91129-04-3Relevant academic research and scientific papers
Bis(phenolate) N-heterocyclic carbene rare earth metal complexes: synthesis, characterization and applications in the polymerization of n-hexyl isocyanate
Zhang, Min,Zhang, Jingjing,Ni, Xufeng,Shen, Zhiquan
, p. 83295 - 83303 (2015)
The rare earth complexes [Ln(L)2K(thf)] bearing a bis(phenolate) N-heterocyclic carbene (NHC) ligand (L = 1,3-bis[O-4,6-di-tBu-C6H2-2-CH2][C(NCH2CH2CH2N)], Ln = Nd (1), Y (2)) were synthesized in situ by the reaction of L1 with KN(SiMe3)2 and Ln[N(SiMe3)2]. The bis(phenolate) NHC precursor L1 also coordinated with rare earth metal forming bis(phenolate) pyrimidinium-bridged rare earth metal complexes [Ln2(L1)3] (L1 = 1,3-bis[O-4,6-di-tBu-C6H2-2-CH2][CH(NCH2CH2CH2N)]+Cl-, Ln = Sm (3), Y (4)). Very high molecular weight (up to 106) and narrow molecular weight distribution (Mw/Mn = 1.7-2.3) polyhexyl isocyanate could be obtained by using the pyrimidinium based NHC rare earth metal complexes 1, 2 as well as imidazolinium based NHC rare earth complexes 5-7. The NHC complexes were found to be highly active towards the polymerization of n-hexyl isocyanate whereas non-NHC rare earth metal complexes 3, 4, 8 were inactive. The radius of rare earth metal, solvent, polymerization temperature and the structure of the ligand greatly affected the catalytic activity of polymerization. The mechanism of the initiation of the polymerization was studied and the NHC moiety played an important role in the initiation step which was evidenced via NMR analysis.
Active non-metallocene pre-catalyst and method for tactic catalytic polymerization of alpha-olefin monomers
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Page column 28-29, (2010/02/05)
An active non-metallocene pre-catalyst featuring a diamine diphenolate complex and a corresponding method for catalytic polymerization, in general, and, tactic catalytic polymerization, in particular, of alpha-olefin monomers using the disclosed pre-catal
Single-step synthesis of salans and substituted salans by Mannich condensation
Tshuva, Edit Y,Gendeziuk, Natalie,Kol, Moshe
, p. 6405 - 6407 (2007/10/03)
A convenient route for the synthesis of a variety of salan-type compounds is introduced. The synthesis is based on a single-step Mannich condensation between readily available starting materials: primary or secondary amines, formaldehyde and substituted phenols. This methodology is suitable for the preparation of chiral salans as well, which may find applications in asymmetric catalysis.
