Di- and trivalent rare earth complexes stabilized by sterically demanding aminopyridinato ligands as initiators in ring-opening polymerization reactions of ε-caprolactone

2007 ◽  
Vol 45 (16) ◽  
pp. 3611-3619 ◽  
Author(s):  
Sophie M. Guillaume ◽  
Michèle Schappacher ◽  
Natalie M. Scott ◽  
Rhett Kempe
Keyword(s):  
Rare Earth ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Rare Earth Complexes ◽  
Sterically Demanding ◽  
Trivalent Rare Earth

Rare-Earth Complexes with Multidentate Tethered Phenoxy-Amidinate Ligands: Synthesis, Structure, and Activity in Ring-Opening Polymerization of Lactide

2011 ◽  
Vol 30 (20) ◽  
pp. 5509-5523 ◽  
Author(s):  
Mikhail Sinenkov ◽  
Evgeny Kirillov ◽  
Thierry Roisnel ◽  
Georgy Fukin ◽  
Alexander Trifonov ◽  
...  
Keyword(s):  
Rare Earth ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Rare Earth Complexes ◽  
Structure And Activity

Rare earth complexes of phenoxy-thioether ligands: synthesis and reactivity in the ring opening polymerization of cyclic esters

2013 ◽  
Vol 42 (25) ◽  
pp. 9338 ◽  
Author(s):  
Mina Mazzeo ◽  
Roberta Tramontano ◽  
Marina Lamberti ◽  
Alessia Pilone ◽  
Stefano Milione ◽  
...  
Keyword(s):  
Rare Earth ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Rare Earth Complexes ◽  
Cyclic Esters

(Iminophosphoranyl)(thiophosphoranyl)methane rare-earth borohydride complexes: synthesis, structures and polymerization catalysis

2015 ◽  
Vol 44 (27) ◽  
pp. 12338-12348 ◽  
Author(s):  
Matthias Schmid ◽  
Pascual Oña-Burgos ◽  
Sophie M. Guillaume ◽  
Peter W. Roesky
Keyword(s):  
Rare Earth ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Trimethylene Carbonate ◽  
Polymerization Catalysis ◽  
Trivalent Rare Earth

The {CH(PPh2NSiMe3)(PPh2S)}−ligand has been used for the synthesis of divalent and trivalent rare-earth borohydride complexes. These compounds enable the ring-opening polymerization (ROP) of ε-caprolactone (CL) and trimethylene carbonate (TMC).

Synthesis and characterization of dinuclear rare-earth complexes supported by amine-bridged bis(phenolate) ligands and their catalytic activity for the ring-opening polymerization of l-lactide

2016 ◽  
Vol 45 (26) ◽  
pp. 10807-10820 ◽  
Author(s):  
Yu-Lai Duan ◽  
Jia-Xuan He ◽  
Wei Wang ◽  
Jing-Jing Zhou ◽  
Yong Huang ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Rare Earth ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Rare Earth Complexes ◽  
Synthesis And Characterization ◽  
Phenolate Ligands

Neutral rare-earth complexes [M2(L)2(THF)4] have been synthesized. Their activities toward the ring-opening polymerization of l-lactides will be presented.

Rare earth metal initiated ring-opening polymerization of lactones

2000 ◽  
Vol 21 (5) ◽  
pp. 195-212 ◽  
Author(s):  
Seema Agarwal ◽  
Christian Mast ◽  
Kurt Dehnicke ◽  
Andreas Greiner
Keyword(s):  
Rare Earth ◽  
Rare Earth Metal ◽  
Ring Opening ◽  
Earth Metal ◽  
Ring Opening Polymerization

The synthesis and polymerization behaviour of silicon-bridged [1]- and [2]ferrocenophanes with sterically demanding trimethylsilyl substituents attached to the cyclopentadienyl rings

1995 ◽  
Vol 73 (11) ◽  
pp. 2069-2078 ◽  
Author(s):  
Timothy J. Peckham ◽  
Daniel A. Foucher ◽  
Alan J. Lough ◽  
Ian Manners
Keyword(s):  
Molecular Weight ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Monoclinic Space Group ◽  
Organometallic Polymers ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cyclopentadienyl Ligands ◽  
Sterically Demanding ◽  
High Molecular Weight Poly

The silicon-bridged [1]ferrocenophane Fe(η-C5H3SiMe3)2(SiMe2) (5) was synthesized via the reaction of Li2[Fe(η-C5H3SiMe3)2]•tmeda (tmeda = tetramethylethylenediamine) with Me2SiCl2 in hexanes. The disilane-bridged [2]ferrocenophane Fe(η-C5H3SiMe3)2(Si2Me4) (7) was prepared using a similar route from the disilane ClMe2SiSiMe2Cl. Despite the presence of sterically demanding SiMe3 substituents on the cyclopentadienyl rings, compound 5 was found to undergo thermal ring-opening polymerization at 170 °C to produce very soluble, high molecular weight poly(ferrocenylsilane) 6 with Mw = 1.4 × 105, Mn = 8.4 × 104. However, the [2]ferrocenophane 7 was found to be resistant to thermal ring-opening polymerization even at 350 °C and decomposed above 380 °C. A single-crystal X-ray diffraction study of 7 revealed that the steric interactions between the bulky SiMe3 groups are relieved by a significant twisting of the disilane bridge with respect to the plane defined by the centroids of the cyclopentadienyl ligands and the metal atom. The angle between the planes of the cyclopentadienyl rings in 7 was found to be 5.4(6)°, slightly greater than that in the non-silylated analogue Fe(η-C5H4)2(Si2Me4) (4a) (4.19(2)°), and dramatically less than the corresponding tilt angle of the strained, polymerizable, silicon-bridged [1]ferrocenophane Fe(η-C5H4)2(SiMe2) (1) (20.8(5)°). The length of the Si—Si bond in 7 (2.342(3) Å) was found to be close to the sum of the covalent radii (2.34 Å). Crystals of 7 are monoclinic, space group C2/c, with a = 23.689(3) Å, b = 11.174(1) Å, c = 31.027(3) Å, β = 109.16(1)°, V = 7758(2) Å3, and Z = 12. Keywords: ring-opening polymerization, ferrocenophane, organometallic polymers.

Synthesis of Rare Earth Catalyst LLa[N(TMS)2]•DME(L=3,5-But2-2-HO-C6H2CH-NH-C5H4N) and Catalytic Behavior for Polymerization of Rac-Lactide

2012 ◽  
Vol 184-185 ◽  
pp. 1302-1306
Author(s):  
Xi Zhu ◽  
Yao Rong Wang
Keyword(s):  
Rare Earth ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Molar Ratio ◽  
Elimination Reaction ◽  
Catalytic Behavior ◽  
Rare Earth Catalyst

A dianionic phenoxyamido ligand was the first to be used to stabilize organo-rare-earth mental amido complex. Amine elimination reaction of La[N(SiMe3)2]3(THF)2 with 3,5-But2-2-HO-C6H2CH-NH-C5H4N in a 1 : 1 molar-ratio gave the anionic phenoxyamido neodymium amide LLa[N(TMS)2]•DME (1) in a high isolated yield. Furthemore, the catalytic behavior of complex 1 for the ring-opening polymerization of rac-lactide was explored.

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