Catalytic activity of phenyl substituted cyclopentadienyl neodymium complexes in the ethylene oligomerization process

New mono- and bis-cyclopentadienyl neodymium ate-complexes, bearing phenyl-substituents in the cyclopentadienyl ring, have been synthesized: KNdCp′Cl3(thf)x (Cp′ = 1,3-Ph2C5H3 (1), 1,2,4-Ph3C5H2 (2)) and KNdCp′2Cl2(thf)x (Cp′ = 1,3-Ph2C5H3 (3), 1,2,4-Ph3C5H2 (4), 1,2-Me2-4-PhC5H2 (5), 1,2-Ph2-4-(4-MeO-C6H4)C5H2 (6)). Their catalytic activity has been studied in ethylene oligomerization process in the presence of Bu2Mg as a chain transfer reagent with the Nd:Mg molar ratios being of 1:20, 1:40 or 1:80. Complex 4 exhibits catalytic activity close to the activity of the known complex [(C5Me5)2NdCl2Li(OEt2)2] (7). The complex 6 has demonstrated the best catalytic activity among all studied complexes. Using selected complexes 2, 4 and 6 as pre-catalysts, terminal iodo-functionalized oligoethylenes have been prepared. Obtained iodooligoethylenes have been studied by 1H NMR technique and MALDI mass-spectrometry with preliminary derivatization, demonstrating 70-90% of functionalization. Crystal structures of ate-complexes [{(1,2,4-Ph3C5H2)Nd(thf)}2Cl5K]2(toluene)4 (2a), [(1,2,4-Ph3C5H2)2NdCl2K(thf)0.53(1,4-dioxane)1.47]2(dioxane) (4a) and {[{1,2-Ph2-4-(4-MeO-C6H4)C5H2}2NdCl2K]2(1,4-dioxane)}(toluene)4 have been studied by the single crystal X-ray diffraction. © 2016 Elsevier B.V. All rights reserved.

Minyaev M.E.1 , Vinogradov A.A.1, 2 , Roitershtein D.M.1, 2 , Borisov R.S. 1, 3 , Ananyev I.V.4 , Churakov A.V.5 , Nifant'Ev I.E.1, 6
  • 1 A.V. Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences, 29 Leninsky Prospect, Moscow, 119991, Russian Federation
  • 2 N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 47 Leninsky Prospect, Moscow, 119991, Russian Federation
  • 3 Peoples' Friendship University of Russia, 6 Miklukho-Maklaya Str., Moscow, 117198, Russian Federation
  • 4 A.N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, 28 Vavilova Str., Moscow, 119991, Russian Federation
  • 5 N.S. Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences, 31 Leninsky Prospect, Moscow, 119991, Russian Federation
  • 6 M.V.Lomonosov Moscow State University, Chemistry Department, 1 Leninskie Gory Str., Building 3, Moscow, 119991, Russian Federation
Ключевые слова
Chain transfer; Cyclopentadienyl neodymium complexes; Ethylene oligomerization; Iodine end functionalized oligoethylenes; MALDI-TOF mass spectrometry; X-ray crystal structures
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