Phospholyl catalysts for olefin polymerization

Synthesis and Properties of [NiCp*(2,5‐tBu2PC4H2)], a 20‐Valence‐Electron Phosphanickelocene

“…Hydrated [Ni(acac) 2 ] was dried by azeotropic distillation with toluene [60] and Li(2,5-tBu 2 PC 4 H 2 )·2 THF (1) was prepared as described previously. [1,18] THF and [D 6 ]benzene were distilled from sodium-benzophenone ketyl and pentane from sodium-benzophenone ketyl-tetraglyme under an atmosphere of dry nitrogen and stored over activated 4 molecular sieves prior to use. Chloroform and dichloromethane were distilled from P 4 O 10 under nitrogen and also stored for short periods over 4 molecular sieves.…”

“…Synthesis: Monophosphanickelocene 2 can be prepared in excellent yield by addition of the lithium phospholide Li(2,5-tBu 2 PC 4 H 2 )·2 THF (1) [17,18] to [NiCp*(acac)] [19,20] in THF at À78 8C [Eq. (2)].…”

Phospha‐Organic Chemistry: Panorama and Perspectives

“…Substituents on the a-positions of the heterocyclic ring prevent this complexation. The two most interesting phospholyl-based precatalysts described to date are 55 [337] and 56. [338] In both cases, the activity and the properties of the resulting polymers are rather similar to those observed with the analogous all-carbon catalysts.…”

Diphospholyl and triphospholyl zirconium π-complexes: Ziegler–Natta oligomerization catalysts and reactive intermediates in P–C cage formation by hydrolysis

“…Target products (g 5 -2,4,5-tri(t-butyl)-1,3-diphospholyl)ZrCl 3 (4), Cp(g 5 -2,4,5-tri(t-butyl)-1,3-diphospholyl)ZrCl 2 (5), and Cp(g 5 -3,5-di(t-butyl)-1,2,4-triphospholyl)ZrCl 2 (6) were isolated and characterized from the respective reaction mixtures in the complete absence of water only (Scheme 2). Other products formed from the same starting materials or closely related ones like (g 5 -3,5-di(t-butyl)-1,2,4-triphospholyl)ZrCl 3 , Cp * (g 5 -3,5-di(t-butyl)-1,2,4-triphospholyl)ZrCl 2 , or the Hf-analogue of (4) (g 5 -2,4,5-tri(t-butyl)-1,3-diphospholyl)HfCl 3 have been observed only spectroscopically, but were too reactive or unstable in our hands for complete characterization. Moisture even in trace amounts present in the reaction mixtures or prolonged reaction times change the course of the reactions completely.…”

“…One approach of modifying the properties of this type of compounds significantly is the introduction of phosphorus atoms into the ring ligands, which results in the transformation of one or both cyclopentadienyls into phospholyl derivatives [2]. The main catalytic application of (p-phospholyl)Zr complexes is polymerization or oligomerization of olefins with or without the help of methylalumoxane (MAO) as a co-catalyst [3], including 1-hexene [4]. Catalytic ring opening of epoxides with TMSCl is another application of (p-phospholyl)Zr complexes [5].…”