (CpR =C5Me5, Ln = Nd, 1a, Ln = La, 1b; CpR =C5H5, Ln = Nd, 2a; CpR =C5H2Ph3, Ln = Nd, 3a). Such complexes display high stability with respect to disproportionation in solution. Combined with dialkylmagnesium, neodymium complexes provide powerful catalysts for stereospecific isoprene polymerisation

show abstract

Section: Isoprene Polymerisationsupporting

confidence: 76%

Section: Stability Of Early Half-lanthanidocenesmentioning

confidence: 99%

New ionic half-metallocenes of early lanthanides

Visseaux

Zinck

Terrier

et al. 2008

Journal of Alloys and Compounds

Self Cite

View full text Add to dashboard Cite

show abstract

“…IR spectra were obtained on a Bruker Tensor 37 FTIR spectrometer equipped with a room temperature DLaTGS detector and a diamond ATR (attenuated total reflection) unit; for the mid‐infrared region, a KBr beamsplitter was used. [(Cp′′′Co) 2 ( μ,η 2:2 ‐As 2 ) 2 ], [Cp* 2 Sm(THF) 2 ], [Cp* 2 Sm] and [(C 5 Me 4 n Pr) 2 Sm] were prepared according to literature procedures.…”

Section: Methodsmentioning

confidence: 99%

“…[(Cp'''Co) 2 (m,h 2:2 -As 2 ) 2 ], [22] [Cp* 2 Sm(THF) 2 ], [38] [Cp* 2 Sm] [39] and [(C 5 Me 4 n Pr) 2 Sm] [40] were prepared according to literature procedures.…”

Section: Experimental Section Generalc Onsiderationsmentioning

confidence: 99%

Open Chain Polyarsenides of the Lanthanides

Schoo

Köppe

Piesch

et al. 2018

Chemistry A European J

View full text Add to dashboard Cite

The reaction of [(Cp'''Co) (μ,η -As ) ] with the decamethylsamarocenes [Cp* Sm(THF) ] or [Cp* Sm], or the bis(tetramethyl-n-propyl)samarocene [(C Me (n-propyl)) Sm] resulted in the mixed d/f polyarsenides [(Cp'''Co) As Sm(η -C Me R) ] (R=Me, n-propyl). They are the first structural representatives of open chain-like polyarsenides as ligands in the coordination sphere of lanthanides. Their formation can be explained by an intramolecular As-As coupling within the cobalt polyarsenide complex after reduction by the divalent samarium complex. Density functional theory calculations give insight into the structural change of the (As ) unit in [{Cp'''Co(μ,η -As )} ] upon reduction.

show abstract

“…39 As a matter of comparison, MMA polymerisation experiments were performed with divalent samarocenes 9, 10 and 11 (Chart 2). 40 No co-catalyst was used, and the experiments were carried out in toluene at 0°C. 3 .…”

Section: S1 Systemsmentioning

confidence: 99%