LAUSR

Abstract Vanadium(V) imido complexes are widely used in olefin polymerization and oligomerization. In this report we present the synthesis and the results of ethylene polymerization studies for a series of vanadium(V) imido complexes with various substituents at the imido fragment. All complexes have been prepared in nearly quantitative yields by the interaction of N-sulfinylamines with VOCl3 or VO(OnPr)3 and characterized using 1H, 13C, 51V NMR and elemental analysis. The solid-state structure of complex V(=NArOMe)(OnPr)3 was established using X-ray. Vanadium(V) imido chlorides and n-propoxides exhibited similar moderate catalytic activities (320–547 kgPE·mol(V)−1·h−1·atm−1). The maximum catalytic activity (547 kgPE·mol(V)−1·h−1·atm−1) was achieved for (adamantylimido)vanadium(V) n-propoxide. The molecular weights of the resulting polyethylenes were higher (Mv = 3.7–6.5·105 Da) for imido n-propoxide complexes as compared to the corresponding imido chlorides (Mv = 2.1–5.5·105 Da). The localization of DFT calculated HOMO on imide nitrogen was proposed to favor the reaction between imide ligand and Et2AlCl used as activator.